Case Studies in Web- Controlled Devices and Remote Manipulation
Contents
1. 4 3 How were the above limitations overcome to achieve the objective The following tasks had to be carried out 1 Configure the server to server HTTP requests 2 Write software allowing HTTP clients to issue commands to the robot via the RS 232 port 3 Write software to initialize the robot and define the work area Server configuration was relatively less complicated and setting up an NT server with an IIS web server to process requests and enabling security authentication and control was smooth An ActiveX control needed to be written in Visual C This component allows Active Server Pages to run executables on the server itself An executable called writetoport exe did the simple task of taking command line arguments and sending these arguments to the robot as commands via the serial port This application was first implemented in C under a DOS environment but when ported to Windows NT the operating system s security management features did not allow direct access to the computer s serial ports 16 This application needed to be re written in a windows environment using Visual Basic 19 4 3 Robot initialization As mentioned previously robot initialization is vital to ensure error free operation especially since the robot s controller unit sends back no signals to the server itself The position of the remote control needs to be fixed and positions within the robot s work area need to be defined There are two b2. Internet Controlled Robot with Video Feedback This Internet Controlled Robot is a robust and repeatable telerobotic manipulator that can be controlled from any Internet enabled computer around the world The aim of this project is to create a functional system that allows the efficient control of a supervised telerobot In supervised telerobotics an operator at a local site utilizes input devices and graphical visualization tools to command the execution of a task at a remote site using a telerobot The robot is controlled from a web page where the operator handles the robot by using a graphical user interface The operator can control each link of the robot separately or move the robot to a given point in 3 D space by inputting the corresponding coordinates The operator sees the movement of the robot on the computer screen in real time via a live video camera broadcast This allows the operator to see the immediate effects of his or her control actions and correct them if necessary Such a system can be used to control a robot that operates in a hazardous or inaccessible environment In addition it offers the benefit that the operator does not have to be in the vicinity of the robot but can be located anywhere throughout the globe Practical applications of the system include remote controlled operations in radioactive or toxic areas which are dangerous for human beings as well as remote reconnaissance and sample collection The designed r
3. Manipulat Figure 5 System Schematics Interfacing between the robot and the server is carried out via the RS 232 serial port which is a standard on the main board of any IBM compatible PC The robot s controller box simply receives commands as ASCII strings through the RS 232 connection An important issue that arises is that there is only one way communication I E once the computer issues commands to the robot the controller box does not send back a signal to indicate a successful or unsuccessful command interpretation and application 15 To overcome this it is important that a flawless trajectory be planned during initialization of the robot and implemented in a manner such that obstacles do not pose a problem Sample commands among others that can be issued to the robot include 17 GC Closes the gripper GO Opens the gripper NT Nest the robot Interfacing between the receiver and the server is implemented through a special interface card which takes the analog feed from the transponder s receiver and converts it into a digital format ready to be broadcast over the internet The PC card receives a feed through a standard coaxial cable such as that used for Cable television The transponder can point at different look angles and at each look angle it can receive feeds at numerous frequencies Interfacing between the server and the internet is relatively simple since it involves setting up and configuri
4. app and returns stdio as string ExecuteWinAppAndWait Execute the specified app as a Windows app and wait for the specified timeout if exec is successful ExecuteWinApp Execute the specified app as a Windows app and return result code immediately Installation To use this ASP component we moved the DLL into a subdirectory such as winnt system32 for NT or windows system for Win95 98 and type 10 regsvr32 aspexec dll For the source code for controlling the robot please see Appendix A Figure 3 shows a screenshot of the controlling interface 14 JINA adira Cian Robotics Write to Port Application Unity of Bridgeport Cpe 460 Puneet Batra e200 pond Euan Cimara Akienpting to execute ciobotice anieloporlene MO H9 C The result of this call was Oe Bigi Sono a PRESS THIS BUTTON BEFORE EACH MEW Eman Bam Sani Butea Kiihai HOVEMASTEL ES connie ony dan oes fale GC Gripper Close Gtk Gripper Open NT Nesi Mic ALC Move bo Position minber 5 wiih mip closed O or open Hah Figure 3 A screenshot of the main interface page http 216 87 101 211 8080 satcontrol aspexec commandrobot asp In this interface the user is allowed to type any of the commands that the robot was designed to accept through the serial port given that the user is aware of their correct syntax using the robot s user manual is recommended Simple commands such as GC GO NT MO specified 11 on the interfa
5. in solving them In a supportive effort towards faster distance learning implementations we present through this work a sequence of projects that have been developed and can serve the process of distance learning education ranging from simple hobby style training to professional guidance material Before proceeding to the details of each project a synopsis of each project is presented Internet Controlled Robot with Video Feedback The project simplifies the control of an inexpensive mobile manipulator and offers a simple web based interface with a video feedback that allows the control of the robot from any point on the web with a few clicks of a mouse The user can activate each link separately or move the robot to a given location and a live stream of the robot will confirm its coordinates WWW Gateway for the Mitsubishi MoveMaster EX Robot Like the majority of manipulators the MoveMaster robot from Mitsubishi offers a mini language set that allows its control when connected to a computer This project demonstrates the ability to interface the robot s language set with a simple web interface thus allowing remote programming of the manipulator Remotely Controlled Monitoring Vehicle The project demonstrates how a low cost monitoring vehicle can be controlled from a remote location providing visual feedback to the remote operator The main applications include security surveillance child monitoring and territory exploration 1
6. make them a reality One idea is to use the large information bandwidth that the Internet can offer and expose a variety of educational materials online A course could for example be offered online through a comprehensive list of multimedia solutions ranging from an online course book and online homework submissions to live video conferencing auditing and examinations There are many methods to create an online course and an appropriate one would have to be chosen considering issues such as security reliability of training educational expectations such as work speed improvement e g math and programming courses physical dexterity e g mechanical medical courses etc Some courses might require specialized hardware for example robotics and automation such as haptic devices combined with virtual reality gear etc It is certainly easy to set up online some of the courses such as computer programming mathematics literature while it is difficult to setup engineering or laboratory based courses due to the custom and specific hardware required For example setting up chemistry or physics laboratories could present potential safety and cost issues medical laboratories bring many additional issues and at an absolute view there could certainly be issues that the current technology could not solve for distance learning purposes We concentrate on some of the aspects of the mentioned problems and present a few implementations that could help
7. port there was no need to produce and use any of the kinematics equations For example the robot can tolerate through the serial port a string such as MV 100 30 0 40 50 0 3 where the first 5 values represent the angles in degrees for each of the joints and the last two values represent the pitch and yaw of the end effector The majority of the robots nowadays do tend to have fully solved IK through their hardware the evaluation of these equations mainly being appropriate in conjunction with the dynamics equations when the robot needs complete software control note that the Mitsubishi Movemaster does not provide dynamics control providing only a set of fixed values for speed and no direct torque actuators control 2 4 The ASPExec component Description ASPExec allows the execution of DOS and Windows apps through the Active Server Pages commandrobot asp executes an executable called writetoport exe which sends the appropriate command to the robot through the RS 232 serial interface The following functionality is available through ASPExec property Application Set the path optional and exe com filename property Parameters Set the app parameters property TimeOut Set the timeout to wait milliseconds Used only for ExecuteDosApp and ExecuteWinAppAnd Wait property ShowWindow Set whether the executing app is visible or not Used only for ExecuteWinAppAndWait and ExecuteWinApp ExecuteDosApp Executes the specified app as a DOS
8. Laboratory Based Distance Learning Case Studies in Web Controlled Devices and Remote Manipulation T Sobh R Mihali B Ghimire K Vovk G Gosine P Batra School of Engineering 221 University Avenue Bridgeport CT 06601 U S A Phone 203 576 4116 Fax 203 576 4766 http www bridgeport edu sobh Abstract The concept of distance learning has been more and more articulated during the past few years and is expected to shortly turn into a practical educational alternative within current high level learning institutions Distance learning could transparently extend colleges and institutes of education and could plausibly turn into a preferred choice of higher education especially for adult and working students Distance learning is being envisioned as an education mechanism that is more accessible comfortable and closer to the learning individual The distance being introduced is between the individual and the physical institution itself but the exact requirements of a degree is maintained This concept would be unachievable without the current technology for example the impressive worldwide accessibility of the Internet The main idea in e learning is to build adequate solutions that could assure educational training over the Internet without requiring a personal presence at the degree offering institution For example being able to obtain a Bachelor s degree in Computer Engineering from an accredited institution while residing tho
9. Pattern Analysis and Machine Intelligence 7 6 721 726 November 1985 10 H Hoppe T DeRose T Duchamp J McDonald and W Stuetzle Surface reconstruction from unorganized points In Computer Graphics SIGGRAPH 92 Proceedings volume 26 pages 71 78 July 1992 11 V Krishnamurthy and M Levoy Fitting smooth surfaces to dense polygon meshes In these proceedings 22 12 P Lacroute and M Levoy Fast volume rendering using a shear warp factorization of the viewing transformation In Proceedings of SIGGRAPH 94 Orlando FL July 24 29 1994 pages 451 458 ACM Press July 1994 13 A Li and G Crebbin Octree encoding of objects from range images Pattern Recognition 27 5 727 739 May 1994 14 W E Lorensen and H E Cline Marching cubes A high resolution 3D surface construction algorithm In Computer Graphics SIGGRAPH 87 Proceedings volume 21 pages 163 169 July 1987 15 S F Chang J R Smith H J Meng H Wang and D Zhong Finding images video in large archives D Lib Magazine February 1997 16 Stavros Christodoulakis and Peter Triantafillou Research and development issues for large scale multimedia information systems ACM Computing Surveys Dec 1995 17 M G Christel D B Winkler and C R Taylor Multimedia abstraction for a digital video library In ACM Digital Libraries 97 pages 21 29 Philadelphia PA 1997 Appendices Appendix A Source code for the commandrobot asp page lt HTML g
10. asic types of movements e Point to Point PTP movement e XYZ movement PTP movement involves specifying the joint variables the joint angles in this case and changing them according to the desired position of the robot XYZ movement involves moving the end effector in an x y or z plane The joint variables are calculated based upon position and desired motion and accordingly changed and recalculated at every point within the trajectory 17 XYZ movement is much slower and inaccurate than PTP movement since the robot needs to perform repeated calculations to determine the desired position Hence PTP movement was used to minimize error between the desired trajectory and the actual trajectory In order to use PTP movement the trajectories need to be well defined each of the joint angles need to be specified and effected simultaneously to allow smooth trajectories 4 4 List of resources not exhaustive Mitsubishi MoveMaster EX robot 20 Satellite transponder and receiver Interface card for receiver IBM PC or compatible Windows NT 4 0 server Internet Information Server 4 0 Languages C Visual C Visual Basic VBscript for ASP technology 4 5 Advantages and potential uses Remote satellite feed for internet users Remote communication Distance learning The project demonstrates the synergy created by combining robotic and computing power On a larger scale this concept can be ported to pragmat
11. ble one available for a Windows NT platform The next step involved setting up HTML forms that allowed users to issue the appropriate commands to the server However an obstacle that arose here was that these commands needed to be sent to the RF chip through the serial port The web server does not have direct access to the computer s serial port since this is a major security issue 8 To overcome this issue we wrote a DLL which allows ASP pages to run commands on the local machine We then wrote a simple application which took commands to be sent to the RF chip as command line arguments 13 The ASPExec module then ran this application with the necessary commands as command line arguments which were sent to the RF chip However the web server browser approach was dropped since limiting access to a single user was not possible and a number of security problems existed Furthermore to be able to provide two way communication between the client and the server for purposes of a visual feedback a browser would not serve the purpose Hence a java based approach was sought We wrote an RMI based server which accepted a maximum of one connection from the client software which was also written in Java This design also allowed IP screening and other security features The Java Server also had direct access to the local machine s serial port thus avoiding the need to write a separate DLL which proved to be a security hole by itself 9 Int
12. ce page are easy enough to use and assure a predictable positioning of the manipulator once the positions have been defined 3 Remotely controlled Monitoring Vehicle 3 1 Objective To come up with a prototype for a low cost monitoring vehicle that can be controlled from a remote location providing visual feedback to the remote operator 3 2 Purpose A small scale prototype of the described product can demonstrate the low cost and ease of setting up a device with an enormous number of potential applications including security surveillance child monitoring hostile territory exploration and even as a toy 6 7 3 3 Available Resources The resource available to build the prototype were limited to the following list Hardware PCs IBM compatible Mitsubishi Movemaster EX robot Generic RC car 12 Radio Frequency RF transmitter Cables and connectors Controller box for Mistubishi Movemaster EX Wireless camera for visual feedback Software Operating Systems Windows NT Linux Programming Languages C Java VB 3 4 Description The two major implementation issues include 1 Issuing commands to the server from a remote machine 2 Interpreting these commands and sending the appropriate signal to the car through the RF chip Issuing Commands to the server from a remote machine Initially we set up a web server Internet Information Server 4 0 was the server of choice since it is the most sta
13. erpreting these commands and sending the appropriate signal to the car through the RF chip The major implementation issue at this point involved deciphering the commands and having the RF chip transmit the appropriate signals To resolve this issue we needed an FPGA controller which would send a unique signal to the RF chip depending on the signal it received from the serial port This approach was the most efficient but involved an expensive FPGA chip and expensive software which was unavailable to us at development time 10 11 The alternative solution we chose was to use a robot to decipher the signals from the server and manually manipulating buttons on the RF chip to send one of four signals back forward left right to the vehicle The availability of all the resources made us pick this as our option for the prototype 14 The controller box for the Mitsubishi Movemaster EX robot accepts commands as strings from a PC s serial port RS 232 Since our client already had this capability we had to program the robot to teach it certain positions and send it commands to move to these positions in order to manipulate the controls on the RF chip The complete design flow chart is depicted in figure 4 a a _ k r client workstation Figure 4 Execution flow diagram 3 5 Applications Potential applications of our web based system include e Security surveillance vehicle e Exploration of ha
14. gt lt INPUT TYPE HIDDEN SIZE 20 NAME command VALUE MO 1 C gt lt INPUT TYPE SUBMIT VALUE Button 1 gt lt FORM gt lt TD gt lt TD gt lt FORM ACTION commandrobot asp gt lt INPUT TYPE HIDDEN SIZE 20 NAME command VALUE MO 2 C gt lt INPUT TYPE SUBMIT VALUE Button 2 gt lt FORM gt lt TD gt lt TD gt lt FORM ACTION commandrobot asp gt lt INPUT TYPE HIDDEN SIZE 20 NAME command VALUE MO 3 C gt lt INPUT TYPE SUBMIT VALUE Button 3 gt lt FORM gt lt TD gt lt TD gt lt FORM ACTION commandrobot asp gt lt INPUT TYPE HIDDEN SIZE 20 NAME command VALUE MO 4 C gt lt INPUT TYPE SUBMIT VALUE Button 4 gt lt FORM gt lt TD gt lt TR gt lt TABLE gt lt HR ALIGN LEFT WIDTH 50 gt lt SMALL gt Mitsubishi MOVEMASTER EX commands only sample commands follow lt BR gt lt BR gt GC Gripper Close lt BR gt GO Gripper Open lt BR gt NT Nest lt BR gt MO C O Move to Position number with gripper closed C or lt SMALL gt lt blockquote gt lt body gt lt html gt open O 24
15. ic and useful web applications using robots Bibliography 1 Korein J and Badler N Temporal Anti Aliasing in Computer Generated Animation SIGGRAPH 83 pp 377 388 2 Potmesil M and Chadkravarty I Modeling Motion Blur in Computer Generated Images SIGGRAPH S3 pp 389 400 21 3 Cook R Porter T and Carpenter L Distributed Ray Tracing SIGGRAPH S 4 pp 137 146 4 Wilhelms J Toward Automatic Motion Control IEEE Computer Graphics and Applications V7 4 April 1987 pp 11 22 5 Zeltser D Toward an Integrated View of 3 D Computer Animation The Visual Computer VI 4 1985 pp 249 259 6 E Grosso G Sandini and C Frigato Extraction of 3D information and volumetric uncertainty from multiple stereo images In Proceedings of the 8th European Conference on Artificial Intelligence pages 683 688 August 1988 7 P Hebert D Laurendeau and D Poussart Scene reconstruction and description geometric primitive extraction from multiple viewed scattered data In Proceedings of IEEE Conference on Computer Vision and Pattern Recognition pages 286 292 June 1993 8 A Hilton A J Toddart J Illingworth and T Windeatt Reliable surface reconstruction from multiple range images In Fourth European Conference on Computer Vision volume I pages 117 126 April 1996 9 Tsai Hong Hong and M O Shneier Describing a robot s workspace using a sequence of views from a moving camera IEEE Transactions on
16. ng a web server to serve HTTP requests from clients Security is an important issue here and user authentication is vital since it is undesirable to have unauthorized individuals controlling the robot remotely and causing damage to the equipment It is also important to ensure that only one individual is controlling the robot at the same time It is also important to initialize the robot so that it starts at a position known to the software Initialization also involves defining key positions in the robot s workspace and defining trajectories that the robot should travel along Lastly the robot must be taught about its surroundings and the environment that it will be operating in This can be done by fixing the position of the remote control unit and defining its position relative to that of the robot This allows the robot to know where the controller unit is and where particular controls on the unit are The robot must be nested prior to operation to ensure that it always starts from the same point thus allowing error free software control 18 4 2 Constraints and limitations Limited set of commands that the robot s controller box can understand Only one way communication between the server and the robot s controller box The web server s clients have no access to the serial port which is the only means of talking to the robot Time constraints Compatibility issues force usage of a certain operating system
17. obot features base rotation shoulder elbow and wrist motion with a functional gripper along with two additional servos to provide steering The electronics and the servo controller are completely assembled A host PC is used to issue positioning commands For the Internet control of the robot we have created a distributed high performance client server architecture 1 In this architecture the client provides a control interface for the user and transmits control commands to the server over TCP IP encoding the data before the transmission The system architecture is based on the thin client model where the client performs only data validation and data transmission routines The server receives and decodes control commands from the client Once the transmitted command has been decoded the server then performs inverse kinematics calculations on the data This is necessary since the user inputs values of x y z coordinates via the client and they have to be transformed into angular values which the robot s micro controller can understand The server then sends robot control signals over an RS 232 serial port to the robot s built in micro controller which performs the required action as long as the requested position has been validated and confirmed to be within the robot s workspace The user receives visual feedback from a video camera that is focused on the robot The video signal comes from a CCD Camera connected to the server via a Univer
18. perated by a human being they can perform more efficiently in unfamiliar and dynamic environments 2 WWW gateway for Mitsubishi MoveMaster EX robot Figure 2 Companion website http www bridgeport edu batra robotics 2 1 Objective The primary objective of this project is to create a www interface to the Mitsubishi MoveMaster EX robot figure 2 thus allowing a user to connect to the robot and control it from a physically distant workstation without the need to download and install special software 2 2 Requirements The following hardware and software was used for implementation e IBM compatible PC e Windows NT server 4 0 Operating System e Internet Information Server 4 0 Web Server e RS232 Serial port interface and cable to connect to robot e Active Server Pages enabled in IIS e The aspexec dll component e Visual Basic to code the app to write to the serial port 2 3 Implementation The objective was accomplished by setting up a web server on the PC connected directly to the robot through the RS232 interface 4 5 Users connecting to the web server through the World Wide Web were able to send commands to the robot by using the ASPExec component which the Active Server Pages used to execute writetoport exe This executable communicated with the robot by sending these commands through the serial port interface Since the Mitsubishi MoveMaster EX allows direct and inverse kinematics control directly through the serial
19. sal Serial Bus interface and has a resolution of 640 x 480 pixels The signal is converted into streaming RealVideo format using RealProducer software encoded at bit rate of 150 Kbps and streamed to the client real video player The system flowchart in figure 1 illustrates the composition and the data flow of the complete robotic system The flow of the data starts from the login prompt where the user has to authenticate him her self and ends with the robot performing the actual motion 2 The data itself is constituted largely of the operation commands to the robot which during transmission are encoded Receives Data from Our Client Decodes Data Sends Data to Robot f Sends Visual L ogin Feedback to Client On Success Robot Control Center Client Robot Control Server Video Camera Controls Inverse Kinematics Motion Motion of Individual Joints Displays Visual Feedback from Camera End Robot Figure 1 System Flowchart The most difficult criterion for most web based telerobots to meet is that of reliability The robot must be available on a permanent basis while requiring minimal maintenance While an operator is waiting for a response from the telerobot they are unable to plan submit the next request To minimize this waiting period the response time should be as small as possible 3 Telerobots have the benefit of human cognitive and perceptual abilities since they are o
20. t lt head gt lt title gt ASPExec Test ExecuteWinApp lt title gt lt head gt A body bgcolor white text black gt A blockquote gt lt H3 gt Robotics Write to Port Application Univ of Bridgeport Cpe 360 lt H3 gt lt H4 gt Puneet Batra amp copy 2000 lt H4 gt lt FORM ACTION commandrobot asp gt lt INPUT TYPE TEXT SIZE 20 NAME command gt lt INPUT TYPE SUBMIT VALUE Execute Command gt lt FORM gt A oe cmd request querystring command Set Executor Server CreateObject ASPExec Execute Executor Application c robotics writetoport exe Executor Parameters cmd Executor ShowWindow True Response Write Attempting to execute amp Executor Application amp amp Executor Parameters amp w lt bre strResult Executor ExecuteWinApp Response Write The result of this call was amp strResult 5 gt lt BR gt lt BR gt lt BR gt lt HR ALIGN LEFT WIDTH 50 gt lt FORM ACTION commandrobot asp gt lt INPUT TYPE HIDDEN SIZE 20 NAME command VALUE NT gt lt INPUT TYPE SUBMIT VALUE Nest Robot gt lt FORM gt lt FORM ACTION commandrobot asp gt lt INPUT TYPE HIDDEN SIZE 20 NAME command VALUE MO 9 C gt lt INPUT TYPE SUBMIT VALUE Raise clear of obstacles gt lt FONT COLOR RED gt lt PRESS THIS BUTTON BEFORE EACH MOVE lt FONT gt lt FORM gt lt TABLE gt lt TR gt lt TD gt lt FORM gt lt FORM ACTION commandrobot asp
21. usands of miles away from it and actually never seeing it except maybe for the graduation ceremony The advantages are immediate and of unique importance to enumerate a few e Scholarship education costs can be reduced dramatically both from a student s perspective and the institution s no need for room and board for example e The usually tedious immigration and naturalization issues that are common with international students are eliminated e The limited campus facilities faculty members and course schedules an institution can offer are no longer a boundary e Working adults can consider upgrading skills without changing their lifestyles The paper offers several instances of projects that can be mainly utilized for distance learning for lab based courses The projects have an engineering laboratory flavor and are being presented in an arbitrary order The control topics range from vision and sensing to engineering design scheduling remote control and operation Our inclination is towards being able to set up Physical labs online thus allowing students to use equipment machines microscopes manipulators for handling substances or various objects part of experiments pulleys etc hence the goal of creating tools to allow engineering lab based courses to be offered via distance learning Introduction Distance learning possibilities have been considered for quite some time however only the recent growth of the Internet did
22. zardous environments e War time espionage e Remote transportation of objects 15 e Support for disabled individuals 12 4 Internet Controlled Satellite Transponder using a remotely controlled robotic manipulator 4 1 Objective To be able to control a satellite transponder from a remote location by using a robotic manipulator to mechanically change controls on the receiver or an UHF infrared remote control of the receiver The reasons a robot was used to mechanically use the controller unit instead of hard wiring the controller unit or the UHF remote control to the server were 1 The process of hard wiring can permanently damage the expensive controller unit and subsequently render the transponder useless 13 14 2 The robot can be easily reprogrammed to adapt to different controller equipment such as working with a remote controller To establish communication between the remote client and the robot via the server and enable the robot to carry out the desired commands without exceeding its limited workspace or running into obstacles the following tasks need to be implemented 1 Interfacing between robot and server RS 232 2 Interfacing between receiver and server 3 Interfacing between the server and Internet 4 Teaching the robot trajectory planning and generation 16 A flowchart of the proposed system is shown in figure 5 SATELLITE aches E TRANSPONDER RECEIVER Remote Control Robotic
Download Pdf Manuals
Related Search