Interconnection and damping assignment passivity-based control for flexible joint robot

This paper presents an interconnection and damping assignment passivity based control (IDA-PBC) for the position and impedance control of flexible joint robot. In considering of the joint damping and with some simplification of friction, a flexible joint robot system is descripted as an port-controlled Hamiltonian system with dissipation(PCHD). Then, giving a desired Hamiltonian function which both shapes potential and kinetic energies, the control laws of position control and impedance control is derived by the algebraic IDA-PBC method, which preserves the PCHD structure of the close-loop system. Comparing with the traditional passivity based control (PBC), the proposed method gives a new explanation of the control of flexible joint robot by introducing the self-damping and cross-damping terms, which make the gain selecting procedure more intuitive and comfortable. Simulation and experiments are done to verify the proposed controller, and the results shows a promising performance both in position and impedance control.