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Validating a local path

Validating a local paths is knowing if, for a given robot corresponding to this local path, the robot will collide moving along this path. The Move3d validation of local path is simple : Being given the local path of a robot, we place this robot at the begining of the path and compute dmin, the closest distance of the bounding boxes of the bodies of the robot to the bounding boxes of the obstacles. This gives us the increment of configuration dq along which the robot can move without that any of its point moves further than dmin. So we can be sure that there will not be any collision along dq. If the bounding boxe of a body overlaps the bounding box of an obstacle, dq becomes regular and very small so we can be sure to detect a collision between the body and the obstacle if there is one (cf Fig gif).

   figure635
Figure: Validation of a local path in Move3D.

The function int p3d_col_test_traj_dist(p3d_rob *rob, p3d_courbe *c, int nmaill, int *ntest, int *nbb)   test if the robot rob collides while moving along the local path made of the nmaill elementary curves contained in the list c. The integer ntest is the number of calls to the collision checker, and nbb the number of times we have to check the distance between the bounding boxes.



Nicola Simeon
Fri Oct 27 09:07:38 MET DST 2000