Adaptive Tracking Control of Flexible Joint Manipulator with Output Constraints

This paper proposes an adaptive tracking control scheme for the uncertain model flexible joint manipulators with output constraints to achieve satisfactory performance. A time-varying arctangent barrier Lyapunov function (TABLF) is first designed to ensure the system output constraints are not violated. By combining backstepping, the negative feedback controller is designed to guarantee the errors remain within the allowable range of the constraints. The unknown dynamic observers are employed to approximate the uncertainties in the system, and a tracking differentiator (TD) is applied to obtain the differentiation of the virtual control laws in the back stepping design. Finally, the comparative simulations are given to illustrate the effectiveness of the proposed scheme.