A PARTIAL STATE-FEEDBACK CONTROLLER FOR TRAJECTORY TRACKING OF RIGID-LINK FLEXIBLE-JOINT ROBOTS USING AN OBSERVED BACKSTEPPING APPROACH

This article presents a partial state feedback controller for a rigid- link flexible-joint (RLFJ) robot using an observed integrator backstep ping approach. The robot controller requires only link position and ac tuator position measurements, and eliminates the need for measuring li nk velocity and actuator velocity. The controller uses two exact knowl edge, second-order nonlinear observers to estimate the link and actuat or velocities. The overall control system achieves a semiglobal expone ntial stability result for the link position and velocity tracking err ors as well as the velocity observation errors. A stability proof and simulation results for the proposed partial state feedback controller are included in the article. (C) 1995 John Wiley & Sons, Inc.