A Study of Single-Link Robots Fabricated from Orthotropic Composite Materials

A dynamic model for single-link robotic arms fabricated from orthotropic composite materials is presented. The equations of motion are derived using Hamilton's principle and include the coupling between the rigid body motion and elastic motion. An optimal controller is designed for rest-to-rest maneuvers without large starting or stopping transients and with minimum residual vibration. Computer simulated results presented for aluminum, steel, graphite/epoxy, and boron/epoxy indicate that the motion-induced vibration is significantly less for the composite robotic arms as well as substantial savings in energy. Furthermore, it is seen that the magnitude of the control spillover effects, an issue of great concern in designing control systems for flexible structures, is very small for the composite robotic arms.