Exact linearization based modeling and control for electro-hydraulic compound regulating integrated actuator

A new designed total pressure control valve, which can keep the sum of high and low pressures of actuating cylinder be a constant and also make the two chambers pressures be controllable, was added to the classic pump controlled electro-hydraulic actuator (EHA) to enhance its natural frequency. This improved EHA is called electro-hydraulic compound regulating integrated actuator (EHCA) which has the same response frequency with valve controlled actuator. For the multiplicative nonlinear problem of system flow, the principle of EHCA and the total pressure control valve operation scheme was analyzed, and exact linearization based modeling and controller design were implemented. The best matching of motor speed and pump displacement regulation in the different working conditions was discussed. Analysis and simulation show that, exact linearization based on EHCA sliding mode control concept achieves the control purposes of high efficiency, energy saving and faster response for dual-variable compound regulation.