Robust servo control design for mechanical systems using mixed uncertainty modelling

In this paper, a servo control synthesis based on the μ method is applied. With this method, a robust compensator that achieves performance specifications can be designed, which provides the track of the predefined reference signal, rejects the effects of the disturbances and takes structured uncertainty into consideration. In the mixed μ synthesis, both the real parametric and the complex uncertainties are handled together, which usually yields a less conservative compensator than the traditional robust control design methods. The design strategy is illustrated for an inverted pendulum device, which involves real parametric uncertainties.