Working principle and design of a double cylinders type traveling wave ultrasonic motor using composite transducer

A double cylinders type traveling wave ultrasonic motor using composite transducer was proposed.The proposed stator contained two cylinders and one composite transducer,and the transducer located on the outer surfaces of cylinders.The composite transducer included two exponential horns located on leading ends,and the horns insected with the cylinders at tip ends.Two degenerated flexural vibration modes spatially and temporally orthogonal to each other were excited in each cylinder by the composite transducer.In this new design,a single transducer could excite two flexural traveling waves in the cylinders.Thus,elliptical motions were achieved at the particles on the teeth.The working principle of the proposed motor was analyzed.The cylinder and transducer were designed with FEM.The resonant frequencies of two vibration modals of the stator were tuned to be the same,and the motion trajectories of nodes on the teeth were analyzed.Transient analysis results show that the motion trajectories of teeth are ellipses.The results of this paper can guide the development of this new type of ultrasonic motor.     

A ring type standing wave ultrasonic motor using cantilever type longitudinal transducers

The disadvantages of classic ring type ultrasonic motor were analyzed.To obtain large mechanical output power,a ring type standing wave ultrasonic motor using cantilever type longitudinal transducers was proposed.There are four pairs of cantilevers on one side of the ring,and four PZT ceramics are set between each pair of cantilevers.A screw fastened the PZT ceramics and cantilevers together to form a longitudinal transducer.The bending vibration mode of the ring is excited by the stretching vibration of the PZT ceramics.Thus,linear simple harmonic motions are achieved at the particle on the teeth.And the driving force is the frictional force between rotor and stator.The working principle of the proposed motor was analyzed.The ring and the longitudinal transducer were designed with FEM.The sensitive parameters of resonant frequency of the transducer and ring could be gained with modal analysis.The longitudinal vibration modal of transducer and bending vibration modal of ring were degenerated,and the motion trajectories of nodes on the teeth were analyzed.The results of this paper could guide the development of this new type of motor.     

大倾角采煤机电气控制系统设计

为在大倾角工作面上运行的电牵引采煤机,设计了四象限变频调速采煤机电气控制系统．介绍了控制系统的总体结构、组成和PLC的主控制回路．分析了变频调速系统的工作原理,并结合四象限变频器的硬件特点,设计了相应的变频器控制程序,两台变频器采用主／从控制方法,对左／右牵引电机进行一拖一控制,实现了牵引变频调速四象限运行．     

双接触面直线驻波超声电机振子的动力学模型与实验分析

提出了一种直线型驻波超声电机振子,该振子通过改变振子激振频率,利用双面驱动,可以实现双向直线运动。推导出超声电机振子运动的动力学模型的解析式,对振子工作模态和工作频率进行实验分析并对理论分析结果与样机的实验结果进行了比较。     

贴片式纵弯复合激励圆筒超声电机

为了有效提高贴片式环形行波超声电机的机械输出性能,利于超声电机的小型化和微型化,研制了一种贴片式纵弯复合激励圆筒超声电机,电机利用d33工作模式和d31工作模式,由单臂变幅杆和一个环形换能器构成,且变幅杆和换能器采用一体结构．在对电机的工作原理进行分析的基础上,利用ANSYS软件完成了电机的设计和仿真,实现了两个振动模态的特征频率简并,并采用多普勒激光测振仪对样机进行了振动测试,测试结果与仿真结果基本一致．样机的机械输出特性测试表明,样机的最大转速为268r／rain,最大输出力矩为1．1N·m．     

双振子自走型直线超声电机的研究

设计了一种双振子自走型直线超声电机,电机的定子由2个同轴的对称布置的弯曲摇头型振子和中部带细颈的柔性振动块组成.2个振子的弯曲振动会激励出中间振动块的摇头振动,使驱动头上的质点产生椭圆运动轨迹,与导轨摩擦接触产生自走直线运动.测量得到定子上振动块的局部弯曲共振频率为20 792Hz,定子的弯曲共振频率约为40 420Hz.仿真发现,以振动块的局部弯曲共振模态作为工作模态能够得到更大的振幅.实验结果表明,在该模态频率下,电机可以提供较大的驱动速度,发热很少,较长时间工作仍旧稳定可靠,故被选作工作模态.在40 420Hz附近电机能够驱动,但是振子发热严重,不易稳定工作.当两相驱动信号的频率为20.8kHz、相位差为90°、驱动信号电压的峰峰值为138V时,电机的驱动速度达到598mm/s,电机的最大驱动力达到1.94N.     

复合型USM压电扭振子设计及其特性分析

介绍利用国产压电材料设计纵扭复合型超声波电机(USM)压电扭振子的理论和制造工艺,主要内容包括:压电材料的选取,压电扭振子的结构,根据等效电路推导出电机扭转振动模式的谐振频率方程,以及扭振子尺寸计算公式;根据实验总结了压电扭振子的制造工艺、黏接及其注意问题.并利用阻抗频谱分析仪测试了按上述理论设计的压电扭振子的频率特性.结果表明:设计理论、黏接剂的选择以及加工方法是合理可行的.据此研制的样机最大输出力矩已达10 Nm以上.     

芯片键合纵弯复合超声换能器的设计与试验

为了解决当前采用一维纵向超声加载模式进行芯片键合时造成结合面不充分的问题,设计纵弯复合超声能量加载模式的压电超声换能器,实现轴向纵振和水平弯振复合的超声振动代替传统单一的轴向振动. 采用ANSYS软件,对换能器有限元模型进行模态分析和谐响应分析,得到换能器纵振和弯振模态的谐振频率及振型. 通过调节换能器结构尺寸,实现纵振与弯振模态的简并. 采用阻抗分析仪对样机的频率和阻抗进行测试,使用激光多普勒测振仪测试换能器的纵振与弯振幅值,测试结果与有限元仿真计算结果一致,发现纵向与弯曲振幅均随着驱动电压的增加呈近似线性上升趋势, 证明设计的压电换能器实现了纵弯复合振动.     

驾驶威胁感知评估方法

为评估驾驶员所处交通态势的威胁感受,基于其主观感受性驾驶行为特征提出了一种量化评估方法。选取横向和纵向上的相对速度、间距以及轨迹交叉角5项驾驶行为特征作为态势因子,以预期避碰点与危险源的距离来测度威胁主观感受。采用统计学方法结合驾驶员直观威胁感受,给出各因子分级化隶属函数构造方法。同时结合模糊推理原理,析取威胁评估规则并建立威胁评估模型。最后结合算例验证了本文方法的实用性与有效性。     

A novel traveling wave ultrasonic motor using a bar shaped transducer

A novel traveling wave ultrasonic motor was proposed. The structure of the motor is rather simple and different from the conventional traveling wave ultrasonic motors. Its production processes are very convenient. It is composed of a stator constituted with a ring and a bar shaped transducer and two cone shaped rotors. The rotors were pressed on inner surface of the ring by means of a pre-pressure system. The bar shaped transducer has a sand- wich-like configuration,where two sets of piezoelectric element are bolted. One set excites a longitudinal vibration of the bar, and the other set excites a flexural vibration of the bar. The ring＇s traveling wave excited with the longitudinal vibration and the bending vibration of the bar transducer was simulated with FEM （finite element method）. The prototype of the motor was made and investigated experimentally for its performance. Its maximum torque and rotating speed are 0.25 N · m and 50 r/min, respectively.     

真空度和温度对超声马达特性的影响

超声马达是一种适合宇航需要的新型驱动器,但是,在非常态下的特性缺乏系统研究.为此,选择了两种工程塑料作为超声马达的转子摩擦材料,利用真空试验机和与其相配的超声马达模拟试验台,采用间断和连续试验两种方式,研究了真空度、温度和预紧力等参数对行波型超声马达驱动特性的影响,得出温度升高,马达转速降低;真空度增加,马达转速降低,堵转力矩增大的结论,并分析了非常态下超声马达驱动特性变化规律.证实了超声马达在真空和较高温度的特殊环境中也可以正常工作,为超声马达在宇航方面应用提供了参考.     

基于低通滤波的新型超声波电机控制系统

为了实现超声波电机驱动电压频率与幅值、相位间的完全解耦,充分利用传统控制器的易调节和基于直接数字合成（DDS）技术的高精度特性.通过分析驱动电压参数要求,确定合理的低通滤波器参数设计方法.对方波进行滤波产生正弦信号,经过功率放大后直接驱动超声波电机.设计一种驱动电压参数精密解耦的超声波电机控制系统.通过调节方波的频率、相位和占空比来精确控制驱动电压的相应电参数.采用该方法实现了能够同时独立控制2台超声波电机的控制系统,相位和幅值精度达10 bits以上,频率分辨率为16 Hz.     

新型换能器式大力矩超声波马达的研究

提出了一种新型换能器式大扭矩超声波马达，以四套频率特性一致的夹芯式压电超声波换能器在一弹性体圆环中激励弯曲行波，打破了传统行波超声波马达压电换能方式的功率限制，从而可以大幅度提高超声波马达的输出功率，从理论上研究了这种马达的工作原理及设计方法，由实验验证了这种原理超声波马达的可行性。     

A new hybrid piezoelectric ultrasonic motor with two stators

A new hybrid piezoelectric ultrasonic motor, which consists of one rotor and two stators, was proposed in this paper. In order to match the resonance frequencies of longitudinal vibration and torsional vibration excited in the stators, a symmetrical structure was adopted in design of the motor. A so-called mass matching method, namely adding two rings to the outside circumference of the two stators respectively, was used to adjust the resonance frequencies of these two vibrations. A finite element model was developed using ANSYS software for the purpose of analyzing the resonance frequencies of longitudinal vibration and torsional vibration as well as the function of the adjusting rings. The results show that the resonance frequency of torsional vibration varies with the position of the ring, but the resonance frequency of longitudinal vibration changes little. By means of adjusting the mass and the position of the rings, the first order resonance frequency of longitudinal vibration is coincided with that of torsional vibration and the value is 20.75kHz. An experimental prototype motor was fabricated according to the analytical results and its performance is in agreement with the theoretical predictions. The speed of motor reaches the maximum 92r/min at the working frequency 19.0kHz.     

Location estimation of autonomous driving robot and 3D tunnel mapping in underground mines using pattern matched LiDAR sequential images

In this study, a machine vision-based pattern matching technique was applied to estimate the location of an autonomous driving robot and perform 3D tunnel mapping in an underground mine environment. The autonomous driving robot continuously detects the wall of the tunnel in the horizontal direction using the light detection and ranging(Li DAR) sensor and performs pattern matching by recognizing the shape of the tunnel wall. The proposed method was designed to measure the heading of the robot by fusion with the inertial measurement units sensor according to the pattern matching accuracy; it is combined with the encoder sensor to estimate the location of the robot. In addition, when the robot is driving, the vertical direction of the underground mine is scanned through the vertical Li DAR sensor and stacked to create a 3D map of the underground mine. The performance of the proposed method was superior to that of previous studies; the mean absolute error achieved was 0.08 m for the X-Y axes. A root mean square error of 0.05 m~2 was achieved by comparing the tunnel section maps that were created by the autonomous driving robot to those of manual surveying.     

超声测距换能器及收发电路的研究

目的　利用超声波进行近距离测试的研究 .方法　根据压电晶体的正逆压电效应 ,发射和接收超声波 ,介绍了换能器的设计结构及收发电路 .结果与结论　超声换能器配以适当的收发电路 ,可以使超声能量的定向传输 ,并按预期目的接收反射波 ,实现超声遥控、测距、防盗等检测功能     

U形直线超声电机结构设计

针对直线超声电机的小型化问题,提出一种新型U形直线超声电机,该电机由U形定子和导轨组成,压电陶瓷片采用粘贴的方式固定在定子上.研究了电机的激振方式与位置,设计并加工了直线超声电机样机和测试装置.将柔性铰链结构应用到直线超声电机夹持中.通过实验确定了电机的最佳工作频率、预压力.研究了输出力和空载速度随工作频率、预压力和电压的变化规律.实验表明,电机在电压值400 Vpp,预压力25N条件下,最大空载速度470 mm/s,最大输出力9N,定子质量25 g,推重比达36;柔性夹持能提高电机的模态一致性和效率,同时简化了电机结构.该研究为电机小型化发展奠定基础.     

变轨迹等厚筛振动方向角的计算及实验验证

提出了一种单轴变轨迹等厚筛分方法,建立了单轴变轨迹等厚筛的动力学模型.基于单轴变轨迹等厚筛的运动特性,提出了振动方向角的几何定义方法,得到了该振动筛振动方向角的计算模型.通过振动信号分析系统获取了振动筛筛箱各点的水平和垂直两个方向上的振动强度以及互功率谱相位,得到了振动方向角的理论值.结果表明,利用该方法得到的计算结果与利用传统的丽萨如(Lissajous)图法求得的结果最大相对误差仅为8.50%,从而验证了振动方向角计算模型的正确性.     

超声电机及其驱动控制技术

综述了近二十年来超声电机及其驱动控制技术的发展 ,介绍了超声电机的特点和新的结构形式 为超声电机及其驱动控制技术在我国的研究提出了自己的建议     

二自由度超声波电机位姿检测与控制

为了探索多自由度超声波电机在微型机器人等控制领域的应用,提出电机的位姿检测与控制方法.以基于三定子的二自由度球形超声波电机为研究对象,以定子角速度的极小范数为优化目标,结合角速度矢量合成原理和电机的相位差调速方式,建立电机的前馈模型;提出基于机械鼠标原理的位姿检测机构,反馈球转子的姿态量,并结合PID分段斜率比较的控制策略实现电机位姿控制.测试结果表明,电机闭环轨迹控制的误差率为13%,位姿检测与控制的效果较好,为二自由度球形超声波电机的推广打下扎实的基础.