Adaptive pre-excitation control of high speed on/off valve for preserving the dynamic performance against temperature effects

Hydraulic valve control systems are frequently utilized in automatic control systems, where high-speed on/off valves (HSVs) are common control components. The prolonged operation of HSVs inevitably leads to an increase in temperature, which affects their dynamic performance and reduces the reliability of the system. Consequently, an adaptive pre-excitation control algorithm (APECA) is proposed to enhance and maintain the dynamic performance of HSVs across varying temperatures. The variation of dynamic performance with rising temperature is studied both theoretically and experimentally. Subsequently, the pre-opening and pre-closing voltage of the APECA is optimized through current feedback, considering the changes in resistance due to rising temperatures. The dynamic performance of HSVs can be effectively improved while preserving their rapid performance and favorable flow characteristics. For a specific HSV, results indicate that with the APECA, the opening and closing delay times of the HSV are reduced from 1.38 ms to 0.21 ms and 7.7 ms to 0.09 ms, respectively, extending the controllable linear range of flow characteristics from 52 % to 87 %. Furthermore, from room temperature to the maximum thermal equilibrium temperature, the variation range of the total switching time and output flow is maintained within 0.01 ms (0.40 %) and 0.009 L/min (0.83 %), respectively. Therefore, the proposed APECA is effective in improving the response speed of the HSV and enhancing the robustness of the system.