电动舵机单闭环控制系统研究与设计

Research and Design of Mono-position Loop Control System for Electromechanical Actuator

为提高电动舵机结构紧凑性,实现电动舵机的单位置闭环,对无刷直流电机驱动与控制策略展开研究。首先,根据无刷直流电机数学模型及PWM驱动逻辑建模,以电路工作原理为基础,对相电流及机械特性进行理论分析。然后,为提高控制精度及抗扰性,提出高频限制二自由度控制算法,并讨论系统稳定性要求。最后,通过仿真表明,单极性驱动下电机具有较好的起动特性,有利于提高控制精度;8°阶跃及200°/s斜坡响应,在频率400 rad/s内闭环相角优于二阶系统;2 rad/s下正弦信号跟踪误差0.027°,结合电位计误差满足精度0.3°要求。无刷直流电机单位置环舵机方案满足系统指标要求。

In order to improve the compactness of the electromechanical actuator and realize the mono-position loop of the electromechanical actuator,the drive and control strategy of the brushless DC motor was studied in this paper.First,according to the mathematical model of brushless DC motor(BLDCM)and PWM drive logic model,based on the circuit working principle,the phase current and mechanical characteristics were analyzed theoretically.Then,in order to improve the control accuracy and immunity,a high-frequency restricted two-degree-of-freedom control algorithm was proposed,and the system stability requirements were discussed.The results indicate that the motor has good starting characteristics under unipolar drive,which was beneficial to improve the control accuracy.And 8°phase step response and 200°/s ramp response,and the closed loop phase angle within the frequency of 400 rad/s is better than the second order system.The trace error is 0.0027°when the sinusoidal signal is 2 rad/s,which satisfies the 0.3°accuracy demand together with the potentiometer error.The mono-position loop feedback control method for BLDCM can meet the system requirement.