Impedance Control of Micro-Macro Robots with Structural Flexibility.

Abstract

In this paper, impedance control of micro-macro robots in the presence of link flexibility of the macro arm is considered. Two control strategies for both the micro and macro arms are proposed. The control strategy of the micro arm is developed to obtain the desirable dynamic characteristics of the end-effector such as that of mass spring dashpot. The partial dynamic decoupling approach is adopted to reduce the link flexural effects in the dynamic behavior of the micro arm. The desirable moment of inertia, damping, and stiffness terms are designed in the task space. The control scheme is derived to guarantee the desired end-effector characteristics. In the control strategy design of the macro arm, a joint trajectory tracking control scheme is derived. Link vibration control input is added to the joint control scheme. Stability of the whole system is demonstrated using the Lyapunov stability theory. Simulation examples illustrate the effectiveness of proposed control method.