Trajectory planning for robot arm positioning
Pearson, J. B.
Master of Science
This thesis deals with the sub-optimal control of robots. Keeping in mind the current applications of robots in industry we propose a control scheme which minimizes a time-energy cost criterion. The control problem is solved for a piecewise linear model which is sufficiently close in a norm sense to the highly non-linear robot. A solution is obtained by splitting the control problem into two sub-problems. i) A trajectory planning problem which is solved off-line and is termed the NODES problem. The nodes problem primarily obtains the average force history. ii) A feedback controller problem which moves the robot between the successive nodes in real time and is termed the LOCAL problem. The nodes problem is solved using monotonicity ideas arising from dynamic programming and an iterative algorithm is presented for its solution. Numerical issues in the implementation of the algorithm are discussed. The local problem is solved by a modification of a recent paper on minimum time-fuel control.