Maze Exploring by Pioneer 3DX

1. Maze Exploring by Pioneer 3DX Team 4

2. Baseline • 1. Maze exploring ->DFS • 2. Shortest path backtracking • We have already accomplish the baseline

3. For the Maze exploring part • Explore the environment and build the topological map at the first round. • Build the node whenever robot make turns or encounter forks road. • Each node contains 4 directions and a source direction.

4. Node structure • struct node { • int number; • bool check; • bool northCheck; • bool southCheck; • bool westCheck; • bool eastCheck; • int src_direction; • bool northdead; • bool southdead; • bool westdead; • bool eastdead; • ArPose position; • struct node *northPtr; • struct node *southPtr; • struct node *westPtr; • struct node *eastPtr; • }; • typedef struct node Node;

5. For the shortest path backtracking part • In second round, execute shortest path backtracking on the map we had built. • Pioneer will directly walk to the exit.

6. Difficulty we faced • The accumulated angle error • The robot may not be parallel with the wall, and may make wrong decisions. • Sol: We have to add some feed back control

7. Difficulty we faced • Sonar Sensor doesn’t work all the time. • Sometimes, the distance it detects is much larger because of reflection. • We may have to add another sensor to aid the sonar.

8. Probably solution • Camera - Edge Based Technique

9. More to do • Obstacle avoidance. • Walk straight, and make accurate turns.