压电舵机动态迟滞建模与带有鲁棒干扰观测器的两自由度控制
Dynamic hysteresis modeling and two-degree-freedom control with robust disturbance observer for piezoelectric rudder

压电宏纤维复合材料(MFC)驱动的舵机具有功耗低、质量小以及可靠性高等优点, 在无人飞行器领域有很大的应用潜力. 压电材料的动态迟滞非线性会降低舵机的控制精度和稳定性, MFC柔性结构使舵机易受外扰影响. 本文首先建立MFC 舵机Hammerstein动态迟滞非线性模型, 并设计了迟滞逆补偿器. 针对模型不确定性和外扰影响, 设计了带有鲁棒干扰观测器的二自由度控制器, 保证在外扰和模型不确定性下控制系统的鲁棒性. MFC舵机控制实验结果表明, 所设计的控制器具有良好的抗干扰性能和鲁棒性, 较传统干扰观测器显著提高了控制性能.
Macro Fiber Composite (MFC) -driven rudder has advantage of low power, light weight and high reliability and has great application potential in UAVs. However, dynamic hysteresis nonlinearities in MFC reduce the control accuracy and stability. Flexible structure of MFC rudder is susceptible to external disturbance. In this article, a Hammerstein model is proposed to model the dynamic hysteresis nonlinearities of the MFC and the hysteresis inverse compensator is designed. Then, a 2 DOF controller with robust Disturbance Observer (DOB) is designed, which guarantees the robustness of the system under the external disturbance and model uncertainties. Finally, it is demonstrated by tracking control experiments of MFC rudder that the proposed controller has a good disturbance rejection and robustness and it improves significantly the control performance comparing with the conventional DOB