Enhanced Robust Control of the EMA system Based on High-Order Extended State Observer

The electro-mechanical actuator (EMA) is widely used in aircraft braking systems due to its high efficiency and high reliability. To improve the dynamic performance and the anti-interference ability of EMA, an enhanced robust control method based on the high-order extended state observer (ESO) is proposed in this paper. Firstly, the operating principle of the EMA system is analyzed and the mathematical model is built. Then, all the system uncertainties and external load variations are considered as the lumped disturbance. A high-order ESO is constructed to estimate the lumped disturbance, and the super-twisting (ST) algorithm is utilized to control the braking torque. Therefore, the composite controller can greatly improve the anti-disturbance ability of the EMA servo system. Finally, the effectiveness of the proposed controller is demonstrated by simulation results.