A novel parameter adaptive nonlinear model of proportional valve

This paper aims at controlling the nonlinear coupled variables force and velocity precisely in the electro-hydraulic proportional system. An open-loop control method based on a certain nonlinear model of force (F), voltage (U) and velocity (V), which is established from formula derivation and experimental data analysis, is presented. The experimental results and applications show that the proposed model achieves high precision in velocity and force control. Depending on realtime online parameters identification and amendment, it can adapt the parameters change caused by unknown factors such as oil temperature variation.