New fuzzy reasoning-based high-performance speed/position servocontrol schemes incorporating ultrasonic motor

A high-performance servo control scheme using compact ultrasonic motors (USMs) as actuators has not yet been practically realized in modern industry and office automation systems because the dynamic and steady-state modeling of USMs is almost impossible from a theoretical point of view. A high-performance speed/positional servo control scheme based on modern fuzzy reasoning concepts and featuring a traveling wave-type USM with high torque at low speed range is presented. The control method of the USM servo system using inverter frequency and voltage control strategies for the speed and amplitude of the traveling wave on the USM stator and the phase difference control scheme between two-phase high-frequency inverters are demonstrated and evaluated using experimental results. In particular, the control implementation is described from a practical viewpoint     

Speed tracking servo control system incorporatingtraveling-wave-type ultrasonic motor and feasible evaluations

A variety of ultrasonic motors (USMs) have attracted special interest as a new type of actuator in servo motion control systems. For practical applications, the speed servo control system incorporating the ultrasonic motor developed in Japan has some special unique features. However, this system has several significant problems, such as the inherent speed ripple characteristics, the speed regulation characteristics under the condition of applied disturbance load torque, and the speed tracking characteristics. In order to solve these practical problems, some control schemes of ultrasonic-actuated motor systems have been proposed and discussed theoretically, which include fuzzy reasoning control, adaptive control, repetitive learning control, and neural-network-based learning control. However, it is considered that these control strategies mentioned above have not been sufficiently substantiated from a feasible experimental point of view. This paper presents a newly proposed precise speed tracking servo control system using the compact traveling-wave-type ultrasonic motor. Its proposed control scheme is composed of both the driving frequency control loop with the variable-gain strategy and the applied voltage control loop with the speed ripple reduction strategy of the USM. The improved speed characteristics realized by this proposed control system are demonstrated and evaluated in experiments     

纵扭复合型驻波超声波电动机的回顾与展望

介绍了国内、外纵扭驻波超声波电动机的发展状况，列举了各主要研究机构具有代表性的纵扭超声波电动机的尺寸参数和运行特性，分析了不同结构的纵扭超声波电动机的优缺点，还说明了新型斜槽式驻波超声波电动机的优缺点。最后指出纵扭超声波电动机实现大力矩输出的难点和一些解决方法，以及它的研究方向和发展前景。     

基于LabVIEW超声马达谐振频率的实验研究

该文对超声马达谐振频率的时效性及不同预压力、电压激励下谐振频率特性的理论分析，采用基于LabVIEW开发平台的阻抗测试系统，自动测量超声马达阻抗特性、谐振频率及其相位，得出超声马达的谐振频率一般会随着预压力的增大而变高，谐振频率和品质因数随着激励的增加而减小，随测试时间而略有变化，并在RTWUM60样机上得到了实验验证，其输出曲线和数据对于超声马达谐振频率的获取、等效电路的导出、马达参数的识别及相应的控制策略均有重要指导意义。     

基于遗传算法的超声波电机模糊自适应速度控制

行波接触型超声波电机是一种利用压电陶瓷的逆压电效应工作的新原理微特电机，与传统电磁型电机截然不同，其驱动力矩并非由电磁感应产生，而是由压电陶瓷超声频域的振动转化而来，参数的时变性，系统内在的非线性、系统的强耦合性等原因导致其动态和稳态数学模型难以获得。在未知控制对象精确参数及数学模型的情况下，该文提出一种新的超声波电机自适应速度控制策略。控制系统包括两个闭环，内环用来补偿由于温度变化造成的机械谐振频率漂移，可以增强响应的快速性与准确性，另一闭环为频率调节环，频率值由模糊控制器根据工作状态随时调整，其模糊控制规则基于遗传算法在线调节。系统较好地实现了设定的速度参考模型的自适应跟踪，具有控制灵活，适应性强的优点，又具有较高的控制精度和较好的稳定性。     

基于小波差动模式的双模态超声波电机驱动特性研究

双模态超声波电机(USM)在研制的小波差动控制下,提高了双模态USM的低速运行性能,并使双模态USM的驱动分辨率达到了纳米量级.小波差动控制的机理是通过改变双模态USM驱动头的运行轨迹来实现双模态USM的微纳驱动,以及通过控制小波驱动元的触发频率以获取所需的双模态USM步进速度.本文以试验的方式,探讨了双模态USM驱动模型,给出了在小波差动控制下的双模态USM位移驱动特性和特点.     

超声波电机频率-温度特性研究

为了研究超声波电机运行过程中温升和频率漂移等关键技术问题,采用自然对流传热问题的牛顿冷却定律和热容理论,建立了超声波电机的温度特性与驱动频率之间的关系表达式,仿真分析了驱动频率对电机温升的影响;考虑电机压电定子的转动惯量和剪切变形等因素,利用能量等效原则和铁摩辛柯梁振动理论建立了超声波电机谐振频率与温度之间的关系表达式,通过仿真研究了温度对电机谐振频率漂移的影响,并通过实验验证了仿真结果的正确性。仿真及实验结果表明:电机的谐振频率随着温度的升高呈线性降低;驱动信号频率越接近电机谐振频率,电机表面温度就越高。最后,根据研究结果提出了减小电机温升和频率漂移的措施,并通过实验验证所提出措施的有效性。     

超声波电机的位置控制

超声波电机是一种利用压电陶瓷的逆压电效应使定子产生超声振动 ,并通过定子和转子间的磨擦来驱动转子运动的新型微特电机 ,工作原理不同于传统的电磁电机。本文简单介绍了超声波电机及利用单片机实现对shinsei公司的USR6 0型超声波电机的位置控制     

QUICK AND PRECISE POSITION CONTROL OF ULTRASONIC MOTORS WITH TWO CONTROL INPUTS

ABSTRACT

Ultrasonic motor (USM) has an excellent performance and many useful features. Since this motor is superior in holding torque and high response characteristic, it has been expected to use as position servomotor for small motors.

There have been reported some mathematical models of the ultrasonic motor. however, these models are too complex to apply for control of the motor. Therefore position controllers based on PI control or fuzzy control have been proposed in recent years. It is difficult to control the ultrasonic motor with high-performance using such controllers, thus simple and convenient mathematical model is necessary for precise control.

This paper presents a new position control scheme of ultrasonic motor, it consists of a PI controller and an adaptive controller which compensates the speed characteristic variations with online parameter identification. Moreover, this system controls both driving frequency and phase difference in order to achieve a quick and precise position control. The effectiveness of proposed control.scheme is demonstrated by experiments.     

超声波电机定转子接触的 摩擦传动模型及其实验研究

Ultrasonic motor (USM) is a new principle motor, which applies piezoelectric vibration and frictional force as the driving source. This article investigates the frictional contact model between stator and rotor of the travelling-wave-type ultrasonic motor. Taking the stick-and-slid feature into account, this article presents analytical expression of characteristics of ultrasonic motor among constructive parameters, which lays a theoretical foundation for design and manufacture of USM. Effectiveness is verified by comparison between theoretical and experimental results of the prototype.     

超声波电机定转子接触的摩擦传动模型及其实验研究

超声波电机是一种利用超声振动和摩擦力为驱动源的新原理电机。对行波型超声波电机定子转子之间的磨擦传动动模型进行了深入研究。在分析过程中,考虑了定转子之间的粘滑特性,获得了行波型超声波电机特性与结构参数之间关系的解析表达式,为电机的设计和制造提出理论依据。     

基于比例积分-准谐振控制器的直驱式永磁同步电机转矩脉动抑制方法

由于受逆变器固有的非线性特性和气隙磁通谐波等因素的影响,永磁同步电机定子电流中含有大量的高次谐波分量,这些谐波电流分量与转子永磁体磁场作用,使电机产生谐波转矩脉动,特别是在直接驱动系统中,转矩脉动更为严重。针对这一问题,从转矩脉动产生的机理出发,提出一种基于比例积分-准谐振控制器的转矩脉动抑制方法。该方法根据理想谐振控制器在谐振频率点处的增益为无穷大,可以对谐振频率点处的正弦信号实现零稳态误差跟踪控制,将谐振控制器与电流环PI控制器并联,对定子电流中的谐波分量进行补偿,改善定子电流波形,实现抑制转矩脉动的目的。仿真与实验结果证明了所提方法的正确性和有效性。     

A new design method and half-step operation for ultrasonic stepping motors

In this paper, a systematic design method and a new half-step operation are proposed for ultrasonic stepping motors (USMs) which are based on the principle of spatially shifted standing vibrations. With emphasis on the combination of the order of vibration mode, the number of spatial phase shifts, the number of electrodes, and the number of simultaneously excited electrodes, the design equations and constraints are newly derived, hence, proposing the design procedure. The finite-element method and impedance measurement are also employed to investigate the vibration of the stator. By borrowing the control idea of electromagnetic stepping motors, the half-step operation is newly applied to this USM so that the step size can be further halved. An 80-step USM is prototyped. The proposed design method and half-step operation are well supported by experimentation.     

超声电机的试验研究

首先叙述了实验研究对超声电机技术发展的重要性。文中简明介绍了自南京航空航天大学超声电机研究中心创建以来 ,超声电机实验仪器设备的建设和超声电机试验研究的进展。重点叙述了超声电机零、部件模态试验、瞬态试验和机械特性试验等的试验目的、方法、仪器设备及经验体会。文中列举了若干典型试验结果。最后强调指出 ,为了进一步提高超声电机产品质量、扩大超声电机应用市场 ,还需继续改进老的试验系统 ,建立更新更多的试验仪器和设备     

超声波电机自激振荡驱动电路的变频控制特性

针对单相超声波电机的自激振荡驱动电路,重点分析了电路选频网络中不同元件参数对电路自激选频特性的影响,建立了电机动态阻抗变化特征、电路自激信号频率和电路参数之间的一个方程组,得出在超声波电机的工作频率范围内,电路自激频率随选频网络中下端电阻的增大而增大,随电感的增大而减小,实验结果与理论推导基本相符。电路中选择不同的电阻和电感值可以实现调频,即对超声波电机的变频控制。在电机稳定工作点的一定频带范围内电路可以实现自动频率跟踪功能。     

Examination of vibration control of linear oscillatory actuator

Linear oscillatory actuators (LOAs) are widely used in linear motor shavers, electric toothbrushes, and mobile phone vibrators as high‐speed oscillatory driving devices. The maximum amplitude of the motor is obtained at a resonant frequency that is determined from the spring constant and the mass of the motor. However, there is a problem with these actuators: the amplitude decreases sharply when the driving frequency differs from the resonant frequency in a mechanical vibration system with minimal damping. In this paper, we propose a control method for the resonant frequency in which the thrust, which shows the characteristics of a spring, is generated on the basis of the displacement of the mover and the damping factor, in which the thrust, which shows the characteristics of damping, is generated based on the velocity of the mover. The proposed method assures that the resonant frequency always corresponds to the driving frequency and that rapid changes in the amplitude are avoided. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(4): 55–62, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21172     

基于RBF神经网络的超声波电机参数辨识与模型参考自适应控制

超声波电机(USM)是近年发展起来的一种新型微特电机，与传统的电磁驱动型电机的工作原理截然不同。由于USM具有小型轻量、无电磁干扰、响应速度快、低速大转矩、高保持力矩、高功率密度等诸多优点，因而在光学仪器、办公自动化、汽车专用电器、智能机器人、航空航天等领域具有良好的应用前景。但USM的高度非线性、时变性和强耦合增加了它的控制难度。该文提出一种新的USM自适应控制策略。系统采用双闭环控制，内环用来补偿定子环机械谐振频率的漂移；外环利用径向基函数神经网络(RBFt~)控制器调节USM的驱动频率，实现速度的自适应控制。经实验证明，该控制系统具有响应迅速、适应性强等优点，具有较高的控制精度和较好的稳定性。     

超声波电机发展、建模研究及展望

超声波电机是一种利用压电陶瓷的逆压电效应使定子产生超声振动 ,并通过定子和转子间的磨擦来驱动转子运动的新型电机 ,工作原理不同于传统的电磁电机。本文简单介绍了超声波电机的发展历史及到目前为止超声波电动机的建模研究 ,并在此基础上指出超声波电机的发展方向     

超声波电机模糊-PI双模自适应速度控制

行波接触型超声波电机与传统电磁型电机截然不同 ,其驱动力矩并非由电磁感应产生 ,而是由压电陶瓷超声频域的振动转化而来。参数的时变性、系统内在的非线性、系统的强耦合性等原因导致其动态和稳态数学模型难以获得。在未知控制对象精确参数及数学模型的情况下 ,提出了超声波电机的模糊 -PI双模速度控制策略 ,系统根据工作状况随时调整控制模式。实验表明 ,系统较好地实现了设定的速度参考模型的自适应跟踪 ,具有控制灵活、适应性强的优点 ,又具有较高的控制精度。     

Ultrasonic motor-actuated direct drive positioning servo control system using fuzzy-reasoning controller

This paper describes a traveling-wave ultrasonic motor (USM)-actuated positioning servo driver, suitable for direct-drive motion systems, which incorporates a fuzzy-reasoning software controller with speed and position-variable feedback schemes. The experimental results of this USM position servo driver operating at two-phase high-frequency resonant inverter are illustrated and evaluated using a one-axis servo motion drive system. The results show that the new system using a compact USM that incorporates a microprocessor-based two-input and one-output fuzzy-reasoning controller is cost effective and suitable for special purposes in the industrial, medical, automotive, space and consumer fields.