【作者】 郝铭；

【导师】 陈维山；

【作者基本信息】 哈尔滨工业大学 ， 机械电子工程， 2009， 博士

【摘要】 超声电机(Ultrasonic Motor,简称USM)是近三十年来发展起来的一种新型压电驱动器。它利用压电陶瓷的逆压电效应将电能转化成超声频微观振动,进一步通过定子将微观机械振动共振放大、叠加,然后摩擦驱动转子(或动子)宏观转动(或直线运动)。同传统式电磁电机相比,超声电机具有结构简单、设计灵活、大力矩度大、低速、响应速度快、定位精度高、断电自锁和无电磁干扰等特点,所以在航空航天、光学仪器、机器人、半导体制造、医疗器械、办公自动化和汽车等领域具有广阔应用前景。目前实际应用的超声电机多是单自由度旋转或直线超声电机,对多自由度超声电机的研究尚属探索性阶段。本文研制了一种新型平面多自由度超声电机及其电学匹配和驱动系统。本文提出了一种新型纵弯复合模态平面多自由度超声电机结构,分析了其驱动机理。它以十字正交聚能器作为驱动器,由同一频率下的两路纵振和一路弯振在单一驱动足上叠加,使驱动足产生所需要的驱动轨迹,能够驱动电机在xOy平面内沿任意方向直线运动。以驱动足作为研究对象,建立了多自由度刚体驱动轨迹解析模型,分析了其在xOy平面各方向上产生直线驱动的输入方式。对驱动器结构参数进行了综合分析,得到各结构参数对纵振和弯振特征频率的影响趋势,进行纵弯模态特征频率简并。采用有限元分析方法,在刚体驱动足驱动轨迹解析模型指导下,针对硬铝材质的驱动足进行振动形态仿真。在驱动足的驱动表面取八个质点,建立了典型驱动方式下八个驱动质点的轨迹图谱,分析各种驱动情况下,驱动效果的一致性。研制了一种单驱动足纵弯复合模态换能器驱动的多自由度平面超声电机样机。对换能器进行了阻抗检测和振动检测,对样机进行了实验研究和测试,验证了纵弯复合模态平面超声电机理论分析与仿真研究的正确。实测电机最大速度达960mm/s、最大推力达100N。提出了超声电机谐振频率分离式电学匹配方法。以开关电源驱动的超声电机为了避免激发出电机的非工作模态振动,需要串联电感滤除高次谐波。串联电感又会与电学上容性的超声电机产生谐振影响超声电机上电压的高低。谐振频率分离式电学匹配方法可以在保证滤波效果的同时,通过调节匹配电容、电感值,按需要设计电机的谐振升压幅度,确保电机工作的稳定、安全。设计了基于数字信号处理器的超声电机驱动控制系统,以数字波合成器作为超声信号发生器,以全桥逆变器为功放。相位调节范围0o~360o,调相精度小于1o;频率调节范围15kHz~150kHz,调频精度不大于1Hz。设计输出功率500W。更多还原

【Abstract】 Ultrasonic motor (USM) is a new type piezoelectric actuator developed during recent three decades. It converts electrical energy to ultrasonic micro vibration using converse piezoelectric effect. The micro vibration then drive rotators (or movers) to rotate (or straightly move) via friction after being resonant amplified and superimposed. Comparing to traditional electromagnetic motor, USM has advantages on simple structure, flexible design, large torque, low speed, fast response, high positioning accuracy, self-lock at power off, and without electromagnetic radiation. Therefore it can be applied widely in many fields, such as aeronautics & astronautics, optical instrument, robotics, semiconductor manufacture, medical apparatus, office automation, and auto industry. At present, almost all the practically used USM have only one degree of freedom (DOF) like linear or rotary movement, and the research on the structure and application on the multi-DOF USM is still in the early stage. This dissertation developed a novel multi-DOF plane liner USM and the relevant electrical match and driving system.A new type multi-DOF plane liner USM based on longitudinal and bending modes was proposed and its motion mechanism was analyzed. Driven by cross orthogonal horn, two channels of longitudinal vibrations and one channel of bending vibration superimposed on one single driving foot, and supply the trajectories for the motor, which could then move straightly in any direction on the xOy plane. Taking the driving foot as the research target, an analytical model of the rigid multi-DOF driving foot trajectories has been developed, and the liner driving input method in every directions of xOy plane has been analyzed.Comprehensive analysis was carried out on structure parameters of the actuator, and the parameters’influence tendency towards the eigenfrequencies was got to realize the longitudinal-bending vibration modal degeneration. By means of the finite element method, combining with the analytical model of the rigid multi-DOF driving foot trajectories, the simulation study on vibration mode of the duralumin driving foot was conducted. Eight driving points on the surface of driving foot was extracted and there trajectories under typical driving method were constructed. The consistency of driving effect under several driving methods was also analyzed.Based on the result of vibration modal eigenfrequencies’degeneration and FEM analysis, a multi-DOF USM with single vibrator driven by longitudinal-bending transducer was proposed and fabricated. The prototype experiment on impedance and vibration showed the validity and reliability of the theoretical analysis and simulation research. The fastest speed was 960mm/s and The most large output force was 100 N.The separation mode electrical match method for the resonant frequencies of USM was presented. To avoid the vibration under non-working modes, inductors should be connected in series to the USM, which is driven by switched-supply power. Meanwhile, since the USM is capacitive, its voltage would be interfered by resonant excited by the inductors. Through adjusting the values of capacitors and inductors, the separation mode electrical match method could arbitrarily obtain the necessary value of voltage to ensure the stability and security of motor, and guarantee the wave filtering effect at the same time.The USM driving control system based on digital signal processor was designed. The digital wave synthesizer was used as the signal generator, and the full-bridge inverter was used in power amplifier. The phase-adjust range is 0o~360o, and adjust resolution is less than 1o; frequency-adjust range is 15 kHz~150 kHz, and adjust resolution is less than 1 Hz. The output power is 500W.更多还原