Load fluctuation estimation and feedback control method for hydraulic steering engine

The invention provides a hydraulic steering engine load fluctuation estimation and feedback control method, which comprises the following steps of: setting time constants of three typical load fluctuation conditions, establishing a simplified approximation model, inputting a steering engine input command signal, and comparing a difference value between a model output signal and a steering engine output signal to obtain three load error signals; carrying out square integral operation, and selecting a minimum load fluctuation condition as a closest load fluctuation condition; designing a load identification compensation feedback signal according to the time constant of the condition, and designing a load identification adjustment total signal according to the load error signal of the condition; the integral sliding mode signal is formed by a valve control cylinder piston displacement signal and a steering engine rotation angle error signal, and the finite time switching softening signal forms ...