Department of Computer, Control and Management Engineering

A nonlinear observer is presented for the estimation of the joint velocities and of the deformation modes and their rates for a two-link flexible robot arm, using only motor encoders and a tip position sensor. The state observer can be used then for trajectory tracking control. By monitoring the mismatch between measured and estimated outputs, we can also detect the occurrence of permanent or intermittent system anomalies such as actuator faults or link collisions.