Control system design and robust stability analysis for a single-link manipulator

This paper is concerned with the control system design for a vertical type single-link manipulator. A design method using the H_∞ control theory, which considers the effect of gravity in the design specification, is proposed. In our design method, we regard the effect of gravity on dynamics of the manipulator as a disturbance at the plant input. The H_∞ norm of a transfer function from this disturbance to plant output is reduced as much as possible in order to reject the effect of gravity. A numerical result shows that our design method achieves better tracking performance than the mixed sensitivity method which is a conventional method when H _∞ control theory is applied to a control system design