Dual mode nonlinear adaptive control and stabilization of an elastic robotic arm

Control of elastic robotic systems with rotational joints is considered. The control system design treats the large joint-angle maneuver problem separately from the terminal stabilization problem. First, a nonlinear adaptive control law is derived such that in the closed-loop system the joint-angles are precisely controlled to track reference trajectories. Once the joint angle enters the vicinity of the desired terminal value, a stabilizer designed using a linear model of the arm is switched to accomplish the final capture of the desired state. Extensive simulation results showed that in the closed-loop system accurate trajectory tracking and elastic mode stabilization can be accomplished