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This paper discusses a complex method for determining the position of the working unit of a tubular linear motor with permanent magnets, which has become very widespread in recent years. Unlike traditional electric drive systems that convert rotary motion into translational motion by means of intermediate mechanisms, direct linear drive systems are devoid of many of the significant disadvantages associated with mechanical transmissions. One serious scientific problem associated with this type of motor is the search for methods for accurately determining the current position of the working unit on the stator that are capable of operating under limited resources of typical microcontrollers, while providing sufficient positioning accuracy. This article proposes a method for determining the position of the working unit using several Hall sensors located on the stator with a shift of 60° (relative to the stator magnetic field), as well as inexpensive analog accelerometers (accelerometers). The proposed method is based on the use of large correction tables created during the calibration process for each stator instance, as well as the use of oversampling methods to increase the effective ADC bit depth. The use of the method made it possible to achieve positioning accuracy within 1 µm, without exceeding the computing resources of a typical microcontroller.

Slotless linear permanent magnet actuators are widely used in applications that require a high dynamics and precision in the motion. However, the windings limit the performances of such motors. A new technology, that consists in printing the windings on a PCB has shown promising results for rotary motor, as well as for tubular linear motor. This paper proposes to study the potential of this technology for a planar linear motor. To that end, an analytical model of the actuator is first presented, from which performance criteria related to the force density and to the force ripple are derived. Then, using those criteria, the results of a bi-objective optimization, based on an existing linear actuator, are presented. Finally, a first prototype is built and characterized in a test bench with a view to validate the optimization results and to make a comparison with the existing motor.

This paper deals with the design of a Dual Halbach-array Tubular Linear Motor for long stroke and large force. The proposed magnetic poles arrangement is able to increase the magnetic flux density in the machine to generate large axial force. Furthermore, compared to a standard tubular linear motor, the yoke of the stator is no longer necessary. In this way, the stator is a set of teeth magnetically separated, which significantly simplifies the manufacturing of the machine. Semi-analytical model and detailed 3D finite element analysis are carried out to evaluate the performance of the proposed structure for tubular linear motor.

This paper presents a method to estimate magnet temperature in permanent magnet tubular linear motor (PMTLM). The proposed method combines stator resistance identification with lumped parameter thermal network. Firstly, stator resistance is identified to represent the knowledge of stator winding temperature by using extended Kalman filter (EKF). Then, a lumped parameter thermal model of PMTLM is established to obtain the relationship between winding temperature and magnet temperature. On this basis, temperatures in different parts of the magnet are calculated. Experimental results validate the feasibility and practicality of this method.

In this paper, the thrust density and thrust fluctuation of tubular C-core modular linear permanent magnet synchronous motor (TC-core MLPMSM) are optimized. In this paper, the characteristics of magnetic density distribution in the core of a tubular linear motor are analyzed. Based on the analysis, this paper proposes that trapezoidal stator slot will lead to a much larger thrust density than rectangular stator slot under the same volume and magnetic and electric load. Aiming at the problem of large force fluctuation in linear motor, modular structure is adopted and the detent force and thrust fluctuation are reduced. 2D finite element method (FEM) results are obtained to verify validity of the methods. Results show that the thrust density increases and the force fluctuation decreases after optimizations in TC-core MLPMSM.

Permanent magnet tubular linear motors (TLMs) arranged in multiple rows and multiple columns used for a radiotherapy machine were studied. Due to severe volumetric and thermal constraints, the TLMs were at high risk of overheating. To predict the performance of the TLMs accurately, a multi-physics analysis approach was proposed. Specifically, it considered the coupling effects amongst the electromagnetic and the thermal models of the TLMs, as well as the fluid model of the surrounding air. To reduce computation cost, both the electromagnetic and the thermal models were based on lumped-parameter methods. Only a minimum set of numerical computation (computational fluid dynamics, CFD) was performed to model the complex fluid behavior. With the proposed approach, both steady state and transient state temperature distributions, thermal rating and permissible load can be predicted. The validity of this approach is verified through the experiment.

This paper presents a Slot-less Tubular Permanent Magnet Linear Motor (ST-PMLM), which does not have the cogging structure in the stator. Meanwhile, its lateral stator core doesn’t split, so the motor only has longitudinal edge effect. Since the ST-PMLM is supposed to be used as the active damper for vehicle suspension system, this paper focus on two aspects: increasing the output thrust and restraining the thrust fluctuation of the motor. Firstly, the equivalent magnetic circuit model of the ST-PMLM is established. The influences of structural parameters, including the thickness of the magnetic pole, the length of the air gap, the thickness of primary iron core and the thickness of primary winding, on the air gap flux density and the output thrust are analyzed. Then, the distribution of the magnetic field at the end of the primary iron core is observed. Length compensation in the end of primary iron core is adopted in order to reduce the thrust fluctuation. Finally, the prototype of ST-PMLM is developed and the experiment test bench is built. Based on the no-load test of the prototype, the effectiveness of the primary core length compensation in suppressing end effects and inhibiting fluctuations are verified.

In this paper, a study of a small-diameter tubular linear motor for biomedical applications is presented. The performance of the motor, through its maximum force and losses, is evaluated as a function of the variation of several design parameters. This is done by performing a numerical analysis using a finite-element analysis software. Moreover, using Simulink, a position and force control strategy is designed and tested. Finally, a prototype has been built and some preliminary results are presented.

A complex hydraulic control system for intelligent wells is costly and cannot use numerous producing layers. Thus, it cannot be easily employed in China oilfields that demand a downhole electric drive inflow control valve, which can be combined with the downhole electronic monitoring system, applied to a 5.5-inch wellbore, and remotely controlled with low cost. In this study, a tubular linear motor is used in developing an incharge inflow control valve (IICV) to drive the sliding sleeve. A rotor displacement detector and a tubular linear motor are integrated to measure the IICV opening. The resulting intelligent well systems only need three 0.25-inch power wires and a 0.25-inch signal transmission cable to control over 12 producing layers. Such intelligent well systems can also reduce the number of holes on the feed-through production packer. The IICV can be combined with the downhole electronic monitoring system to achieve the electronization of intelligent well systems and reduce costs. Field application results show that the IICV continuously ran fault-free in the downhole for 15 months. The cumulative increase in oil production capacity is > 8 × 106 kg, which directly increased profit by >$3 million. The proposed systems can effectively use reservoir energy and enhance oil recovery.

A Novel Two-Phase Brushless Tubular Linear Motor And Its Precise Positioning Control System Are Presented In This Paper. The Magnetic Field Distribution In The Air Gap Of The Linear Motor Is Trapezoidal With Optimization By Halbach Magnet Array, And An Ironless Structure Is Adopted To Eliminate Force Ripples. A Simple And Practical Controller Called Active Disturbance Rejection Controller Is Used To Implement Positioning Control Of The Linear Motor Prototype, Which Is Affected By Parameter Uncertainties And Friction. Simulation And Experimental Results Show That The Position Step Response Is Smooth And Micrometer Positioning Accuracy Is Achieved Without Significant Overshoot Or Oscillation. It Can Be Concluded That The Proposed Linear Motor Is Suitable For Smooth And Precise Linear Motion Applications.

This paper deduces from Finite-Element Analysis (FEA), the influence of leading design parameters on the performance of a novel T-shaped permanent magnet (PM), quasi-Halbach magnetized tubular linear motor. The proposed motor is designed and developed for small reciprocating applications. In order to obtain the maximum power density, a two-dimensional Finite-Element model is developed to investigate the performance of the proposed machine. The proposed T-shaped PM structure has a higher power density as compared to the conventional rectangular-shaped PM structure. The losses of the motor, such as copper loss and iron loss, as well as the efficiency, are established as functions of a set of motor leading design parameters. It is shown that the developed motor produce satisfactory output power, around 85 W, which is enough to operate the direct-drive reciprocating compressor of a household refrigerator.

Trabalho final de mestrado a obtenção do grau de Mestre em Engenharia Eletrotécnica – ramo de Energia Neste trabalho é descrita a modelação de um posicionador eletromecânico linear, usando métodos sensorless, para a estimação de posição e velocidade, a fim de permitir o controlo da trajetória do veio de um motor linear tubular de ímanes permanentes. Apresenta-se numa primeira fase o motor em estudo, conceção e aplicações do mesmo. São apresentados os modelos matemáticos do motor linear tubular e do conversor eletrónico de potência. Apresenta-se também a síntese do gerador de sinais de comando e das cadeias de controlo de posição, velocidade e binário do controlador eletrónico de posição. É apresentada ainda uma síntese dos sensores de posição e codificadores tradicionalmente utilizados no posicionador, como os codificadores e sensores de efeito de Hall, tradicionalmente usados para a obtenção das grandezas de posição e velocidade. Após o desenvolvimento do modelo matemático do posicionador eletromecânico linear, fez-se um estudo sobre os métodos sensorless, apresentando as metodologias e conceções das mesmas. Este estudo teve como alvo a escolha dos métodos sensorless mais aptos à implementação no posicionador eletromecânico linear, tendo-se optado pelo estudo de simulação numérica de dois métodos adaptativos de excitação fundamental. Assim, desenvolvem-se os modelos matemáticos dos observadores de Luenberger e de modo de deslizamento, escolhidos para modelação e aplicação no posicionador eletromecânico linear. Para ambos os métodos são obtidos os resultados de simulação numérica em ferramenta computacional Matlab/Simulink®. É também simulado o posicionador eletromecânico linear com sensor de posição, considerado como um sistema de primeira ordem, com o objetivo de ter um termo de comparação com os métodos sensorless. São por fim obtidos os resultados de simulação numérica para o posicionador eletromecânico linear com sensor de posição. Por fim comparam-se os métodos escolhidos, a fim de determinar qual apresenta melhor desempenho e robustez no funcionamento do posicionador eletromecânico linear. De entre os métodos sensorless escolhidos, o observador de Luenberger e o observador por modo de deslizamento, os resultados de simulação numérica demonstram que o observador por modo de deslizamento apresenta melhor desempenho e robustez. É feito também o estudo do erro relativo de posição com a variação de carga e velocidade no funcionamento do motor linear tubular síncrono de ímanes permanentes, verificando-se um melhor desempenho do observador por modo de deslizamento a velocidade constante, sendo um desempenho com o mesmo erro médio relativo do posicionador eletromecânico linear com sensor de posição. In this thesis, it is described the construction of a linear electromechanical positioning drive, using sensorless methods for the position and speed estimation, to control the trajectory of the linear tubular motor shaft. In a first stage, its presented the linear motor, conceptions and applications. It is also presented the mathematical model of the motor and power converter. It is also presented the s curve and the position and speed controller. It is presented a synthesis of position sensors and encoders, traditionally used in electromechanical positioning drives. After the mathematical model of the linear electromechanical positioning drive, this thesis presents a study of the sensorless methods to choose the appropriate methods to implement. It is chosen the Luenberger observer and the sliding mode observer, to implement. It is first modulated the proper mathematical models of the observers, and then its implemented on the positioning drive. After it is obtained numerical simulation results for both methods using Matlab/Simulink® software. It is also modulated a positioning drive using a position sensor, to use as comparison with the sensorless methods. It is obtained numerical simulation results for the positioning drive using a position sensor. In the end, it is made the comparison between methods, to determine the most effective and which has more robustness using a sinusoidal position function in different load conditions. After the results, the sliding mode observer has more robustness and accuracy. It is also made the position relative error changing load and speed conditions, verifying better performance in sliding mode at constant speed condition, with the same performance as the positioning drive with position sensor. N/A

Accurate mover position is vital for a permanent magnet tubular linear motor (PMTLM) control system. In this paper, two linear Hall sensors are utilized to detect the mover position. However, Hall sensor signals contain third-order harmonics, creating errors in mover position detection. To filter out the third-order harmonics, a signal processing method based on the extended Kalman filter (EKF) is presented. The limitation of conventional processing method is first analyzed, and then EKF is adopted to detect the mover position. In the EKF model, the amplitude of the fundamental component and the percentage of the harmonic component are taken as state variables, and they can be estimated based solely on the measured sensor signals. Then, the harmonic component can be calculated and eliminated. The proposed method has the advantages of faster convergence, better stability and higher accuracy. Finally, experimental results validate the effectiveness and superiority of the proposed method.

The air gap of tubular linear motors moves linearly, causing heat transfer states of the motor to alternate repeatedly. Thus, the heat transfer coefficients of the mover inner surface and the stator outer surface vary constantly. In this paper, the combination model of the thermal circuit and temperature field is established to calculate the transient temperature rise of a tubular linear motor with short and movable primary. The equivalent thermal circuit model of the moving air gap and the temperature field models of the primary (also named as mover) and secondary (also named as stator) are established. The thermal boundary conditions and the correlations among them are analyzed. By this method, the complicated variation and distribution of the heat transfer coefficients are gained. Moreover, the transient temperature rise of the motor is calculated. This method takes advantage of the flexibility of the thermal circuit method and the accuracy of the temperature field method. The calculated and tested results of the prototype are compared and analyzed.

This paper presents a finite element method approach for motor thermal analysis. Specifically, the 2-D temperature field model of a slotless tubular permanent magnet linear motor is established. The heat convection coefficients of the mover are then calculated based on fluid field analysis. This paper focuses on the winding to obtain an accurate winding temperature gradient distribution and to the highest temperature region from the high overload motor. Therefore, the improved equivalent layered model of the ring-shaped winding is particularly applied to the temperature field simulation of the tubular linear motor. As verification, the temperature rise of the motor is calculated accordingly, and the results are compared with the actual experiments.

Dissertação para a obtenção do grau de Mestre em Engenharia Eletrotécnica, Ramo de Energia Esta Tese descreve a aplicação do método dos elementos finitos ao estudo e análise de uma máquina linear tubular de ímanes permanentes. Apresentam-se algumas aplicações relevantes deste tipo de máquinas elétricas, nas áreas da energia, indústria e dos transportes. Neste trabalho desenvolve-se o modelo geométrico da máquina linear tubular recorrendo à ferramenta de desenvolvimento baseada no método dos elementos finitos, Finite Element Method Magnetics, FEMM©. O modelo de elementos finitos da máquina linear tubular é testado em ambiente de simulação numérica Matlab/Simulink®, que integra os componentes de um posicionador eletromecânico linear constituído pela máquina linear tubular, conversor de eletrónica de potência e sistema de controlo. Descrevem-se todas as sub-rotinas desenvolvidas para a integração do modelo de elementos finitos da máquina linear tubular no modelo de simulação numérica do posicionador eletromecânico linear. Desta forma, é possível obter de forma automática as suas características de funcionamento. O modelo de elementos finitos da máquina linear tubular desenvolvido, permitiu obter os parâmetros analíticos que modelam matematicamente o comportamento dinâmico da máquina elétrica, bem como algumas características internas, como sejam a força eletromotriz desenvolvida, a força de retenção e a força eletromagnética desenvolvida em função do ângulo de carga. O modelo de elementos finitos da máquina linear tubular contém um modelo geométrico paramétrico que, através da linguagem de programação Lua©, permitiu ajustar de forma automática todos os elementos construtivos do modelo geométrico às características conhecidas da máquina elétrica real. Abstract: This thesis describes the finite element method application in the study and analysis of a permanent-magnet tubular linear machine. Some relevant applications of these electrical machines in the areas of energy, industry and transport are presented. In this work, a geometric model of the tubular linear machine is developed using the finite element method software, Finite Element Method Magnetics, FEMM©. The finite element model of the tubular linear machine is tested in numerical simulation environment Matlab/Simulink®, which integrates components of a linear electromechanical positioner formed by tubular linear machine, power electronic converter and control system. All the developed subroutines for the integration of the finite element model of the tubular linear machine in numerical simulation model of linear electromechanical positioner are described. This allows to obtain automatically its operating characteristics. The developed finite element model of the tubular linear machine allows the analytical parameters that mathematically model the dynamic behavior of the electric machine, as well as some internal characteristics of the machine, such as, the electromotive force, cogging force and the developed electromagnetic force as a function of the electric load angle. The finite element model of the tubular linear machine contains a parametric geometric modelthat, through the Lua©programming language, allowed to automatically adjust all the constructive elements of the geometric model to the real electrical machine known characteristics. N/A

Halbach array has been widely applied to improve the magnetic and force performance of tubular linear motors for its attractive features. Conventionally, the Halbach permanent magnet (PM) array is mounted inside the windings to be the mover. Herein, the other kind of structure in which Halbach array is mounted outside the windings also draws our interest. The magnetic and force performances of the two kinds of motors are analyzed with Bessel functions and Lorenz Law. The analytical models of the magnetic field and the output force are then validated by the numerical simulations, respectively. Optimization analysis with a penalty function method is conducted as follows, and the magnetic and force performance of the two topologies are compared. The result of this paper can provide a basis for the generic motor designs.

This paper presents a new flexible linear actuator. It is a two-phase permanent-magnet tubular linear motor. An elastomer offers the desired actuator flexibility both between the coils of the stator and between the magnets in the mover. We determined the motor dimensions in a numerical parameter optimization and used various finite element models. The novel artificial muscle actuator is designed for tensile loads. It is electrically powered and obtains variable forces. Weights up to 750 g were lifted with a minimal bending radius of 200 mm. The outer diameter of the flexible linear direct drive measures about 30 mm.

A coupled field-circuit model of a 5-phase permanent magnet tubular linear motor A method for modeling of the dynamics characteristics for a 5-phase permanent magnet tubular linear motor (PMTLM) is presented. Its electromagnetic nonlinear field analysis with finite element method (FEM) has been coupled with the circuit model. The calculation model includes the equations for electrical circuits and mechanical quantities as well. They have been obtained using Lagrange's method. The calculated and measured waves of the mover position have been compared for several values of the excitation current. This comparison yields a good agreement. Presented calculation model is very useful in designing and optimization of the PMTLM and in the calculation of the parameters for the control algorithms intended for such a type of actuators.

Purpose – A fundamental disadvantage of three‐dimensional finite element (FE) simulations is high computational cost when compared to two‐dimensional models. The purpose of this paper is to present an approach to minimize the computation time by achieving the same simulation accuracy.Design/methodology/approach – The applied approach for avoiding high computational cost is the multi‐slice method. This paper presents the adoption of this method to a tubular linear motor.Findings – It is demonstrated that the multi‐slice method is applicable for tubular linear motors. Furthermore, the number of slices and thereby computation time is minimized at the same accuracy of the simulation results.Practical implications – The results of this paper offer a faster computation of skewed linear motors. At this juncture, the results are independent from the deployed FE solver.Originality/value – The methods developed and proved permit a faster and more accurate design of tubular linear motors.

Recent advances in Electric Power Steering technology have promised significant improvements in vehicle handling performance and safety. Electric power steering is a new kind of power steering which is developing rapidly these years due to their superior energy efficiency and energy conservation. This paper presents a possible design solution of an electric power steering actuator for hybrid electric vehicles. The design criteria of a tubular linear motor with interior permanent magnet are described and a tubular interior permanent magnet linear motor is designed and optimized with respect to weight and force ripple for Electric Power Steering application. Such an application requires low motor vibration and low force fluctuations which are considered in design process. A finite element analysis is used to validate the results obtained from the analytical model, comparing the magnetic field quantities as well as the mechanical force.

This paper presents a model for analyzing a five-phase fractional-slot permanent magnet tubular linear motor (FSPMTLM) with the modified winding function approach (MWFA). MWFA is a fast modeling method and it gives deep insight into the calculations of the following parameters: air-gap magnetic field, inductances, flux linkages, and detent force, which are essential in modeling the motor. First, using a magnetic circuit model, the air-gap magnetic density is computed from stator magnetomotive force (MMF), flux barrier, and mover geometry. Second, the inductances, flux linkages, and detent force are analytically calculated using modified winding function and the air-gap magnetic density. Finally, a model has been established with the five-phase Park transformation and simulated. The calculations of detent force reveal that the end-effect force is the main component of the detent force. This is also proven by finite element analysis on the motor. The accuracy of the model is validated by comparing with the results obtained using semianalytical method (SAM) and measurements to analyze the motor’s transient characteristics. In addition, the proposed method requires less computation time.

We have calculated magnetic field distribution and integral parameters for the slotted, five-phase, permanent-magnet tubular linear motor (PMTLM). We used a finite element (FE) model for the field analysis. We carried out the field analysis for different values of the exciting current and for variable mover position. To obtain experimentally the field distribution and its integral parameters, we developed and tested a physical model of the motor. We compared the calculation results with the measured ones and found a good conformity.

The Permanent Magnet Tubular Linear Motor (PMTLM) system using Hall-effect sensors as the position feedback devices is discussed in this paper. In order to have high precision position detection, simulation by the Finite Element Analysis (FEA) software Flux 2D and real experimentation are conducted. By choosing suitable Hall-effect sensor mounting positions, detecting the axial and radial directions of magnetic field and using double Hall sensors, high precision results are obtained. The results show the possibility of using Hall-effect sensors for linear motor position detection especially for low-cost linear servo systems.

This paper presents a novel Synchronous Reluctance Tubular Linear Motor (SyncRTLM) for high precision motion control applications, such as machine tools. Finite Element Analysis (FEA) of the motor is conducted to simulate the motor performance and to analyse the magnetic fields in the motor. The design and development of the built motor is outlined, where a novel construction technique is described. The position, velocity and force performance is measured using a modified servo current control algorithm.

Conventional linear machine consists of only one stator and one mover. In this paper, a permanent magnet (PM) tubular linear motor with multiple movers is proposed to improve the efficiency of stator field. The outer and inner movers can produce independent motions by interacting with the PM stator. It can be used in large systems requiring multiple driven elements and space saving. The employment of tubular structure helps to reduce the flux leakage and improve the system working efficiency. The design concept and operating principle of the proposed linear machine are introduced. The magnetic field distribution in the machine is formulated by using Laplace's and Poisson's equations of magnetic vector potential. Following that, the modeling of force output for this machine is obtained based on Lorentz law. Numerical computation is also conducted on the flux field. It shows that the derived analytical model fits with the result of finite element analysis (FEA) well.

The electromagnetic linear machines have wide applications in the electromagnetic aircraft launch systems [1] and in transportation systems [2]. Additional energy saving and efficiency can be achieved using a linear motor in the refrigeration application [3]. Linear electromagnetic machines are also very suitable for high-speed packaging, manufacturing sectors and precision positioning. There are different linear motor topologies. Tubular permanent-magnets are particularly attractive since they have a high thrust force density and high efficiency, no end windings, and zero net attractive force between stator and armature. There are various tubular motor topologies, in which the armature may be either air-cored or iron-cored. This paper describes the analysis and design of an improved axially magnetized Ferrite Tubular Linear Motor (FTLM) in which several innovative constructive solutions have been carried out to build a, low cost, easy to assemble and robust machine. Moreover, the purpose of this article is to investigate the application of ferrite in a permanent magnetic tubular linear motor. Several results are given illustrating the system response to various inputs.

Archives of electrical engineering 64(4), 605-616 (2015). doi:10.1515/aee-2015-0045, Published by Versita, Warsaw

This paper presents a minimization of eddy-current loss (ECL) in permanent-magnet (PM) of three tubular linear PM motors (TLPMMs). Three-dimensional Finite-Element Analysis has been used for the simulations. The ECL component is usually not taken into consideration in conventional PM motors. In present technologies, ECL is generated inside magnets of PM motors, due to both the high conductivity of the rare-earth magnets and the harmonics of the slot. This loss can increase the temperature inside the magnets and that may deteriorate their magnetic properties and potential risk of thermal demagnetization. Therefore, in the translator, segmented magnets has been used, because the cancelation of the ECL with this technique is possible as illustrated by the FEA results. Meanwhile, for the stator core of the three proposed motors, soft magnetic composite (SMC) material, Somaloy 700 has been used for its low cost and approximately zero ECL.

In robotic surgery without contact force transmission characteristic between master and slave system, the risk of a medical mistake becomes high. Then, a novel surgical assistance robot with force transmission is expected to be developed. This paper firstly introduces a two-degree-of-freedom (2-DOF) haptic system which can realize pitching motion and yawing motion. The system is composed of four half-circle-shaped tubular linear motors. Then, this paper focuses on the pitching motion system of the 2-DOF system. In this system, the effect of gravity and friction force is changed by the position and the velocity of motor. This paper proposes a disturbance model based on a trigonometric function of position and velocity for this system. It realizes vivid force transmission between master and slave motor in bilateral control. Bilateral control test of this system with disturbance model is performed. Experimental results are presented to validate the proposed model.

Direct-driven Electrical Hydrostatic Actuator (D-EHA) is a novel actuator for large aircraft Power-By-Wire (PBW) system. Achieving high dynamic response is an important task for D-EHA. In this paper, a tubular oscillating motor with improved Halbach array and non-ferromagnetic mover tube is proposed for high-dynamic system. Its structure and operating principle is first clarified. Then, focusing on the novel magnet array, analytical modelling is put forward and validated by FEM simulation. Comparisons with common used quasi-Halbach design over flux distribution, flux density and thrust are conducted. The results indicate that this novel magnet design has superior thrust and dynamic performance over traditional ones, especially for oscillating motor with relatively small stroke.

The calculation results for the thermal field of the permanent magnet tubular linear motor (PMTLM) have been presented in the paper. For the analysis of heating, four different mathematical field models have been created. Each of them uses the finite element method (FEM). In the most simplify model only the standard convective heat transfer coefficient has been implemented. In the most sophisticated model, thermal radiation, convective heat transfer and dependence of the coil resistance vs. temperature have been included. The numerical models have been verified experimentally.

This paper proposes a dual Halbach array to improve the thrust force of tubular linear machines. The force output of a single phase permanent magnet tubular linear motor (PMTLM) is obtained analytically. It is validated with finite element method (FEM). Based on the analytical force model, penalty method and scanning method are employed to conduct parameter optimization to maximize the force output for a given machine volume. One set of optimal parameters are determined, and used in the design of a research prototype.

The mathematical and physical models of the permanent magnet tubular linear motor (PMTLM) including control and supply system are presented in the paper. In the analysis a field-circuit model is used. The field model is calculated using the finite element method (FEM), while the circuit model is implemented in Matlab/Simulink software. The control algorithm as well as the graphical user interface (GUI) have been developed in the Matlab/Simulink package using the extended toolboxes. The controller uses a Texas Instruments digital signal processor (DSP) TMS320F2812. Data transfer is realized using the LPT port supported by the Real Time Workshop. Thus, it is possible to compare the results from the numerical model with the measured ones. A good conformity is obtained.

Tubular linear motor (TLM), with high thrust density, is suitable for space launchers. In this paper, the slot-less structure is adopted for the tubular linear motor, its thrust increases nearly with the phase current linearly, so it is more appropriate for the application occasions with a wide range of loads. This paper calculates and analyzes the motor losses and their distribution. In consideration of the high winding loss, the temperature rise of a single winding in a virtual is tested through the online testing system, and the temperature rise law of the circular winding with different high current density is gained. Then, the temperature of windings installed in the motor is also tested, and the result is compared with that of the single winding, and the reasonable estimate method of the winding is proposed.

An active pedal is installed in the vehicle accelerator. Unlike mechanical pedal, it has an electrical motor generating counter push-back force against drivers' foot press to give notices of the excessive gas consumption or emergency situation as the need arises. Since the linear motor needs no gears and shafts, it makes a simple active pedal structure compared with rotary motor. This paper presents a linear motor design scheme and a force ripple free control algorithm for the active pedal. The motor design is optimized to satisfy requirements; high force density and low detent force. The finite element method is used to analyze the motor. And considering the force ripple and reduction by non-uniform stator flux density, current profiles are developed for the active pedal with the hall signal and the accelerator pedal position signal. Experimental results are presented to verify the motor design result and proposed a force ripple minimization control method.

This paper discussing all the design literature review for electromagnetic suspension systems for passenger vehicle. Electromagnetic suspension is the alternative for existing conventional suspension system that uses passive suspension system. Generally, linear motor is used in the design of the suspension. This is due to the behavior of the motor that can exert linear force directly to the attached load. In addition, the linear force from linear motor is controllable. This paperreview with the effects of all types of electromagnetic suspension systems to the passenger's comfort. The reliability of fully active suspension system for vehicle also highlighted in this paper. A quarter-car model is used to assess the vehicle body vibration. This paper also deals with regenerative properties of linear motor that can improve the performance of lightweight vehicle.

Permanent magnet tubular linear motors have shown potential for use as direct drives in high precision machine tools. These devices are capable of replacing the traditional ball screw, given their ability to overcome or reduce many of the fundamental mechanical properties that limit the precision performance of the ball screw. However, given the desire from industry to increase speed and acceleration, the physical size of the motor must be minimised while maintaining high force output to increase bandwidth in high precision applications. This paper presents a new optimal tooth design to reduce the frame size of a slotted tubular linear motor. Several design aspects of the optimal tooth are considered and general solutions are derived. Data from finite element analysis and from an experimental machine is presented to validate the new designs.

As a pushing motor, a Tubular linear motor (TLM) can provide high instantaneous starting thrust. According to the characteristics of the pushing motor, this paper studies the thrust characteristics of tubular linear motor and analyses the starting thrust characteristics in different conditions including: materials of the secondary, length of air-gap and width of the primary tooth. The analysis results provide a foundation for the optimum design of TLM for pushing unit.

Electromagnetic force with minimum ripple is desirable in many applications. Therefore, the cogging force must be analyzed and solutions for its reduction must be worked out. This paper investigates two possible ways of skewing the magnets of a permanent magnet excited tubular linear synchronous motor to reduce the cogging force. In bioengineering applications, specially upper limb prostheses, minimizing losses is also an issue to prevent tissue overheating, which can lead to hemolysis and thrombogenicity. Hence, the eddy current and hysteresis losses are investigated and related to the ohmic losses.

This paper presents the optimization of a small tubular linear motor in order to obtain the best relationship of power, efficiency and volume. A genetic algorithm method with a mathematical model consisting in a Finite Element program and analytical expressions is employed. The obtained results are compared to experimental ones.