On adaptive impedance control of robot manipulators

Impedance control specifications for robot manipulators are given in terms of a desired motion trajectory and a desired dynamic relationship between position errors and interaction forces. An adaptive implementation is proposed as an alternative to reduce the design sensitivity due to model-manipulator parameter mismatch. Two adaptive controllers that globally achieve the impedance objective for the general nonlinear dynamic model are presented. The controller structures consist of a nonlinear feedback of positions, velocities, and end-effector applied forces. Computer simulations were carried out to demonstrate stability and performance control.<
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