Table of Contents
Lab02 - Reactive-based Autonomous Robot Behavior
| Motivations and Goals |
|---|
| Become familiar with reactive-based robot control |
| Become familiar with collision-avoidance and be aware of robot sensors |
| Be able to implement reactive based control of mobile robot |
| Tasks (teacher) |
| Implement “Tangent Bug algorithm” for autonomous reactive-based navigation of hexapod walking robot (2 Points) |
| The robot has to pass through the environment using the implemented algorithm |
| Lab resources |
| Lab scripts: lab02 resource files |
| V-REP scenes: simple_distance.ttt, obstacles.ttt |
| V-REP remoteAPI: hexapod_vrep |
Bug algorithm
Reactive algorithm for obstacle avoidance 1) assuming only a local knowledge about the environment.
Uses only two motion primitives:
- Follow a wall (left or right)
- Move in straight line towards the goal
Different types of bug algorithm
Tangent bug algorithm
- Head towards the goal
- Follow obstacles until you can head to the goal again
- Repeat
Bug algorithm 1
- Head towards the goal
- Circumnavigate obstacles and remember how close you get to the goal
- Return to the point which was closest to the goal and head to the goal
- Repeat
Bug algorithm 2
- Head towards the goal along the straight line $m$ connecting start and goal
- Circumnavigate obstacles until you encounter the $m$ line again
- Continue towards the goal along the $m$ line
- Repeat
Task 1
Think of the pitfalls for individual versions of the bug algorithm. What are upper/lower bounds on the path length that the robot takes?
Think of the pitfalls for individual versions of the bug algorithm. What are upper/lower bounds on the path length that the robot takes?
Task 2 (2 Points)
Implement the tangent bug algorithm and test its performance in
Implement the tangent bug algorithm and test its performance in
obstacles.ttt scene. Set the goal position of the robot to be [-1.6, 1.6].