激光干涉接触式轴承表面轮廓综合测量

介绍了一种可用于测量滚动轴承曲面形貌的表面轮廓综合测量仪，在测量中应使杠杆处于平衡位置，以减小测量力；用衍射光栅干涉位移传感器作为位移测量系统代替传统的电感位移传感器；z向工作台采用粗、细两级驱动定位，利用步进电机驱动斜面导轨进行粗级定位以扩大量程，压电陶瓷做微位移驱动实现精密定位以提高测量精度。论述了该仪器的整体结构、测量原理、工作台的定位控制以及衍射光栅干涉信号的处理。     

扫描隧道显微镜微位移工作台的 神经网络PID控制方法研究

提出了一种基于神经网络理论的微位移工作台控制方案。该工作台以压电陶瓷作为微位移驱动元件,对伺服电机大位移进行位移补偿。分析了压电陶瓷微位移驱动器的原理,建立了工作台的数学模型。神经网络PID控制器对工作台进行闭环控制,利用BP网络的自学习和自适应能力,实时调整网络加权值,改变PID控制器的控制系数,减小工作台的位移误差。采用专用的压电陶瓷驱动电源对工作台的位移进行了实验,相对于常规PID控制器,微位移为11.41 μm时的响应时间从1.5 s缩短到1 s,稳态位移误差从3.13％减小到1.05％,工作台的稳定性和定位精度得以提高,改善了扫描隧道显微镜的工作性能。     

大行程纳米级共平面二维精密工作台的研究

研究开发了一种大行程纳米级共运动平面二维工作台,该工作台采用宏/微两级驱动,宏驱动由滑动导轨、直流无刷电机、精密丝杠组成,微驱动由平行平板柔性铰链和压电陶瓷组成。对平行平板柔性铰链进行了力学分析,并推导计算了其固有频率。工作台移动范围为50mm×50mm,可实现5nm的运动分辨率。工作台在X、Y方向分别装有衍射光栅计量系统,宏微位移由同一套衍射光栅计量系统进行位移计量,计量系统的有效位移分辨率为2.3nm。该二维工作台具有通用化和小型化特点,可以用于微纳米表面的测量与微机电系统的控制与加工。     

基于PSD的微轮廓测量仪及其控制系统研究

涉及到一种基于PSD原理的高精度三维轮廓测量仪.X-Y工作台采用了宏驱动与微驱动相结合的工作方式.宏工作台采用步进电机驱动,进给精度达1微米;微工作台采用精密压电陶瓷驱动,进给精度最小可达1纳米.这样,使得X-Y测量步距达到1纳米的条件下,测量物件的尺寸范围可以扩大为20mm×20mm,不仅适合微小构件的精密测量,而且适合较大器件的精密测量,且X-Y方向的位移测量精度最小可达1纳米.Z方向位移传感器采用激光单点位置探测器PSD,Z轴方向的位移测量精度达10纳米.对微轮廓测量仪的控制系统作了程序设计,得到了较满意的效果.     

压电陶瓷驱动的铰链放大式微动工作台研究

研制了一种新的压电陶瓷驱动的铰链放大式微动工作台。介绍了该微动工作台的基本原理,利用原子力显微镜技术测定了压电陶瓷与铰链放大臂的微位移和微振动,确定了铰链机构的放大比及微动工作台的时间响应频率。结果表明,该微动工作台能以0.5μm～5μm的步长实现平稳的微位移,最大速度达到250μm/s。     

压电驱动超精密定位工作台的研究

研究、设计了一种压电式超精密微定位工作台。此工作台在伺服电机驱动的滚珠丝杠进给系统的基础上，采用压电陶瓷作为微位移驱动器，柔性铰链为导向机构，对工作台运动位置自动补偿，实现了超精密定位。文中对柔性铰链机构进行了合理的设计，以实现长行程超精密定位。压电陶瓷配合柔性铰链使用使工作台定位精度达到0．01μm，可满足精密、超精密加工需要。     

基于叠片式柔性铰链和压电陶瓷电动机的大行程直线驱动导轨设计

提出了一种叠片式柔性铰链导轨工作台,可以在保持柔性铰链微位移工作台高直线度的前提下,大幅度提高行程,同时还保持了柔性铰链微位移工作台无机械爬行现象的优点。采用压电陶瓷电动机作为叠片式柔性铰链工作台的驱动器,压电陶瓷电动机应用超声波驻波或行波驱动,具有定位精度高、行程大、频响高等优点,驱动分辨率可达20nm以下。     

新型二自由度微动工作台的设计和有限元分析

介绍了一种无耦合运动的二自由度微位移工作台,该结构便于微位移工作台尺寸的小型化。文中推导了工作台载荷与位移的关系式;采用有限元的方法对工作台三维模型进行仿真计算,得到该工作台对应于载荷的位移和应力值。有限元计算的结果和推导公式的计算结果相吻合。     

闭环控制的微动工作台设计

介绍了一种以弹性导轨为支承的平面三自由度微动工作台的原理、结构、设计计算方法及闭环控制的基本原理。采用电致伸缩微位移器驱动弹性导轨 ,电涡流传感器测量工作台的微位移 ,能可靠地保证微动工作台的运动精度 ,并使其结构简单、紧凑。     

三自由度微定位工作台的设计与特性分析

设计一种用于平面磨削主动控制的新型数控微定位工作台。该工作台采用三个安装在底座上的压电陶瓷 (PZT)驱动器驱动动平台 ,三个圆形凹槽弹性铰链构成的弹性环节实现对压电陶瓷驱动器的预紧。为了提高定位精度采用三个高精度的电容式位移传感器用来测量动平台的输出 ,从而形成闭环控制系统。采用有限元分析软件ANSYS对微定位工作台的静、动态特性进行了数值分析。     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

RLS and LMS blind adaptive multi-user detection method and comparison in acoustic communication

RLS and LMS blind adaptive multi-user detection algorithm and multi-user detector was proposed to solve the problem of multi-user signal detection problem encountered in underwater acoustic communication networks.In simulation analysis,RLS and the LMS blind adaptive multi-user detector were designed and tested for synchronous and asynchronous multi-user communication process.The results of SIR comparison and MMSE comparison show that,both of the two methods can realize blind adaptive detection when any user change in multi-user communication,during this process,the training communication sequences are not needed.The RLS algorithm has about 5 dB higher in SIR compared with LMS algorithm,and the convergence velocity of RLS algorithm is also higher than LMS algorithm when the communication users change.RLS algorithm has better ability in multi-user detection than that of LMS algorithm,and it has great attraction and guiding significance for solving the problem of multiple access interference(MAI) in multi-user communication.     

Robust Impedance Control of Robots Using an Adaptive Interaction Force Observer

For robot interaction control,the interaction force between the robot and the manipulated object or environment should be monitored.Impedance control is a type ...     

Research on key techniques of expendable conductivity temperature depth measuring system

This paper analysis the developing of expendable conductivity temperature depth measuring system(XCTD)and introduce its principle of measuring about temperature,salinity and depth of ocean.Some key techniques are put forward.According to the real needs of XCTD,conductivity sensor with high sensitivity is designed by principle of electromagnetic induce,the ocean conductivity from induced electromotive force has been calculated.Adding temperature correction circuit would help to reduce error of conductivity measurement because of sharply changing temperature.Advanced temperature measuring circuit of high precision and the constant current source is used to weaken effect of self-heating of resistance and fluctuation of the source.On respect of remote data transmission,LVDS is a good choice for the purpose of guarantee the quality of data transmitted and the transmission distance is reaching to thousand meters in the seawater.Modular programming method is also brought into this research aimed at improve the stability,reliability and maintainability of the whole measuring system.In February,2015,the trials in South China Sea demonstrate that the developed XCTD realize effective measurement at a speed of 6 knots and detection depth at 800 m.The consistency coefficient of the acquired data is greater than 0.99 and the success rate of probe launching is above 90%.     

CHARACTERISTCS OF FLUID FILM IN OPTIMIZED SPIRAL GROOVE MECHANICAL SEAL

In order to investigate the sealing performance variation resulted from the thermal deformation of the end faces, the equations to calculate the fluid film pressure distribution, the bearing force and the leakage rate are derived, for the fluid film both in parallel gap and in wedgy gap. The geometrical parameters of the sealing members are optimized by means of heat transfer analysis and complex method. The analysis results indicate that the shallow spiral grooves can generate hydrodynamic pressure while the rotating ring rotates and the bearing force of the fluid film in spiral groove end faces is much larger than that in the flat end faces. The deformation increases the bearing force of the fluid film in flat end faces, but it decreases the hydrodynamic pressure of the fluid film in spiral groove end faces. The gap dimensions which determine the characteristics of the fluid film is obtained by coupling analysis of the frictional heat and the thermal deformation in consideration of the equilibrium condition of the bearing force and the closing force. For different gap dimensions, the relationship between the closing force and the leakage rate is also investigated, based on which the leakage rate can be controlled by adjusting the closing force.     

OPTIMIZATION METHOD ON IMPELLER MERIDIONAL CONTOUR AND 3D BLADE

An optimization method for 3D blade and meridional contour of centrifugal or mixed-flow impeller based on the 3D viscous computational fluid dynamics (CFD) analysis is proposed. The blade is indirectly parameterized using the angular momentum and calculated by inverse design method. The design variables are separated into two categories: the meridional contour design variables and the blade design variables. Firstly, only the blade is optimized using genetic algorithm with the meridional contour remained constant. The artificial neural network (ANN) techniques with the training sample data schemed according to design of experiment theory are adopted to construct the response relation between the blade design variables and the impeller performance. Then, based on the ANN approximated relation between the meridional contour design variables and impeller performance, the meridional contour is optimized. Fewer design variables and less calculation effort is required in this method that may be widely used in the optimization of three-dimension impellers. An optimized impeller in a mixed-flow pump, where the head and the efficiency are enhanced by 12.9% and 4.5% respectively, confirms the validity of this newly proposed method.     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...