WINDOW-SHAPED OBSTACLE AVOIDANCE FOR A REDUNDANT MANIPULATOR

The window-shaped obstacle avoidance problem is studied in this paper, Several research papers regarding obstacle avoidance including the me thod proposed by Zghal et al, which we believe is the most suitable fo r three-dimensional (3-D) window-shaped obstacle avoidance are studied , Consequently, several shortcomings of the Zghal's method are discove red. The Zghal's method will produce chattering solution sequences in joint rates due to its deficiency in determining the shortest distance between the manipulator links and the window edges. This paper propos es a new scheme to determine the shortest distance. This new scheme wi ll remedy the chattering problem, Moreover, the nearest link (NL) meth od is developed for further improvement. Because the NL method only co nsiders the nearest link in the performance criterion, the on-line wei ghting assignment problem of the Zghal's method is removed, also, less redundancy is required to accomplish the goal for obstacle avoidance, Therefore, the NL method will allow more redundancy to be useful for the other goals under multiple-goal application environments.