21世纪超声电机技术展望

首先回顾了超声电机技术在２０世纪国内外发展的情况，叙述了南京航空航天大学超声电机研究中心在超声电机研究方面的进展，其次预计了在２１世纪国内外市场对超声电机的需求，特别列举了超声电机技术将对我国国防和国民经济各部门起到的重大作用，最后论述了２１世纪超声电机技术的研究人员所面临的任务，针对我国在超声电机理论、实验和材料研究工作的现状，提出了２１世纪为发展我国超声电机技术急需解决的若干重要课题。     

超声电机在南京航空航天大学的研究与发展

介绍了南京航空航天大学超声电机研究概况；叙述了南京航空航天大学超声电机研究中心在超声电机技术方面所取得的研究进展和成果；列举了该中心在研究超声电机中所解决的若干关键技术；总结了取得这些进展和成果的主要原因和经验。最后，提出了本中心当前的研究任务，展望了超声电机未来的发展。     

光学精密航天仪器运载中的环境振动试验研究

环境振动试验是鉴定结构或仪器设备能否承受预计的振动环境，保证在实际环境下结构的完整性或仪器设备性能、精度不降低的一种必要手段。文中对光学精密航天仪器在运载中的振动问题进行了研究，分析了不同路面、不同车速条件下运载光学精密航天仪器的随机振动响应，实验测量了多点的加速度信号，并用信号分析仪进行了数据处理，获得了该机振动的参数，为光学精密航天仪器的防振、抑振提供了参考。     

超声电机技术的发展和应用

回顾了超声电机的发展和应用情况,叙述了超声电机的特点,总结了超声电机的分类方法,指出了超声电机技术的发展趋势。针对我国超声电机技术开发和研究现状,提出了我国超声电机产业化进程中亟待解决的一些关键问题。     

超声电机温升特性测试系统设计

针对超声电机温升特性测试的需要,设计了一套测试系统。测试系统包括铂电阻温度传感器、温度变送电路、MSP430单片机和PC机。测试系统采用LabVIEW作为上位机开发软件,通过RS232串行接口实现PC机与MSP430单片机的通讯。测试系统可实现电机温升数据的实时采集,可靠性高和实用性强。开展了针对某型航天用超声电机温升特性测试,获得了电机表面温升数据。试验证明,超声电机在-30～+50℃不同环境温度下,温升基本稳定,运行温度在允许范围内,满足航天设备的特殊性。     

日本超声电机的产业化,应用和发展

叙述了日本超声电机的产业化现状、应用研究和新型超声电机的发展情况。大量实例充分证明：日本超声电机技术处于世界的前列。在这个技术领域,我国与日本尚有很大的差距。文中分析了产生这个差距的原因,并提出了迅速地缩小这个差距的有效途径。最后总结出我国必须努力跟上世界超声电机技术的发展步伐,并且要在短期内达到与日本超声电机技术相同的水平的结论。     

超声电机寿命测试的方法研究

介绍了超声电机寿命测试的原理和试验方法。利用计算机并行接口实现了对超声电机转速、运转周数和运转时间等数据的实时采集和对超声电机运转、停止的控制。该方法成功地应用于南京航空航天大学TRUM系列行波型超声电机的寿命试验。经测试，TRUM系列行波型超声电机的使用寿命达到了300h。     

直线型超声电机的发展及应用

概述了直线型超声电机的运动机理，综述了国内外直线型超声电机的发展及其研究现状，列举了一些典型例子，总结了直线型超声电机的应用领域。针对现在直线型超声电机在理论、实验、材料等方面存在的问题，指出了在其研究开发中需要解决的关键技术。     

旋转型超声电机伺服特性探讨

旋转型超声电机机械特性不能全面反映它的运行特性。为了更好地将旋转型超声电机应用于伺服系统,有必要对旋转型超声电机的运行特性进行全面的研究。为此,笔者搭建了一个测量旋转型超声电机运行特性试验系统,以江苏丰科超声电机科技有限公司早期生产的TRUM-60型超声电机为试件,在固定输出频率和固定输出电压两种情况下,得到TRUM-60型超声电机的机械特性曲线族和调节特性曲线族。实验结果表明,该型超声电机的机械特性和调节特性均为单值函数,它们都满足伺服系统对伺服电机运行特性的要求。因此,TRUM-60型超声电机能够作为伺服电机而使用。     

超声电机在真空高低温环境下的驱动性能

为了对行波型旋转超声电机在同向负载下的驱动性能进行测试,并研究真空高低温环境对电机驱动性能产生的影响,设计并搭建了一套测试系统,从而实现了对超声电机转速和负载扭矩的测量,并对测试设备采取了控温措施,保证设备在高低温环境下的测试精度不会下降。试验结果表明,利用该系统可获得有效测试数据,得到超声电机在真空高低温环境下的驱动性能曲线,并将其与常温常压环境下的曲线进行比对,可以看到真空高低温环境对超声电机在同向负载下的驱动性能产生了一定影响。本研究成果为超声电机在航天领域的广泛应用奠定了可靠基础。     

超声电机的低速检测与分析系统

利用虚拟仪器技术构建超声电机低速测试和分析系统,旨在用LabVIEW软件实现对超声电机低速检测与电参量的特征分析,设计测速方法、滤波和拟合处理来解决低速测试的难点。文章从系统结构、软件设计方法和试验测试几个方面进行详细论述。经试验证明,该系统简单、实用,实现可靠的低速测试与分析。     

Fabrication of stepped hole on zirconia bioceramics by ultrasonic machining

Zirconia (ZrO₂) is a highly biocompatible ceramic material providing fracture strength properties that allow application as dental implants in biomedical engineering. In this present research, experimental analysis has been made for generating stepped hole on zirconia bioceramics with desired quality using ultrasonic machining (USM) process. Four independent controllable input process parameters are abrasive grain diameter, power rating, concentration of abrasive slurry, and tool feed rate. Material removal rate (MRR), overcut of larger diameter (OLD) hole, and overcut of smaller diameter (OSD) hole of stepped hole are considered as the responses. Response surface methodology (RSM) is used for modeling the performance of USM process. Multiobjective optimization has been performed to maximize the MRR and minimize the OLD hole and OSD hole of stepped holes. All the responses are improved at the optimal parametric condition and verified by confirmation test. The present research opens up the application feasibility of USM process for stepped hole generation on bioceramics and its utilization in biomedical field.     

超声加工韧性材料的材料去除率模型

超声加工是现代超声技术的重要组成部分,在不同类型材料的加工领域都有着广泛的应用.由于在超声加工中脆性材料和韧性材料的材料去除机理完全不同,因此有必要建立韧性材料的材料去除率的数学模型.本文基于接触力学的理论建立了一个新的超声加工韧性材料的材料去除率模型.通过与引用的实验结果进行比较,发现该模型的理论预测值与实验结果十分...     

On the Application of Six-Port Technology (SPT) in Ultrasonic Imaging for Medical Diagnosis

In this paper, an introduction of six-port technology to ultrasonic imaging for medical diagnosis is presented for the first time. Calculations are made to explore the possibilities and advantages of this application. Analysis shows that the introduction of six-port technology for medical ultrasonic imaging to detect the phase information of the reflected signal will improve the measurement accuracy and simplify the instrumentation of imaging technologies used in medical diagnosis.     

Analysis on profile accuracy for ultrasonic machining of alumina ceramics

Ultrasonic machining (USM) is a mechanical material removal process which has great potential for machining hard and brittle materials such as ceramics, semiconductors, glasses, etc. The accuracy of the job profile generated by USM can be improved by optimal control of the process parameters. This paper presents the study on the influences of ultrasonic machining process parameters such as abrasive grit size, slurry concentration, power rating, tool feed rate and slurry flow rate on generated hexagonal hole profile. The angular deviations at corner angles, dimensional deviations across flat surfaces and dimensional deviation across corners of the hexagonal hole profile have been studied. Based on experimental results, the influences of abrasive grit size, slurry concentration, power rating and tool feed rate were analysed. From the analysis of parametric influences based on various test results, the best parametric combination was found as grit number of 600, slurry concentration of 30 %, power rating of 50 % and feed rate of 1.08 mm/min for achieving better profile accuracy during machining of Al₂O₃ ceramics. The experimental investigations carried out for determining the influence of USM process parameters will provide effective guideline to select parametric settings for achieving desired job profile accuracy on non-circular holes during ultrasonic drilling of alumina.     

Chipping minimization in drilling ceramic materials with rotary ultrasonic machining

Ultrasonic machining (USM) has been considered as a new cutting technology that does not rely on the conductance of the workpiece. USM presents no heating or electrochemical effects, with low surface damage and small residual stresses on workpiece material, such as glass, ceramics, and others; therefore, it is used to drill microholes in brittle materials. However, this process is very slow and tool wear dependent, so the entire process has low efficiency. Therefore, to increase microhole drilling productivity or hole quality, rotary ultrasonic machining (RUM) is considered as a strong alternative to USM. RUM, which presents ultrasonic axial vibration with tool rotation, is an effective solution for improving cutting speed, precision, tool wear, and other machining responses beyond those of the USM. This study aims to reduce the microchipping or cracking at the exit of the hole, which inevitably occurs when brittle materials are drilled, with consideration of tool wear. To this end, response surface analysis and desirability functions are used for experimental optimization. The experimental results showed that the proposed RUM scheme is suitable for microhole drilling.     

Frequency characteristics of non-contact ultrasonic motor with motion error correction

The purpose of this research is to achieve real time motion error correction of the rotor in a non-contact ultrasonic motor (non-contact USM). The rotor is installed in a cylindrical stator with a small gap and designed so that it has a resonant frequency of 22.2 kHz, the 8th flexural mode of vibration. The multi-layered piezoelectric actuators excite the flexural wave traveling in the circumference direction. The ultrasonic vibration produces a sound field that levitates the rotor, and the traveling wave induces a near-boundary streaming to rotate the rotor by viscous force. In this paper, we describe an experimental test of the performance of a non-contact USM. When the flexural vibration amplitude was 0.3 μm, the rotational speed was 4 rpm. The rotational speed and starting torque was proportional to the vibration amplitude. The starting performance to attain rotational speed had a time constant of 2 s for several different amplitudes hence the rotational torque is independent of the rotational speed and the resistance force on the rotor is governed by viscosity. In addition, the non-contact USM has the capability of contact-free micro positioning of the rotor by controlling the deformation of the piezoelectric actuators. The PI controller was constructed to correct the detected motion error of the rotor in the radial direction. As a consequence, a motion error of 0.8 μm for one rotor revolution was reduced to 0.1 μm.     

超声电机的定子振动测试与分析

超声电机（Ultrasonic Motor,简称USM）是近二十年发展起来的一种全新原理的电机。基于虚拟仪器、硬件传感器及计算机搭建了超声电机的测试平台,通过数字滤波等处理和频域分析,实现对超声电机的重要元件（定子）振动信号的检测与分析。从系统硬件选择、软件设计及试验测试几个方面进行了详细论述。经试验证明,该系统结构简单,可以稳定运行。     

超声电机基于模糊-PI技术的位置控制

通过超声电机的工作原理分析,选定驱动频率作为其速度控制变量。将模糊-PI技术用于超声电机的控制。其中,PI控制在于减小稳态误差,模糊控制旨在实现电机快速定位。为设计模糊控制器,选定位置偏差和转速为其输入变量、驱动频率为其输出变量,并分别以三角、高斯型函数定义了输入、输出变量的模糊子集;根据电机手动操作经验,建立了超声电机模糊控制规则;基于GO-400控制卡构建控制系统,实现了电机控制;实验结果表明模糊-PI技术可实现超声电机快速高精度(偏差≤0.17°)定位。     

Some aspects of the design of a barometric capacitance capsule

This paper is primarily concerned with the analysis of a barometric capacitance capsule for air data systems, flight test equipment, and special-purpose test instrumentation.