【作者】 董维杰；

【导师】 孙宝元；

【作者基本信息】 大连理工大学 ， 机械电子工程， 2003， 博士

【摘要】 传感器和执行器的集成是微机电系统、智能材料与智能结构的基本要求，分为结构集成和功能集成两种方式。功能集成的传感器和执行器被称为自感知执行器(self-sensing actuator)，其换能元件既作执行器又作传感器．自感知执行器使系统体积和重量减小、节省空间、实现同位控制、提高控制的稳定性。 本文所做工作包括自感知执行器的理论研究和应用研究两方面。在应用研究方面，以单一均质压电材料制成的自感知执行器为研究对象。 基于双向换能器理论，利用机电双向换能器的传输矩阵，建立了自感知执行器数学模型。该数学模型不仅可以描述压电自感知执行器和磁致伸缩自感知执行器的机电变换规律，而且为已有基于电桥电路和基于观测器等自感知执行器实现方法找到理论根据；根据自感知执行器传输矩阵，预测了空分复用和时分复用解耦方法，为进一步完善、拓展自感知执行器研究打下基础。 自感知执行器首先是执行器，然后是传感器。压电执行器的输出特性与机械和电学边界条件关系密切。本文深入研究总结了边界条件与压电方程、压电迟滞特性的关系，推导了中间电极厚度不可忽略的压电双晶片的输出力／位移与驱动电压的关系，得出了双晶片自由位移与应变的关系、力与应力的关系式，为任意边界条件下压电双晶片自感知执行器的设计和状态计算提供了理论依据。 在理论研究基础上，研究了基于电桥电路和基于观测器的两种解耦方法及应用。自感知执行器实现方法不同，应用领域也有所不同。 基于电桥电路的压电自感知执行器采用常规的电压驱动，通过电桥电路提取出与速度成比例的电流，适用于振动控制一类的动态应用。面向结合悬臂梁的振动主动控制，本文设计了仪用放大器、低通滤波器和以高压运算放大器3583为核心的控制器，针对电桥电路略有不平衡情况，引入了相位滞后校正环节。实验结果表明，基于电桥电路的自感知执行器不仅能作为速度检测器，而且对悬臂梁的振动控制效果明显。 基于观测器的压电自感知执行器在作执行器的同时还能检测位移和力两个变量，实现的关键是要同时已知压电电压和电荷两个电学量，根据压电方程设计应变和应力观测器。本文以设计自感知压电夹钳为应用目标，研究了压电驱动方法、迟滞补偿和观测器设计等问题。鉴于压电电压与位移之间存在迟滞，设计观测器时需要作迟滞补偿，本文采用MaxwCu迟滞模型，对其模型表述作了修改，以便可以用递归最小二乘法拟合模型参数、降低模型误差．通过对比电压驱动和电荷驱动的优缺点，根据目标要求，研制了在电压驱动的同时能获得电荷的程控复合驱动电路。该复合电路不仅可以用于电压驱动，而且可以进行电荷控制，不仅支持动态驱动，而且支持静态驱动。该复合电路为观测器解耦法搭建了硬件平台，其输出的驱动电压和电荷是观测器的输入． 根据压电方程为双晶片夹钳设计了观测器，观测器的输出是应变和应力，根据位移与应变的关系、力与应力的关系式，可换算成位移和力。用涡流位移传感器和砝码做校验，结果表明，夹钳能够很好地感知自由位移或感知夹持力;在夹钳夹持物体的过程中，夹钳能够同时感知位移和力两个物理量，感知结果接近实际测量值。但是由于夹持过程中压电边界条件变化，所以需要切换不同的观测器。 展望下一步研究工作，在自感知执行方法研究方面，除了继续深入研究观测器方法外，还应该探索空分复用和时分复用等可能解祸方法;在自感知执行器研究对象方面，除了块体陶瓷之外，还可以研究石英和压电薄膜自感知执行器;在自感知执行器应用领域研究方面，要加大研究在微机电系统方面的应用研究。更多还原

【Abstract】 The integration of sensor and actuator is essential demand of MEMS and smart materials and structures. Two integration patterns are summarized which are structural integration and functional integration. Functional integration can be termed as self-sensing actuator (SSA), in which a single element simultaneously functions as a sensor and an actuator. SSA has advantages in decreasing system volume and weight, saving space, true collocation and increasing stability.This paper studies the SSA made by simplex uniform material. This kind of SSA is a contribution to composite smart materials and structures and MEMS in sensor and actuator integration. The work includes the theory study and the application study.Piezoelectric and magnetostrictive materials are two typical bilateral materials that can be made into SSAs. Up to now the study on these two kinds of SSAs is mainly limited on the application and improvement of bridge-circuit based approach. This paper attempts to describe the theoretical model of SSA. Based on the theory of bilateral electromechanical transducer, SSA is modeled by transfer matrixes of bilateral transducers. This model can not only describe the electromechanical energy conversion laws of SSA, but also give a perfect explanation of existing bridge circuit based SSA approach and observer based SSA approach. After investigating the characteristic of the transfer matrixes of SSA, this paper predicts two possible SSA approaches of space-sharing and time-sharing, which will be most important to the design and further study of SSA if validated.Self-sensing actuator is firstly actuator and then sensor. Because the output of piezoelectric actuator has close relation to mechanical and electric boundary condition, this paper analyzes the relations between boundary condition and piezoelectric equation as well as hysteresis. The output force and displacement versus voltage of bimorph with inner thick electrode are derived, which provide the design basis for SSA under arbitrary boundary condition.Besides, this paper studies the bridge based and observer based self-sensing approaches and their applications. There are different application fields due to different decoupling approaches.Bridge based piezoelectric SSA adopts voltage driving. The current proportional to the strain rate can be drawn from driving voltage through a bridge circuit, so in most cases, the SSA realized by this method is suitable for dynamic application. A piezoelectric SSA is implemented basing on a strain rate bridge circuit in order to control the vibration of cantilever beam. Instrumentation amplifier and low-pass filter are designed to deal with the sensed weak signal. A simple controller consisting of high voltage amplifier 3583, proportional adjustment and phase lag compensation is designed in view of the bridge is slightly unbalanced. The experimental results show that bridge based SSA not only can be a vibration detector but also has good performance in vibration control of beam.Observer based SSA can act as not only actuator but also displacement sensor and forceHIsensor. The key issue is to get both voltage and charge of piezoelectric element, and then design strain and stress observer according to piezoelectric equations. Aiming the application at self-sensing piezoelectric gripper, driving method, hysteresis compensation and observer design are studied. The Generalized Maxwell Slip model is adopted to describe voltage versus charge relation and some modifications are made in order to fix model parameters using Least Mean Square. The model error and model predicting error are proved to be within 2.5%. After comparing the advantages and disadvantages of voltage driving and charge driving, the author proposes a programmable compound circuit to meet the demand of static application, which can voltage-drive piezoelectric actuator and get the resulting charge concurrently, and is a hardware platform for the observer based SSA approach. Based on the compound circuit, the driving voltage and charge of piezoelectric bimorph更多还原