Composite control for electric load simulator based on iterative learning

A composite torque controller combining iterative learning control and the feedforward compensation of a rudder angle was built for an electric load simulator in order to increase loading accuracy. The spring beam was used to improve the system stability and the loading accuracy, and constraints to the stiffness coefficient of the spring beam were analyzed based on system response speed, frequency width and stability. The mathematical models of plants were established, and three close loops were used. The feedforward compensation of the rudder angular displacement was introduced into the torque controller. The iterative learning controller was designed by modifying the magnitude and the phase of the command torque to improve loading effects, and P-type iterative learning controller was used. Finally, experiments of loading torque and testing the extraneous torque were performed, and experiment results proved that this controller is effective in achieving a perfect torque tracking accuracy and restraining the extraneous torque for electric load simulators.