Home

ICAD COURSE.

1. 25 2 12 What to do after the text has been edited 20 2 5 CHAPTER 3 ICAD DESIGN LANGUAGE AND COMMON LISP 3 1 3 1 What iS IDE ene sh Aig th aren ete pee SRG GSR Cae REGS Tes eS ass 3 1 3 2 What kind of language is Common LISP 00006 3 1 3 3 What do you have to know about Object Oriented Languages 3 1 3 4 What rules are to be considered in Common LISP 3 2 3 5 What are expressions in Common LISP en 3 2 3 6 What about conditional expressions 2 0 0 cee eee eee 3 3 3 7 What predicate functions are available for conditionals 3 3 3 8 Where you do and where you do not use conditionals 3 4 3 9 What additional LISP functions are used 000 00s 3 4 3 10 What does IDL consist of ee 3 6 3 11 What is a defpart 25 013 i666 WS phi ver Sar CL ee Coke eee 3 6 3 12 What can you do with the ICAD Browser Mik Gite tn E E EES 3 6 3 13 What should you have learned until now 00000 eee 3 7 ICAD course Version 1 1 Date 27 01 92 CHAPTER 4 DEFPART ELEMENTS as oon san ers ee he eS OE eS 4 1 4 1 How to construct an IDL description 0 50 e eee eae 4 1 4 2 What about sattributes 45 tarten dennie ree 4 1 4 3 Which specialities of attributes are known 0 0 0 000002 cee 4 2 44 What are parfs osn nessen aes he BOE ROS se le 4 2
2. 36 57 89 f sin 30 g brick h sheight 6 i height 6 j the height 6 k the height 6 L 5 222 7 3 m sin 30 n 5 2 2 2 7 3 EXERCISE 3 3 What are the results of next expressions a eql three 3 b between 2 5 5 1 c gt 2 9 8 d oddp 8 e or not eql abe abc oddp 8 ICAD course Versions 1 1 Date 27 01 92 IDL and Common LISP Page 3 6 EXERCISE 3 4 What does the defpart description from the example of the usage of the IF statement on page 3 4 3 10 What does IDL consist of Programming in IDL consists of Defining descriptions of objects using defpart This is done using the EMACS Editor window Defparts are stored in files Creating objects from their description using the Make Part command This is done using the ICAD Browser window They are used to get results drawings reports data files etc Objects can be stored 3 11 What is a defpart A defpart consists of a name mixins attributes and other features A name is always a symbol Attributes define information about these parts Mixins define the kind of relationship this is also called inheritance These mixins may be defined als defparts though often only box is used Each mixed in defpart require values for certain attributes For instance a box requires a length width and heigth Let us see the next example pay attention to the L
3. Fill in the Top Level Inputs using any number you want Don t forget the Line Feed key to signal completion of each entry With your inputs specified select the Accept command at the top of the Top Level Inputs Select the ModifyGraphics command and match it with te Product Structure Tree The geometry appears in the Free Graphics Viewport 5 5 3 What are the leaves and nodes used for You can expand any node of a tree by matching it with the Leaves or Children command Children shows only the immediate Children of a node and Leaves shows all of the node s descendants EXERCISE 5 3 Check whether the house has Children and Leaves 5 5 4 What is the ModifyGraphics command used for Ordinarily you use ModifyGraphics to draw the leaves of the matched node then to Draw Node Add Node or Add Leaves The ModifyGraphics command can be set to other drawing commands though Once you set up ModifyGraphics it does what you specified until you change the set up EXERCISE 5 4 Open the ModifyGraphics template Change the set up of the ModifyGraphics command and match the command with the workspa ce First predict what will happen 5 5 5 What is the EditView command used for With the EditView command you can change the Browser screen EditView can be matched with the following browser objects Graphics viewport A node of the Product Structure Tree The entire Workspace or browsable part The ModifyGraphics c
4. position position keyword expression should return a number It can be positive or negative 6 6 What if you do not wish to position in respect to the defpart You may have noticed that in the previous example all the parts were positioned relative to its parent It is also possible to position a part with respect to an object other than its parent This can be done with the LISP command from The format of the position command is than changed to position position keyword from the part name expression With this command you are able to position sub assemblies relative to other object in the assembly which sometimes comes in very handy You have to be very carefull to use this command though because the positioning in other dimensions isn t affected Example defpart house box attributes height 10 slength 20 width 10 parts first floor stype box first floor door type box sheight 0 1 width 3 ICAD course Version 1 1 Date 27 01 92 Positioning and Orientation Page 6 4 length 3 position left from the roof 0 5 svertical 5 roof type box sposition above 0 EXERCISE 6 1 Define a wall that has a door and a window The door is positioned in respect to the defpart wall The window is positioned in respect to the door height width thickness positioning Wall 10 20 0 1 Door 5 2 0 05 3 left from wall center Window 2 1 0 05 1 right from door Wall
5. CHAPTERS TRICKS SPECIAL Because every beginner has to deal with some programming problems this chapter is written to help you with some of these problems CHAPTER 9 EXERCISE This chapter contains some exercises to test your knowlegde about ICAD page 0 2 CONTENTS CHAPTER 1 PHILOSOPHY o lt 4ssa are CS erneer G 1 1 1 1 Introduction sro bremer AERA AEE See ein 1 1 1 2 What is Knowledge based Engineering eee 1 2 1 3 What benefits do knowledge based CAD systems give us 1 3 1 4 What disadvantages are there to knowledge based CAD systems 1 3 1 5 What kind of applications knowledge based CAD systems can be used for 1 4 CHAPTER 2 GNU EMACS EDITOR AND SYSTEM COMMANDS 2 1 2 1 What is the purpose of this document 0 0 eee eee eee 2 1 2 2 What you have to know before you even touch the SUN system 2 1 2 3 How to enter the SUN system eee 2 1 2 4 How to leave the SUN system 2 0 ccc ee eens 2 2 2 5 Can Sunview be left temporary eee 22 2 6 What do you have to know about GNU EMACS Editor 2 3 2 7 For what is GNU EMACS editor used and how is it working 23 2 8 How to get descriptions of defparts in the EMACS Editor 23 2 9 How to save the buffer 0 0 eee ee eee 2 4 2 10 How to edit a text in the Text area eee 2 4 2 11 Where to find a summary of all editing commands
6. Figure 8 6 7 What about orientation Objects which are not explicitly oriented default to the orientation of the containing defpart And in contradiction to positioning a part can only be reoriented in respect to the faces or axis defined by the containing defpart Two types of rotation are possible orthogonal and non orthogonal rotation ICAD course Version 1 1 Date 27 01 92 Positioning and Orientation Page 6 5 Syntax for an orthogonal rotation orientation crotate rotation keyword Syntax for a non orthogonal rotation orientation numeric roll axis angle The keywords for a 90 degree orthogonal rotation are right left front rear top bottom These keywords rotate the part according to the right hand rule Point your right thumb in the indicated direction and your fingers will curl in the direction of rotation Keywords for 180 degree rotations are lateral longitudinal vertical and will cause a rotation around the selected axis of the defpart To rotate an object at other than right angles the non orthogonal rotation is used The options for axis are lateral longitudinal vertical The angle is expressed in radians 2x radians equals 360 degrees There is a function called degree that you can use for expressing angles in degrees You can refer to by using pi 2 pi and pi 2 are also defined Example of rotation defpart cube box attributes height 10 length 20 width 1
7. 4 5 What about generic parts oee eee 4 3 4 6 What about inputs 0 0 0 2 cece ee ee eee en 4 3 4 7 What about optional inputs oee eee 4 4 4 8 What other ways are possible to ask for input 0 4 4 4 9 What about the tree structure 2 0 ees 4 5 4 10 What about inheritance eee eee eeen 4 8 4 11 What about reference chains 0 0 000 cee cee eee eee ene 4 8 CHAPTER 5 THE ICAD BROWSER an deer emd bes i Sa tease ee Wee 5 1 5 1 What do you have to know about the ICAD Browser 5 1 5 2 What is the ICAD Browser used for and how does it work 5 1 5 3 How to switch to the ICAD Browser 00 00 cece eee eee 5 2 5 4 How to quit and leave the ICAD Browser 0 00000 e eee 5 2 5 5 How to work with the ICAD Browser 00000 e eevee 5 2 5 5 1 What to do with the menubars sr ser senen es aes 5 2 SS How to get an instance of a defpart on the Browser screen 5 3 5 5 3 What are the leaves and nodes used for 0 004 5 5 5 5 4 What is the ModifyGraphics command used for 5 5 5 5 5 What is the EditView command used for ee 5 5 5 6 Where to find more information about the Browser commands 5 6 CHAPTER 6 POSITIONING AND ORIENTATION eenen 6 1 6 1 What is needed for building objects 2 00 00 eee eee 6 1 6 2 What are faces and axis of a def
8. You have referred to an attribute while trying to define it This is called a circular definition This is a nasty one because this condition does not produce an error message You know you are in an infinite loop when the browser command takes an uncommonly long time and in fact will never finish Return to the EMACS Window then press CTRL C twice to stop the ICAD Browser Correct the circular reference and recompile 8 3 4 The variable XXX is unbound Probably missing a quote in front of a symbol 8 3 5 The argument given to the SYS INTERNAL instruction XXX was not a number You supplied XXX where a number was expected Usually means a problem with a referencing chain 8 4 How can you generate descriptions without introducing failures It is difficult to generate defpart descriptions without making failures The answer to this question is you need a Jot of experience and even then it is not quaranteed that no failures will be present However there are no rules which prevent you from making failures there are some guidelines to minimize the number of bugs 8 5 How to minimize the number of bugs First of all avoid complex defparts Use small defparts Create hierarchy of defparts which are tested one by one Test out each change that you make to your defparts That way you catch the bug as soon as it is introduced in the defpart Second evaluate first before you update text ICAD course Version 1 1 Date 27
9. box sinputs robot height parts palm type box height half the height position top 0 finger type box height half the height width 0 05 the robot height slength 0 05 the robot height sposition bottom 0 ICAD course Version 1 1 Date 27 01 92 Defpart elements Page 4 8 4 10 What about inheritance There is something you should know about inheritance See next two descriptions Example inheritance defpart wall box defpart wall box sattributes sattributes height 8 height 8 parts parts beam type box beam type box length 2 slength 2 width 4 width 4 height the height These examples tell you that you do not have to specify the height of the beam when it has the same height as the wall itself This is called inheritance Not only height but width and length have this behaviour too Other attributes do not 4 11 What about reference chains You already have seen reference chains and the usage of it probably without realizing that it were reference chains What is a reference chain and what is it used for are questions we will answer here Example reference chains defpart Robot box attributes height 8 parts beam type box length 2 width 4 sheight the height The macro called the which is used in the parts definition of the beam the height begins a reference chain In part beam we
10. but they are not in the right place Slightly harder to detect Use the editor indenting commands CTRL META or CTRL META Q indent expression and TAB to see if the indentation is correct or use LINE This will lead you to the place with the misbalanced parentheses Using non standandard indentation by manually spacing over means you can not use this important tool 8 2 3 Function undefined You probably misspelled a function name Possibilities are You might have used an extra set of parentheses so that you have some other valid symbol in the first position of an expression an invalid place You left out a in front of an attribute name or a quote in front of a list of data 8 2 4 Redefining old version You have chosen a name for a defpart that is already being used as one and was not defined in this file DO NOT IGNORE THIS WARNING Answer NO and choose a new name unless you really want to redefine the old version ICAD course Version 1 1 Date 27 01 92 Tricks special Page 8 2 8 3 What run time errors can be made 8 3 1 No parent could handle the XXX message You referred to an attribute that was not available because you misspelled the name itis not a descendant attribute itis not really there 8 3 2 The function XXX is undefined Often means that you have misspelled the name of a part or that you just forgot to compile it 8 3 3 The control or binding stack overflowed
11. eql is preferred is used to determine whether two numbers are exactly equal Both arguments must be numbers Many other predicates are available The names of these functions are often named ending with a p or with a The ones that end in are usually ICAD defined These predicates are described in Chapter 5 of the User s Manual Here are some of the Common LISP and IDL predicates LISP predicates lt plusp string equal gt oddp string lessp lt evenp tring greaterp gt zerop between minusp ICAD course Version 1 1 Date 27 01 92 IDL and Common LISP Page 3 4 You can combine test expressions with and and or You can invert the meaning of a test expression with not 3 8 Where you do and where you do not use conditionals Normally you use these expressions at places of values of attributes default values of optional inputs and defaulted inputs supplied values in part specifications and amount of positioning offsets Places where these expressions less frequently used are orientation keyword values and types of parts Places where these expressions are never allowed are orientation keywords positioning keywords mixin list and defpart keywords because they are for values and not for keywords Examples of expressions with their results are eql tabe abc result TRUE not eql abc abc result FALSE 3 1 2 result TRUE string lessp A
12. spec attributes length spec block2 domain _ number default 10 prompt length ICAD course Version 1 1 Date 27 01 92 Exercise Page 9 3 position spec domain selection list front rear top bottom right left default front prompt select position sparts 0 EXERCISE 9 4 1 Define a block which has one clock plate The plate itself has a minute and an hour hand that are positioned in the center The clock plate has 4 12 or 60 ticks The time can be chosen Use the IDL description given below You have to be able to position and orientate the plate on any surface of the block so that the hand is on the outside 2 Save the description as EXER4 LISP Hints Use for the positioning of the ticks and hands the position about command defpart clock box base spec sheet attributes length the width width the length spec height the width spec controls graphics after action draw spec attributes chour spec domain number display width 2 vinvalid cond gt the hour spec 24 Hour cannot be larger than 24 lt the hour spec 0 Hour cannot be smaller than 0 prompt hour sminute spec domain number display width 2 ICAD course Version 1 1 Date 27 01 92 Exercise Page 9 4 invalid cond gt the minute spec 59 Minute cannot be larger than 59 lt the minute spec 0 Minute cannot be smaller t
13. 2 8 3 2 The function XXX is undefined naor maren es an SHO ws 8 2 8 3 3 The control or binding stack overflowed 4 8 2 8 3 4 The variable XXX is unbound 0 0 0 cee eee eee 8 2 8 3 5 The argument given to the SYS INTERNAL instruction XXX was not a number rin we ae ee Naa E SNE Bae Ree aye 8 2 8 4 How can you generate descriptions without introducing failures 8 2 8 5 How to minimize the number of bugs eenen 8 2 8 6 How to debug ersten en vene eb ea eee Bat SEES IG ed 8 3 CHAPTER 9e EXERCISE 32g vsg viet oie wae eae kere Sa aw es 9 1 9 1 What is the meaning of this final exercise chapter 9 1 APPENDIX A ANSWERS TO EXERCISES 0 cece eee eee Al ICAD course Version 1 1 Date 27 01 92 Philosophy Page 1 1 CHAPTER 1 PHILOSOPHY 1 1 Introduction The most important factors for succes in today s competitive environment are reduced time to market and attention to customer specific needs These factors are realised through responsiveness adaptabi lity and flexibility Especially the flexibility is of great importance to a company because it results in short production runs reduction in throughput time and a greater product range leading to a higher efficiency and higher profits In mechanical design there are several problems which need to be adressed in order for companies to bring new products to market quicker while being responsive to customer sp
14. ICAD course Version 1 1 Date 27 01 92 Exercise Page 9 1 CHAPTER 9 EXERCISE 9 1 What is the meaning of this final exercise chapter This is the last part of the introduction course to ICAD You are supposed to know how to work and to describe defparts with it From now on you will have to use the manuals to look up the answers for the problems that will occur but were not dealt with in this course The goal of this exercise is to define a clock as shown in the figure To build this clock the exercise is divided in five logical parts In this way the problem will be tackled in the most easy manner EXERCISE 9 1 A block is defined which has a clock on one or more sides The specification of a clock is it has a clock plate a minute and an hour hand and ticks There is a set ratio between the length s of the hands One can choose whether the clock has 4 12 or 60 ticks and what time the clock has to show 1 Construct the tree of this block with the clocks 2 Define the input and output variables 3 Describe in a global way how you would construct the IDL description do not write the IDL description in detail EXERCISE 9 2 The input can be realized in different ways One possibility is to use the user interface type as described below This will be shown as a input window in the Browser as soon as you create an instance of the defpart 1 Type the IDL description as shown below and compile it Explain it s w
15. ICAD window the CMDTool window or the Console window For this moment don t mind the CMDTool and the Console window In the other cases you must first quit the window What is meant by quit the window This mean that you must disable the window For quiting the GNU EMACS you place the Mouse Cursor at the top of the window in the black header Then you press and hold the right Mouse Button A popup menu will be shown in which you can select the option quit window Select this option by moving the Mouse Cursor and releave the button You are now asked to confirm the action Move the Mouse Cursor to this window and use the left Mouse Button to confirm For quiting the ICAD Browser the Mouse Cursor has to be placed on the ICAD symbol which can be found in the top of the window on the left of title The ICAD Browser and above the symbol Then push the key stop this key can be found on the top left of the keyboard When you quit this window it is likely that the GNU EMACS window is still active Quit this window as described above Now you have to place the Mouse Button on the grey area around the windows Press and hold the right Mouse Button This pops up a menu of commands With the right Mouse Button still depressed drag the mouse downward until the command Exit SunView is highlighted Then release You are asked to confirm this action Click on the left Mouse Button Then the screen shows the login prom
16. Model MATERIALS INPUT REQUIREMENTS STD PARTS eee CATALOGS INPUTS ENGINEERING TABLES DATA BASES DESIGNERS KNOWLEDGE GEOMETRY DEFINITION PRODUCT STRUCTURE ENGINEERING RULES MFG CONSTRAINTS PART DEPENDENCIES EXISTING DESIGNS ANALYSIS RESULTS COSTS ANALYSIS PROCESS PLANS 3D CAD MODELS TO CAD Figure 1 The Knowledge based Engineering Process The product model is a means of integrating the knowledge from many organizations departments and people which contribute to the creation of the company s products Using product models engineers can evaluate design alternatives quickly and generate new designs automatically Since design engineers knowledge is captured in the model the manual intervention of the designer is eliminated and designs are recreated automatically given a new set of input requirements The knowledge based engineering product model must include The product structure ICAD course Version 1 1 Date 27 01 92 Philosophy The knowledge based engineering product model can include Rules for altering the product structure given a new set of input requirements Dependencies between parts of the product such that if one part or an attribute of a part changes other parts or attributes which depend on it change automa tically Not that the dependencies are created by the designer or engineer Engineering design rules from multiple engineering gr
17. Remove Graphics command will wipe out the Free Graphics Viewport EXERCISE 5 5 Try some of the options of the EditView pop up window in combination with the Graphics Viewport Try some of the options of the EditView pop up window in combination with the Product Structure Tree Try some of the options of the EditView pop up window in combination with the Workspace 5 6 Where to find more information about the Browser commands For more information about the Browser and all the commands that can be used we refer to the ICAD Browser User s Manual ICAD course Version 1 1 Date 27 01 92 Positioning and Orientation Page 6 1 CHAPTER 6 POSITIONING AND ORIENTATION 6 1 What is needed for building objects From the preceding chapters you know that you have to define defparts attributes and parts But until now we have not discussed something important namely the positioning and orientation of the parts with regard to the root defpart A lot of your programming time will be spend on how to position and how to orientate the parts We think that this is one of the difficult issues of ICAD For this reason we will spend some time on discussing these subjects First we wil discuss the positioning later we will discuss orientation 6 2 What are faces and axis of a defpart and a part Assemblies are usually defined as a box in order to define a new local coordinate system with conveniently placed faces for positioning its p
18. by providing a means of storing product design information as a set of engineering rules for generating product and process designs automatically ICAD course Version 1 1 Date 27 01 92 Philosophy Page 1 2 1 2 What is Knowledge based Engineering Knowledge based engineering technology provides a means of storing product or process information as a set of engineering rules and requirements for generating designs or process plans automatically With conventional CAD systems the user interactively creates and manipulates the geometric design data The result is a geometric representation of a part which can be viewed or altered by interactive ly modifying the geometric data directly The engineering which precedes the design is performed off line and when changes are made to design specifications the engineering must be reevaluated manually before the designs are again manually changed Unlike traditional CAD systems that capture geometric design information only knowledge based systems like ICAD can capture the intent behind the product design With knowledge based engineering systems engineers build a model of a product or process which is used to create the geometric design When product specifications are changed or new versions of the product are desired the rules in the model evaluate the new specifications and a new geometry instance is created automatically A representation of a product model is shown in the figure below Product
19. code is without errors If errors exist you will find out that about 75 of these are created by false or forgotten brackets See our chapter Tricks special In case that there are no errors you can switch to the ICAD Browser ICAD course Version 1 1 Date 27 01 92 IDL and Common LISP Page 3 1 CHAPTER 3 ICAD DESIGN LANGUAGE AND COMMON LISP 3 1 What is IDL The programming language you use is called IDL ICAD Design Language This language is based on the Common LISP programming language Therefore before we can tell you something about IDL we have to tell something about Common LISP It is not our intention to Jearn you everything about this language but there are still a few things you should know 3 2 What kind of language is Common LISP Common LISP is a Object Oriented Programming language The purpose of this language is that programming is made more comfortable so that even Mechanical Engineers are able to construct programs How must you imagine this Compared with other languages like Fortran Basic and Pascal the way of programming is different The way you would describing things in the real world is the way to describe these things in LISP you see objects in the world around you so you describe objects and their functionality in LISP You describe things in a natural way but this does not mean you can describe these things in English or Dutch For this reason you have to know some things about object or
20. right and the third from the rear member of a matrix quantified along the lateral and the longitudinal axes Other commonly used keywords specify a relative position first last First and last specify the first and last members respectively for a series or pair And finally you have got the first n command which refers to the nth member of a pair or series Example defpart wall box attributes Glength 0 15 no of studs round the width 0 4 parts ICAD course Version 1 1 Date 27 01 92 Quantification Page 7 5 stud ctype 2x4 quantify series lateral the no of studs small window I1 stype box sheight 0 6 width 0 2 position on right from the stud first 0 1 small window 2 type box sheight 0 6 width 0 2 position on right from the stud first 4 0 1 wall type box defpart 2x4 box sattributes length 0 05 width 0 1 WALL Front View WALL Stud 0 Stud 1 Stud 2 Stud 3 Stud 4 stud 5 Stud 6 Stud 7 Window 0 Window 1 Wall Figure 11 ICAD course Version 1 1 Date 27 01 92 Quantification Page 7 6 7 4 How to distinguish a certain quantified object In order to make quantified objects different from each other you must be able to distinguish one from another in the parts statement The following keywords do this Index is an attribute associated with quantified parts Its value is a number for a pair or series or a list of two number
21. 0 parts oriented cube type box sheight 2 slength 4 width 2 sposition rear 0 sorientation rotate top ICAD course Version 1 1 Date 27 01 92 Positioning and Orientation Page 6 6 EXERCISE 6 2 Type in this example In the ICAD Browser you will notice that the oriented cube is positioned and oriented according to the programcode Change the keywords in the position and orientation commands and predict the results 6 8 Can I specify more than one rotation and translation As you might have guessed you can specify more than one rotation and translation to get the object in the desired orientation and on the right place For this you can use the same LISP commands as were previously explained You simply adapt these commands to Syntax for more than one rotation and translation position position keywordl expressionl position keyword2 from the part name expression2 position keyword3 expression3 orientation rotate rotation keywordl snumeric roll axis angle For the translation part the order in which the translations are presented do not matter for the orientation part though the order in which the rotations are specified determines the end result ICAD course Version 1 1 Date 27 01 92 Quantification Page 7 1 CHAPTER 7 QUANTIFICATION 7 1 What is Quantification Quantification is a means of replicating parts using a single parts statement In this way there is not the need fo
22. 01 92 Tricks special Page 8 3 Third make generic parts Generic parts by definition can be tested independently of the rest of the tree Fourth try to make defpart descriptions with a uniform layout Try to reuse verified layouts And this applies especially for the way you put the parentheses Fifth make backups of your IDL description Six use names for the objects from which you can easily read what the meaning of the object is So do not use mb1 when you mean motorbike 1 This way of describing will be not only a help to you but also to another who tries to read your description for the first time 8 6 How to debug Since it is not guaranteed failures are not present you need some strategy to solve the failures An important step is to ISOLATE The trick to debugging quickly is to isolate the bug Perhaps next items will help Work only on one bug at a time Selectively expand and draw branches of the tree to isolate erroneous parts Use the inspector in the ICAD Browser to evaluate that attribute to insure that the error is isolated Evaluate dependent attributes to see if they give the expected results Comment out the suspect attribute or replace with a new attribute definition to see if any dependency problems result Aggravate your bugs do not coddle them That helps to isolate them EXERCISE 8 1 Try to find the errors in the file error1 lisp This file contains four errors
23. 1 Page A 1 Date 27 01 92 Answers to exercises Page A 2 EXERCISE 3 4 When the owner of a chair is the president or the vice president then the chair will be of leather Otherwise the chair will be of vinyl EXERCISE 4 1 In Browser a input window will be shown You have to enter the ceiling heigth It is not necessary to enter the wall thickness A box will be drawn with the desired dimensions One other box will be drawn in this first bounding box Another will be drawn on top of it EXERCISE 4 2 Torso box Head box Upper arm box Palm box Hand Finger box Upper arm box Hand a Palm box Finger box ROBOT OBO Left arm Right arm Figure 12 EXERCISE 4 3 CHAPTER 5 THE ICAD BROWSER EXERCISE 5 1 EXERCISE 5 2 ICAD course Version 1 1 Date 27 01 92 Answers to exercises Page A 3 EXERCISE 5 3 House has two children and two leaves EXERCISE 5 4 CHAPTER 6 POSITIONING AND ORIENTATION EXERCISE 6 1 EXERCISE 6 2 CHAPTER 7 QUANTIFICATION EXERCISE 7 1 for example defpart wall box soptional inputs window width 0 9 window height 1 2 sattributes length 0 15 parts wall ctype box windows type box width the window width sheight the window height position stop 0 3 quantify series lateral 3 door stype box sheight 2 the window height position bottom 0 EXERCISE 7 2 for example defp
24. CISE 2 4 Load the file tryout1 lisp in the buffer Change the first line from file tryout1 into file tryout2 Save the file with the name tryout2 lisp Load the file tryout1 lisp again to see if this text has changed Load the file tryout2 lisp to see if you have created a new file Clear the buffer 2 11 Where to find a summary of all editing commands For more information of the editor and a summary of all the editing commands we refer to GNU EMACS Quick Reference page 1 26 to 1 36 2 12 What to do after the text has been edited After editing the text you are of course curious of what the result is of your created defparts The first thing to do is to compile your buffer text After you do so do not forget to save the buffer it is not a bad habbit to do this always before of just after you have compiled the text When you compile the text it is essential that your text cursor is in the text area where your defpart is described this applies too in case of saving the buffer Now you use the command META SHIFT B press all these keys at the same time remember that de META key is the diamond key on the left of the spacebar What is going to happen next is that your text is being compiled When syntax errors exist these will be presented in the Compilation area This is the area beneath the Text area Remember that when no errors are presented this does not mean that your text
25. ICAD COURSE Mathieu A J de Vries Johan M M Zentjens Eindhoven Prinsenbeek 27 januari 1992 WPA reportnr 1235 Version 1 1 Supervisors dr ir F L M Delbressine ir R de Groot Bijzondere Onderwerpen Produktie en Meetmiddelen 4U041 Copyright c 1992 Eindhoven University of Technology page 0 1 CONTENTS CHAPTER 1 PHILOSOPHY This chapter explains something about Knowledge based Engineering CHAPTER 2 GNU EMACS EDITOR AND SYSTEM COMMANDS Chapter 2 tells you how to handle with the SUN computer and how to use the GNU EMACS Editor CHAPTER 3 ICAD DESIGN LANGUAGE AND COMMON LISP This chapter deals with some aspects about Object Oriented Programming in Common LISP and about how to use the ICAD Design Language CHAPTER 4 DEFPART ELEMENTS One of the most important things about ICAD are defparts This chapter will explain more about these CHAPTER 5 THE ICAD BROWSER The ICAD Browser is the tool to show you your defined object In this chapter the most important aspects will be explained CHAPTER 6 POSITIONING AND ORIENTATION In the real world objects are placed and oriented The same is done in ICAD This chapter will show some examples of how to position and orientate objects CHAPTER 7 QUANTIFICATION Quantification is a means of replicating using a single object In this way it is not necessary to specify more than this single object Chapter 7 will tell you something about this
26. art wall box soptional inputs ICAD course Version 1 1 Date 27 01 92 Answers to exercises Page A4 window width 0 9 window height 1 2 sattributes length 0 15 parts wall ctype box windows type box width the window width sheight the window height sposition top 0 3 quantify series lateral 3 quantify box width the width 3 sposition left 1 door type box sheight 2 the window height sposition on right from the window first 0 1 CHAPTER 8 TRICKS SPECIAL EXERCISE 8 1 Lines 3 10 10 14 the roof the roof 15 unbalanced parantheses after 0 5 17 misbalanced parantheses have to be placed between 20 and 21 CHAPTER 9 EXERCISE EXERCISE 9 1 EXERCISE 9 2 EXERCISE 9 3 EXERCISE 9 4 EXERCISE 9 5 see listing klok2 lisp ICAD course Version 1 1 Date 27 01 92
27. arts even if the assembly is not really box shaped This box may be a bounding box but does not have to be In the next figure the bounding box with the axis and the faces of a reference part is shown To these axis and faces a part can be positioned and oriented to in respect to the reference part E ose lateral Se en ereveld Figure 7 ICAD course Version 1 1 Date 27 01 92 Positioning and Orientation Page 6 2 6 3 What about position With the position of a part the position of a part in respect to a reference part is meant Each part has a default position at the center of the local coordinate system of the containing defpart The part s default position can only be overridden in the parts statement of its parent by using a position keyword Explicit positioning can be defined either face to face or center to center in respect to the reference part Face to face positioning allows positioning of a part relative to a face of the reference object Cen ter to center positioning allows the positioning of a part relative to the center of the reference object rather than a face Some important rules in ICAD for positioning are You can mix and match the different kinds of positioning You can use only one keyword for each axis If you do not specify a position in a dimension the part will be positioned in the center of that dimension of the containing defpart Example of positioning defpart hou
28. bott M Zane B result TRUE Example of the usage of the IF statement defpart office chair box inputs owners job title attributes upholstery material if or eql the owners job title president eql the owners job title vice president leather vinyl 3 9 What additional LISP functions are used Next additional LISP functions are used max min Returns the maximum or minimum of the given numbers for exmaple max the length the width half Divides the given number by 2 div Divides two numbers yielding a floating point result twice Multiplies the given by 2 round These four functions perform integer division when truncate given two numbers and convert a floating point number ceiling to an integer when given one number The only ICAD course Version 1 1 Date 27 01 92 IDL and Common LISP Page 3 5 floor difference is in their rounding behavior degree Returns radians given degrees degree 30 0 5235995 sin cos tan Returns the sin cos or tan of the given angle where the angle is given in radians Example sin degree 30 expt Raises a number to a power expt 3 2 9 sqrt Returns the square root of the given number EXERCISE 3 1 What type of elements are next elements of a 32 b BMW with sidecar c 15x15 d 32 e 456 EXERCISE 3 2 What are the LEGAL and ILLEGAL expressions a 34 b 3 ce 3 4 d brick e
29. dice box inputs dice dimension sattributes height the dice dimension length the dice dimension width the dice dimension Do not pay attention to the the expression this will be explained later at the What about reference chains In the ICAD Browser you choose now the Makepart function What will happen is that ICAD presents you a window called inputs ICAD expects from you that you enter the dice height If you do not type in a number then ICAD can not present you your nice dice Do not forget to use ICAD course Version 1 1 Date 27 01 92 Defpart elements Page 4 4 the accept function in the window to accept your input Inputs are the mechanism which make classes of parts interesting The defpart describes the characteristics of the class without any specific values for them This is nice because otherwise you have to go back to EMACS Editor to change the values if you want to see a dice with other dimensions Another form of input is the optional input 4 7 What about optional inputs These are inputs for which a default value is supplied that means a value is defined in the defpart definition This value will be shown at the moment that you create an instance in the ICAD Browser If a value for the input is not supplied in the definition of the parent its value will be the default value provided in the child The default value is only overridden when the value of the inpu
30. ecific needs which include Repetitive designs Even though similar products are designed from similar components analyzed and produced in similar ways each individual design is treated as a new event 7 Expertise is scattered In most companies knowledge about designing and manufacturing products is scattered throughout the organization This situation can lead to high engineering and manufacturing costs slow response to customer requests bottlenecks caused by the unavailability of a few key people and loss of knowledge when key people retire Non concurrent engineering Manufacturing and engineering departments are usually physically separated and the design process proceeds sequentially through each group The knowledge and experience of the manufacturing engineers and process planners are often not considered until the design is essentially complete Because of this the design process can be lengthy when changes are needed to accomodate manufacturing criteria Improving quality is difficult Because the optimization phase of the design is a time consuming effort improvements in quality are often left incomplete in order to bring products to market quickly Knowledge based engineering is an advanced technology which addresses the need for companies to bring new high quality products to market quickly while adapting to customer specific design needs Knowledge based engineering systems automate the design and engineering process
31. ers each of them contains 500 cc The number and the contents of cilinders we can call attributes Atrributes provides a means of attaching information to a part In LISP we can define attributes in many ways in terms of other attributes information contained in a catalog arithmetic expressions or conditional expressions Attribute values may be ICAD course Version 1 1 Date 27 01 92 IDL and Common LISP Page 3 2 given as inputs or depend on the value of an input creating generic parts With this above in mind we are now able to describe mechanical systems in a hierarchical way in the same way as we would describe parts of subassemblies of subassemblies of and so on Until sofar we described Object Oriented Languages but we did not tell how to use and program in Common LISP 3 4 What rules are to be considered in Common LISP Common LISP defines several kinds of elements three of which are described here A series of letters and digits defines a symbol There may be any number of letters and digits in its name Words in symbol names are usually seperated by hyphens A keyword is a symbol whose name begins with a colon Here are some symbols abcd x15 123q length A series of digits with an optional decimal point defines a number Fractions by themselves are legal numbers too Examples 800 3 26 1 3 A balanced set of parantheses defines a list The other objects in the list are called elements An element of a
32. etail how to create defparts and how to use the ICAD Browser ICAD course Version 1 1 Date 27 01 92 Defpart elements Page 4 1 CHAPTER 4 DEFPART ELEMENTS 4 1 How to construct an IDL description Most of your programs will have the next structure Structure in package IDL User defpart defpartnamel primitivenamel defpart defpartname2 primitivename2 For this course you always start with the definition in package IDL User The computer has to know that you are an ICAD user In every IDL description the name defpart is used to tell ICAD that a new defpart will be defined lt defpartnamel gt and lt defpartname2 gt are free to be chosen lt primitivenamel gt and lt primitieve name2 gt are primitives like lt box gt lt cylinder gt These names are system defined Other then these primitives are user defined primitives At the place of lt gt several expressions are defined which will be mentioned in the rest of this chapter 4 2 What about attributes An attribute is a way to associate any piece of information or knowledge with a particular defpart It has two parts Its name which is always a keyword Its value which is always defined by an expression the actual values of the attribute is the result of the expression Example of attributes attributes length 20 width 2 40 ICAD course Version 1 1 Date 27 01 92 Defpart elements Page 4 2 4 3 Which specia
33. han 0 prompt minute length spec domain number default 10 sprompt length sratio spec domain number default 0 8 invalid cond gt the ratio spec 1 Ratio cannot be larger than 1 lt the ratio spec 0 Ratio cannot be smaller than 0 prompt ratio sticks spec domain item list 4 12 60 default 4 prompt select ticks position spec domain selection list front srear top bottom right left prompt select position parts EXERCISE 9 5 1 Do the same as in the preceding exercise but now clock plates can be placed on one or more clock block surfaces at the same time 2 Save this description with the name EXERS LISP Hints Use the quantify and the index command ICAD course Version 1 1 Date 27 01 92 Answers to exercises APPENDIX A ANSWERS TO EXERCISES CHAPTER 2 GNU EMACS EDITOR AND SYSTEM COMMANDS EXERCISE 2 1 EXERCISE 2 2 EXERCISE 2 3 EXERCISE 2 4 CHAPTER 3 ICAD DESIGN LANGUAGE AND COMMON LISP EXERCISE 3 1 a aes number symbol number keyword number list with one element list which also is a legal expression EXERCISE 3 2 pg cro roe me oe oe illegal illegal illegal illegal illegal legal legal illegal illegal legal illegal legal illegal illegal EXERCISE 3 3 a sans FALSE TRUE TRUE FALSE FALSE ICAD course Version 1
34. hing randomly on all the keys you can find because you think something must happen It might happen that you have given a wrong command or that you believe you have given a command In these cases there is always a way to turn back properly In worst case you have given a command that causes a dead lock which results in a deaf and blind computer that ignores everything you tell him When this occures don t pray but get some help of the system manager 2 3 How to enter the SUN system SUN computers belong to computers that deal with the UNIX Operating System For this reason you have to log in with a log in name and a password Be sure to obtain one from your instructor When you first sit down you see a login prompt on the screen Now the following actions have to be taken 1 gt Type your log in name followed by RETURN key 2 gt Type your password followed by RETURN key Notice that your password is not shown on the screen What happens then The screen turns grey showing you that the system is starting SunView the Sun windowing system and the ICAD system This takes several minutes because the ICAD system is being loaded EXERCISE 2 1 Try to log in ICAD course Version 1 1 Date 27 01 92 EMACS Editor and System Commands Page 2 2 2 4 How to leave the SUN system The actions to be taken for leaving the system depend on the window in which you are working This can be the GNU EMACS window the
35. iented languages 3 3 What do you have to know about Object Oriented Languages All the things you describe are called objects for example a BMW bike is an object These objects are part of classes for example the gt BMW bike is an object belonging to the class conveyance Classes represent generic characteristics of objects Each object contains all knowledge about itself The object can have interactions with other objects for example with a man who is riding on this bike Now there is coming a difficult one We talk about object instances which define actual objects for which specific values have been supplied as inputs for example we talk about object BMW bike but the instances actual object of these objects could be a BMW R80 type or BMW R100 type The process of creating an object instance from a class definition is called instantiation Classes of objects are defined this is the same as talking about things With instantiation object instances are made and this is the same as the being there of the things Let us consider ICAD In de EMACS Editor we talk about things in other words we describe defpart elements see further on When we move on to ICAD Browser and represent our defparts then we create actual objects or instances with a Makepart function The things you describe have characteristics For example the BMW R80 has two cilinders each of them contains 400 cc a R100 has two cilind
36. ion for the door On the keyword used for referencing ICAD course Version 1 1 Date 27 01 92 Tricks special Page 8 1 CHAPTER 8 TRICKS SPECIAL 8 1 What can you use this chapter for The meaning of this chapter is to give you some guidelines to work easier with EMACS and ICAD Browser But also some main errors will be explained 8 2 What compile time and edit time errors can be made Often most of these compile errors can be avoided or more fully explained by using IDL Help CTRL META 8 2 1 Unbalanced parentheses Unbalanced really means that there are not enough closing parentheses Easily detectable because the defpart will not compile Sometimes you will get a very long error message that scrolls quickly through the bottom window of the editor This is an unbalanced parentheses error The editor commands CTRL META b move backward to the beginning of the expression are helpful for finding unbalanced parentheses Another way of finding these parentheses is to remove some closing parentheses in a defpart and put new ones in For each new one EMACS Editor will show the matching opening parentheses Enter now as many closing parentheses until you match the opening parentheses which is in front of defpart However this does not guarantee that all the parentheses are placed correctly 8 2 2 Misbalanced parentheses Misbalanced means that you have the right number of parentheses
37. lange thickness width the width twice the flange thickness I BEAM Trimetric View I BEAM Flange 0 Flange 1 Web Front View Define a wall which has a series of 3 windows and one door 7 2 What if I don t want the quantified objects evenly spaced As was mentioned in the previous paragraph the default positioning of quantified objects is evenly spaced along the specified axis and centered otherwise If this is not the position that you want the parts to have you will have to specify an alternate bounding box rather than the parent s bounding box to fill evenly with the quantified parts The default position of this alternate box is the center of the parent s local coordinates but it can be placed in any place you want ICAD course Version 1 1 Date 27 01 92 Quantification Page 7 3 The format of the IDL statement that defines the box and places it is quantify box dimension expression position position specification Example defpart wall box soptional inputs window width 3 window height 4 sattributes length 0 6 sparts wall type box windows type box width the window width sheight the window height position top 1 squantify series lateral 3 quantify box width the width 10 position left 1 7 3 What about referencing quantified objects In the chapter Defpart Elements some aspects of reference chains are explained N
38. ling height wall thickness the wall thickness position bottom 0 The height of the house is defined as twice the ceiling height which is an input The first floor part refers to the definition of ceiling height defined by the house for the definition of its height The first floor part refers to the definition of wall thickness defined by the house for the definition of its wall thickness In the definition of the robot in the following example the head refers to the definition of the left arm for its width the left arm upper arm width where Torso ROBOT Head Left arm Upper arm Width Figure 3 ICAD course Version 1 1 Date 27 01 92 Defpart elements Page 4 10 EXERCISE 4 3 Generate next code and predict and show what happens in package IDL User defpart house box inputs ceiling height material wall thickness attributes height twice the ceiling height sparts first floor ctype first floor sheight the ceiling height wall thickness the wall thickness position bottom 0 roof type box sheight the ceiling height position top 0 defpart first floor box zinputs wall thickness sparts front wall type box length the wall thickness position front 0 rear wall stype box slength the front wall length position rear 0 right wall stype box width the wall thickness position right 0 left wall st
39. list may be a list itself This is called a nested list Examples are abc length 6 3 5 What are expressions in Common LISP An expression is the basic result of computation in Common LISP All LISP programming consists of writing expressions Another word for expression is form An expression can be A constant which is a number a keyword a quoted symbol or a quoted list A variable which is a unquoted symbol A list whose first element is a symbol naming a function and whos remaining elements are expressions Examples of functions are cos tan This is the most common expression A list whose first element is a symbol naming a macro and whose remaining elements are determined by the documentation of the macro This usage is less frequent except for the macro named defpart An expression ALWAYS RETURNS A RESULT which is the answer from the expression They are used for computation in many aspects of IDL Parentheses organize expressions Examples of expressions are 36 57 89 the height 6 An important class of expressions are the conditional expressions which are not shown above ICAD course Version 1 1 Date 27 01 92 IDL and Common LISP Page 3 3 3 6 What about conditional expressions Conditional expressions are the means by which rules are incorporated into the definition of an object The term conditional means that part of the expression is evaluated only under cer
40. lities of attributes are known There are some specialities 1 The primitives box cylinder etc have system defined attributes For box the attributes length width height are defined 2 Other attributes names then the defined ones are allowed Notice that these names are constants 3 There is no specific ordering necessary with respect to the way in which the attributes are defined 4 Instead of 2 40 other expressions are allowed One of the used expressions will be shown at What about reference chains 4 4 What are parts When we look at a house we could distinguish several parts like the first floor and the roof We could describe this house in IDL code Example House in package IDL user defpart house box sattributes length 30 width 25 height 20 sparts first floor type box roof type roof defpart roof box sattributes height 3 We see these parts create a tree structure of a house All these parts have a name which is a non keyword that will appear in the tree structure and a type which is a symbol naming a defined def part It is obvious that a house could have more parts then just these two Like this house every defpart represents an assembly and the parts are sub assemblies Each defpart therefore specifies one level of the product structure tree So a two level tree requires at least one user defined defpart An N level tree requires N 1
41. loor wall thickness the Page 4 5 Create a defpart like described here compile it and use Makepart Describe what happens sheight the ceiling height wall thickness position bottom 0 roof stype box theight the ceiling height position stop 0 4 9 What about the tree structure If someone would ask you to describe the family you belong to you problably would model your family by drawing a hierarchical tree and you would use names like father mother parents ancestors The same we can do with products In ICAD between parts Tree structure HOUSE First floor Chimney Figure 2 ICAD course Version 1 1 part descriptions are used to name relations Roof Shingles Date 27 01 92 Defpart elements Page 4 6 NODE An object in the tree which represents a part The tree in the figure has five nodes CHILD A node which is immediately below another node First floor and Roof are the cildren of HOUSE Singles and Chimney are the children of Roof PARENT A node which has other nodes immediately below it in the tree House is the parent of First floor and Roof Roof is the parent of Shingles and Chimney SIBLINGS Nodes which have the same parent First floor and roof are siblings and Shingles and Chimney are siblings ROOT The single node in the tree which has no parent HOUSE is the root in the model LEAVES The nodes in the tree which have no children First floor Shingle
42. name Ctrl x Ctrl w Saving it to the file with a new name See also page 1 14 of the introduction manual The way in which you describe the defparts can be found in plenty examples around you Let us view the most basic commands of editing the text 2 10 How to edit a text in the Text area To edit the text you have to put the Mouse Cursor in the Text area Click on the left Mouse Button to make sure of that you are really working in the Text area You will see a black text cursor At the place where this cursor stands you can delete or add text The easiest way to move around the Text area with this cursor is by moving the Mouse Cursor and clicking the left Mouse Button at the place where you want to edit Adding and deleting text is not the same as in most other Text editors You have to get used to it We recommend you to experiment with it See page 1 13 page 1 21 to 1 23 of the introduction manual for editing commands The most important commands are for adding text just type characters at the desired place in the area for deleting text use the delete key on the keyboard When you add text you will probably use the RETURN key at the end of a sentence to go to the next line What happens then is that the text cursor goes to the beginning of the next line In stead of using the RETURN key you can use the LINEFEED key ICAD course Version 1 1 Date 27 01 92 EMACS Editor and System Commands Page 2 5 EXER
43. ntries Package and Part name The Package is already specified The entry for part name is blank After you have selected this entry you can type the name of the desired defpart you want to instantiate When you have accepted this input by selecting the Accept command at the top of the template you have to match the MakePart command with the Workspace This is how matching is done first you have to select the desired command e g MakePart EditView etc by clicking the left mouse button on the desired command You will notice that the command starts to blink to show that it is selected Secondly you have to match the command with an object e g Empty Workspace Partname etc this is done by clicking the middle mouse button on the object you want to match the command with EXERCISE 5 1 Retrieve in the GNU EMACS Editor the file house1 lisp Compile this defpart description Switch to the ICAD Browser Open the MakePart template by clicking the right mouse button Select the second entry under the words Part Name This places the text editing cursor an ICAD course Version 1 1 Date 27 01 92 The ICAD Browser Page 5 4 I beam in the text box showing you where your text will be entered Type house followed by the Line Feed key and accept this input Match the MakePart command with the Empty Workspace 5 5 2 2 How do I get the instance drawn In the previous paragraph you have defined the defpart that y
44. ommand The Print command Certain attributes in inspector windows SL dn The first three possibilities will be explained in this course for the other ones we refer to the ICAD ICAD course Version 1 1 Date 27 01 92 The ICAD Browser Page 5 6 Browser User s Manual 5 5 5 1 How to use Editview with the graphics viewport When you match the EditView command with the graphics viewport a pop up window will appear This window shows you the ways you can edit the graphics view Selecting Cancel cancels the EditView operation with no changes made Selecting any item in the list makes the appropriate change 5 5 5 2 How to use EditView with the product structure tree When you match the EditView command with a node of the tree of your defpart a pop up window will appear This window shows you the appropriate commands for that node If you select Inspector a window is placed below the the node of the tree The inspector viewport shows you all of the node s attributes and their values The inspector command is probably the one you will use most often The explanation of the other commands is explained in ICAD Browser User s Manual and pages 1 55 to 1 57 of the Introduction Manual 5 5 3 How to use EditView with the workspace You can match EditView with the entire browsable part to change the way you view the part This makes that an EditView window pops up Then you can select any command displayed E g se lecting the
45. orking 2 Add the IDL commands needed so that the information from the interface is used to draw a block with the selected body in the center of it this body must have di mensions smaller than the block 3 Save the description as EXER2 LISP defpart block box base spec sheet attributes length the width width the length spec height the width spec controls ICAD course Version 1 1 Date 27 01 92 Exercise Page 9 2 graphics after action draw spec attributes length spec domain number default 10 prompt length body spec domain item list cylinder box prompt select body sparts EXERCISE 9 3 1 Define a cylinder which has a block on it This block block1 is placed on the edge of the top of the cylinder The length of the cylinder is 0 5 the radius is 5 The dimensions of block1 height 0 5 width 0 5 length 0 5 This total object has to be placed on the outside surfaces of another block block2 The dimensions of block2 length width and height 10 Use the IDL description which is given below 2 Save the description as EXER3 LISP Hints Use for orientation of the cylinder the following command orientation numeric alignment etc defpart block2 box base spec sheet attributes length the width width the length spec block2 height the width spec controls graphics after action draw
46. ots of Insane Silly Parentheses Example of a defpart defpart house box sattributes length 30 width 25 sheigth the width house is a name box is a mixin list attributes is a defpart keyword sheigth length and width are attribute names the width is a attribute value expression 3 12 What can you do with the ICAD Browser The ICAD Browser is the tool you use to show your instantiated defparts Every time you start up the Browser your first action is to use the Makepart function With this function you instantiate a object of your defpart definition How you should use the remaining functions will be explained in one of the next chapters You can imagine that after the object has been presented you do not ICAD course Version 1 1 Date 27 01 92 IDL and Common LISP Page 3 7 like this version of the object and do want to change the definition To do so you have to stop and leave the ICAD Browser and recall the EMACS Editor This can be done several times of course 3 13 What should you have learned until now Until sofar you should have been become a little familiar with object oriented languages the language Common LISP and IDL You should know what the characteristics are of this knowledge based engineering tool Also should you know what has to be done to create defparts instantiate the objects and the possibility to change the defpart definitions Next chapters will explain in more d
47. ou want to draw an instance of You will see that the workspace contains three aspects of this part the Top Level Inputs the Free Grap hics Viewpoint and the product Structure Tree See the figure below 9 Show Hide Break AddTool Delete Children Leaves Condense Expand amp Draw SetRoot Jl updat EditView Evaluate Ri odif yOraphics DrewLeaves F Undo Redo CHEN entity EditOtject DeleteOdject MakePart RewewChoices 7 HOUSE ROUSE Top Level Inputs Figure 6 Top Level Inputs is a template showing you the list of inputs that the defpart requires before it can be fully instantiated You can fill in this template just like you filled in the MakePart template earlier A house s inputs are Length Width and Height Other defparts have other inputs Additiona ly all part have optional inputs These inputs can be filled in but don t have to When you have accepted the settings the inputs are applied to the instance of the defpart The Top Level Inputs template goes away whenever you use the Accept command You now have a fully specified house instantiated in the workspace As you will see when you use ModifyGraphics to show the geometry of your part and EditView to show the Top Level Inputs template again Notice that the Product Structure Tree shows only the root node House followed by showing that this part may have children ICAD course Version 1 1 Date 27 01 92 The ICAD Browser Page 5 5 EXERCISE 5 2
48. oughout the company has to be gattered this will take a lot of time and highly educated people Itis hard to predict the break even point for knowledge based systems You can not point exactly where the benefits will be In this way it is hard to convince managers of the need of these systems ICAD course Version 1 1 Date 27 01 92 Philosophy Page 1 4 1 5 What kind of applications knowledge based CAD systems can be used for There are different classes of applications suited for knowledge based engineering solutions One type of application is the design and engineering of a family of products The products need not have a constant topology since rules can be built into the model to vary the product s topology from a given set of input specifications Characteristics of these applications may include many design rules dependencies between parts of the product redundant designs catalog look up input require ments from existing CAD systems or complex iterations to optimize the product for cost performan ce or quality An example of this type of applications is family of motorbikes or cars Another type of application is the design of complex one of a kind products which have long design cycles due to factors such as many design iterations and multiple engineering disciplines involved in the design process A good example that falls into this category is a jet engine turbine blade Prior to using the ICAD system it was not uncommon
49. oups which contain the knowledge for creating the part geometry or process information automatically from a given set input specifications Engineering design rules for optimizing the product or process for cost performance and quality Decision criteria for extracting information from external data bases as with selection of standard parts from catalogs material properties from material tables or parts from feature based design libraries Rules for interfacing with and analyzing results of engineering analysis programs Rules for using geometric design data which is imported from a CAD system as a geometric design constraint In addition the resulting geometric data which is generated from the product model can be sent to a CAD system for further completion of the detailed design generation of NC programs and documentation 1 3 What benefits do knowledge based CAD systems give us Page 1 3 The benefits of Knowledge based engineering to a company are reduced time to market capturing of the engineering knowledge and the ability of concurrent engineering All these benefits are caused by the capturing of all the needed engineering knowledge into one integrated product model 1 4 What disadvantages are there to knowledge based CAD systems The disadvantages of Knowledge based engineering to a company are The high efforts of time and money that have to be made to make a product model All the knowledge which is scattered thr
50. ow we will explain how you can refer to a specific member of a quantified set of objects Referencing will be used to refer direct or indirect to an attribute of that member There are certain conditions that a referencing chain has to forfil Firstly the referencing chain has to be augmented with keywords which specify the member Secondly the chosen keywords should respect the axes that were defined in the quantify statement and be chosen for their readability One commonly used keyword is any This allows you to refer to one member of the set without having to be specific about which particular one Someone reading your code will then infer that all of the members of the set are the same in this respect An example is the stud any stud length ICAD course Version 1 1 Date 27 01 92 Quantification Page 7 4 The QUANTIFY BOX Does not appear in the WALL Browser WALL Ne Window 0 Window 1 Window 2 JO Figure 10 Another set of keywords are the direction keywords You specify a direction and expression which indicates the relative position of the part Note that the numbering starts with O The direction keywords that can be used are top bottom right front rear Examples the stud front 2 height which refers to the height of the third from the front member of a series quantified along the longitudinal axes the stud right rear 3 2 height which refers to the height of the fourth from the
51. part and a part 6 1 6 3 What about position eee eee 6 2 6 4 What keywords are used for face to face positioning 6 2 6 5 What keywords are used for center to center positioning 6 3 6 6 What if you do not wish to position in respect to the defpart 6 3 6 7 What about orientation eee eeen 6 4 6 8 Can I specify more than one rotation and translation 6 6 ICAD course Version 1 1 Date 27 01 92 CHAPTER 7 QUANTIFICATION oo tmsrstee tre vis OOS We awe He IAA A 7 1 7 1 What is Quantification 0 0 0 0 0 cc ec ce ee eee ee eee 7 1 7 2 What if I don t want the quantified objects evenly spaced 7 2 7 3 What about referencing quantified objects 00 eua 7 3 7 4 How to distinguish a certain quantified object 0020065 7 6 CHAPTER 8 TRICKS SPECIALS oas beret aae EEEE ates 8 1 8 1 What can you use this chapter for 0 0 cece sro eee ee 8 1 8 2 What compile time and edit time errors can be made 8 1 8 2 1 Unbalanced patenthesesn s ones ont ee ASE RARER ER 8 8 1 8 2 2 Misbalanced parentheses tn varens vut NG AS eee ee ae tn 8 1 8 2 3 Function undefined nn sedert OE Ray he Pa ee ewe 8 1 8 2 4 Redefining old version uaa eke ke ven ee a eR 8 1 8 3 What run time errors can be made eee 8 2 8 3 1 No parent could handle the XXX message 5 00455 8
52. pilation area of the GNU EMACS Editor This is the area where your compilation remarks are shown See chapter about GNU EMACS Editor If the text cursor is still in the Text area you have to move the mouse cursor to the meant Compilation area and click the left mouse button Then enter the command CONT followed by RETURN key Perhaps you will notice that some things started blinking in the ICAD Browser window This means that the ICAD Browser is active Now you just have to move your mouse cursor to the header of this window and click the left mouse button The ICAD Browser is brought to the front of the screen 5 4 How to quit and leave the ICAD Browser For quiting the ICAD Browser the mouse cursor has to be placed on the ICAD symbol which can be found at the top of the window Then push the stop key this key can be found at the upper left corner of the keyboard The GNU EMACS window is active again Select this window and it wil be ready to use again You don t have to quit the Browser to use the GNU EMACS Editor You can always select it If you haven t quited the Browser you are able to change and save the text in the GNU EMACS Editor but you won t be able to compile it for this you have to quit the Browser 5 5 How to work with the ICAD Browser Moving the mouse around you can see that an arrow the mouse cursor moves around the screen in a similar fashion To use the Browser you will put the mouse cursor on
53. pt again EXERCISE 2 2 Try to log out when you are already logged in Otherwise experiment with the log in and log out routines 2 5 Can Sunview be left temporary Yes this is possible The meaning of this option is that you can walk away from the system to get a cup of coffee without the possibility of anyone damaging your files When you log in again you will find all the windows as they were before you left the system How can you leave the system temporary Well you have to place the Mouse Cursor on the grey area as described before and turn on the popup window Now you do not select the Exit Sunview command but select the Services command A new pop up menu will be shown from which the Lock Screen command can be chosen SunView will show you now the Lock Screen When you want to continue with the SUN system you only have to enter the password This option prevents anyone else from using the Sun system ICAD course Version 1 1 Date 27 01 92 EMACS Editor and System Commands Page 2 3 EXERCISE 2 3 Log in if you are not logged in and execute the Lock Screen command 2 6 What do you have to know about GNU EMACS Editor Everything about GNU EMACS Editor can be found in the manual Introduction to GNU EMACS on the Sun A lot of the subjects described in the mentioned manual are not needed to make your first ICAD program Here the most important aspects are presented These aspects are the ones
54. r specifying two or more similar parts that only differ in position or orientation The quantify statement that is used for this reason can be used as if it were an input in the part specification All the other inputs on the other hand are given to each of the quantified part The default positioning of quantified parts is to evenly fill the parent s bounding box The parent s bounding box is the box that holds defpart Al the defpart s parts are positioned and oriented in res pect to the axis and sides of this bounding box The replication itself can be done in one of the three ways mentioned below in case of a pair of parts quantify pair direction keyword in case of a series of parts quantify series direction keyword quantity in case of a matrix of parts quantify matrix direction keyword 1 quantity 1 direction keyword 2 quantity 2 The direction keywords that can be used in the statements above are lateral longitudinal and vertical At the place of quantity used in the second and third statement you have to fill in the number of similar parts you want to place in one direction Example defpart I beam box attributes width 0 8 sheight 0 6 slength 5 flange thickness 0 2 sparts flange _ type box width the flange thickness ICAD course Version 1 1 Date 27 01 92 Quantification web Figure 9 EXERCISE 7 1 Page 7 2 squantify pair lateral type box sheight the f
55. s for a matrix Example the stud first index results in 0 You must use the Lisp functions first and second in order to get the individual numbers out of this list The messages are also very useful is nth from end direction keyword is the same as index but lets you specify a direction context in which to compute the index The direction must corres pond to the axis or axes of the quantify statement Options for the direction are right left front rear stop and bottom First and last return true when referring to the first or last member respectively of a quantified set Note that these are different from first and last without the These keywords are used in conditional expressions defpart wall box attributes length 0 15 theight 3 width 4 5 sparts wall stype box window type window position top the child index 2 0 25 quantify series slateral 3 quantify box width the width 5 defpart window box sattributes width 2 sheight 3 ICAD course Version 1 1 Date 27 01 92 Quantification Page 7 7 EXERCISE 7 2 Define a wall with a series of three windows and a door Position the door 0 3 meter to the right of the last window in the series of windows Experiment with different alternatives for referring to the last member of the series of windows to insure they give the same result What effect does rotating the wall have on the position specificat
56. s and Chimney are the leaves in the model DESCENDANTS Those nodes which are directly below another node First floor Roof Shingles and Chimney are the descendants of HOUSE Shingles and Chimney are the descendants of Roof ANCESTORS Those nodes which are directly above another node HOUSE and Roof are the ancestors of Shingles and Chimney HOUSE is the ancestor of First floor SUB TREE A node and its descendants Roof Shingles and Chimney form a sub tree in the model EXERCISE 4 2 Try to draw the tree from the text here below is given Defpart Robot box inputs robot height sattributes length 0 1 the robot height sheight half the robot height width 0 3 the robot height parts torso ctype box ICAD course Version 1 1 Date 27 01 92 Defpart elements Page 4 7 head stype box sheight 0 15 the robot height width 0 15 the robot height position above 0 left arm type arm srobot height the robot height sposition on left 0 top 0 right arm type arm srobot height the robot height position on right 0 top 0 Defpart Arm box sinputs robot height sattributes height 0 4 the robot height width 0 1 the robot height sparts upper arm type box sheight 0 8 the height position top 0 hand type grabber srobot height the robot height sheight 0 2 the height position bottom 0 Defpart Grabber
57. say The height of the beam is the same as the Robot s height We could also refer to the height of another part or subpart l Syntax reference chain the partname attribute name ICAD course Version 1 1 Date 27 01 92 Defpart elements Page 4 9 If no partname is given reference is to an attribute of the defpart in which the appears we have already seen this usage If no attribute name reference is to a part You must define the explicit path down the tree to a part or attribute Defining the path means explicitly naming the parts down from the parent part that you and the target part have in common You do not name the parts in the path up to the common parent nor the parent itself This is what makes a reference into a reference chain You may refer to attributes of children grandchildren or more distant descendants It is not good practice to define the value of an attribute with a long referencing chain It is better to define an input and use the long referencing chain to specify the value from the part above Using inputs makes the lower part generic since it does not use the referencing chain This is also the way to build generic parts In the definition of house in the following example Example House defpart house box sinputs ceiling height wall thickness attributes height twice the ceiling height parts first floor height the cei
58. se box sattributes cheight 10 length 20 width 10 parts first floor type box roof type box position above 0 6 4 What keywords are used for face to face positioning For positioning inside a face defined by the defpart containing the position use the keywords right sleft top bottom front rear For example the top keyword will put the top face of a part certain distance from the top face of the containing defpart In this case top is defined as what the containing defpart would think the top is not what the part bing positioned does This can sometimes be difficult to see Positive expressions position the part closer to the center For positioning outside a face defined by the containing defpart use these keywords on right on left above below in front in rear For example the above keyword will position the bottom ICAD course Version 1 1 Date 27 01 92 Positioning and Orientation Page 6 3 face of a part a certain distance from the top face of the containing defpart Bottom is defined as what the defpart would think the bottom is Positive expressions position the part further from the center 6 5 What keywords are used for center to center positioning For positioning a part relative to the center of another object rather than a face the following keywords can be used lateral positive to right vertical positive to top longitudinal positive to rear The expression used in
59. t is given in the parts list or supplied in the Make Part command Syntax of optional inputs soptional inputs name 1 expression l sname 2 expression 2 see Some remarks have to be made 1 Inputs have a name and an expression 2 The name is specified in the current defpart The value is specified in the next higher level 3 Values of inputs are specified in the Top Level Inputs for the root node the parts section of a defpart for all other nodes Parts and nodes are explained further on 4 Many attributes of primitives i e height and width for box are automatically inputs 4 8 What other ways are possible to ask for input The way in which input is asked is called the user interface This can be done as described above Another way to do this is to use the user interface type for which you use spec sheets en spec attri butes An example will be presented in one of the exercises of chapter EXERCISES If you want to know more about these user interfaces please see the ICAD Production UI Toolkit manual For your work you will probably need this info so do not forget to read it ICAD course Version 1 1 Date 27 01 92 Defpart elements EXERCISE 4 1 Save this defpart description as house1 lisp in package IDL User defpart house box sinputs ceiling height material soptional inputs wall thickness 1 attributes height twice the ceiling height sparts first f
60. t to make a new file with a defpart then you need this command Another way of loading an existing file is done by using the Mouse Put the Mouse Cursor on the Text area Then press the right Mouse button A popup menu will be shown Move the cursor to the command Dired and select it by pressing the left Mouse cursor A list with files is shown Move the Mouse cursor to and hold it on the file name which you want to load Select this file by pressing the left Mouse button Then press the f key Your file will be loaded What has happened after your text is shown The computer has put the existing file in a buffer temporary file and this buffer is shown in the Text area The changes to this buffer will not affect ICAD course Version 1 1 Date 27 01 92 EMACS Editor and System Commands Page 2 4 the existing file on disk Remember therefore that you always save the buffer at regular times 2 9 How to save the buffer Saving the buffer is done by moving the Mouse Cursor to the Text area and pressing and holding the right Mouse Button A popup menu will be shown with commands One of them is save buffer Select this one The question Save buffer as name Y N yes no is shown in the mini buffer the area beneath the Text are in the same EMACS window Answer this question by pressing the y or n key You can also save the buffer with the commands Ctrl x Ctrl s Saving it to the file with the same
61. tain conditions An IF THEN statement is a conditional expression IF is a LISP conditional operator which is used to choose between two alternatives Structure of conditional expression if test expression which returns t or nil then expression which executes if the test expression is true else expression which executes if the test expression is nil More conditional expressions are known in IDL like ecase Look up in the ICAD manual s what other conditionals are known Some of these conditionals you will need for the exercises in chapter EXERCISES All LISP conditionals depend upon a test expression succeeding or failing Any expression may be used as a test expression An expression which returns the symbol NIL is FALSE An expression which returns anything except NIL is TRUE A convential non NIL result used when there is no other meaningful result is the symbol T An expression which returns TRUE or FALSE is called a predicate Remember that a conditional cannot be used to choose between alternate keywords it cannot choose between front and rear It may be used everywhere in IDL where an expression is required For example a conditional can be used to specify the value of an attribute 3 7 What predicate functions are available for conditionals There are predicates used to test for equality Eql is used to determine whether two symbols are identical The function eq is identical but
62. that you probably will use most often 2 7 For what is GNU EMACS editor used and how is it working This editor is used for creating defparts Defparts are objects which can be presented in ICAD Browser Examples are houses tables cars machines More about defparts will be presented in the next chapters The description is done by using the ICAD Design Language IDL which is based on the LISP language Don t be frightened we will not put you on a LISP course In next chapter you will learn more about defparts LISP and IDL most of them from examples After you have described defparts you have to check the description This means that you have to compile your des cription When this is OK to the computer you can switch to ICAD Browser from where you can draw your objects 2 8 How to get descriptions of defparts in the EMACS Editor The description of defparts can be found in existing files or can be created as new ones in the editor First let us assume that there are already existing file on disk Then these first have to be put in the editor This is done by the command Ctrl x Ctrl f This is push and hold the Ctrl key and push sequentially x key en f key You will see at the bottom of the EMACS window that a prompt has appeared that asks for a filename Type the name of the file followed by the RETURN key See also page 1 12 and page 1 15 of the GNU EMACS Editor introduction manual Also when you wan
63. to the number of design iterations to approach 50 or more with process taking about 6 months to complete When one integrated model was used for all engineering groups to work with the iteration process was shortened from weeks to minutes In addition the engineers get immediate feedback on the result of a design change and can more easily see its effect on other parts of the product ICAD course Version 1 1 Date 27 01 92 EMACS Editor and System Commands Page 2 1 CHAPTER 2 GNU EMACS EDITOR AND SYSTEM COMMANDS 2 1 What is the purpose of this document The purpose of this document is not to present you a fully described user manual because there exists one already see Introduction to GNU EMACS on the Sun Then why is there a need for some additional paper We believe that this document helps you to find your way quickly throug hout the ICAD system 2 2 What you have to know before you even touch the SUN system The system you work on is a SUN Sparc workstation This computer is different from computers like personal computers An important difference is that you never turn on or shut off the SUN computer and SUN monitor Only the system operator is allowed to do this Another issue is that of PATIENCE Though this computer is very fast it can happen that after you have given a command it takes some time before something will happen Especially in the beginning you should learn to wait what is going to happen Never start pus
64. user defined defparts You will be writing lots and lots of defparts to ICAD course Version 1 1 Date 27 01 92 Defpart elements Page 4 3 build your product s hierarchical structure A few remarks have to be made 1 Instead of roof type roof we could write roof 2 Type is pronounced is a as in The first floor is a box or The roof is a roof 3 Notice that however you use the name Parts this not means that you have to describe more than one part 4 5 What about generic parts A fully generic part is a defpart all of whose abstract parameters are either inputs or attributes whose _ values depend on those inputs or are constants These parts are easy to reuse duplicate and move around in the tree Genericness is a goal to strive for A given defpart may be generic in certain respects and not in others Generic parts define a class of objects that represent all possible configurations for that part By giving inputs to the generic part you define a particular instance of the class 4 6 What about inputs Inputs are used to tell the defpart that there has to come some information from outside Without this information you can not draw an instance of your defpart on the screen So where does this information come from There are a number of possibilities One of them is the next one For example your defpart definition is something like this Example of inputs in package IDL User defpart
65. various items and operate the mouse buttons All three of the mouse buttons have a different function The left mouse button is to select The middle mouse button is to match The right mouse button is to open a template The meaning of the words select match and open a template will get clear to you when you go on reading 5 5 1 What to do with the menubars In this course we assume that you use a three line menu because it contains all the options you can use Is this menu shown at the top of the screen at this moment If not act as follows Move the mouse cursor to the ICAD logo Select the menu you want to use by clicking the left mouse button You may have to click a few times for this ICAD course Version 1 1 Date 27 01 92 The ICAD Browser Page 5 3 5 2 How to get an instance of a defpart on the Browser screen 5 5 2 1 What do I use the MakePart command for You use the MakePart command to create instances of defparts The MakePart command is found in the bottom line of the menu If this command is chosen by clicking the right mouse button on it you will notice that a template is opened almost similar to the one shown in the picture below Close Accept Make Part Package idl user Part Name aa Part or Spec Part Spec Figure 5 Lets examine it closer The Close command at the top of the MakePart template makes the template go away without you changing anything The MakePart template has two e
66. ype box width the right wall width position left 0 ICAD course Version 1 1 Date 27 01 92 The ICAD Browser Page 5 1 CHAPTER 5 THE ICAD BROWSER 5 1 What do you have to know about the ICAD Browser Everything about the ICAD Browser can be found in the ICAD Browser User s Manual A lot of the subjects described in this manual are not needed to start with Here we present the most im portant aspects of the Browser These aspects are the ones that you probably will use most often 5 2 What is the ICAD Browser used for and how does it work The ICAD Browser is a program that lets you create and examine instances of defparts Defparts are objects that are created and compiled in the GNU EMACS Editor Examples of instances of defparts e g a house are a villa a two storey house a castle etc The Browser screen consists of menubars a workspace and menu tabs You can work with it by using the mouse and keyboard In the figure below the Browser screen is shown Show Hide Break AddTool Delete Children Leaves Condense Expand amp Draw SetRoot Updat EditView Evaluate Ripize Scrol ScrotBack Print Modif yeraphics DrawLeaves Undo Redo IE HE Era iO Identify EditObject DeleteObject MakePart RewewChoices Initial Workspace Figure 4 ICAD course Version 1 1 Date 27 01 92 The ICAD Browser Page 5 2 5 3 How to switch to the ICAD Browser To switch to the ICAD Browser your text cursor has to be in the Com

ICAD COURSE.

Contents

Download Pdf Manuals

Related Search

Related Contents