Adaptive feedforward control of the steer-by-wire system based on the online parameter estimator
The adaptive feedforward control method is presented in this paper to improve the tracking performance of the SBW system. Due to model nonlinearities, noise disturbance and mechanical complexity, the system parameters vary with bounded uncertainties. To get an accurate system model, an online adaptive parameter estimator is proposed to realize parameter identification of the control model, based on the output error identification method. Meanwhile, the parameter gradient projection method is applied to eliminate the parameter drift, while a full order state observer is developed to weaken the effects of noise disturbance during the parameter identification. The experiment results show the effectiveness and robustness of the adaptive estimator, and a better tracking performance for the SBW system is achieved by applying the adaptive feedforward control method.