A Novel Composite Control Algorithm for Restraining Nonlinear Superfluous Forces

A novel composite control algorithm is proposed to restrain nonlinear superfluous forces of a dual-channel load simulator. The dual-channel load simulator is utilized to measure the dynamic characteristic of an integrated hydraulic driving unit. The superfluous force cannot be avoided almost certainly and show a strong nonlinearity. Based on the speed synchronizing control algorithm, the composite control algorithm considers the two non-linear time-varying parameters of the flow gain Kq and the flow pressure gain Kc of the servo valve, and further considers the non-linearity and time-varying of the position disturbance electro-hydraulic servo control system. The fuzzy self-tuning PID control is applied to automatically adjust the PID parameters so that the superfluous force of the system can achieve the desired control effect. The accurate simulation of the load force is realized.