Abstract:In order to improve the control precision of hydraulic system, the following two aspects were done. Firstly, in terms of driving strategy, the driving strategy was considered and the dynamic characteristics of the valve core under several common driving strategies were analyzed. After considering the following aspects, a multi-stage adaptive voltage excitation driving strategy was put forward accordingly. The strategy had better dynamic characteristics than the commonly used dual voltage excitation strategy. Under this multi-stage adaptive voltage excitation driving strategy, the valve core and the closing time were reduced to 2.2ms and 1.7ms, respectively. At the same time, the coil thermal power was reduced by 68.5%. Moreover, a driving circuit which can output any voltage between 0V and 60V through PWM modulation was designed. Secondly, in terms of control strategy, the BP neural network was used to adjust the PID parameters to achieve precise control of hydraulic cylinder displacement. The network PID controller of BP neural had the characteristics of short response time, small overshoot and good robustness and so on. Under the combined control of adaptive voltage excitation and BP neural network, the hydraulic cylinder displacement error of constant flow hydraulic system was controlled within -0.3~0.3mm. Meanwhile, thanks to the combined control of adaptive voltage excitation and BP neural network, the hydraulic cylinder displacement error of variable flow hydraulic system was controlled within -0.5~0.5mm. The research had a great promotion to the study of this field.