Abstract: High speed on/off valve(HSV) is the core component of digital hydraulic technology. The dynamic characteristic of HSV is the key to improve the response performance and control accuracy of digital hydraulic technology. A multi-voltage compound excitation algorithm is proposed to optimize the initial currents of the switching processes by preloading method. Together with current feedback decision and logic triggering principle, the adaptive switching of the 5 voltages is realized, so that a fast response and low energy driving can be achieved. The effects of initial current and driving voltage on the dynamic performance of the HSV are explored by theoretical analysis, and the methods to improve the dynamic characteristics are obtained. A simulation model of HSV is established, and the dynamic performance experiments of HSV are carried out. The effectiveness of the proposed multi-voltage compound excitation algorithm is verified by direct and indirect measurement. The results show that compared to the double-voltage excitation algorithm, the multi-voltage compound excitation algorithm greatly improved the response speed of the HSV by optimizing the opening and closing initial current without increasing the driving voltage. The opening delay time is reduced by 66.7%, and the closing delay time is decreased by 87.5%. In addition, the flow control characteristic is also improved whose flow linear range was expanded by 17.1%. Meanwhile, the thermal power loss is reduced by 64.8%, the extrusion force of the operation balls is lessened, and the service life is extended.

Key words: high speed on/off valve, multi-voltages compound excitation, preloading method, dynamic performance