【作者】 袁义坤；

【导师】 赵向东； 王育平；

【作者基本信息】 山东科技大学 ， 机械电子工程， 2005， 硕士

【摘要】 超声电机是一种应用全新原理获得驱动力的电机,它利用压电陶瓷的逆压电效应使定子产生超声波振动,通过定子和转子间的摩擦力来驱动转子。与传统电机相比,它只有结构紧凑、低速高转矩、响应快、不受磁场影响、断电自锁等优点,因而具有广阔的应用前景。但是,由于超声电机研究起步较晚,且系统呈现高度非线性,难于进行控制,从而影响了其在实际中的广泛应用。应用机电类比原理,建立超声电机的等效电路模型,可以简化超声电机的驱动控制电路,本文正是在此基础上对超声电机的等效电路进行了研究。 本研究主要完成了以下工作: 1、系统地总结了国内外超声电机的历史和发展状况,介绍了超声电机的特点及其应用,对其研究难点和发展方向进行了归纳和总结,突出了本义研究内容的迫切性。 2、简要介绍了压电效应的定义和压电陶瓷的特性,从压电晶体的本构关系出发推导出压电方程,并重点介绍了描述压电材料物理特性的几个重要参数;从机电能量转换的角度入手介绍了压电振子的振动模态,及其谐振特性。 3、基于假设振型,利用分析动力学的Lagrange方程,建立了基于压电陶瓷诱发应变激振的超声电机复合定子的机电动力学模型;采用振型假定法计算出超声电机定子在该特定模态下的模态质量、模态刚度、压电陶瓷交变电压激振的等效力系数。 4、根据机电类比原理,得到超声电机定子的基本等效电路,并求得电路中的各参数;在定子基本等效电路的基础上,考虑预压力、负载、温度等因素的影响,据此行到较完善的定子等效电路模型;将所建立的等效电路模型在Matlab环境下仿真,并将仿真结果与实验结果进行比较,从而验证所建等效电路模型的正确性。 5、对超声电机进行理论研究及仿真计算的基础上,进行了基于孤极反馈电压测量的扫频实验、基于压电陶瓷导纳测量的扫频实验、预压力对超声电机输出特性影响的实验研究:确定了引起电机失效的原因并进一步提出了改进方案。更多还原

【Abstract】 An ultrasonic motor is a kind of motor with a completely new driving principle to obtain turning force. The motor converts a piezoelectrically excited resonant vibration of the stator into a rotational movement of the rotor by frictional forces. As compared with conventional electromagnetic motor, the ultrasonic motor possesses the following features: compactness in size, high-torque at a low-speed range, fast response, insensitive to magnetic fields, high holding torque when power if off and so on, the ultrasonic motor has the wide application foreground. But the following defaults affect the application of the USM, such as late development, high-nonlinear behaviors, difficult in control. The equivalent circuit model (ECM) can predigest the driving and controlling model of the USM. This paper carries on the research to the ECM on this foundation.This research mainly completed the following work:1. Systemically analysis is done on the history, development status, feature, application and so on. The research difficulty and development way is concluded. It is emphasized the urgency of this paper.2. The definition of the piezoelectricity and the characteristic of the piezoceramics arc introduced. The piezoelectricity equation is calculated from the basic relation of the piezoelectricity crystal. A few important parameters describing the physics characteristic of the piezoelectricity material is introduced.3. Modal assumption method is used to build the electro-mechanical dynamic model based on Lagrange Equation. It can calculate the modal mass, modal stiffness, natural frequency and the force factor.4. The electro-mechanical analogy principle is used to calculate the parameters of the ECM. The perfect ECM is educed considering the effect of the preload force, load and temperature. Thereafter, the derived model has been simulated in a Matlab-Simulink environment by suing the power-system toolbox and the results achieved have been compared to the real performance of the motor and thereby the validity of the model has been established.5. The experimental investigation of the performance characteristics of the motor is studied when operating under various working conditions. Based on the experimental data the invalidation reason of the USM is found and the perfect project is studied.更多还原