| As the actuator of the whole flight control system, aircraft electromechanical actuator(EMA) is one of complex mechatronic systems and also a kind of position servo system with high accuracy which plays an important role in flight vehicle. The output shaft should handle multiple time-varing load torque during rudder deflection process, which requires EMA can overcome the influence of load torque, ensuring the correct attitude. Combined with the actual situation, a permanent magnet synchronous motor(PMSM) servo drives is designed, the method of rotor position estimation based on two-phase switch hall is studied, the speed control of EMA is completed, on the basis of which, the anti load disturbance control strategy of PMSM is further studied.First, the working principles of PMSM servo is analyzed, as well as its mathematical model. On this basis, the theory of vector control is elaborated, then we determines the control method with id = 0 and derives the control block diagram and the equivalent transfer function of the system. Moreover, EMA load characteristics and its effect on electric steering performance is analyzed.Secondly, the rotor position detection plays an important role in vector control. This paper analyses the theory of rotor position detection of two-phase orthogonal type switch hall. The inherent error caused by hall position estimation method and non-orthogonal installation is analyzed. The accuracy of rotor position detection using two-phase orthogonal hall sensor is verified by simulation.What’s more, torque current needs to be compensated in order to inhibit the speed fluctuation caused by the load change. This paper presents a full-order and reduced-order observer, and the two observers are compared by simulations, which show that the reduced-order observer has more advantages. Then, it analyzes the influence of inertia on the load torque observation, using a gradient correction method for the identification of inertia, and analyzed the parameters effecte on the results.Finally, this paper develops a 1.5k W PMSM driver. Rotor position detection and anti load disturbance experiments are carried out. Which show that using two-phase orthogonal hall sensor for rotor position detection, better precision can be achieved. The design of reduced-order load torque observer can observe torque change effectively. Introducing current feedforward compensation in vector control, can effectively improve the robustness of PMSM servo speed loop. |
