基于扩展卡尔曼滤波算法的感应电机定子磁链观测器设计

为了提升感应电机定子磁链的辨识精度,设计了基于扩展卡尔曼滤波算法的感应电机定子磁链观测器,并应用到感应电机无传感器直接转矩控制系统中。在Matlab/Simulink中构建感应电机无传感器直接转矩控制系统进行仿真,仿真结果表明所设计的观测器能够对感应电机定子磁链进行有效辨识。     

电动汽车用异步电机直接转矩控制的仿真研究

以交流异步电机作为电动汽车的驱动电机,建立了异步电机的数学模型,将直接转矩控制技术运用于电动汽车驱动系统。在Matlab/Simulink平台上搭建了电动汽车用异步电机直接转矩控制系统的仿真模型,详细介绍了模型中各个子模块的组成和功能,并进行电机运行仿真。仿真结果表明,控制系统动态响应迅速,调速性能良好,验证了控制系统的正确性。     

采用模糊逻辑调节器的直接转矩控制感应电动机

介绍了基于直接转矩控制(DTC)的感应电机驱动器,并对其进行模糊逻辑控制仿真分析。直接转矩控制的感应电机使用的内置控制器为AC4的驱动模型,使用模糊逻辑控制的直接转矩控制系统产生的电磁转矩脉动纹波比传统的DTC少。     

基于Simulink的三相异步电动机直接转矩控制系统研究

基于直接转矩控制工作原理,利用Simulink搭建三相异步电动机直接转矩控制系统仿真模型,采用定子磁链轨迹近似圆形的控制方案,对系统进行仿真。仿真结果表明,该直接转矩控制系统仿真模型能够很好地模拟实际调速系统的相关性能,体现了更优越的静动态性能。此外,通过搭建实际调速系统,测量电机转速、转矩参数,验证了仿真模型的有效性。     

基于MATLAB的异步电机直接转矩控制系统仿真

利用MATLAB所提供的电气系统模块库Simulink，构造了一个异步电机直接转矩控制系统，对系统的相关子模块进行了较为详细的介绍，并给出具体的结构图。通过对仿真系统进行实验，可以得到系统的磁链、转速等仿真波形。实验结果表明，该系统设计是有效的，可以根据此系统制作一个基于直接转矩理论的电机控制器。     

电主轴直接转矩控制系统的设计与仿真研究

基于高速加工机床用电主轴及直接转矩控制基本工作原理,设计了电主轴直接转矩控制系统。利用MATLAB/Simulink模块库中提供的各种基本模块及子系统封装技术,建立完整的高速加工机床用电主轴直接转矩控制系统模型。并对该系统模型在恒定负载和负载变化两种情况进行了仿真研究。仿真结果表明,设计的电主轴直接转矩控制系统具有良好的动静态特性,将直接转矩控制方法应用于电主轴驱动控制系统是可行的,适应高速数控机床驱动控制系统的快速响应要求。     

基于模糊逻辑的感应电机矢量控制系统仿真

通过对感应电动机动态电磁关系的分析,引出了感应电动机的数学模型和在M-T坐标系上的数学模型表达式,指出了感应电动机的模型是一多变量、强耦合的非线性系统。将模糊控制技术应用于感应电机的变频调速中,设计了一种转速模糊控制器,并用MATLAB/Simulink对基于模糊控制的感应电机矢量控制系统进行了仿真。仿真结果表明:对于感应电机来说,模糊控制器的控制性能优于常规的PID控制器。     

五相永磁同步电机的直接转矩控制仿真及优化

在三相永磁同步电机数学模型的基础上建立了五相永磁同步电机的数学模型,并在MATLAB/Simulink环境下进行仿真分析。在Simulink中封装了五相永磁同步电机的模型,采用直接转矩来控制五相电机。仿真结果表明,五相电机得到了很好的控制,但是有着很大的转矩脉动,这是直接转矩控制的缺陷。由于五相电机在空间中可以输出更多的电压矢量,因此通过采用优化的空间电压选择矢量表,使转矩脉动得到了大幅的减小。     

基于Simulink的开关磁阻电机直接转矩控制的研究

由于具有特殊的工作原理,开关磁阻电机在常规的控制方式下会产生很大的转矩脉动,限制了其应用范围。针对这一问题,对开关磁阻电机的直接转矩控制进行了研究,并在MATLAB/Simulink环境下搭建了8/6级开关磁阻电机直接转矩系统仿真模型。结果表明:应用直接转矩控制开关磁阻电机,运行时的转矩脉动明显减小,拥有良好的调速性能和转矩动态响应。     

基于SVPWM的异步电机直接转矩控制系统仿真研究

分析了异步电动机直接转矩控制原理,在此基础上,给出了一种基于空间矢量脉宽调制(SVPWM)的直接转矩控制方法。通过MATLAB/Simulink对该控制系统进行了仿真,仿真结果表明,基于SVPWM的异步电机直接转矩控制系统能够有效地减小电动机转矩和磁链的脉动,改善该交流调速系统的稳态性能。     

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.