Geometric control in a regulator problem for electrohydraulic servos

A five-dimensional nonlinear mathematical model of the electrohydraulic servo(mechanism) is considered. In the system equilibria analysis, the critical case of a zero eigenvalue occurs. The Lyapunov-Malkin theorem and Routh-Hurwitz criterion provide conditions for controllers to stabilize all relevant equilibria in the closed-loop system. Geometric control paradigm is then applied in synthesis and the performance of the obtained controlled system is numerically validated from viewpoint of the regulator classical problem.