基于特征结构配置的电磁轴承高速电机刚性转子系统鲁棒输出反馈控制器的设计

Design of Robust Output Controller for an Active Magnetic Bearing High-speed Motor Rigid Rotor System Based on Eigenstructure Assignment

特征结构配置法直接建立反馈控制器参数与闭环系统特征结构之间的联系,物理意义明确且适用性强,在飞行器、振动主动控制等对象的控制器设计中得到广泛的应用。针对电磁轴承(active magnetic bearing,AMB)高速电机刚性转子系统,提出一种基于特征结构配置的鲁棒输出反馈控制器的设计方法。首先,引入交叉微分反馈,建立两自由度简化转子模型。然后,给出特征结构配置的具体步骤,并从稳定性和动态性能、偏置电流变化对系统性能的影响、不平衡振动响应以及控制能量这4个角度选择优化目标以设计鲁棒比例微分控制器。最后,进行数值仿真和实验,发现鲁棒输出反馈控制下的AMB转子系统不仅能够在不同偏置电流条件下0.1s内快速起浮,而且在全转速范围内最大振幅不超过0.04mm,远小于转子与保护轴承之间的径向间隙,验证该控制器的有效性。

Eigenstructure assignment associates parameters of feedback controller directly with eigenstructures of closed-loop systems.Due to its clear physical meanings and broad applicability,eigenstructure assignment has been widely used in the design processes of controllers for aircrafts,active vibration controls and other objects.In this paper,a design method for robust output feedback controller based on eigenstructure assignment was proposed for an active magnetic bearing(AMB)high-speed motor rigid rotor system.The differential cross feedback control scheme was introduced,and the simplified two-degree-of-freedom AMB high-speed motor rigid rotor model was established.The concrete steps of eigenstructure assignment were given.In order to design the robust output feedback controller,the optimization objective was selected from four aspects,including the stability and the dynamic performance,the influence of the variation of the bias current on system performance,the unbalance vibration responses,and the control efforts.Finally,numerical simulations and experiments were carried out,and the results show that the robust output feedback controller can not only help the AMB high-speed motor rigid rotor system reach the reference position within 0.1s,but also ensure that the maximum vibration amplitude of the system over the full rotational speed range be less than 0.04mm and far less than the radial gap between the rotor and the backup bearing,which confirms the effectiveness of the proposed controller.