普通V带传动的优化设计

普通V带传动是机械中应用极为普遍的一种传动形式.在常规设计中,一般根据给定的已知条件如功率、转速、中心距以及其工作环境等参数来确定.本文采用优化设计方法对普通V带进行设计,并用内点惩罚函数法建立寻优数学模型,找出设计变量、目标函数和约束条件,通过迭代得到最优解.文中给出了具体设计实例.     

不完全概率信息的V带传动可靠性灵敏度设计

根据V带传动疲劳断裂和打滑失效。建立了V带传动可靠性数学模型。结合可靠性设计理论和灵敏度分析方法,讨论了具有不完全概率信息的V带传动可靠性灵敏度设计问题,提出V带传动可靠性灵敏度设计的计算方法。已知基本随机参数的特性,可迅速获得不完全概率信息的V带传动设计信息。     

普通V带传动的无校核设计方法

针对普通V带传动设计因校核带来重复运算的缺陷,在总结现有的设计资料的基础上,按照带轮直径、带长尺寸的数据结构,建立带轮直径与带长、主动带轮与从动带轮之间的指数关系;通过构造带传动体积与带根数、带功率的辅助函数,运用带传动体积取得极小值的条件确定小带轮直径指数和带根数。从而解决了普通V带传动的无校核设计的问题。同时证明:当1i≤5.7时,不需要验算包角。     

V带传动常规设计的可视化编程技术

V带传动常规设计在机械中相当重要 ,一般根据给定的已知条件如传动功率、转速、中心距以及其工作环境等参数来确定。本文运用Matlab语言强大的计算及图形可视化功能[1 ] ,编制M 函数进行V带传动常规设计 ,其特点简洁、高效 ,正越来越为广大工程技术人员所接受 ,具有广阔的发展前景     

V带传动常规设计的Matlab可视化编程实现

V带传动常规设计在机械设计中相当重要 ,一般根据给定的已知条件如功率、转速、中心距以及其工作环境等参数来确定。本文运用 Matlab语言强大的计算及图形可视化功能 ,编制 M-函数进行 V带传动常规设计 ,其特点是简洁、高效 ,具有广阔的应用前景。     

普通V带传动的优化设计

在普通V带传动设计中,传统的方法存在工作量大、设计效率低等缺点.采用优化设计方法对V带进行设计,按最小带传动体积为优化目标,并用内点惩罚函数法建立优化模型以获得最优解.     

基于遗传算法的普通V带传动的优化设计

在普通V带传动设计中，大多采用传统设计方法，存在计算精度低，难于找到最优解等问题。本文提出将遗传算法应用于普通V带传动的优化设计过程，以最小带轮体积为优化目标函数进行优化设计。计算实例表明，在满足传动承载能力的前提下，可有效减小带轮体积。此方法可应用于同类零件的优化过程。     

窄V带在压缩机传动中的设计应用

分析了窄V带在压缩机传动设计应用中的特点，并与普通V带进行了比较。     

基于Visual Basic的V型带传动计算机辅助设计

为了提高V型带传动设计效率及可靠性,通过分析传统设计中图表数据的特点,提出了普通V带传动设计中有关数据、表格和线图的程序化方法及较实用的可靠性模型。并采用Visual Basic完成了计算机辅助设计的编程。使用结果表明,大大简化了设计过程,具有一定的应用价值。     

实用V带传动系统可靠度计算

利用可靠性设计原理，在常规设计基础上，借助于变差系数，介绍了V带传动的可靠度计算方法，并给出了V带传动可靠度计算实例。     

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.     

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...     

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.