Road Models in Adams/Tire
Contents
1. 1 00 0 0 0 for a local coordinate system e 1 0 for a distance defined perturbation LENGTH The length of the perturbation LENGTH is used in defining the local coordinate system Road Models in Adams Tire Adams 3D Spline Road Model 15 Keyword Description WIDTH The width of the obstacle The obstacle width can be specified independently of the road width FRICTION The friction coefficient of the obstacle ROAD_TYPE The perturbation type Coordinate System Keywords Depending on the COORDINATE_SYSTEM keyword you selected as shown in Keywords Independent of Perturbation Type you can use two types of coordinate systems Local coordinate system The START and STOP keywords define the local coordinate system while the interconnecting line and the LENGTH keyword provide the direction of the perturbation Adams 3D Spline Road projects the road profile height in the local coordinate system onto the smooth road surface e Distance coordinate system The START and STOP positions are expressed in distance along the road centerline or chord length The direction and length are therefore defined implicitly The following combinations of coordinate system and perturbation types are valid Valid Combinations of Perturbation Type and Coordinate System Coordinate system Perturbation type CROWN X CURB X PLANK X POLYLINE X POTHOLE X RAMP X ROOF X2. Number of Points 50 Start Poirt 3300 0 4000 00 End Point Current Active File D ADAMS pave_road_pts xmi Save Save As Cancel Curvature This function will create a curve Inputs required for this function are Number of Points Start point Center point Tangent Point Radius Arc Length Width Bank mu Left and mu Right 42 Adams Tire Adams 3D Spline Road Model E Road Builder Header Global Soil Properties Road Points Obstacle Road Generator Start Point foo 400 00 Center Poit 00 0000 22 Tangent Poit 5000 4000 00 Radus C Arc Length fissey oo mu Lett mu Right Export Points to Data Tabie Current Field Unit Current Active File D 7ADAMS pave_road_pts xmi Save Swe As Cancel Transition This function will connect the start and end point of the road Inputs required for this are segment 1 segment point segment 2 segment 2 point Width Bank mu Left and mu Right User Defined Points This functionality allows the user to define their road points directly This functionality is more useful in the case when a user wants to use the existing road point which is already in the old road data file format Road Models in Adams Tire Adams 3D Spline Road Model The points are appended to the road points table B Road Builder OJADAMS pave_road_pts xmi Header Global Soil Properties Road Points Obstacle Road Generator Name S
3. Select Show X Y Plot or Show X Z Plot to create a plot of the road as shown in the figure above for x y values To fit the display of the plot into the plotting window do one of the following e Select Fit e Right click the plot and then select Fit To view the data points in the plot e Right click the plot and then select Show Symbols e To view the data points as a curve e Right click the plot and then select Show Curve To zoom the display 1 Select Zoom 2 using the mouse draw a box around the area of the plot you want to view 36 Adams Tire Adams 3D Spline Road Model To modify the road data points 1 Right click the plot and then select Show Symbols 2 Drag the points using the mouse The new coordinates for the data points update in the table on the right 3 Select OK The road data points are not updated in the main table until you select OK To exit the plot Inthe upper right corner select the X Defining Obstacles The Obstacle tab shows the 3D Spline Road obstacles also called road perturbations If there is more than one road obstacle the Obstacle tab displays the Obstacle table as shown in the figure below If there is only one road obstacle the Obstacle tab shows the Obstacle Property Editor You can only create a new obstacle in the Obstacle table For each obstacle all parameters are stored in the XML format 3D Spline Road property file This will make it easy to change obst
4. resulting in the left and right profilez i S 5z As This is done such that the two signals are completely independent if corr 0 0 and identical ifcorr 1 0 Corr Zs Z 8 5 z s 2 5 corr 8 zls 1A eas 8 8 Adams Tire Using the 2D Road Model If ROAD_TYPE stochastic_uneven then the parameters are PARAMETERS for Road Type of Stochastic Uneven The parameter Indicates intensity Variable to control intensity of white velocity noise which approximates measured spectra of road profiles fairly well path_constant Variable to control high pass integration filter correlation_rl Variable to control correlation between left and right track If0 no correlation If 1 complete correlation that is left track right track Can be any value between 0 and 1 start Start of unevenness travel distance Parameters for Road Type of Sweep If ROAD_TYPE sine_sweep then the parameters are PARAMETERS Data for Road Type of Sine Sweep The parameter Indicates start Start of swept sine wave travel distance S end End of swept sine wave travel distance amplitude_at_start Amplitude of swept sine wave at start travel distance a s amplitude_at_end Amplitude of swept sine wave at end travel distance a wave_length_at_start Wave length of swept sine wave a start travel distance A s Road Model
5. 53 54 Adams Tire OpenCRG Road Model Adams SmartDriver support The crg files can also be used for the desired path on the x y plane in case of a Full Vehicle Analysis Course Event or a Full Vehicle Analysis Adams SmartDriver analysis The x and y coordinates are derived by converting the u at v 0 coordinates towards the x y coordinate system Also the Full Vehicle Analysis gt Path Optimization tool can deal with the crg files Adams Car and Adams Chassis quasi statics When quasi statics does not converge setting the following environment variable may help QS_USE_VARINF YES
6. 0 25 for grid size in long direction visualization_increment_v 0 25 for grid size in lat direction visualization_start_u 10 0 point where visualization starts visualization_start_v 5 0 point where visualization starts visualization_end_u 700 0 point where visualization ends visualization_end_v 5 0 point where visualization ends Notes If the visualization_start and visualization_end values exceed the measured road area the output of CRG is shown in a difference color green e Ifthe increment values are smaller then the measured grid value the measured grid value is taken The SROAD_CRG_VISUALIZATION can also be specified in the a master rdg file that is referring to another file using the SROAD_CRG_FILI E block 2 Adams Car MD Adams R4 Patches in red with detailed grids can be shown by adding SROAD_CRG_VISUALIZATION_PATCH_ blocks within the SROAD_CRG_VISUALI ZATION data block see the example SROAD_CRG_VISUA ization_increment_u visual visual ization_increment_v visual visual visual visual The defined start end and increment values of patches may be modified by the visualization routines to lization_s lization_s below tart_u tart_v lization_end_u lization_end_v LIZATION_PATCH_1 0 014 0 0132 20 0 12 0 22 0 1 0 fit the patch in the global grid size of the road Road Models in Adams Tire OpenCRG Road Model
7. 3D Spline Road Model Road Builder Eile Settings Road File mdids Hacar_shared roads tbl road_3d_sine_exarnple xml S Header Global Soil Properties Road Points Obstacle Road Generator j Units Length meter File Version 2 000 Force newton Date 2005 1 1 02 10 43 19 0500 rad Product Name MSC AFC Angle radian Mass fkg Time fsec Revision Comment Current Field Unit Current Active File P release acar shared_car_database cdb roads tbVroad_3d_sine_example xml Save Save As Cancel Creating a 3D Spline Road Property File To create a new 3D Spline Road property file From the File menu select New When you create a new 3D Spline Road property file the default values of the road vertical are set to 0 0 0 0 1 0 Note that the road vertical is normalized at the Adams Solver level Opening an Existing 3D Spline Road Property File To edit an existing 3D Spline Road property file do one of the following From the File menu select Open and then browse for the desired file Road Models in Adams Tire Adams 3D Spline Road Model Le e To the right of the Road File text box select the Browse button ly and then browse for the desired file Changing Units To change the units 1 From the Settings menu select Units 2 Change the units and then select OK Saving Changes To save changes you make to the XML file 1 At the bottom of the Road Builder select either Save or
8. ROUGHNESS X SINE X SWEEP X GRID X 16 Adams Tire Adams 3D Spline Road Model Keywords for Crown Perturbation Type If ROAD_TYPE CROWN then you must specify the keyword DATA_BLOCK CROWN DATA with the name of the subblock CROWN_DATA The subblock consists of three columns of numerical data e The first column is a set of distance values in ascending order The second column contains the height of the crown The third column contains the crown coefficient The road profile heightz is a function of width coordinates p obstacle widthw heightZg and crown coefficientc a C 2 p z9 47 p See Illustration of Crown Keywords for Curb Perturbation Type If ROAD_TYPE CURB then you must specify the following keywords Illustration of Curb Keywords Keywords for Curb Perturbation Type Keyword Description HEIGHT Height of the curb s ROUND_OFF Round off radius of the top of the curb TOP_WIDTH The width of the top of the curb EDGE_WIDTH The width of the edge of the curb SIDE The side of the road where the curb is positioned lt LEFT e RIGHT BOTH Keywords for Plank Perturbation Type If ROAD_TYPE PLANK then you must specify the following keywords Illustration of keywords for e Edged Plank Road Models in Adamsy Tire 17 Adams 3D Spline Road Model e Rounded Plank Keywords for Plank Perturbation Type Keyword Descript
9. Save As 2 If you selected Save As enter the file name and then select OK Displaying Header Information and Adding Comments The Header tab shows information about the road file and the units of the 3D Spline Road object You can add comments in the Revision Comment area as shown in the figure below To display header information and add comments 1 Select the Header tab 2 View the information and in the Revision Comment area enter any comments to help you manage the road property file 29 30 Adams Tire Adams 3D Spline Road Model Road Builder Eile Settings Road File mdids acar_shared roads tb road_3d_sine_example xml Header Global Soil Properties Road Points Obstacle Road Generator File Version 2000 Date 2005 11 02 10 43 19 05 00 Product Name MSC AFC Enter Comments Revision Comment here Current Field Unit Current Active File P release acar shared_car_database cdb roads tbl road_3d_sine_example xml Setting Global Parameters Parameters that apply to the entire road are defined in the Global Tab shown below Learn more about the global parameters To edit the parameters 1 Select the Global tab 2 Change the parameters as explained in global parameters Tip To help you correctly enter values the units for the current parameter appear in the Current Field Unit text box Road Models in Adams Tire 31 Adams 3D Spline Road Model E Road Builder Elle S
10. TIME Unit of time Model Details The MODEL block defines the road model and version MODEL METHOD 3D_SPLINE VERSION 1 00 MODEL Keywords The keyword Determines METHOD Road contact algorithm that Adams Tire uses You must set method 3D_SPLINE to instruct Adams Tire to use the Adams 3D Spline Road spline algorithm VERSION Version of 3D_SPLINE algorithm being used currently 1 00 Road Models in Adams Tire 23 Adams 3D Spline Road Model Global Parameters The GLOBAL_PARAMETERS block defines parameters applying to the entire road GLOBAL PARAMETERS CLOSED_ROAD NO SEARCH_ALGORITHM FAST ROAD_VERTICAL 0 0 0 0 1 0 FORWARD_DIR NORMAL MU_LEF T 0 5 MU_RIGHT 0 6 WIDTH 5 000 BANK 0 0 GLOBAL_PARAMETERS Keywords The keyword Specifies CLOSED_ROAD Whether the road is closed or open If the road is not structured to be closed the beginning and end of the road are not facing each other and you select the closed option Adams Tire creates a deformed road e YES The road is closed e NO The road is open SEARCH_ALGORITHM The type of algorithm to be used to determine the contact location For smooth roads we recommend Fast algorithm e FAST Specifies Fast algorithm With Fast algorithm caching is 6 used if the input point is within 1x10 m distance from the previous input point e SLOW Specifies Slow algorithm With Slow a
11. can generally have small wavelength content Therefore the combination of tire and contact methods should be able to handle this type of excitation Any number of perturbations can be defined If an overlap exists between the perturbations then Adams 3D Spline Road superpositions the perturbations 14 Adams Tire Adams 3D Spline Road Model Adams 3D Spline Road Perturbation Keywords The following sections explain the keywords for each perturbation type and those independent of the perturbation type e Independent of Perturbation Type Coordinate System e Crown Perturbation Type e Curb Perturbation Type e Plank Perturbation Type e Polyline Perturbation Type e Pothole Perturbation Type Ramp Perturbation Type e Roof Perturbation Type e Roughness Perturbation Type e Sine Perturbation Type e Sweep Perturbation Type e Grid Perturbation Type Keywords Independent of Perturbation Type You must specify the following data in the rdf file independent of the type of perturbation Keywords Independent of Perturbation Type Keyword Description COORDINATE_SYSTEM The type of coordinate system e local for a local perturbation bound coordinate system e distance if the perturbation is defined along the length of the road START The start position of the perturbation e 0 0 0 0 0 0 for a local coordinate system e 0 0 for a distance defined perturbation STOP The stop position of the perturbation
12. file formats and tools for the detailed description of road surfaces The predecessor of OpenCRG is a format called CRG which has been used internally for several years by Daimler AG An entire suite of MATLAB and FORTRAN tools had been developed for the handling evaluation and generation of CRG data This knowledge and a whole new series of tools including a new C API shall be made available to the broad public by means of the OpenCRG initiative Users shall be enabled to use all data libraries and code samples on this website with minimum opensource licensing restrictions For details about the use and format of the CRG road files is referred to the users manual available at the website Below the use of CRG within Adams is explained The OpenCRG road can be used with any Adams Tire tire model Positioning of the OpenCRG road In general the position of the CRG measured road data will not match with the required position for your vehicle model There are two options to change the position of the road 1 Change the position and or orientation of the road tire reference marker std_tire_ref 2 Define the x y z reference point in the crg file by adding the following data block see also OpenCRG user s manual SROAD_CRG_MODS refpoint_x 666 0 refpoint_y 132 5 refpoint_z 29 8 refpoint_phi 0 0 Note Some crg files contain binary formatted data blocks Adding ascii statements in such crg file may easil
13. 0 000 0 900 1 00000E 01 1 84741E 15 0 00000E 00 000 000 0 900 1 25000E 01 2 30216E 15 0 00000E 00 000 000 0 900 1 50000E 01 2 77112E 15 0 00000E 00 000 000 0 900 1 75000E 01 3 22586E 15 0 00000E 00 000 000 0 900 2 00000E 01 3 69482E 15 0 00000E 00 000 000 0 900 CROWN COORDINATE_SYSTEM distance START 7 STOP 16 WIDTH 4 ROAD_TYPE CROWN DATA_BLOCK CROWN_DATA FRICTION 0 900 CROWN_DATA S HEIGHT CROWN 7 00000E 00 0 00000E 00 0 00000E 00 8 00000E 00 1 25000E 02 3 12500E 03 9 00000E 00 5 00000E 02 1 25000E 02 1 00000E 01 8 75000E 02 2 18750E 02 1 10000E 01 1 00000E 01 2 50000E 02 1 20000E 01 1 00000E 01 2 50000E 02 1 30000E 01 1 00000E 01 2 50000E 02 1 40000E 01 1 00000E 01 2 50000E 02 1 50000E 01 1 00000E 01 2 50000E 02 1 60000E 01 1 00000E 01 2 50000E 02 Using the Road Builder END_ 900 900 900 900 900 900 900 900 900 DATA_POINTS The Road Builder lets you create and edit 3D Spline Road property files in XML format It is available in Adams Car and Adams Chassis The following sections explain more about the Road Builder e Conversion of TeimOrbit Format 3D Spline Road Property Files to XML Format e Starting the Road Builder Road Models in Adams Tire 27 Adams 3D Spline Road Model e Creating Road Property Files e Opening Road Property Files e Changing Units e Saving Changes e Displaying Header Information and Adding C
14. 1000 100 3000 100 100 3001 50 0 4000 100 100 6 Adams Tire Using the 2D Road Model The XZ_DATA subblock can be extremely large In this case only the portion that is needed at the moment is loaded To facilitate efficient reloading while simulation is running do not use any comment lines in a subblock that contains more than 2000 lines Parameters for Road Type of Pothole If ROAD_TYPE pot_hole then the parameters are PARAMETERS Data for Road Type of Pothole The parameter Indicates depth Depth of pothole start Start of pothole travel distance length Length of pothole Parameters for Road Type of Ramp If ROAD_TYPE ramp then the parameters are PARAMETERS Data for Road Type of Ramp The parameter Indicates height Height of ramp start Start of ramp travel distance slope Slope of ramp 1 means 45 Parameters for Road Type of Roof If ROAD_TYPE roof then the parameters are PARAMETERS Data for Road Type of Roof The parameter Indicates height Height of roof triangle shaped obstacle start Start of roof travel distance length Length of roof measured along x axis Parameters for Road Type of Sine If ROAD_TYPE sine then the parameters are Road Models in Adams Tire 7 Using the 2D Road Model PARAMETERS Data for Road Type of Sine The parameter Indicates amplitude Amplitude of sine wave a wave_lengt
15. Road Models in Adams Tire Adams Tire Using the 2D Road Model Using the 2D Road Model This section of the help provides detailed technical reference material for using Adams Tire to define roads along which to maneuver a vehicle It assumes that you know how to run Adams Car Adams Solver Adams View or Adams Chassis It also assumes that you have a moderate level of tire modeling proficiency The 2D Road model lets you model two dimensional road excitations including a flat road Learn about e 2D Road Types Examples of 2D Roads 2D Road Model Parameters 2D Road Types The available road types are e DRUM Tire test drum requires a zero speed capable tire model e FLAT Flat road e PLANK Single plank perpendicular or in oblique direction relative to x axis with or without bevel edges e POLY_LINE Piece wise linear description of the road profile The profiles for the left and right track are independent e POT_HOLE Single pothole of rectangular shape e RAMP Single ramp either rising or falling e ROOF Single roof shaped triangular obstacle e SINE Sine waves with constant wave length e SINE_SWEEP Sine waves with decreasing wave lengths e STOCHASTIC_UNEVEN Synthetically generated irregular road profiles that match measured stochastic properties of typical roads The profiles for left and right track are independent or may have a certain correlation Examples of 2D Roads Samp
16. S Deformation Modulus KyO 002 A os Deformation Modulus Kyi 0013 140000 0 Elastic Viscous Properties Elastic Modulus G1 7100 0 Elastic Modulus G2 1072000 0 Viscosity 7140000 0 Current Field Unit Current Active File P release acar shared_car_database cdb roads tbl road_3d_sine_example xmil Save Save As Cancel Defining Road Data Points The Road Points tab shows the Road Data Points table as shown in the figure below Learn about 3D Spline Road data points Using the table you can add and delete road data points and display the points as a plot so you can visualize the road and make changes to it e Working with Data Rows e Plotting Road Data Points Road Models in Adams Tire 33 Adams 3D Spline Road Model Road Builder Eile Settings Road File mdids acar_shared roads tbV road_3d_sine_example xml Header Global Soil Properties Road Points Obstacle Road Generator Name Filter fr Current Active File P release acar shared_car_database cdb roads tbV road_3d_sine_example xml Save Save As Cancel Working with Data Rows You can edit any of the data in the rows of the Road Data Points table and add or delete rows The following provide you with the basics of enter data points in the table To edit the values in a row e Select the value you want to change and then type a new value Learn about the data point values To add rows to the Road Data Points table 1 Select A
17. TH Length of the base of the triangular roof Keywords for Roughness Perturbation Type The roughness perturbation type uses a mathematical model developed by Sayers 1 The model is empirical it is based on the observed characteristics of many measured profiles of roads of various types The model provides the synthesis of profiles for both the left and right wheel tracks If ROAD_TYPE ROUGHNESS then you must provide the following keywords Keywords for Roughness Perturbation Type Keyword Description GE Elevation PSD parameter GS Velocity PSD parameter GA Acceleration PSD parameter SAMPLE_INTERVAL _ The distance between the road profile data points CORRELATION_BASE Correlation base length for filtering recommended value 5 0 m LENGTH SEED Seed for random numbers e If seed is negative the computer s clock is used as a seed An infinite number of profiles can be generated to match the same set of Sayers model parameters e If seed is greater than zero the value of the seed is used as the seed to the random number generator This is a means of generating reproducible profiles with the Sayers model References 1 Sayers M W Dynamic Terrain Inputs to Predict Structural Integrity of Ground Vehicles UMTRI Report No UMTRI 88 16 April 1988 114 pp Keywords for Sine Perturbation Type If ROAD_TYPE SINE then you must provide the following keywords Il
18. acle type for a particular obstacle if data already exists Road Builder mdids acar_shared roads tbV road_3d_sine_example xml S Header Global Soil Properties Road Points Obstacle Road Generator Name Fitter hame _ Obetacha Typa Sian Loe X Str Loc Y Start Loe Z Stop Loc x Stop Loc Y Siop Loe Z Sit Oiience Sip Ditance fto Add Name Type Obstacle Parent Road3D gt Current Field Unit Current Active File P release acar shared_car_database cdb roads tblroad_3d_sine_example xmi Save Save As Cancel Adding Deleting and Renaming Obstacles To create a new road obstacle in the Obstacle table 1 In the Name text box enter the name of the obstacle Road Models in Adams Tire 37 Adams 3D Spline Road Model 2 Select Add 3 Enter the values for the obstacle as explained in Adams 3D Spline Road Perturbation Keywords To rename an obstacle e Right click the obstacle name in the table select Rename Obstacle and then enter a new name To delete an obstacle e Right click the obstacle name in the table select Delete Obstacle Using the Obstacle Property Editor The Obstacle Property Editor shown in the figure below shows the common and obstacle specific parameters The obstacle specific parameters portion of the dialog box only shows those parameters that belong to the selected obstacle type Note that you cannot change the coordinate system in the Common Obstacle portion as the ob
19. crete triangular patches the tire as a set of cylinders This model lets you simulate a vehicle that is hitting a curb or pothole or moving on rough irregular road surfaces The 3D Shell Road uses data from both the tire property and road property files The road model uses these blocks from the tire property file e Units e Unloaded_Radius e Width Shape From the road property file it uses these blocks e Title e Units e Model e Offset e Nodes e Element Applying the Tire Carcass Shape This section discusses how the three dimensional shell road applies the tire carcass shape which is defined in the tire property file for more information on defining shape in the tire property file see Fiala Tire Carcass Shape The contact algorithm interpolates the tire carcass shape to a given number of equally spaced points You define the tire carcass shape as a set of points in the shape table of the tire property file Adams Tire assumes that tire carcass shape is symmetrical over the center line of the tire Therefore you need to enter shape points for only half of the tire width If the tire carcass shape is not defined Adams Tire defines it as a rectangular shape based on the radius and width of the tire You define carcass shape in terms of relative values scales Absolute coordinate values for the shape are computed by multiplying relative values with the unloaded radius and half width of the tire The relative width of the ti
20. dd Road Points located below the table 2 Enter the number of data points you want to enter and then select OK The Road Builder adds the rows to the end of the table 34 Adams Tire Adams 3D Spline Road Model To delete rows in the Road Data Point table e Select the row or rows you want to delete right click the column Number and then select Delete Row s The Road Builder renumbers the rows of the table To add a single row to the end of the table e Right click the column Number and then select Add Row To insert a single row below a selected row e Right click the row in the column below which you want to add a row and then select Insert Row To copy and paste data in rows e Highlight the text you want to copy and then select an copy CTRL C data from a source and paste CTRL V it in the road data points table Plotting Road Data Points You can visualize the road data plots by plotting them as x y x values versus y values or x z plots x values versus z values Note that if both the x y plot and x z plots are active changes to road data points in one plot are not automatically updated in the other plot Close and reopen the plot after updating the main road data points table Road Models in Adams Tire 35 Adams 3D Spline Road Model E Road Point Editor X Y 1 2 Displays 6 table of 7 points S which can edit directly t 5000 IMN 616 67 To plot the road data points
21. eep start S The actual frequency is given by Soo oS Sots S s s Road Models in Adams Tire 11 Adams 3D Spline Road Model Adams 3D Spline Road Model Learn how to use the Adams 3D Spline Road model to define a road e About Adams 3D Spline Road e Adams 3D Spline Road Perturbation Types e Adams 3D Spline Road Perturbation Keywords e Using Adams 3D Spline Road About the Adams 3D Spline Road Property File About Adams 3D Spline Road Adams 3D Spline Road lets you define an arbitrary three dimensional smooth road surface such as parking structures racetracks and so on A smooth road is a road surface with a curvature which is less than the curvature of the tire In addition Adams 3D Spline Road lets you model three dimensional road obstacles which are placed on top of the underlying smooth road surface The road centerline width bank angle and left and right friction levels define the road surface completely The road data is stored in an XML file which you can create and modify using the Road Builder Learn more about Using the Road Builder The legacy TeimOrbit road definition file rdf is still supported and can be translated to XML using the Road Builder For a description of the information contained in the rdf file see About the Adams 3D Spline Road Property File By specifying the coordinates of the road centerline you can construct any line in three dimensional space Adams 3D Spline Road assu
22. ettings Road File mdids acar_shared roads tbVroad_3d_sine_example xml Header Global Soil Properties Road Points Obstacle Road Generator Settings Forward Direction Search Algorithm Closed Road Normal C Invert C Fast Slow C Yes No Loc x Loc y Loc z Road Vertical fo 0 foo fi 0 Displays Global parameters units of I Road Width foo 1 a y IM Road Banking p 0 parameter M Road Friction Let 50 F Road Friction Right p 0 Current Field Unit Current Active File P jrelease acar shared_car_database cdb roads tbl road_3d_sine_example xml Setting Soil Properties In case that the road is used for the Soft Soil Tire model the soil properties should be entered These properties are used by the Soft Soil Tire model only when the Soil Properties are in the road data file but another tire model is used they are ignored Note that the Soil Properties will be valid for the whole road area no sections with specific other values can be defined 32 Adams Tire Adams 3D Spline Road Model E Road Builder Ele Settings Road File file 0 ADAMS 3d_flat_soft_soil xml Header Global Soil Properties Road Points Obstacle Road Generator f Generic Properties r Elastic Plastic Properties __ Friction Angle loss Cohesive Modulus 13700 Cohesion 000 Frictional Modulus 814000 0 Deformation Modulus Kx 0 043 Sinkage Exponent I0 Deformation Modulus Ki 0035 AO ba Sti
23. h Wave length of sine wave A start Start of sine waves travel distance s The road height z is given by z s a sin 22 s s Parameters for Road Type of Stochastic Uneven A stochastic uneven road profile both for left and right wheels is generated with properties very close to measured road profiles In a first step discrete white noise signals are formed on the basis of nearly uniformly distributed random numbers Two of these numbers are assigned to every 10 mm of travel path The distribution of these random numbers is approximated by summing several equally distributed random numbers taking advantage of the law of large numbers of mathematical statistics Next these values are integrated with respect to travel distance using a simple first order time discrete integration filter The independent variable of that filter is not time but travel path That is why the filter cutoff frequency is controlled by a path constant instead of a time constant The filter process results in two approximate realizations of white velocity noise that is two signals the derivatives of which are close to white noise Signals with that property are known as road profiles with waviness 2 Several investigations in the past showed that the waviness derived from measured road spectral densities ranges from about 1 8 to 2 2 The last step is to linearly combine the two realizations of the above process Z 105 24 S
24. he sampled point MU_RIGHT Road friction on the right side of road with respect to the centerline of the road at the sampled point OBSTACLES The name of block that contains the perturbation information This entry is optional Sample Road Data File MDI_HEADER MDI_HEADER FILE_TYPE rdf FILE_VERSION 5 00 FILE FORMAT ASCII COMMENTS comment_string Example of 3d Smooth road UNITS UNITS LENGTH meter FORCE newton ANGLE radians ASS kg TIME sec S DEFINITION MODEL ETHOD 3D_SPLINE ROAD_PARAMETERS GLOBAL_PARAMETERS CLOSED_ROAD NO SEARCH ALGORITHM FAST ROAD_VERTICAL 0 0 0 01 0 FORWARD _DIR NORMAL MU_LEFT 0 5 MU_RIGHT 05 WIDTH 5 000 BANK 0 0 DATA_POINTS DATA_POINTS X Y 7 WIDTH BANK MU_LEFT MU_RIGHT OBSTACLES 12 50000E 00 4 60432EF 15 0 00000E 00 7 000 0 000 0 900 0 900 10 50000E 00 4 60432E 15 0 00000E 00 7 000 0 000 0 900 0 900 5 50000E 00 4 60432E 15 0 00000E 00 7 000 0 000 0 900 0 900 CROWN 0 50000E 00 4 60432E 15 0 00000E 00 7 000 0 000 0 900 0 900 26 Adams Tire Adams 3D Spline Road Model 1 53081E 18 1 42109E 17 0 00000E 00 000 000 0 900 2 50000E 00 4 68958E 16 0 00000E 00 000 000 0 900 5 00000E 00 9 37916E 16 0 00000E 00 000 000 0 900 7 50000E 00 1 39266E 15 0 00000E 00 00
25. ion HEIGHT Height of the plank BEVEL_EDGE_LENGTH Length of the beveled edge A beveled edge has a 45 slope When BEVEL_EDGE_LENGTH lt 0 3D Spline Road uses rounded corners instead of beveled edges In this case the radius of the corner is IBEVEL_EDGE_LENGTHI Keywords for Polyline Perturbation Type If ROAD_TYPE POLYLINE then you must specify the keyword DATA_BLOCK XZ_DATA with the name of the subblock XZ_DATA The subblock consists of three columns of numerical data e The first column is a set of distance values in ascending order The second and third columns contain the road profile height of the left and right tracks respectively Keywords for Pothole Perturbation Type If ROAD_TYPE POTHOLE then you must specify the DEPTH keyword which specifies the depth of the pothole Illustration of Pothole keywords Keywords for Ramp Perturbation Type If ROAD_TYPE RAMP then you must specify the following keywords Illustration of Ramp keywords Keywords for Ramps Perturbation Type Keyword Description HEIGHT Height of the ramp SLOPE Slope of ramp 1 corresponds to 45 Keywords for Roof Perturbation Type If ROAD_TYPE ROOF then you must specify the following keywords Illustration of Roof keywords 18 Adams Tire Adams 3D Spline Road Model Keywords for Roof Perturbation Type Keyword Description HEIGHT Height of the roof LENG
26. le files for all the road types for Adams Car are in the standard Adams Car database install_dir shared_car_database cdb roads tbl Sample files for all the road types for Adams Tire are in install_dir solver atire Sample files for all the road types for Adams Chassis are in Road Models in Adams Tire 3 Using the 2D Road Model install_dir achassis examples rdf Note that you must select a specific contact method such as point follower or equivalent plane to define how the roads will interact with the tires Not all combinations of road tire and contact methods are permitted Allowable combinations are explained in Tire Models help under the description of the specific tire model 2D Road Model Parameters The PARAMETERS block must contain the following data some of which are independent of the type of road Learn about parameters Independent of Road Type e Drum e Flat e Plank e Polyline e Pothole e Ramp e Roof e Sine e Sweep Stochastic Uneven Parameters Independent of Road Type The following parameters are required regardless of the road type PARAMETERS Independent of Road Type The parameter Indicates offset A constant shift of the road height values For a flat road and offset 0 the road height is zero 4 Adams Tire Using the 2D Road Model The parameter Indicates rotation_angle_xy_plane Rotation angle of the xy plane about the road z axis In Adams Car
27. lgorithm no caching is used and the greatest accuracy is achieved ROAD_VERTICAL Vector specifying the z axis of the user coordinate system with respect to ISO coordinate system This option allows you to specify the road data points in your preferred reference frame During simulation Adams Tire converts all the data points to the ISO reference frame based on the ROAD_VERTICAL values 0 0 0 0 1 0 The z axis of user reference frame with respect to ISO reference frame FORWARD_DIR Forward direction of the road e NORMAL Vehicle travels along the specification of road data point e INVERT Vehicle travels in a direction opposite to that of specified road data points 24 Adams Tire Adams 3D Spline Road Model The keyword Specifies MU_LEFT Road friction value on the left side of the road with respect to the centerline of the road Specifying road friction under GLOBAL_PARAMETERS overwrites any specification of road friction values in the DATA_POINTS block See Data Points Information MU_RIGHT Road friction value on the right side of the road with respect to the centerline of the road Specifying road friction under GLOBAL_PARAMETERS overwrites any specification of road friction values in the DATA_POINTS block See Data Points Information WIDTH Width of the road If you specify WIDTH it takes precedence over the WIDTH value specified in the DATA_POINTS block Even if this parameter is se
28. lustration of Sine keywords Road Models in Adams Tire 19 Adams 3D Spline Road Model Keywords for Sine Perturbation Type Keyword Description AMPLITUDE Amplitude of the sine wave a WAVE_LENGTH Wave length of the sine wave 1 The road profile height z is given by 27 2 8 a sin 2 s Keywords for Sweep Perturbation Type If ROAD_TYPE SWEEP then you must provide the following keywords Illustration of Sweep Keywords Keywords for Sweep Perturbation Type Keyword Description AMPLITUDE_AT_START Amplitude of the sine wave at start asa AMPLITUDE_AT_END Amplitude of the sine wave at end aed WAVE_LENGTH_AT_START wave length of the sine wave at start Is 2 Adams Tire Adams 3D Spline Road Model Keyword Description WAVE_LENGTH_AT_END Wave length of the sine wave at end le L e SWEEP_TYPE z s a where Sag a sin SWEEP_TYPE 0 then frequency changes linearly SWEEP_TYPE 1 then frequency changes logarithmically Depending on the value of SWEEP_TYPE the road profile height is given by the following functions Linear sweep The frequency changes linearly with distance s The road profile height z is given by a a s 5 on f 7 in 2 Sot 97 Se Ss Logarithmic sweep With every cycle the wavelength decreases by a constant factor The road profile i
29. ma i Cet CO t S Type Points C Linear C User Function Curvature C Transition User Defined Points wah hoo Bak 00 mule 03 muRigt 09 het b t wa ladle Current Field Una Current Active File D7ADAMS pave_road_pts xml Save SweAs Cancel User Defined Functions User can calculate points using their own functions For example User function s 75 s 10 0 Function Start 10 Function End 10 Calculation of Road Point 1L0 75 1L0 1 0 0 9 75 9 10 0 8 753 84 10 0 43 44 Adams Tire Adams 3D Spline Road Model E Road Builder Ge Settings Road Fite D ADAMS pave_road_pts xmi Header Global Soil Properties Road Points Obstacle Road Generator a Name Segment 5 Comment Type C Unear Curvature User Defined Points s 75 s 10 0 Fuction Function Stat 000 O Function End 1000 amp 0 Current Active File 0 ADAMS pave_road_pts xml Sem Sweas Cancel Road Models in Adams Tire Adams Tire 3D Shell Road Model Adams Tire 3D Shell Road Model The 3D Shell Road utilizes a three dimensional tire to road contact model that computes the volume of intersection between a road and tire From the intersection volume the method computes an equivalent plane s effective road normal penetration tire to road contact point and effective road friction The road is modeled as a set of dis
30. mes a flat cross section for which the bank angle and width can be specified for each data point In addition you can specify friction levels for left and right road sides Using Adams 3D Spline Road You can reference the Adams 3D Spline Road just as you do any other rdf by selecting your desired road from an appropriate database In addition both Adams Car and Adams Chassis have a Adams 3D Spline Road event called 3D Spline Road Graphics for the road are automatically generated for animation purposes In the current version of Adams 3D Spline Road both Adams Car and Adams Chassis offer multiple methods to access the Adams 3D Spline Road capabilities e When running any full vehicle simulation you may use an Adams 3D Spline Road data file for the road e When using with Driving Machine you may also use a road data file as you would a driver control data dcd file to specify the vehicle path The Driving Machine will then drive the vehicle along the centerline of the road e When using with Adams SmartDriver you can use the road data file to replace the driver road data drd file In this case the vehicle will use the x y and z road centerline to define the vehicle path 12 Adams Tire Adams 3D Spline Road Model Examples of event xml file for use with Driving Machine and Adams SmartDriver are shown next For Driving Machine lt DcfMini name 3D_SMOOTH_ROAD active true userDefined false smoothingTime 0 1 acti
31. n contain more data than what the 3D Shell Road currently requires The 3D Shell Road searches for the blocks and keywords it needs and disregards any additional information in the file Any line that is not recognized as input data is treated as a comment and therefore skipped Therefore you can use almost any character to begin a comment line but we recommend that you use s s or s to avoid confusion Avoid using comment lines beginning with a square bracket or lines that could interfere with keywords Tables must always appear as one set of data No comment or empty lines are allowed between lines Tables must always have a header line beginning with a brace 48 Adams Tire Adams Tire 3D Shell Road Model A keyword and its value are separated by an equal sign You must enter strings within single or double quotes Examples of Blocks Units Block Block header UNITS Keywords Allowed values LENGTH meter mm cm km inch mile Model Block The method keyword in the block determines the road contact algorithm Adams Tire uses You must set method 3D to instruct Adams Tire to use the 3D Shell Road algorithm Block header MODEL Keywords Allowed values METHOD 3D Nodes Block Block header NODES Keywords Allowed values NUMBER_OF_NODES lt an integer number gt Tabular data node x_value y_value z_value 1 lt a real number X gt lt a real n
32. omments e Setting Global Parameters e Setting Soil Properties e Defining Road Data Points e Defining Obstacles e Defining Analytical Road Conversion of TeimOrbit Format 3D Spline Road Property Files to XML Format The Road Builder does not use TeimOrbit property files If you open a TeimOrbit 3D Spline Road property file in the Road Builder it automatically converts it to XML format This XML 3D Spline Road property file is stored in the working directory and loaded in the Road Builder Starting the Road Builder To start the Road Builder in Adams Car e From the Simulate menu point to Full Vehicle Analysis and then select Road Builder To start the Road Builder in Adams Chassis In Build mode from the Utilities menu select Road Builder In both cases the Road Builder starts with the road_3d_sine_example xml example road property file loaded as shown in the figure below The Road Builder consists of six tabs e Header Displays header and units information and lets you enter comments Learn more e Global Sets parameters for the entire road Learn more e Soil Properties If road is used for the Soft Soil Tire model the soil properties should be entered Learn more e Road Points Sets parameters that define the points in the road Learn more e Obstacle Defines obstacles in the road Learn more e Road Generator Allows the user to create modify road data file using segments Learn more 28 Adams Tire Adams
33. quency 0 functionString 0 gt lt DcfSmartDriver name Smartdriver active true userDefined false task vehicle_ limits courseFile mdids acar_shared roads tbl 3d_road_smooth_ramp xml max_driving_accel 70 max_braking_accel 70 max_lh_turn_accel 70 max_rh_turn_accel 70 samplePeriod 0 01 gt Adams 3D Spline Road Perturbation Types The available road perturbations are e CROWN Road crown along the road centerline e CURB Curb at left right or both sides of the road e PLANK Single plank with beveled edges or rounded corners e POLYLINE Cubic spline description of the road profile for left and right wheel track e POTHOLE Pothole of rectangular shape e RAMP Ramp either rising or falling e ROOF Roof shaped triangular obstacle e ROUGHNESS Generated irregular road profiles with stochastic properties similar to measured roads e SINE Sine wave with constant amplitude and wavelength e SWEEP Sine wave with variable amplitude and wavelength e GRID Regular Grid obstacle the road height is defined by a matrix of road height points at equal distance Note that a specific contact method has to be selected which defines how Adams 3D Spline Road interacts with the tires Not all combinations of road tire and contact methods are permitted For more information see the topics under Tire Model in the Table of Contents Be aware that Adams 3D Spline Road perturbations
34. re must be given in ascending order from 0 0 to 1 0 where the value 0 0 corresponds to the center line of the tire Tire Carcass Defined Using Given Shape and Interpolated Values 45 46 Adams Tire Adams Tire 3D Shell Road Model Gyen points for the shape Interpolated points forthe shape f Tire center line Tirewidth Road Property File The contact algorithm works from a triangle tessellated road representation The figure below depicts a road surface formed by six nodes numbered 1 through 6 The six nodes together form four triangular patch elements denoted as A B C and D The unit outward normal for each triangular patch is shown for the sake of clarity Much like finite element mesh convention you define a road by first specifying the coordinates of each node in the road reference marker axis system Subsequently you specify the three nodes that form each triangular patch For each triangular patch you can specify a coefficient of friction Road Models in Adams Tire 47 Adams Tire 3D Shell Road Model Road Representation in Adams Tire Defining the 3D Shell Road Surface You use a road property file to define the three dimensional road surface The road property file consists of five data blocks e Header e Units e Model e Nodes e Elements These blocks of data can appear in any order in the file and keywords can appear in any order within the block to which they belong The road property file ca
35. ring which the drum is accelerated to a nominal rolling speed Parameters for Road Type of Flat If ROAD_TYPE flat then no further parameters are required Road Models in Adams Tire 5 Using the 2D Road Model Parameters for Road Type of Plank If ROAD_TYPE plank then define the following parameters PARAMETERS for Road Type of Plank The parameter Indicates height Height of plank start Start of plank travel distance length Length of plank measured along x axis bevel_edge_length Length of bevel edge measured along x axis Bevel edge has 45 slope When bevel_edge_length lt 0 rounded corners instead of bevel edges are used In this case radius of the corner is Ibevel_edge_lengthl direction Direction of plank relative to y axis If the plank is placed crosswise direction O If the plank is along the x axis direction 90 Parameters for Road Type of Polyline If ROAD_TYPE poly_line then the PARAMETERS block must have a XZ_DATA subblock The subblock consists of three columns of numerical data e Column one is a set of x values in ascending order e Columns two and three are sets of respective z values for left and right track The following is an example of the full PARAMETERS Body for a road type of polyline PARAMETERS PARAMETERS OFFSET 0 ROTATION_ANGLE_XY_PLANE 180 Z_DATA 0 0 1000 100 50 2000
36. s given by 4 a S S5 _ Fe FA 455 D a ak eros 2 fe L s is the distance at which theoretically an infinitely high frequency is reached with respect to the start ss Keywords for Grid Perturbation Type If ROAD_TYPE GRID then you must specify the keyword DATA_BLOCK GRID DATA with the name of the sub block GRID_DATA The sub block should contain the road height data points as function of the x and y position The local start coordinates will correspond to the first row and the center column will run along the line from START to STOP In the example below the Z413 corresponds to the local START coordinates Column 3 will be along the START to STOP direction Pld Z21 z311 z411 Zoi zZ6l ZTL z12 Z22 Z32 z42 252 z62 272 z13 Z23 Zo3 z43 Z53 z63 z73 z14 Z24 z34 z44 z54 z64 z74 PALS Z25 z735 z45 ZOD z65 ZID Road Models in Adams Tire 21 Adams 3D Spline Road Model 281 z82 z83 z84 z85 791 292 293 294 295 The lateral distance between two points in a row is determined by the WIDTH of the obstacle and the number of points in a row distance_y WIDTH number of points in a row 1 Similar the longitudinal distance between two points in a column is determined by the LENGTH of the obstacle and the number of points in a column distance_x LENGTH number of points in a column 1 3D Spline Road will calculate the road height using cubic spline
37. s in Adams Tire Using the 2D Road Model 9 The parameter Indicates wave_length_at_end Wave length of swept sine wave at end travel distance Must be less than or equal to wave_length_at_start 10 Adams Tire Using the 2D Road Model The parameter Indicates sweep_type e sweep_type 0 frequency increases linearly with respect to travel distance e sweep_type 1 wave length decreases by a constant factor per cycle Depending on the value of sweep_type the road height is given by the following functions where Linear sweep sweep_type 0 The frequency increases linearly with respect to travel distance The road height value z s as function of travel distance s is calculated as follows Note the factor 2 in the denominator is not an error The actual frequency derivative of the sine function argument with respect to travel path divided by 27 this is not equal to that factor that is multiplied by 27 s s in the sine function is given by the following fe f s z S SeT Ss fis f e Logarithmic sweep sweep_type 1 with every cycle the wave length decreases by a constant factor The road height value is calculated as follows z s a lt s sin 2nf 5 2 In e Sy TSS where e S Sefe s2 5 S S the travel path where theoretically an infinitely high frequency was reached measured relative to sw
38. s through the road height data points See Illustration of Grid keywords About the Adams 3D Spline Road Property File The following sections explain the data blocks in the Adams 3D Spline Road property file rdf The last section contains a sample rdf e File Details e Units Details e Model Details e Global Parameters e Data Points Information e Sample Road Data File File Details The first block of data MDI_LHEADER describes the TeimOrbit file MDI_HEADER FILE_TYPE rdf FILE_VERSION 5 00 FILE FORMAT ASCII COMMENTS User entered comments go here MDI_HEADER Keywords The keywords Contains FILE_TYPE The file type FILE_VERSION Version of file to be changed when modifications to this file are made 22 Adams Tire Adams 3D Spline Road Model The keywords Contains FILE_FORMAT The format of the data for TeimOrbit this is always ASCII COMMENTS Descriptive comments about the file such as what road this represents User entered comments when the data was acquired and so on go here Units Details The UNITS blocks defines the units for the road UNITS LENGTH meter FORCE newton ANGLE radians MASS Ike TIME sec UNITS Keywords The keywords Specifies LENGTH Unit of length FORCE Unit of force ANGLE Angle in radians or degrees MASS Unit of mass
39. stacle type determines whether Local or Distance should be used You manage the data in the tables for the Polyline and Crown obstacle types in the same way you do road data points For more information on adding deleting and copying pasting of data see Defining Road Data Points To display the Obstacle Property Editor do one of the following e Right click the obstacle name in the Obstacle table and then select Modify with PropertyEditor e Double click the obstacle name in the obstacle table To return to the Obstacle table e Click the arrow rel at the top left side e To edit the values e Change the values as explained in Adams 3D Spline Road Perturbation Keywords Tip To help you correctly enter values the units for the current parameter appear in the Current Field Unit text box 38 Adams Tire Adams 3D Spline Road Model Parameters common toal obstacles Parameters specific to the selected obstacle Eje Settings Road File mdids acar_shared roads tbVroad_3d_sine_example xml Header Global Soil Properties Road Points Obstacle Road Generator e Name SINE Comment Common Parameters Obstacle Type sine Width 20 Length eo 0 Friction fo 9 Coordinate System Local Distance Loc X Loc Y Stat Location 300 OO foo Stop Location 400 O 006 oO Obstacle Specific Parameters Amplitude foot Wavelength 80 o oo Wavelength Offset 00 8 Current Field Unit C
40. t you must specify the WIDTH parameter in DATA_POINTS If this parameter is not required then you can omit it from the road data file rdf See Data Points Information BANK Slope angle of the road around its centerline in each data point Zero bank means a horizontal width line A positive value specifies a slope along a clockwise direction in ISO reference frame If you specify this dimension then it takes precedence over the BANK value specified in the DATA_POINTS block Even if you set this dimension you must specify a BANK value If this dimension is not required then you can omit it from the rdf file See Data Points Information Data Points Information The DATA_POINTS block contains the road information in a tabular form The following information needs to be supplied for each entry DATA_POINTS X w Z WIDTH BANK MU_LEFT MU_RIGHT OBSTACLES DATA_POINTS Keywords The keyword Specifies X X coordinate of sampled road data point Y Y coordinate of sampled road data point Z Z coordinate of sampled road data point WIDTH Width of road at the sampled point BANK Angle of road at the sampled point positive value specifies a slope along a clockwise direction in ISO reference frame Road Models in Adams Tire Adams 3D Spline Road Model 25 The keyword Specifies MU_LEFT Road friction on the left side of road with respect to the centerline of the road at t
41. the road points click on Export points to Data Table this will calculate the road points according to the segment function and export them to the Road Points tab in the GUI Road Builder Bille Setting Road File fle D ADAMS pave_road pts xml Header Global Soil Properties Road Points Obstacle Road Generator Namefiter gt 1481 63265306 1346 93877551 1279 59163673 1212 24489795 1144 89795918 1077 55102041 1010 20408163 242 857142057 808163265306 740816326531 336 734693878 269 387755102 202 040816327 134 693877551 AJ 49 5 gag7755 pes Show X Y Plot Show XZ Plot Add Road Points Generate 3d Road gt ean Current Field Und Current Active File D ADAMS pave_road_pts xml Save SawAs Cancel To see the road points in 2D click button Show X Y Plot amp Show X Z Plot To see the road profile with shell graphics click on Generate 3d Road To see in 3D user should have Adams Car license Description of Functions Linear This function will create a straight line between two given points Inputs required are Number of points Start point End point Width Bank mu Left and mu Right Road Models in Adams Tire 41 Adams 3D Spline Road Model Road Builder fe isting Road Fite OJADAMS pave_road_pts xmi amp Header Globa Sod Properties Road Points Obstacle Road Generator Name Sema a Co Type Uneor C Curvature User Defined Powts
42. umber Y gt lt a real number Z gt 2 lt a real number X gt lt a real number Y gt lt a real number Z gt lt an integer number gt lt a real number X gt lt a real number Y gt lt a real number Z gt Elements Block Block header ELEMENTS Keywords Allowed values NUMBER_OF_ELEMENTS lt an integer number gt Tabular data node_l node_2 node_3 mu lt an integer number gt lt an integer number gt lt an integer number gt lt a real number gt lt an integer number gt lt an integer number gt lt an integer number gt lt a real number gt lt an integer number gt lt an integer number gt lt an integer number gt lt a real number gt Road Models in Adams Tire Soft Soil Road Model Soft Soil Road Model When using the Adams Tire Soft Soil tire model the road file needs a section that with the soil properties All Adams Tire road formats can be used in combination with the Soft Soil tire model as long as the road file contains a section in which these soil properties are specified For further details see the section Using the Soft Soil tire model 49 j Adams Tire OpenCRG Road Model OpenCRG Road Model The OpenCRG Road Model CRG Curved Regular Grid is based on the open source code delivered at http www opencrg org The website states about the background of this road model Its objective is the provision of a series of open
43. urrent Active File P release acar shared_car_database cdb roads tbl road_3d_sine_example xml Defining Analytical Road Following example illustrates how to create modify a road model analytically from scratch in Adams Road Builder Road data can be created with multiple segments each segment representing predefined formulations like Linear Curvature and Transition Curve or through User Defined Functions and User Defined Points Road Models in Adams Tire 39 Adams 3D Spline Road Model Steps to Create a Road Data File New tab Road Generator is added to the Road Builder GUI This tab allows the user to create modify road data file using segments Road Builder Bile Settings Road File DADAMS pave_road_pts xml Header Global Soil Properties Road Points Obstacle Name Filter 3300 0 400 0 0 0 0 0 400 0 0 0 0 0 400 0 0 0 0 0 0 0 0 0 500 0 400 0 0 0 0 0 0 0 0 0 400 0 pareri User Functior Add Name Segment_4 Type RoadSegment Parent Road30 Expor Points to Data Table Current Field Unit length meter Current Active File D7ADAMS pave_road _pts xml Save Save As Cancel To create a new segment enter segment name in the Name field and click Add button Segment name should be unique To make it easier for the user to create road profile some basic functions were created User can use these functions by giving appropriate values Adams Tire Adams 3D Spline Road Model To see
44. veFlag true abortTime 1 stepSize 0 01 hMax 0 gt lt DcfDemand name Steering active true userDefined false demandType steering actuatorType rotation controlMethod machine controlMode absolute controlType constant constantValue 0 initialValue 0 finalValue 0 startTime 0 duration 0 rampValue 0 maximumValue 0 cycleLength 0 amplitude 0 initialFrequency 0 frequencyRate 0 maximumFrequency 0 functionString 0 gt lt DcfMachine name machine active true userDefined false steerControl file dcdSteerFile mdids acar_shared roads tbl 3d_road_smooth_ramp xml1 steerRadius 0 steerEntry 0 turnDirection right pathPositioning default speedControl lon_accel velocity 0 acceleration 0 jerk 0 startTime 0 1 samplePeriod 0 01 gt For Adams SmartDriver DcfMini name 3D_SMOOTH_ROAD active true userDefined false smoothingTime 0 1 activeFlag true abortTime 1 stepSize 0 01 hMax 0 gt lt DcfDemand name Steering active true userDefined false demandType steering actuatorType rotation controlMethod SmartDriver Road Models in Adams Tire 13 Adams 3D Spline Road Model controlMode absolute controlType constant constantValue 0 initialValue 0 finalValue 0 startTime 0 duration 0 rampValue 0 maximumValue 0 cycleLength 0 amplitude 0 initialFrequency 0 frequencyRate 0 maximumFre
45. vehicles start running along the negative x axis by default It also might be convenient to use positive x values in the rdf In that case choose rotation_angle_xy_plane 180 deg mu Road friction correction factor not the friction value itself to be multiplied with the respective rubber friction values of the tire model Default setting mu 1 0 Parameters for Road Type of Drum If ROAD_TYPE drum then define the following parameters PARAMETERS for Road Type of Drum The parameter Indicates diameter Diameter of the tire test drum When the diameter is lt 0 the road model simulates the outer drum With positive rolling speed the inner drum will rotate clockwise and the outer drum counter clockwise v Rolling speed of drum surface be sure to keep vehicle at speed zero otherwise the wheels move away from the drum Drum center is located at x 0 number_cleats Number of extra cleats on drum number_cleats 0 allowed cleat_height Height of extra cleats cleat_starting_angle Drum angle coordinate of first cleat cleat_length Length of cleat measured in circumferential direction of drum Example of specifying cleat_length cleat_bevel_edge_length Length of bevel edge of cleat measured in circumferential direction of drum Bevel edge has 45 slope Example of specifying cleat_bevel_edge_length acceleration_time Optional time span at the beginning of the simulation du
46. y destroy the format and make the file un readable for the OpenCRG code One may avoid editing the existing crg file by using the ROAD_CRG_FILE feature in a master crg file An example of a master file is the sample_country_road_repositioned crg in the acar_shared tires tbl folder Messaging by OpenCRG By default the messaging level is set to writing out fatal errors only level 1 Changing the messaging level can be done by setting the environment variable CRG_MESSAGE_LEVEL Road Models in Adams Tire 51 OpenCRG Road Model CRG_MESSAGE_ LEVEL 0 dcCrgMsgLevelNone 1 dCrgMsgLevelFatal 2 dCrgMsgLevelWarn 3 dCrgMsgLevelNotice 4 dCrgMsgLeveliInfo 5 dCrgMsgLevelDebug E File Edit View Adjust Simulate Review Settings Tools Help MDI_Demo_Vehicle pies xelil OpenCRG road visualization Visualization of the OpenCRG roads is supported within Adams Car At the end of a simulation the road grid will be visualized using default settings for grid and overall road size The maximum number of grid datapoints used in these default settings can be changed using an environment variable CRG_MAX_VIS_POINTS CRG_MAX_VIS_POINTS 10000 52 Adams Tire OpenCRG Road Model However the user can specify his own detailed preferences for visualization by adding his specification ina SROAD_CRG_VISUALIZATION data block in the crg file SROAD_CRG_VISUALIZATION visualization_increment_u
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