基于KF-LESO-PID洛伦兹惯性稳定平台控制

Lorentz inertial stability platform control based on KF-LESO-PID

为克服现有惯性稳定平台使用机械轴承干扰量大,使用气/液浮轴承难度高,使用磁阻力磁轴承线性度差的缺点,提出一种基于洛伦兹力偏转磁轴承的新型洛伦兹惯性稳定平台(LISP)。为克服耦合效应和承载摩擦谐振干扰对平台偏转通道高频姿态补偿控制的影响,提出一种基于LESO-PID结合卡尔曼滤波(KF)反馈的数字控制方案。根据洛伦兹力磁轴承(LFMB)支承偏转系统结构特点,建立了LISP转子偏转动力学模型;利用模型分析径向两自由度偏转特性,提出在PID控制器的基础上,引入线性扩张状态观测器(LESO)和卡尔曼滤波反馈以抑制摩擦谐振干扰及耦合效应;搭建了以DSP和FPGA为核心的数字控制系统,并以离散形式将控制方法进行数字化实现。采用对数频率特性判据和Nichols曲线对所提控制方法的稳定性进行分析,通过仿真比较引入LESO-KF前后转子偏转通道的稳定性。实验结果表明:PID控制条件下在高频时失真,引入LESO-KF后明显降低噪声及干扰,同时还可对系统内部状态参数进行实时观测。实验结果验证了所提控制方法对摩擦谐振干扰及耦合效应的抑制作用。

To overcome the disadvantages of the existing inertial stabilization platform such as large interference for using mechanical bearings,high difficulty for using air/liquid bearings and poor linearity for using magnetic resistance magnetic bearings,a new Lorentz inertial stability platform(LISP)based on Lorentz force deflection magnetic bearing is proposed.To suppress the influence of coupling effect and load-bearing friction resonance interference on the high-frequency attitude compensation control of the platform deflection channel,a digital control scheme based on LESO-PID combined with Kalman filter(KF)feedback is proposed.According to the structural characteristics of rotor tilt supported by Lorentz force magnetic bearing(LFMB),a dynamics model for LISP deflection is established;the tilting relationship of two radial channels is analyzed with the established model,and the linear extended state observer(LESO)and Kalman filter feedback control is introduced into PID controller to suppress friction resonance interference and coupling effects;a digital control system based on DSP and FPGA is construed,and the control method is digitalized in a discrete form.The stability of the proposed control method is analyzed by logarithmic frequency characteristic criterion and Nichols curve,and the stabilities of the rotor deflection channel before and after importing LESO-Kalman are compared through simulation.Experimental results show that with traditional PID,the rotor system causes serious distortion at high frequency,while the system reduces noise and interference greatly after importing LESO-Kalman control.Meanwhile,the internal state parameters of the system can be monitored in real time.Experimental results verify the effectiveness of proposed control method to suppress the frictional resonance interference and coupling effects.