基于状态观测器的压电自感知执行器研究  

STUDY ON OBSERVER BASED PIEZOE-LECTRIC SELF-SENSING ACTUATOR

作　　者：董维杰[1] 孙宝元[1] 崔玉国[1] 杨志欣[1] 

机构地区：[1]大连理工大学机械工程学院,大连116024

出　　处：《机械工程学报》2002年第7期80-83,共4页Journal of Mechanical Engineering

基　　金：国家自然科学基金(69774020);教育部博士学科点专项科研基金(98014106)资助项目

摘　　要：压电执行器存在迟滞非线性,常需要附加位移传感器以组成闭环校正。拟用执行器自感知位移和力,省去外部传感器。对压电双晶片执行器设计了电压驱动电路,同时用积分电路获取其上电荷的复合电路。基于此电路,无外载荷下,执行器可以自感知位移;有外载荷下,采用状态观测器方法,执行器可估计自身结构位移和应力,观测器中用广义Maxwell滑动模型描述迟滞以补偿迟滞非线性。基于观测器的自感知方法避免了电桥法自感知电路阻抗不易匹配的问题。试验证明了上述方法用于压电自感知位移执行器的有效性。Piezoelectric actuators often work in a close-loop feedback position control system due to hysteresis. The objec-tive is to make an actuator self-sense its output force and dis-placement without using extra sensors. The technique is termed self-sensing actuator/actuation (SSA). A compound circuit is proposed to voltage-drive the piezoelectric actuator and get the resulting charge concurrently. Based on the circuit, the un-stressed actuator can self-sense its free strain. If the actuator is externally stressed, an observer is constructed to estimate the actuator's stress and strain state. The observer-based self-sensing approach depends on the fact that the electric field is controllable and the electric displacement is measurable. In order to compensate hysteresis, voltage versus charge relation is modeled using generalized Maxwell slip (GMS) modeL, and the observer is improved to a nonlinear one. The observer-based SSA approach successfully bypasses the impedance mismatch-ing problem bothering the bridge-based SSA approach. The self-sensed average strain of piezoelectric bimorph is coincident with the tip displacement measured by proximitor.

关 键 词：压电陶瓷 执行器 电荷驱动 状态观测器 自感知执行器 

分 类 号：TH86[机械工程—仪器科学与技术]