【作者】 王剑；

【导师】 郭吉丰；

【作者基本信息】 浙江大学 ， 电气工程， 2009， 博士

【摘要】 柱状超声波电机是近二十年来发展起来的一种新原理电机,较其他类型的超声波电机更具有力矩体积比高和可控性好的特点,在光学器械、医疗设备和航空航天等领域已经取得了应用。近年来柱状超声波电机的研究一直围绕着大力矩、高精度、高稳定性等方向发展,因而需要全面深入研究此类电机的力传递模型、结构设计与优化、材料与制作工艺、驱动与控制等层面蕴含的科学和技术问题,针对这若干问题,所作的研究工作和取得的研究成果主要有：首先在阐述超声波电机发展历史的基础上,重点是结合柱状超声波电机的研究进展和应用现状,论述了此类电机亟需解决的科学和技术问题。建立了柱状弯曲型超声波电机的力接触与传递的数学模型。结合柱状弯曲型超声波电机的结构和工作原理,理论和实验研究了定、转子的接触方式,指出了存在单点和双点两种接触方式。并给出了定转子间的力接触传递模型及其电机效率计算式。分析了电机性能与预紧力的关系,给出了临界预紧力概念。利用理论模型对电机样机参数进行优化,研制的φ14mm样机的空载转速为300r/min,堵转转矩为0.11N·m,且电机性能稳定,运行可靠。提出了一种新型的中空短柱状的复合型超声波电机,利用其由径向振动衍生的纵向振动和扭转振动的复合,是一种变型的纵扭复合型超声波电机。针对此类圆柱壳结构,利用弹性力学理论建立该圆柱壳的解析模型,并求解了径向和扭转振动频率方程,理论表明此类电机能完全调谐,形成了此类电机的调谐理论基础。形成了中空短柱状的径向-扭转复合型超声波电机的设计理论和制造工艺技术。首先给出了中空短柱的夹心式定子结构,围绕径振和扭振频率的调谐,分析了电机结构参数对一阶径振和扭振谐振频率的影响,并通过有限元分析和样机实验证实此结构能完全调谐。在此基础上,从定子、转子、压电陶瓷和摩擦材料四个方面入手,对电机结构和材料进行了优化设计。研究并形成了复合型超声波电机制作的工艺流程和工艺要求,重点阐述生产过程中的技术要点。通过对样机的机械特性测试,确定了电机最佳的工作参数和性能参数。制作了性能良好的φ60mm样机,空载转速为25r/min,堵转力矩为5N·m。研究表明,这类电机具有结构简单、短柱(定子长径比为0.68)、制造容易和力矩/体积比高等特点,另外,此类电机的转速较行波型电机更低,且在低速区运行稳定,更适合一些要求低速场合的直接驱动控制用。分析了径向-扭转复合型超声波电机的驱动特点,利用硬件与软件相结合的方法设计了驱动电源,将数字键盘输入和LCD显示一并纳入考虑,使超声波电机的频率、相位差和幅值都可以实时调节和直观显示,同时进行了开关功率电路和匹配电路设计。建立了基于DSP的超声波电机测控系统,对电机的瞬态和稳态性能进行了测试,用于分析驱动频率、电压幅值和相位差等参数对电机输出的影响。在速度控制中,利用模糊比例控制调节驱动频率的方法,实现了电机在低速下的稳定运行。在位置控制中,利用转速控制的研究结果,设计了位置/速度双闭环控制器,实现了电机高精度的位置控制。本文为两类柱状超声波电机的优化设计,性能提升和研究成果应用提供了理论和实验基础。更多还原

【Abstract】 The cylindrical ultrasonic motor is a new type motor that has been developed in recent twenty years. It has the higher torque per volume and the better controllability compared with other kinds of ultrasonic motors. It has been adapted to optical, medical especially the aeronautics and astronautics fields. The researches of cylindrical ultrasonic motor are focused on the developments of the high torque, high precision and quality stability in recent years. So several technical matters such as the force transferring model, the design and optimization of the structure, the drive and control of the motor, and the manufacture technology should be studied deeply and roundly. The research work and method of this thesis are as follows:Based on the representation of the history of ultrasonic motor and combined with the research progress and the application of the cylindrical ultrasonic motor at home and abroad, the problems that have to be solved in this research are discussed.The single-point and the double-point contact modes are discovered and the force transferring model was put forward, on the foundation of the structure and working principle of the cylindrical ultrasonic motor with bending vibration mode. The performance of this motor is analyzed around a critical point of the pre-pressure. AΦ14mm prototype was fabricated. Its maximum torque is 0.11N·m, the no-load speed is about 300r/min.The analytical model of a cylindrical shell is established and solved. The radial and torsional vibrations of this shell are analyzed accurately. It’s the basic research to the new type motor.A new radial-torsional vibration hybrid type ultrasonic motor (abbr. RTUSM) is put forward, which utilizes longitudinal vibration derived from radial vibration by Poisson effect. The hollow and short cylindrical structure is easy to make resonant frequencies of first-order radial and torsional vibrations into degeneracy. The FEM method is used to optimize the motor geometry from the stator, rotor, PZT ceramics and friction material. The process flow and requirements are generalize to guide the fabrication of this motor. AΦ60mm prototype is fabricated, and the mechanical characteristics is tested in order to determine the best work and performance parameters. The no-load speed and maximum torque of the motor are 25r/min and 5N·m, respectively.The driving system of the RTUSM is designed, according to its requirements, which considers the key input and LCD display. The driver can adjust the frequency, voltage and phase difference in real time.A high-performance test control system of RTUSM is developed,which is based on the DSP. Through the test of steady-state and transient-state characteristics of the motor, its output performance can be studied in the condition of different driving frequency, voltage and phase difference. In the speed control, the fuzzy proportion control can be selected to adjust the driver frequency to realize the steady rotation in low speed. In the position control, the position/speed dual closed loop control system is studied and designed.更多还原