A flexible shaft based travelling wave ultrasonic motor with high-precision positioning characteristics

To improve positioning precision of the traveling wave ultrasonic motor (USM), a flexible shaft was used, and the structure was redesigned to reduce the fluctuations of step angles and speed. The start and stop response performances of the motor were analyzed theoretically and tested by a high-resolution test rig. The step characteristics were calculated, which showed the minimum step angle is below 0.20″ under different torques. The positioning process included two modes: continuous mode and step mode. In continuous mode, the speed of the motor was controlled by PID control based on the tests of frequency-speed characteristic of the motor. In step mode, the step characteristics of the motor was tested under different load torques and applied different lengths of driving voltage to find the minimum of step angle. From the tests, the step angle increases rapidly with the periods of driving voltage and the single-step angle fluctuations of the motor with flexible shaft is much less than that of motor with normal shaft. Finally, the positioning performances of USM were tested. The results showed that the minimum positioning error of the motor with flexible shaft could achieve 0.37″ (1.79 μrad) and the time costed was below 1 s.     

火炮身管精密加工与在线检测技术研究

火炮身管是火炮的关键零部件,由于其长径比大、要求精度高,它的加工属于深孔精密加工范畴,而国内对此加工的生产水平落后,加工效率低、质量差。火炮身管药室高效精密数控镗床的设计制造满足药室加工多锥段、高精度要求,加工效率较传统工艺提高数倍。该设备能够实现多品种、小批量、高精度加工生产的需求。火炮身管缠度检测原理样机由炮膛爬行器、缠度测头和计算机控制与数据处理系统3部分构成,经检测可实现较低的测量误差。     

慢走丝线切割加工高精度小直径深孔的工艺研究

以某光学仪器镜筒中高精度小直径深孔的加工为对象,针对该零件特点及技术要求,分析了采用传统加工方法加工该零件存在的问题,并选择慢走丝线切割的方法加工该零件。在研究慢走丝线切割加工特点及工艺规律的基础上,通过大量试验研究,总结出一套有效的工艺措施及加工参数组合。经三坐标测量仪检测,表明加工效果理想。该加工方法及参数可以广泛运用到其他类似材料和结构的零件中,为高精度小直径深孔的加工开辟出一条新的思路。     

多种物探方法在内蒙古水泉沟地区找矿效果分析

研究区在探矿初期采用多种地球物理相结合的方法,开展了1∶1万高精高磁法测量、1∶1万激电中梯测量,在激电异常较好地段,开展了激电测深测量。通过对异常的解译、筛选,在异常套合较好、异常强度高的地段,地表布设槽探揭露,深部钻孔进行查证,大致了解了区内地质背景、地层岩性、岩体分布、构造格架特征和异常与矿产的关系,发现了数条铜铅锌矿体,说明异常与多金属矿化有关,证明了勘查区具有一定的找矿潜力。同时说明这种综合物探方法在该区寻找多金属矿效果显著。     

高精度四辊可逆冷带轧机的设计特点

简要介绍了从国外引进的６５０ｍｍ高精度四辊可逆冷带轧机的设计和组成。该轧机配备有必要的控制手段，以满足各种工艺要求，同时它还体现了经济实用的设计特点。其核心的设计思想就是为了能够经济地生产出高质量的带材，这对于国内中小型冷轧机的设计特别具有参考意义。     

高精密步进放大器在频谱分析仪中的应用研究(下)

该文首先介绍了高精密步进放大器的工作原理,然后对其在频谱分析仪的增益调节、幅度校准过程、平坦度补偿中的应用进行了详细的分析.     

基于CAN总线的新型智能阀门电动执行器

介绍了基于CAN总线的智能阀门电动执行器，其具有精度高、可靠性好的特点，可对阀门工作特性进行补偿。基于现场总线的控制方式可使执行器单元纳入整个控制网络中，便于智能化控制系统的集成。     

高精度非回转类液压元件精密加工技术研究

针对液压系统中非回转类阀、泵等液压元件的高精度特点,以上阀体零件为例,采用模态分析、动态切削力分析及瞬态响应分析等方法,对上阀体加工过程的变形规律及切削力状况进行了分析,研究了不同装夹方式对零件加工质量的影响。通过改进上阀体夹具设计方案,设计制造了高精度夹具,并以此消除了加工过程产生的不平衡力和不平衡力矩,解决了上阀体加工过程中的变形及振动问题,最终实现了此类高精度非回转类液压元件的精密制造。     

光学透镜的高精度定心无变形胶合技术

介绍了一种光学透镜胶合的高精度定心和面形无变形技术的原理、方法及工艺特点。     

Cost-efficient drilling using industrial robots with high-bandwidth force feedback

Here we present a method for high-precision drilling using an industrial robot with high-bandwidth force feedback, which is used for building up pressure to clamp-up an end-effector to the work-piece surface prior to drilling. The focus is to eliminate the sliding movement (skating) of the end-effector during the clamp-up of the end-effector to the work-piece surface, an undesired effect that is due to the comparatively low mechanical stiffness of typical serial industrial robots. This compliance also makes the robot deflect due to the cutting forces, resulting in poor hole position accuracy and to some extent in poor hole quality. Recently, functionality for high-bandwidth force control has found its way into industrial robot control systems. This could potentially open up the possibility for robotic drilling systems with improved performance, using only standard systems without excessive extra hardware and calibration techniques. Instead of automation with expensive fixtures and precise machinery, our approach was to make use of standard low-cost robot equipment in combination with sensor feedback. The resulting sliding suppression control results in greatly improved hole positioning and quality. The conceptual idea behind the force control is useful also in many other robotic applications requiring external sensor feedback control.