Self-correcting PWM control for dynamic performance preservation in high speed on/off valve

High speed on/off solenoid valve (HSV) has often been used for pressure and flow control in hydraulic systems, which require faster and more stable dynamic performance of HSVs to improve control preciseness. For some kinds of HSVs which rely on the hydraulic pressure to operate, their dynamic performance is greatly influenced by the magnitude of the hydraulic pressure. In this paper, a self-correcting PWM control algorithm for highspeed on/off valves is proposed to improve and even maintain the HSVs' original dynamic performance under changing pressures. Using current feedback analysis based on critical switching currents, the operational state of the HSV is estimated and the adaptive switching of different duty ratios of power source is also realized to optimize the switching behavior of HSV. Finally, through numerical and experimental studies, it is demonstrated that with the proposed control algorithm, the dynamic characteristics of the HSV is not only greatly improved but adapted to pressure changes, and the variation range of the dynamic performance can be controlled within 7.4% (0.3 ms) under 4-20 MPa operating conditions. The presented control algorithm is effective and can be applied in HSV-controlled systems to improve the robustness of the target actuator.