Adaptive Control of Flexible Joint Manipulator

In this paper control of a flexible joint manipulator is designed using an adaptive output-feedback controller based on a backstepping design. The parameters of system are assumed to be unknown and only motor position and link position measurements are used for the synthesis of the controller. A canonical state representation of the system is derived and filters are designed to obtain the estimates of the derivatives of motor angle and link angle. Then adaptive control law for the trajectory control of link displacement angle is derived. Compared to the same adaptive controller which measures just a link displacement angle, the order of the proposed controller becomes a half (order of 2) and complexity of control law can be reduced dramatically. Also the proposed controller does not require the bounds on uncertain parameters for the control law derivation compared other output adaptive control law.