Cooperative%20Robotic%20Simulator%20Environment%20Simulator

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Cooperative Robotic SimulatorEnvironment
Simulator

• Masters Report
• Scott J. Harmon
• May 12, 2004
• Cooperative Robotics Simulator Group

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Outline

• Introduction
• Overall system
• Demo
• Environment Module
• Main Loop
• Map Component
• Robot and Sensor Components
• Module Communications/Major Protocols
• Robot lt--gt Environment
• Viewerlt--gt Environment
• Future Work
• Network improvements
• Map improvements
• Reflection

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Overall System Architecture

• Multiple Modules written in Java
• Environment
• Robot
• Viewer
• Control Panel
• Communications

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Overall System Architecture-2
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Example Deployment
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Demonstration
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System Components
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Environment Components
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Environment Module

• Coordinates and drives the simulation
• Main Loop using time-step based approach
• Models the virtual environment
• Keeps track of positional and state information
  of all objects in the virtual environment

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Environment - Main Loop

• Iterated for each time-step
• Time-steps size is set at runtime
• Drives the simulation

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Environment - Main Loop-2
1 waitForRobots() 2 setState(STATE_ROBOTS) 3
sendObjectsToVRMLClients() 4 currentTime 0 5
running true 6 setState(STATE_RUNNING) 7
while(running) 8 //get the event for this
timestep from each Robot 9 //lock the
robotqueue 10 synchronized(robots) 11 //This
double-stepped get allows the stuff to travel
here before I block trying to get it. 12 for
(int i 0 i lt robots.size() i)
13 EnvironmentObjectRobot robot
(EnvironmentObjectRobot) robots.get(i) 14 robot
.prepGetEvents(currentTime) 15 16 for (int i
0 i lt robots.size() i) 17 EnvironmentObj
ectRobot robot (EnvironmentObjectRobot)
robots.get(i) 18 robot.queueEvents() 19 20
21 //process queue from front
(top). 22 processActionEventQueue() 23 //send
out sensor readings to robots. 24 processSensorEve
ntQueue() 25 //add timestep to
VRMLUpdates. 26 for (int i 0 i lt
viewerUpdateQueue.size() i) 27 ((ViewerUpdat
eLocation)viewerUpdateQueue.get(i)).timestep
currentTime 28 29 //send out VRMLUpdates to
the VRML viewer 30 sendViewerEvents(viewerUpdateQu
eue) 31 currentTime 32 try 33 Thread.sleep(
steppausetime) 34 catch (InterruptedException
e) 35
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Communications between Modules

• Java Socket used
• Each component connects on a pre-determined port
  to the Environment.
• Serializable objects are sent over the Socket
  connection.

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Robot lt--gt Environment Protocol
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Viewer lt--gt Environment Protocol
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Conclusions

• Simulator is distributable because of the
  modularity
• Modules communicate using protocols over a socket
  connection
• Environment module is responsible for
  orchestrating the simulation and for modeling the
  virtual environment.

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Future Work

• There are three areas in the Environment module
  to improve
• Network
• Map
• Reflection

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Future Work Network

• Network is utilized for communications between
  modules
• Enhancements
• Optimize by reducing amount of communications
• Improve latency
• Fetch Robot commands in separate threads while
  previous commands are being evaluated

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Future Work Network-2

• Example Protocol

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Future Work Map Component

• Map Component in charge of modeling the virtual
  environment
• Enhancements
• Domain specific Map components
• What physics needs to be modeled?
• Collision Detection improvements
• Java3D
• Grid World (Change time into space)
• Distribute
• Can we distribute the maintenance of the virtual
  environment across multiple system?
• Compound objects (grouping)
• A robot might be made up of more than one
  geometric shape.

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Future Work Reflection

• Java Reflection allows the dynamic loading of
  classes by name
• Enhancements
• Make all sensors and effectors loaded dynamically
  by name
• Allows us to add sensors and effectors without
  the need to modify the original code
• Different Maps (virtual environment maintainer)
  loadable by name
• Allows pluggable components

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References

• 1 The Official Project website,
  http//www.cis.ksu.edu/sdeloach/ai/projects/crsim
  .htm

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Acknowledgements

• Committee
• Dr. DeLoach
• Dr. Gustafson
• Dr. Hsu
• Teammates
• Venkata Prashant Rapaka, Arun Prakash Ganesan,
  Esteban Guillen, and Aaron Chavez

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Questions