Real-Time Control of Robot Manipulators in the
Shaygan Kheradpir · 1988
Industrial robots typically perform tasks in environments hosting multiple obstacles. The control algorithm responsible for maneu- vering the robot in such workspaces must achieve both trajectory tracking and obstacle avoidance. This paper suggests a new approach to the problem of obstacle avoidance for a point robot moving among circular or elliptical/spherical or ellipsoid obstacles. The Obstacle Avoidance Strategy (OAS) translates each state constraint (obstacle) into a State Dependent Control Constraint (SDCC). Each SDCC defines a hyper- plane in the control space U. The intersection of the SDCC sets with the hard control bounds forms a polygon in U. The Optimal Decision Strategy (ODS) control algorithm is then used to find the control which lies in this polygon-assuring obstacle avoidance-and minimizes the deviation between the acceleration vector of the point robot and a desired acceleration field. Simulation results display the effectiveness of the algorithm for a workspace hosting multiple obstacles. The OAS al- gorithm has been implemented successfully on a small Cartesian coordi- nate robot.