Optimal design of butterfly-shaped linear ultrasonic motor using finite element method and response surface methodology

A new method for optimizing a butterfly-shaped linear ultrasonic motor was proposed to maximize its mechanical output. The finite element analysis technology and response surface methodology were combined together to realize the optimal design of the butterfly-shaped linear ultrasonic motor. First, the operation principle of the motor was introduced. Second, the finite element parameterized model of the stator of the motor was built using ANSYS parametric design language and some structure parameters of the stator were selected as design variables. Third, the sample points were selected in design variable space using latin hypercube Design. Through modal analysis and harmonic response analysis of the stator based on these sample points, the target responses were obtained. These sample points and response values were combined together to build a response surface model. Finally, the simplex method was used to find the optimal solution. The experimental results showed that many aspects of the design requirements of the butterfly-shaped linear ultrasonic motor have been fulfilled. The prototype motor fabricated based on the optimal design result exhibited considerably high dynamic performance, such as no-load speed of 873 ram/s, maximal thrust of 27.5 N, maximal efficiency of 43%, and thrust-weight ratio of 45.8.

Design of a Transverse-flux Permanent-magnet Linear Generator and Controller for Use with a Free-piston Stirling Engine

Transverse-flux with high efficiency has been applied in Stirling engine and permanent magnet synchronous linear generator system,however it is restricted for large application because of low and complex process.A novel type of cylindrical,non-overlapping,transverse-flux,and permanent-magnet linear motor（TFPLM） is investigated,furthermore,a high power factor and less process complexity structure research is developed.The impact of magnetic leakage factor on power factor is discussed,by using the Finite Element Analysis（FEA） model of stirling engine and TFPLM,an optimization method for electro-magnetic design of TFPLM is proposed based on magnetic leakage factor.The relation between power factor and structure parameter is investigated,and a structure parameter optimization method is proposed taking power factor maximum as a goal.At last,the test bench is founded,starting experimental and generating experimental are performed,and a good agreement of simulation and experimental is achieved.The power factor is improved and the process complexity is decreased.This research provides the instruction to design high-power factor permanent-magnet linear generator.

Review of Linear Switched Reluctance Motor Designs for Linear Propulsion Applications

Linear switched reluctance motor(LSRM)and its applications in different industries have been an interesting research topic for the past few years.LSRMs have proved to be a suitable alternative in a variety of applications requiring linear motion.However,its use is not that popular which instigated an active interest in the evolution of newer LSRM configurations.Enhancement in its propulsion force along with the reduction in force ripples,weight,acoustic noise,and vibration have been the main objectives in recently proposed LSRM designs.In this paper,recently proposed LSRM designs are reviewed and analyzed.The paper presents a one-stop introduction and a complete update to the designs,both in terms of qualitative and quantitative parameters.In addition,it takes into account the challenges in the implementation of these designs.Based on a detailed comparison of these designs as presented in this paper,an appropriate design can be chosen for a given application.

Design of Axial-Flux Motor for Traction Application

This paper deals with the design of high power – low dimensions axial-flux permanent-magnet motor intended for trac-tion application. First, two motor configurations are analytically designed and compared using finite element calcula-tion. Then, the configuration yielding the best performances is integrated and modelled with the whole traction chain under MATLAB/SIMULINK environment in order to demonstrate the motor operation on a large speed band.

Robustness-tracking control based on sliding mode and H_∞ theory for linear servo system

A robustness-tracking control scheme based on combining H_∞ robust control and sliding mode control is proposed for a direct drive AC permanent-magnet linear motor servo system to solve the conflict between tracking and robustness of the linear servo system. The sliding mode tracking controller is designed to ensure the system has a fast tracking characteristic to the command, and the H_∞ robustness controller suppresses the disturbances well within the close loop(including the load and the end effect force of linear motor etc.) and effectively minimizes the chattering of sliding mode control which influences the steady state performance of the system. Simulation results show that this control scheme enhances the track-command-ability and the robustness of the linear servo system, and in addition, it has a strong robustness to parameter variations and resistance disturbances.

Design to Improve Thrust Force Performance of Dual-side Primary Permanent-magnet Vernier Linear Motor

A novel dual-side primary permanent-magnet vernier linear(DS-PPMVL)motors is proposed.The novelty of the proposed motors is the design of asymmetric consequent poles on the mover,which can effectively enforce the flux-modulation effect and improve the thrust force performance.First,the topologies and operation principle are introduced.Subsequently,the structure relationships between the existing and proposed motors are discussed.Then,a unified analytical model is built.Accordingly,the magnetic field generated by the consequent pole is calculated.Meanwhile,the performance improvement mechanism with the asymmetric consequent pole is analyzed.To improve the efficiency of motor optimization,multi-objective optimization method is adopted to obtain the global optimal solution combination of structure parameters.The proposed motors exhibit higher thrust force,higher force density,less PM consumption,and better overload performance than the existing DS-PPMVL motor.Finally,experiments are conducted based on the existing prototype to verify the accuracy of the design and analysis.

Optimal design of FRMSM to decrease detent force

An optimal configuration of the flux-reversal linear synchronous motor (FRLSM) with the optimal number of attachment permanent magnets (PMs) was presented. The optimal model of 2 000 N was designed to reduce the detent force by redesigning the air-gap structure and skewing. The design parameters,mover PMs and stator core,were selected for optimal design by DOE. The thrust and the detent force of the designed optimal models were compared by finite element analysis (FEA). As a result,the thrust of the optimal model is slightly decreased by 1.97% compared with the basic model,and the detent force of the optimal model is greatly decreased by 88.47% compared with the basic model.

永磁同步直线电机的矢量控制

由于旋转电机加滚珠丝杠的传统机械结构加入了中间传动环节,无法进一步提升使用性能,研究了永磁同步直线电动机矢量控制算法.针对永磁同步直线电动机开展矢量控制算法分析以及验证工作,在矢量控制系统框架下进行了硬件搭建与软件设计,搭建了永磁同步直线电机矢量控制验证平台,测试核心算法,经过试验,设计的软/硬件能够对永磁同步直线电机进行有效控制,有较好的鲁棒性.

无铁心双层绕组超导直线同步电机参数优化设计

超导电动磁悬浮(electrodynamic suspension,EDS)技术具有自稳定、效率高、工作气隙大等优势,是高速磁悬浮列车发展的主要方向之一。以应用于超导电动悬浮列车的双层绕组直线同步电机为研究对象,首先,利用谐波分析法推导该电机电磁推力表达式并分析推力波动产生原因。接着,利用三维有限元法研究电机结构参数对电机推力及其波动的影响规律,明确主要结构参数的选取准则。针对磁场的空间衰减特性,提出内外层绕组结构匹配设计方法。然后,基于上述研究确定了一套实验样机尺寸参数,并仿真分析样机电磁性能。最后,研制实验样机并通过推力测量,验证设计方法与理论分析的有效性。

模块化永磁直线同步电机考虑制造公差的推力鲁棒性优化

模块化永磁直线同步电机(MPMLSM)具有效率与推力密度高、可靠性和可加工性好等优点,非常适用于长行程运输系统;缺点是批量生产中性能易受到加工公差的影响。针对这一问题,该文提出了一种考虑制造公差的综合多目标鲁棒优化设计方法。首先,基于六西格玛设计方法建立了鲁棒优化模型;其次,采用拉丁超立方采样方法在尺寸公差范围内根据正态分布规律进行抽样,模拟大规模生产时电机尺寸受公差影响可能会出现的各种变化;再次,在尺寸优化范围内均匀抽样构成足够的训练样本,由有限元软件仿真这些抽样方案的推力性能,并基于反向传播神经网络建立电机设计代理模型;然后,应用该代理模型对拉丁超立方采样得到的样本进行电机性能的计算,求解样本整体对应的各优化目标的均值与方差,进而计算多目标优化的适应度;最后,采用非支配排序遗传算法Ⅱ进行全局优化,得到鲁棒优化方案,与不考虑公差的确定性优化方案相比,验证了该方法的有效性。鲁棒优化方案虽然略微增加了电机体积和推力波动,但是其失效概率低,受公差影响小,更加符合产品批量生产过程中的质量要求。

System construction of a four-side primary permanent-magnet linear motor drive mechanical press

A primary permanent-magnet linear motor (PPMLM) has a robust secondary structure and high force density and is appropriate for direct-drive mechanical press. The structure of a four-side PPMLM drive press is presented based on our previous research. The entire press control system is constructed to realize various flexible forming processes. The control system scheme is determined in accordance with the mathematical model of PPMLM, and active disturbance rejection control is implemented in the servo controller. Field-circuit coupling simulation is applied to estimate the system’s performance. Then, a press prototype with 6 kN nominal force is fabricated, and the hardware platform of the control system is constructed for experimental study. Punch strokes with 0.06 m displacement are implemented at trapezoidal speeds of 0.1 and 0.2 m/s;the dynamic position tracking errors are less than 0.45 and 0.82 mm, respectively. Afterward, continuous reciprocating strokes are performed, and the positioning errors at the bottom dead center are less than 0.015 mm. Complex pulse trajectories are also achieved. The proposed PPMLM drive press exhibits a fast dynamic response and favorable tracking precision and is suitable for various forming processes.

一种钹型直线式压电电动机的设计

针对高端精密机械领域对响应快、大行程、运动速度快的压电直线电动机的设计需求,设计了一种基于惯性驱动压电陶瓷的新型直线压电直线电动机。通过对压电电动机工作原理及压电电动机应用环境的分析,设计了新的电动机结构,并制作了原理样机。通过试验数据分析后得知:在一定频率范围内,该款压电定子可以保持纵振幅度足够大且稳定,最大幅值可达740 nm;电动机最大无负载速度为8.56 mm/s,最大负载能力1.5 g。这种电动机结构简单,容易实现小型化。钹形振子更容易放大压电陶瓷的振幅,使该电动机更易于实用化,适合用于物体精密定位、精细物料输送或振动切割工具。

一种压电元件驱动的惯性式精密直线马达的设计

为解决传统精密马达精度低、行程短、驱动力小、结构复杂和无法实现小型化等一系列问题,利用压电元件作为动力源,结合惯性式马达的运动原理,设计一种精密直线马达,利用有限元和控制变量法优化其关键尺寸,并利用有限元验证其关键部件的应力和固有频率,结果均满足设计要求。

Design of magnet arrays for permanent magnetic linear motor

An iron-less single side permanent magnetic linear motor structure is presented,and two-dimensional analytical formulae for its magnetic field are deduced to design the types of magnetic arrays,the thickness of permanent magnet,and the duty ratio of magnet arrays,etc.With certain design parameters,conventional arrays are used instead of a piecewise Halbach arrays,and the machining and assembling of the motor are greatly simplified.Calculation results coincide with that of ANSYS.The analytical formulae can be used in designing cored linear motors by modifying boundary conditions.A linear motor driven bench with a single degree of freedom is realized,where the travel reaches 27 mm,the mass of the moving parts is 1.4 kg,and the maximum acceleration is 11.5 m/s^(2).

直线电机驱动技术的研究现状与发展

直线电机直接驱动系统具有结构简单、动态响应快、速度和加速度大、精度高、振动和噪声小等一系列优点 ,是各类超高速、精密机床的理想传动方式。本文介绍了直线电机的工作原理与结构类型 ,阐述了直线电机理论分析、设计以及直线伺服驱动系统控制等方面的研究现状与发展趋势 。

磁控形状记忆合金蠕动型直线电机研究

磁控形状记忆合金(MSM)是一种新型具有形状记忆功能的合金材料,不仅变形率大,易于控制,动态响应速度高,而且功率密度大和机电能量转换效率高,特别适合于制造高精度的运动与位置控制执行器。该文首先介绍MSM材料在磁场作用下的变形机理与磁控特性,然后分析利用仿生学蠕动原理将MSM小步距的位移累加形成直线电机所需要的大行程的工作原理,而后论述蠕动型MSM直线电机的设计与控制方法,最后给出样机的试验结果。

压缩机用直线电机及其关键技术发展综述

随着节能降耗要求的提高,直线压缩机因其具有传统压缩机无可比拟的优点而成为目前国内外研究的热点。该文对直线压缩机驱动用动圈式、动磁式和动铁式直线电机进行结构和原理介绍以及特点分析,归纳和总结了国内外在直线电机的结构改进、动力学分析、电机设计、电机控制等方面的研究和应用的现状及发展趋势,并对其中的关键技术进行了分析和总结。最后讨论了未来压缩机驱动用直线电机的关键技术发展的主要方向。所作研究为涉及该领域的科研工作者提供了参考。

直线超声电机设计、建模和应用的研究进展

直线超声电机作为一种新型作动器,以其独特的结构和驱动原理,在高新技术领域有着广泛的应用。首先,回顾了电机结构设计方面的研究进展,提出了电机的设计理论和方法,阐述了电机结构形式的演化和夹持结构的设计方法;其次,介绍了有关电机理论模型的研究进展,提出了定子机电耦合模型、摩擦接触模型和定/动子冲击模型等;最后,报道了直线超声电机在高精度运动平台、细胞显微操作、微夹持器和绝对重力仪方面的最新应用。

机床进给用永磁同步直线伺服单元的设计与实验研究

在与其他形式电机比较的基础上,研究了满足数控机床要求的永磁同步直线电机电磁结构设计和伺服控制系统的软硬件开发,解决了直线电机性能实验加载、与速度相关的参数记录等问题,对研制开发的实验样机进行了性能测试,特别给出了定位力的实验方法和测试结果,测试结果表明所开发的样机具有较好的性能。

直线感应电动机的优化设计研究

介绍直线感应电动机的优化设计。优化的目标是直线电机的力能指标最大。对直线电机的其它性能指标引入约束条件。采用Ｈｏｏｋ－Ｊｅｅｖｅｓ法进行优化。约束处理采用外点罚函数法。优化的结果表明，优化后的直线电机的力能指标比优化前有较大提高。