Forward and backward chain-code representation for motion planning of cars

The path-planning problem is presented to show a car of any desired shape moving from a starting position to a destination in a finite space with arbitrarily shaped obstacles in it. In this paper, a new chain-code representation is developed to record the motion path when forward and backward movements are allowed. By placing the smooth turning-angle constraint, we can obtain more realistic results to the actual motion of cars. Meanwhile, by combining rotational mathematical morphology and distance transformation, we can obtain the shortest collision-free path. As soon as the distance map and the collision-free codes have been established offline, the shortest paths of cars starting from any location toward the destination can be promptly obtained online. Experimental results show that our algorithm works successfully in different conditions. We also extend our algorithm to the automated parallel parking and three-dimensional path planning.