1. Don’t Crowd Me Summary of and comments on Brogan and Hodgins’ Group Behaviors for Systems with Significant Dynamics Cailin K. Andruss Virginia Commonwealth University NSF BBSI Program 2005 - 2006

2. Introduction To move as a group, animals mustTo move as a group, animals must –Maintain close proximity –Avoid collisions –Compensate for significant dynamics

3. Significant Dynamics Significant Dynamics: the motion of an individual is significantly affected by its dynamic properties.Significant Dynamics: the motion of an individual is significantly affected by its dynamic properties. –Acceleration –Velocity –Turning radius

4. The Goal An algorithmAn algorithm –Natural looking low-level behaviors Walking, running, bicycling, etc.Walking, running, bicycling, etc. –Realistic interaction with an unpredictable environment Obstacle avoidance, grouping, rough terrain locomotion, etc.Obstacle avoidance, grouping, rough terrain locomotion, etc. Can be applied to physical robots performing useful tasksCan be applied to physical robots performing useful tasks

5. The Algorithm Perception Perception PlacementObstacle Avoidance PlacementObstacle Avoidance

6. The Agents

7. One-legged RobotsOne-legged Robots

8. The Agents One-legged RobotsOne-legged Robots Rigid-body model of human riding bicycleRigid-body model of human riding bicycle

9. The Agents One-legged RobotsOne-legged Robots Rigid-body model of human riding bicycleRigid-body model of human riding bicycle Point-mass systemPoint-mass system

10. Results

11. Results Grouping

12. Results Turning (Click here for movie)

13. Results Obstacle Avoidance (Click)

14. Results Obstacle Avoidance

15. Results Summary Point-masses: moved more tightly under changes in velocity because of the more exact control of velocity.Point-masses: moved more tightly under changes in velocity because of the more exact control of velocity. Robots: more variability and motion within the group. Separation distance was made larger to prevent collisions between members.Robots: more variability and motion within the group. Separation distance was made larger to prevent collisions between members. Bicyclists: the control system was not as robust, and the they were not able to perform as well on the turning test.Bicyclists: the control system was not as robust, and the they were not able to perform as well on the turning test.

16. Limitations Reflexive reactions to collisionsReflexive reactions to collisions Information about other individuals is too accurateInformation about other individuals is too accurate Models are simplifiedModels are simplified Heterogeneous populationHeterogeneous population

17. References Brogan, D.C., Hodgins, J. K., 1997. Group Behaviors for Systems with Significant Dynamics. Autonomous Robots 4, p. 137-153.