Abstract:In order to solve the problem that most variable valve controllers cannot achieve full valve variability, a servo piezoelectric hydraulic actuator containing piezoelectric and hydraulic components was proposed. An adaptive feedforward controller was used to implement effective control of the servo piezoelectric hydraulic actuator. A simplified model of a servo piezoelectric hydraulic actuator was constructed, and the mathematical models of the piezoelectric structure, servo piston structure, and hydraulic structure in the servo piezoelectric hydraulic actuator were established. An adaptive feedforward controller with two feedforward controllers and one feedback controller was designed. MATLAB software was used to simulate the servo piezoelectric hydraulic actuator, and the control results were compared with the traditional PI controller. The results show that the tracking performance of the servo piezoelectric hydraulic actuator with the adaptive feedforward controller is significantly improved, the tracking error is reduced by about 50%, and the control voltage range is also greatly reduced. By using this actuator, the effective control of the camless internal combustion engine can be realized effectively.