A COMPARISON OF THE CONTROL OF A FLEXIBLE ROBOT ARM CONSTRUCTED FROM GRAPHITE-EPOXY VERSUS ALUMINUM

The focus of this study is on the enhancement of the end-effector posi tional accuracy of high-speed, lightweight, flexible robotic manipulat ors. The problem arises from the undesired structural static and dynam ic deflections. The approach presented here improves both the controll er and the structural designs. This is done by employing advanced comp osite materials in the design of the robot arm and by implementing a n onlinear control technique using actuating forces. All the coupling te rms between rigid and flexible motions are maintained. Nonlinear contr ollers with PID compensators are implemented to control vibration of t he tip of the manipulator. A comparison is made between arms construct ed from graphite/epoxy and aluminum to investigate the effect of struc tural design modification. It is demonstrated that construction of the flexible link from advanced composite materials and the use of a nonl inear rigid-and-flexible motion controller has a significant effect on reducing residual vibration of the end-effector and required control torques.