直线感应电机的转差频率控制仿真研究

本文介绍了直线感应电机的结构和工作原理，给出了把边端效应考虑在内的直线感应电机数学模型，对直线电机进行恒转差频率控制，仿真结果表明该控制系统的实现方法是可行的。     

直线电机热误差动态建模与仿真分析

为提高单轴直线电机的运动精度,对该类直线电机热变形建模与仿真进行了研究。分析了影响单轴直线电机热变形的因素,在直线电机托板上建立了一维动态热传导数学模型,并借助ANSYS对该类直线电机机构的热传递进行了仿真分析,并建立了一维热变形数学模型,依据仿真数据计算出热变形随时间变化数据。不仅提供了单轴直线电机热变形的建模方法,且表明了直线电机热传递的特征,有利于直线电机热变形补偿的进一步研究。     

自动门用直线感应电机设计与仿真

直线感应电机传动结构在自动门中的应用越来越广泛。本文设计出一种自动门用的直线感应电机,并进行了有限元软件的电磁场仿真和运动仿真,将电磁设计结果与仿真结果进行比较,两者相吻合。从而验证,该直线电机电磁设计具有可行性。     

老虑边缘效应直线感应电机矢量控制系统仿真

考虑直线感应电机的动态纵向边缘效应，建立直线感应电机数学模型。利用Simul建立了矢量控制模型，对考虑与不考虑动态纵向边缘效应的仿真结果作了对比，结果证明了考虑边缘效应的正确性与有效性。     

直线感应电机模型分析与直接转矩控制系统仿真

考虑直线感应电机的动态纵向边缘效应，建立直线感应电机数学模型。推导出直线感应电机直接转矩控制的数学模型，用Simulink建立直线感应电机直接转矩控制系统仿真模型，对考虑与不考虑边缘效应的直接转矩控制结果做出比较。结果证明了考虑边缘效应的数学模型正确性与有效性，并且考虑边缘效应后控制系统的动态性能更好。     

直线电机保护装置的设计与控制方法

直线电机具有精度高、响应快等优点,广泛应用于半导体制造设备中。直线电机控制机构Z向运动时,经常出现掉电或故障导致的电机动子跌落而发生损坏晶圆的情况。利用电磁铁螺线管设计了一种电机掉电保护装置,建立动力学模型,应用Adams软件进行了动力学仿真,获得了挂钩转角与时间的关系曲线,并通过搭建实验平台,测试了该系统的反应时间。实验表明,反应时间的仿真与实验结果吻合较好,该装置可以应用于直线电机保护中。     

直线同步电机的直接牵引力控制系统仿真

直线同步电机是直线电机牵引中最常采用的类型,目前德国、日本所建造磁悬浮列车采用的是直线同步电机。文章在其数学模型的基础上建立了同步直线电机的直接牵引力控制系统模型,并阐述了电压空间矢量脉宽调制方法(SVPWM)的原理及算法,并以永磁同步直线电机为例,利用MATLAB/SIMULINK进行仿真。仿真结果表明控制系统具有较好的动态特性。     

自主机器人直线行进过程的数字PID控制

针对自主机器人的直线行进过程，提出一种通过硬件电路确定直流电机模型的方法，即利用光电编码器测得机器人驱动轮电机转速信号，经硬件电路将每个周期时间内的脉冲数记录下来，从而得到电机输出转速响应曲线，确定电机的数学模型。在电机模型确定的基础上，实现了自主机器人直线行进过程的数字PID控制。数字PID参数的确定采用Ziegler—Nichols法，同时借助Matlab／Simulink仿真软件对所得PID参数进行了进一步的整定，取得了良好的控制效果。     

一种直线压电电机驱动足的结构优化设计

直线压电电机在精密仪器、生物医学和半导体封装等行业具有广阔的应用前景,其定子结构特性直接影响了电机运行的稳定性和输出性能。以一种直线压电电机定子驱动足的位移输出特性为优化目标,研究该类电机驱动足结构优化设计方法,提高该类电机的综合输出性能。通过分析驱动足的微观几何位移特性,理论研究了驱动足结构参数对输出端宏观运动特性的影响。研究了不同结构下驱动足的输出特性,确定驱动足的结构参数及最优值。最后对优化后的驱动足位移输出性能和力学性能进行仿真分析。加工优化样机,并测试电机的机械输出性能。实验结果表明,电机的输出力为0.64 N,比优化前增大了52.4％。     

一类行波型直线超声电机定子的优化设计

针对一类环形行波型直线超声电机定子的动态设计提出一种间接优化方法。数值研究表明，该优化方法能保证定子存在按设计所需的正交的弯曲振动模态。对自行研制的直线超声电机定子，进行了激光测振，实验结果表明定子的弯曲振动固有频率差的设计计算值与相应的共振频率差的测试值吻合。     

A non-autonomous chaotic system with no equilibrium

Recently, researchers showed that adding a stepwise control pulse to the Sprott C system (with two equilibrium points) can create a translational multi-butterfly attractor. In this research, a sinusoidal control pulse is added to a system with no equilibria. So, a non-autonomous chaotic system with no equilibria is designed and studied. The sinusoidal term causes an extension in the chaotic attractor. Dynamical behaviors of the proposed oscillator are studied. Bifurcation analysis by changing the frequency of the sinusoidal term shows its unbounded solution at some parameters. Also, bifurcation diagram of the oscillator by the force's strength is studied. Lyapunov exponents show that the oscillator has chaotic dynamics in the entire studied interval of force's strength. In addition, circuit implementation shows its feasibility.     

一种新型电动式地震振源发生装置

研制了一种新型电动式地震振源发生装置，介绍了它的特点和优点、实现新装置的技术措施，以及该装置的技术参数、结构和工作原理、测试数据及其结果分析。该装置为建筑物的抗震性能研究和地层结构分析等提供了新的分析和试验手段。     

Multiferroic Clusters: A New Perspective for Relaxor‐Type Room‐Temperature Multiferroics

Multiferroics are promising for sensor and memory applications, but despite all efforts invested in their research no single‐phase material displaying both ferroelectricity and large magnetization at room‐temperature has hitherto been reported. This situation has substantially been improved in the novel relaxor ferroelectric single‐phase (BiFe_0.9Co_0.1O₃)_0.4–(Bi_1/2K_1/2TiO₃)_0.6, where polar nanoregions (PNR) transform into static‐PNR as evidenced by piezoresponse force microscopy (PFM) and simultaneously enable congruent multiferroic clusters (MFC) to emerge from inherent strongly magnetic Bi(Fe,Co)O₃ rich regions as verified by magnetic force microscopy (MFM) and secondary ion mass spectrometry. The material's exceptionally large Néel temperature T_N = 670 ± 10 K, as found by neutron diffraction, is proposed to be a consequence of ferrimagnetic order in MFC. On these MFC, exceptionally large direct and converse magnetoelectric (ME) coupling coefficients, α ≈ 1.0 × 10^?5 s m^?1 at room‐temperature, are measured by PFM and MFM, respectively. It is expected that the non‐ergodic relaxor properties which are governed by the Bi_1/2K_1/2TiO₃ component to play a vital role in the strong ME coupling, by providing an electrically and mechanically flexible environment to MFC. This new class of non‐ergodic relaxor multiferroics bears great potential for applications. Especially the prospect of a ME nanodot storage device seems appealing.     

A Touchpad for Force and Location Sensing

This paper presents the design and fabrication model of a touchpad based on a contact‐resistance‐type force sensor. The touchpad works as a touch input device, which can sense contact location and contact force simultaneously. The touchpad is 40 mm wide and 40 mm long. The touchpad is fabricated by using a simple screen printing technique. The contact location is evaluated by the calibration setup, which has a load cell and three‐axis stages. The location error is approximately 4 mm with respect to x‐axis and y‐axis directions. The force response of the fabricated touchpad is obtained at three points by loading and unloading of the probe. The touchpad can detect loads from 0 N to 2 N. The touchpad shows a hysteresis error rate of about 11% and uniformity error rate of about 3%.     

A Laterally‐Driven Bistable Electromagnetic Microrelay

In this letter, a laterally‐driven bistable electromagnetic microrelay is designed, fabricated, and tested. The proposed microrelay consists of a pair of arch‐shaped leaf springs, a shuttle, and a contact bar made from silicon, low temperature oxide (LTO), and gold composite materials. Silicon‐on‐insulator wafers are used for electrical isolation and releasing of the moving microstructures. The high‐aspect‐ratio microstructures are fabricated using a deep reactive ion etching (DRIE) process. The tandem‐typed leaf springs with a silicon/gold composite layer enhance the mechanical performances while reducing the electrical resistance. A permanent magnet is attached at the bottom of the silicon substrate, resulting in the generation of an external magnetic field in the direction vertical to the surface of the silicon substrate. The leaf springs show bistable characteristics. The resistance of the pair of leaf springs was 7.5 Ω, and the contact resistance was 7.7 Ω. The relay was operated at ±0.12 V.     

一种用于机器人手爪的PVDF接触力传感器设计

利用PVDF压电薄膜的压电敏感特性,设计了一种用于机器人手爪的接触力传感器,包括一个电荷放大装置,并建立了数据采集和处理系统。所设计的传感器具有体积小,柔顺性好,信号处理简单的特点。实验分析表明传感器可很好地满足机器人手爪的要求,为机器人手爪提供接触力信号,以实现稳定可靠地抓取。     

参数对理想光伏探测器光生电动势的影响

介绍了光伏效应的产生过程,建立了光生电动势的数学模型,并讨论了各参数对理想光伏探测器的光生电动势的影响.     

用于微摩擦测试的微力传感器及其制作

微构件表面的摩擦状况和磨损机理与宏观构件有较大的区别，需一种能够测量微米尺度样品摩擦特性的专用仪器。给出了一种新型硅微力传感器的设计原理、结构、制作工艺及其弱信号采集方法。静态性能测试结果表明，传感器最大输出电压2000μV，重复性约为1．3％，灵敏度约为65V／N，分辨率为46μN，总精度为2．3％，基本上满足了微摩擦测试的需要。实验及计算表明，通过优化微力传感器的结构，改进芯片的封装，可以大大减少其体积，并提高其各项性能指标。     

手指压力数据采集系统

某些实验中,需要及时准确地检测手指压力传感器的数据。本文设计了一个手指力量数据测量和处理系统,能实时采集实验者的手指压力传感器的数据,并将采集的数据用串口发送到上位机,还可以暂存测量数据。系统由8051单片机、16位模数转换器MAX1177、存储器、信号调理电路和串口电路等构成。实验显示,该系统满足要求,加以扩展,可以用于多种场合。