ABSTRACT
In this chapter, the authors adopt the Lyapunov min-max approach for robust control design for flexible joint manipulators. The main difficulty in directly applying the work in this area to flexible joint manipulators is the lack of the matching condition. The authors propose to overcome this difficulty by first introducing a state transformation. Uniform ultimate boundedness in practical stability means that the response of the system enters and remains within a particular neighborhood of the equilibrium position after some finite time. To design robust control, the authors propose a two-step procedure. This is also similar to Freeman and Kokotovic. A robust control scheme is proposed for flexible joint manipulators. The features of the manipulators, which distinguish the current problem from others, are that the dynamic system is nonlinear, uncertain, and mismatched. The analysis of the original system performance based on that of the transformed system is demonstrated.
