Nonparametric Identification and Control of Flexible Joint Robot Manipulator

We discuss nonadaptive and adaptive control strategies for tracking the end effector of a flexible robot with collocated and noncollocated sensors attached at the end effector and 0.5m from the elbow joint. Collocated joint sensors satisfy hyperstability conditions but are unable to capture nonminimum phase (NMP) response which is achieved by noncollocated sensors. Nonadaptive control with collocated and noncollocated sensors results in poor tracking, but adaptive control leads to excellent tracking regardless of sensor location. Nonparametric identification procedure for the flexible robot is also presented and its convergence is discussed.