四轴球体研磨机超精密研磨的机理及试验

根据四轴球体研磨机弹簧加压和高点切削作用,运用创成性加工原理和误差均匀化效应对四轴球体研磨机能实现球体超精密研磨的机理作了深入地探讨,解释了该机“以粗干精”的特性,提出了实现球体超精密研磨的基本工艺方法.并以此作指导,对小型静电陀螺仪球形转子的研磨进行了验证.     

4轴球体研磨机研磨圆度趋小化机理分析

从建立４ 轴球体研磨机弹簧加压球体研磨的力学模型入手,运用高点切削作用机制和误差趋小化效应,解释了球体圆度误差趋小化机理并得到了试验验证。由４ 研具对球面研磨的包络原理,提出了未研磨包络区是产生残存圆度误差（圆度误差趋小值）的主要因素,并用试验结果证明了研磨压力、研磨速度、磨料粒度是决定球体研磨圆度趋小化进程的主要工艺参数。     

四轴球体研磨机球体研磨圆度误差均匀化效应的机理分析

从建立四轴球体研磨机弹簧加压球体研磨的力学模型入手,运用高点切削作用机制和误差均匀化效应,解释了球体圆度误差趋小化研磨机理。根据四研具对球面研磨的包络原理,提出了未包络研磨区是产生残存圆度误差的主要因素,并探讨了未包络研磨区、四研具初始压力误差、研具磨损不均匀性产生的原因和对研磨残存圆度误差的影响及解决措施。为进一步改善研磨工艺和提高球体研磨圆度提供了参考。     

金属球体密封面研磨工艺的研究

介绍了金属密封球体研磨加工的研磨特点和类别,给出了球体研磨机的结构原理和操作特性。分析了球体研磨过程中磨料粒度、磨料浓度、研磨速度及其单位压力与研磨效率和加工表面粗糙度的关系。     

四轴球体研磨机的研磨均匀性

为了分析四轴球体研磨机的研磨去除量,建立了四轴球体加工时的力学模型,分析了四研具在空间位置的几何关系和加工球与四研具之间的运动关系,给出了研具上的一点相对加工球的速度矢量.在Preston方程基础上,建立了四轴球体研磨机实现球面均匀研磨的分析模型,并应用Matlab软件对单位时间去除量进行仿真分析.以离散化的旋转角为变量,间距取0.01°,采用方差为指标评价研磨去除量的均匀性.分析结果显示,研磨去除量与角速度成线性关系,研具改变转向的相位角为90°时方差最小,研磨过程中不断改变四个研具的旋转方向,可获得好的研磨均匀性.实验结果表明,四轴球体研磨机是高精密加工非常有效的方法.     

四轴球体研磨机的运动学分析

通过对四轴球体研磨机的位置、速度、球面研磨成原理进行了分析,为该机设计时主要技术参数的确定提供了设计规范。尤其是利用相对运动不变原理分析研具对球体研磨的成型过程,在揭示研具对球体研磨具有展成包络性的同时,建立了球面设计的计算公式,为该机的工艺和误差分析奠定了基础。     

高精密球体研磨方式的研究

本文论述了研磨原理及球体圆度误差趋小化研磨机理；对现有的各种研磨方式的研磨原理、研磨精度、研磨效率等进行了较为全面的比较。     

四轴球体研磨机实现球体均匀研磨的充分必要条件

根据四轴球体研磨机的球体研磨原理,由实现球体均匀研磨所需的压力和速度条件,对该机的结构参数和运动参数进行了解析和图解分析,建立了实现球体均匀研磨的充分必要条件。     

立式数控平面研磨机力/位控制方法及试验研究

针对平面研磨的加工特点及现实要求,提出了一种扭矩限制与定尺寸控制相结合的立式数控平面研磨机力/位控制方法。将压力控制等效为扭矩控制,通过理论分析和试验找出了Z轴电机输出扭矩与研磨压力之间的函数关系,在速度模式下通过限制电机输出扭矩实现了研磨压力的调节。同时,利用伺服电机速度模式下的扭矩限制有效避免了加工中出现压力过大灼伤加工面的情况。设计了定尺寸机构实现最终负载端外环位置检测,直接控制工件加工尺寸,避免了中间环节的误差。试验结果表明该力/位控制方法研磨效果良好,压力控制稳定性和定位精度均能够满足研磨加工的工艺要求。与传统立式研磨机的控制方法相比,该方法不仅提高了研磨质量,且省去了液压或气压机构,避免了停机人工测量,提高了加工效率。     

平面研磨机行星机构设计中若干问题的探讨

现代金属切削方法中加工精度及光洁度最高的方法应首推研磨加工。如长度尺寸的精度水平达±0.025μm、球体圆度达0.25μm、柱体圆度达0.1μm、光洁度达(?)14。之所以达到如此高的精度与研磨原理、研磨工艺及研磨剂有关之外,还与研磨机的设计密切相关。设计精良的研磨机应能保证工件的加工表面上各点均有相同或近似相同的切削条件,同时还要保证研具表面上各点有近似相同的磨损条件。     

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...     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

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。     

基于多目标非支配解提取法的电力系统无功优化

针对传统的电力系统多目标粒子群优化算法采用权重系数法将多目标转化为单目标,从而忽视了各目标函数间的竞争关系这一问题,提出将非支配解提取法运用到电力系统多目标无功优化中,并设定了一套提取规则,以电力系统中的有功网损、电压偏差和电压稳定裕度为目标,使目标在充分竞争的情况下得出Pareto最优解,利用IEEE-14节点系统对多目标非支配解提取法的电力系统无功优化进行了仿真测试。研究结果表明,该算法一次运行可以得出多组非支配解,既有偏向单个目标的解也有兼顾所有目标的解,克服了权重系数法的盲目性和单一性,可使电力决策者根据实际问题选择最优解,具有较好的灵活性与多样性。     

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%.