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This paper deals with the robust control method for permanent magnet synchronous motor (PMSM) speed-regulation system based on active disturbance compensation. Different from the classical PMSM disturbance compensation scheme, a novel disturbance feed-forward compensation based on extended state observer (ESO) is designed for speed loop and q-axis current loop of PMSM. The disturbances of current loop include unmodeled dynamics of back electromotive force and parameters variations of stator are considered as lumped disturbance to compensate actively. In this way, the dynamic response of q-axis current loop can be improved to guarantee the anti-disturbance ability. A composite controller using sliding mode control and ESO is designed as speed loop controller, and an ESO-based proportional-integral controller is designed for q-axis current loop. Moreover, a transition process of reference signal is introduced to replace the step reference signal, which reduces the initial error and increases the range of feedback gain to improve system robustness. Finally, simulations and experiments are given to demonstrate the effectiveness of the proposed strategy.

Abstract:Addressing the simulating issue of the helicopter-manipulating booster aerodynamic load with high-frequency dynamic load superimposed on a large static load, this paper studies the design of the robust controller for the electro-hydraulic loading system to realize the simulation of this kind of load. Firstly, the equivalent linear model of the electro-hydraulic loading system under assumed parameter uncertainty is established. Then, a hybrid control scheme is proposed for the loading system. This control scheme consists of a constant velocity feed-forward compensator, a robust inner loop compensator based on disturbance observer and a robust outer loop feedback controller. The constant velocity compensator eliminates most of the extraneous force at first, and then the double-loop cascade composition control strategy is employed to design the compensated system. The disturbance observer-based inner loop compensator further restrains the disturbances including the remaining extraneous force, and makes the actual plant tracking a nominal model approximately in a certain frequency range. The robust outer loop controller achieves the desired force-tracking performance, and guarantees system robustness in the high frequency region. The optimized low-pass filter Q(s) is designed by using the H8 mixed sensitivity optimization method. The simulation results show that the proposed hybrid control scheme and controller can effectively suppress the extraneous force and improve the robustness of the electro-hydraulic loading system.

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The objective of this paper is to design a pump that can match its delivery pressure to the aircraft load. Axial piston pumps used in airborne hydraulic systems are required to work in a constant pressure mode setting based on the highest pressure required by the aircraft load. However, the time using the highest pressure working mode is very short, which leads to a lot of overflow lose. This study is motivated by this fact. Pressure continuous regulation electrohydraulic proportional axial piston pump is realized by combining a dual-pressure piston pump with electro-hydraulic proportional technology, realizing the match between the delivery pressure of the pump and the aircraft load. The mathematical model is established and its dynamic characteristics are analyzed. The control methods such as a proportional integral derivative (PID) control method, linear quadratic regulator (LQR) based on a feedback linearization method and a backstepping sliding control method are designed for this nonlinear system. It can be seen from the result of simulation experiments that the requirements of pressure control with a pump are reached and the capacity of resisting disturbance of the system is strong.