Modeling and optimization of orifice parameter matching for high speed on/off valves via response surface methodology

Abstract

To mitigate spool displacement fluctuations in digital hydraulic valves piloted by high-speed on/off valves (HSVs), this study proposes an orifice-parameter matching optimization method based on the performance of the main spool. The method aims to reduce spool displacement fluctuations by optimizing the HSV port geometry. Firstly, a theoretical steady-state analysis is performed to derive an analytical expression for spool displacement fluctuations, revealing the dominant influence of the orifice parameters. Then, a cascaded optimization method based on response surface methodology (RSM) is proposed, in which a surrogate model linking orifice parameters to the performance objective is constructed. The optimal orifice parameters are determined using a genetic algorithm (GA) based on RSM. Finally, the HSV was manufactured and tested using the optimized port parameters. Compared to the baseline, the optimized design achieved notable performance gains. For step and rectangular excitation (1.75–5.25 mm), the maximum error (M_e) from 0.186 to 0.091 mm (51.1%), the fluctuation amplitude (|Δe|) from 0.357 to 0.171 mm (52.1%), and the threefold standard deviation (3σ) from 0.189 to 0.107 mm (43.4%). For sinusoidal tracking, the 3σ reduced from 0.421 to 0.317 mm (24.7%).