A novel response time prediction method of high-speed on/off valve considering multi-field characteristics variation

Electro-hydraulic servo control systems that use the high-speed on/off valve (HSV) are widespread in aerospace, automotive, and engineering machinery due to its programmable control and energy-efficiency. The ability to predict the response time in advance significantly impacts the control accuracy of the HSV system. However, existing prediction methods oversimplify operating conditions, which makes accurate response time prediction challenging. This paper innovatively proposes an accurate response time prediction method considering variable electromagnetic characteristics and variable acceleration motion. Firstly, the inductance and magnetic force for different conditions are acquired by HSV electromagnetic finite element simulation. Secondly, the equation for electrical delay time is derived by relating the critical switching current and the coil current dynamic equations. The electrical delay time for the coil current to reach critical switching values is then calculated segmentally, incorporating variable inductance. Thirdly, the spool motion is divided into multiple uniformly accelerated motion to determine the time required for variable acceleration motion. By using multi-field characteristics variation and coil current discrete expression, the magnetic and load forces of each segment are iteratively calculated to obtain an accurate mechanical delay time. Finally, a series of experiments were conducted and the results show that the response time predictions made by the proposed method are highly consistent with the measurements under all conditions. The prediction errors are within 7.3%, with a maximum prediction accuracy improvement of 47.7% compared to existing prediction methods. This research proposes an accurate HSV response time prediction method which supports the flow linearization of HSV under various operating conditions, ensuring the HSV system's control accuracy and broadening its range of applications.