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 positional accuracy of high-speed, lightweight, flexible robotic manipulators. The problem arises from the undesired structural static and dynamic deflections. The approach presented here improves both the controller and the structural designs. This is done by employing advanced composite materials in the design of the robot arm and by implementing a nonlinear control technique using actuating forces. All the coupling terms between rigid and flexible motions are maintained. Nonlinear controllers with PID compensators are implemented to control vibration of the tip of the manipulator. A comparison is made between arms constructed from graphite/epoxy and aluminum to investigate the effect of structural design modification. It is demonstrated that construction of the flexible link from advanced composite materials and the use of a nonlinear rigid-and-flexible motion controller has a significant effect on reducing residual vibration of the end-effector and required control torques.