A novel current-based identification method for dynamic performance of high-speed on/off valve

Digital hydraulic systems (DHS) are widely used in complex engineering fields. Their response speed and control accuracy depend on the dynamic performance of High-speed on/off valve (HSV), which serves as the core control component of DHS. However, the compact structure and embedded installation configuration of the HSV make it difficult to accurately measure its dynamic performance. To address the problem, a novel current-based identification method (CBIM) is proposed in this study. Considering the B-H hysteresis characteristic of the soft magnetic alloy, the influence of the spool moving velocity on the coil current derivative is explored. On this basis, each feature point obtained from the current derivative model can be matched with every switching state of the HSV. Compared with the laser displacement detection method, results show that the proposed CBIM can accurately measure the moving characteristic of spool under different temperature rise conditions. Of these, the maximum identification error of individual switching state time is 3.96 % (compare 0.97 ms with 1.01 ms). Meanwhile, the maximum identification error of total dynamic time is only 1.49 % (compare 8.57 ms with 8.70 ms). Additionally, under different supply pressures, the feature points of the coil derivative curves are also obvious. Therefore, the experimental results all validate the effectiveness of CBIM, and it has scalable applications in the future.