Impedance control with adaptation for robotic manipulations

Two adaptive impedance control algorithms are presented. In this treatment, it is assumed that some parameters in the manipulator dynamics may be uncertain, and the measurements from the wrist force sensor utilized are imprecise. By introducing the concept of target-impedance reference trajectory (TIRT), which characterizes a desired dynamic relation of the end-point with the environment and a refined Lyapunov approach, it is shown that the adaptation mechanisms previously suggested can be injected into N. Hogan´s (1987) conventional impedance control scheme. The two resulting algorithms are compared in terms of implementation feasibility as well as computation efficiency. Simulation results are presented to illustrate the proposed algorithms