Fast collision avoidance for manipulator arms: a sequential search strategy

A sequential strategy is presented for planning collision-free motions for a manipulator arm. The basic idea behind the approach is to plan the motion of each link successively, starting from the base link. Suppose that the motion of links to link i (including link i) has been planned. This already determines the path of one end (the proximal end) of link i+1. The motion of link i +1 is now planned along this path by controlling the degree of freedom associated with it, which is a 2-D motion planning problem. This strategy results in one 1-D (the first link is degenerate) and (n -1) 2-D planning problems. The 2-D motion planning problem is to plan the motion of a single link as one end of this link moves along a fixed path. This problem is posed in t×θ space, where t is the parameter along the path and θ the angle to be planned. The obstacles in t×θ space are approximated by discretizing t. Fast and efficient techniques are then used to plan a path in t×θ space. Thus, the strategy leads to fast and efficient algorithms and is especially suited for highly redundant arms