Electromagnetic Linear Actuator Research Articles

Design and Fabrication of an Optimized Cylindrical Electromagnetic Pulsed Actuator

In this paper, we present a strategy for designing a high-power linear electromagnetic pulsed actuator considering thermal, electromagnetic, and mechanical aspects. The optimization process was based on a first-principle calculation of the maximum current that the different parts of the coil and the materials conforming the device can resist without taking damage or altering their properties significantly due to thermal or mechanical stresses. Specifically, the minimum coil resistance (and the maximum safe current) for a given applied voltage was computed for a variety of wire diameters. Then, we employed a tailored numerical code to compute the coil geometry that produces the maximum pull/push force per ampere for typical commercial permanent magnet sizes. The combination of the optimized coil resistance and the optimized normalized force gives a maximized total force developed in the solenoid actuator. The designed coil was fabricated and characterized in order to analyze its performance. The results were compared with the calculations to perform an experimental validation of the numerical code obtaining and excellent agreement between computed and experimental results.

Cascade compound controller for direct-drive gear shift modules in automated mechanical transmission

A direct-drive gear shift module, which is based on electromagnetic linear actuator (EMLA), is introduced to improve the performance of the shift-by-wire system in automated mechanical transmission. The research background and approaches are first proposed. Then, the structure, characteristics and dynamic model of the EMLA are presented. In order to improve the shift quality, the position and force modes of the EMLA are divided to realize piecewise control strategy for the gear shift process. A cascade two degree of freedom compound controller is designed for these two modes. Specifically, the feedforward controller is based on the differential flatness to achieve high-response tracking performance and the feedback controller is based on the linear extended state observer to ensure robustness against plant uncertainties and disturbances. Simulation and experiment results proved that this cascade compound controller is effective, the duration of the whole shifting process is minimized, and the shift quality is significantly improved. The direct-drive gear shift module is technically feasible.

Research of Heat Dissipation Technologies for Electromagnetic Linear Actuator

As the core drive component of Electromagnetic Driven Valve Train (EDVT), Electromagnetic Linear Actuator (ELA) directly determines the performance of EDVT, and thus affects the dynamic performance and fuel economy of the engine. During high-velocity motion, ELA produces heat that will negatively affect its property or even make some damages. On the basis of analysis of temperature rise and temperature distribution of ELA, three heat dissipation technologies were proposed in this study, and relevant experimental test was carried out for each of the three technologies. Through comparing data of temperature rising test and considering factors such as noise and space usage, the method of silent fan equipped with cooling fin was selected as optimal heat dissipation scheme. This study provides sound test data on heat dissipation technology of ELA and is of important engineering significant.

Energy efficient active vibration control strategies using electromagnetic linear actuators

Energy efficient current control methods in electromagnetic linear actuators are required to minimize the electrical power requirements imposed by active vibration control strategies. In this paper an efficient bidirectional buck-boost converter is discussed in two scenarios: an active vibration isolation system and an active dynamic vibration absorber ( ADVA ) using a voice coil motor (VCM) actuator. An electrical analogous circuit of an experimental test platform is used as part of the simulation model. This test platform is based on a vibration shaker that provides the based excitation required for the single Degree of-Freedom (1DoF) vibration model under study. The proposed bidirectional non-isolated buck-boost converter can recover the energy when the VCM acts as a generator and store it for future use. Simulation results prove that this type of topology is far more efficient than linear amplifiers typically used in active vibration control. Within the context of slender structures, this efficient current control method improves the viability of using active vibration control in flexible structures such as beams.

Static Analysis of the Tubular Electromagnetic Linear Actuator with Permanents Magnets

Abstract In this paper a results of a static analysis of the tubular linear electromagnetic actuator is presented. The linear actuator consist of two parts: a cylindrical unmovable coils surrounded by a soft ferromagnetic case, and a runner made from sequence of permanent magnet with a soft ferro-magnetic gasket. In the first part of the paper the analytical method was performed for preliminary analysis. In the second part of the paper the more detailed analysis was depicted with using finite element method (FEM). The magnetic circuit shape and impact of selected dimensions on static characteristics is presented. Then the axial and radial electromagnetic force as a function of the runner dimensions were analysed.

Electromagnetic Linear Actuator providing High Force Density per Unit Area without Position Sensor as a Tactile Cell

Electromagnetic Linear Actuator providing High Force Density per Unit Area without Position Sensor as a Tactile Cell

공간적 제한 하의 전자기-열 연성 해석을 통한 철도차량 2차 현가장치용 선형 전자기식 액추에이터의 설계

공간적 제한 하의 전자기-열 연성 해석을 통한 철도차량 2차 현가장치용 선형 전자기식 액추에이터의 설계

Point-to-point motions control of an electromagnetic direct-drive gas valve

Electromagnetic linear actuators are widely used as drives in gas regulating valve, which is the key factor to determine the performance of the gas valve. In order to improve the performance of Electromagnetic direct-drive gas valve (EMDGV), a compound controller for non-repetitive point-to-point motions was proposed in this paper, combining with the advantages of Active disturbance rejection control (ADRC), Time-optimal control (TOC) and Sliding mode control (SMC). Simulation and experimental results show that the proposed method has the characteristics of fast response and high precision, and can achieve soft landing control. The response time is less than 8 ms, the control accuracy is 0.02 mm, and the seating velocity is within 0.04 m/s. The proposed method also has strong robustness to actuator parameter variation and good anti-disturbance ability.

Analytical Model-Based Multiphysics Optimization of a Nanopositioning Electromagnetic Actuator

This paper presents the multiphysics optimization of a new class of nanopositioning actuators, termed as flexure-based electromagnetic linear actuator (FELA). The optimization is carried out analytically based on the derived closed-form magnetic field, force, and thermal models, while its objectives include the maximizing of force generation and minimizing of thermal generation, which are both crucial for the nanopositioning actuators. The optimization results show that the new version of FELA achieved 67.3% improvement in force generation for certain current and 46.2% thermal reduction for certain output force, compared to the previous version of FELA with the same size, which was optimized using the numerical methods. The optimization results are also validated by the experiments of the new version FELA prototype, where 56.2% improvement in current–force sensitivity and 43% above reduction in thermal power are demonstrated experimentally. Furthermore, by utilizing the established modeling framework, several fundamental questions on the design of FELA are answered theoretically in this paper, such as the effect about the uniform and radial magnetization of the permanent magnet and the performance tradeoff between the different number of magnet segments.

Constrained optimization using penalty function method combined with genetic algorithm

In the paper the way of adaptation of the penalty function method to the genetic algorithm is presented. In case of application of the external penalty function, the penalty term may exceed the value of the primary objective function. This means, that the value of the modified objective function is negative, while in genetic algorithm the adaptation must be of positive value, especially it in the selection procedure utilizes the roulette method. The sigmoidal transformation is applied to solve this problem. The computer software is developed in the Delphi environment. The proposed approach is applied to optimization of the electromagnetic linear actuator.

A Model-Assisted Reduced-Order ESO Based Cascade Controller for Sensorless Control of Independent Gear-Shifting Actuators

Independent gear-shifting actuation systems, which are based on linear electromagnetic actuators (LEMAs), have tremendous potential to minimize the shifting duration of automated mechanical transmission (AMT). A velocity estimator based on the measurements of current is designed to achieve sensorless control of the actuator by using only electrical subsystem, thus avoiding the use of a complete system model that contains mechanical uncertainties. The elimination of the position sensor simplifies the structure of the gear-shifting system and reduces the manufacturing cost. To enhance the robustness of the position control, model-assisted reduced-order extended state observer (ESO) based cascade controller is constructed, which take parameter uncertainties and external load force as the lumped disturbance to observe and compensate them dynamically. Finally, simulation and experimental results are shown to demonstrate the effectiveness of the proposed velocity estimator and control method.

Thermal analysis of an electromagnetic linear actuator

This article presents a new electromagnetic linear actuator applied in the electromagnetic-driven valve train. To clarify the actuator’s temperature rise and heat distribution, a heat transfer mode...

Neural network–based speed control method and experimental verification for electromagnetic direct drive vehicle robot driver

The article presents an application of neural network to an electromagnetic direct drive vehicle robot driver. To achieve the accuracy and adaptability of speed control for driving vehicle with manual transmission and automatic transmission in various test conditions, a new neural network–based speed control method of the direct drive vehicle robot driver is presented. The mechanical actuators of the direct drive vehicle robot driver are directly driven through electromagnetic linear actuator. The coordinated control system structure of the direct drive vehicle robot driver is described. The mechanical actuators include the driving mechanical legs and the shift manipulator of the direct drive vehicle robot driver. The driving mechanical legs are consisted of the throttle mechanical leg, the brake mechanical leg, and the clutch mechanical leg. The displacement of the mechanical actuators represent the displacement of the driving mechanical legs, and the displacement of the shift manipulator. The number of the network hidden node is five, and a tangent transfer function is used as the neurons transfer function. The actual vehicle speed is as the variable of the network output layer, and a linear transfer function is as the neurons transfer function. The neural network training algorithm adopts the Levenberg–Marquardt training algorithm. The vehicle tests manipulated by the robot driver in different driving conditions are conducted. The proposed control method of the robot driver is verified and compared with the performances of other control method and human driver.

Mechanical Design of Innovative Electromagnetic Linear Actuators for Marine Applications

AbstractWe describe an engineering solution to manufacture electromagnetic linear actuators for moving rudders and fin stabilizers of military shipsItalian Ministry of Defence, General Direction of Naval Equipments (NAVARM), Projects ISO (2012-2014) and EDDA (2015-2017).. The solution defines the transition from the conceptual design of the device initially studied from an electromagnetic point of view to mechanical configurations that really work. The structural problems that have been resolved with the proposed configuration are described. In order to validate the design choices discussed we illustrate some results of the numerical simulations performed by the structural finite elements method. These results quantitatively justify the suggested mechanical solution by evaluating stresses and deformations in a virtual prototype of the structure during its functioning. The parts of the device that have been studied are the most critical because in cases of excessive deformation/stress, they can irreparably compromise the actuator operation. These parts are the pole piece-base set and the retention cages of the permanent magnets. The FEM analysis has allowed us to identify the most stressed areas of the previous elements whose shape has been appropriately designed so as to reduce the maximum stresses and deformations. Moreover, the FEM analysis helped to find the most convenient solution to join the pole pieces to the respective bases. The good results obtained by the suggested engineering solution have been experimentally confirmed by tests on a small prototype actuator purposely manufactured. Finally, a qualitative analysis of the engineering problems that have to be considered to design electromagnetic linear actuators bigger than the one already manufactured is illustrated.

Design and control of electromagnetic clutch actuation system for automated manual transmission

There is a growing interest towards Automatic Transmission in India as it provides better comfort and drivability. But the high cost of this system is limiting itself to be successful in the Indian markets. Due to this, Automated Manual Transmission (AMT) is considered which provides a better solution towards automation as it enhances the drivability and fuel consumption characteristics of a manual transmission at lower costs. However, torque lag and comfort are major issues with AMT which can be addressed by reducing the shift time. In this paper we describe an Electromagnetic Linear Clutch Actuator as a replacement to current electrohydraulic and electromechanical actuator. A control system for the actuator is presented and a clutch engagement strategy is also implemented which reduces the engagement time to 0.78 seconds while reducing jerk and torque lag. The actuator and control system is simulated on a MATLAB Simulink and agreeable results have been obtained.

Fuzzy-neural-network-based speed control method and experiment verification for electromagnetic direct drive robot driver

Vehicle test has a great significance for the development of new vehicle products. It is necessary for a new type of vehicle stereotypes to conduct a lot of vehicle test. Some vehicle test, such as emission durability test, vehicle performance test, vehicle noise test, high and low temperature environment test, vehicle road test, vehicle bench test, is more suitable for the operation by robot. Robot driver is an intelligent robot that can realize automatic driving under harsh environment in vehicle test instead of a human driver without any modification. Because of the vehicle is not required to be modified, and the vehicle robot driver can be directly installed in the different vehicle cab. The drive way of the vehicle robot driver includes the hydraulic drive, the pneumatic drive and the servo electric drive. The hydraulic drive is steady, but it needs an oil cylinder. It is not easy for the pneumatic drive to accurate positioning and the real-time property. As a driving device of the robot driver, the servo electric drive needs a mechanism of rotary motion into linear motion. Electromagnetic linear motor can solve the shortcomings of three other drive styles. It can improve the transmission efficiency and transmission accuracy, and make the transmission mechanism simple. A control approach of speed in an electromagnetic direct drive robot driver based on fuzzy neural network is proposed in this paper, in order to realize the accurate speed tracking of different driving test cycle conditions. The electromagnetic direct drive robot driver adopts an electromagnetic linear actuator as the driving device in this paper. The throttle mechanical leg, the brake mechanical leg, the clutch mechanical leg and the shift manipulator are directly driven through the electromagnetic linear actuator. The control system structure and the coordinated motion control model of the electromagnetic direct drive robot driver are given. On the basis of this, the speed control model based on fuzzy neural network of the electromagnetic direct drive robot driver is designed. The shift manipulator displacement, the throttle mechanical leg displacement, the clutch mechanical leg displacement and the brake mechanical leg are the input variables of the fuzzy neural network model, and the vehicle speed of the test vehicle is the output variable of the fuzzy neural network model. The number of the input variable membership functions is three, and the type of the input variable membership functions is gbellmf. The fuzzy neural network training algorithm adapts the hybrid learning algorithm combing with back propagation algorithm and least square method. The proposed control method of the electromagnetic direct drive robot driver is experimentally proved and compared with other control methods and with human driver performances. Actual vehicle test results and error comparison analysis show that the vehicle speed tracking accuracy of robot driver using the proposed approach is higher than that of robot driver using PID control method and human driver. Besides, the proposed method has good adaptability under all kinds of driving test cycle, which can ensure the accuracy and effectiveness of vehicle test.

A Review: Design Variables Optimization and Control Strategies of a Linear Switched Reluctance Actuator for High Precision Applications

This paper presents the review of design variables optimization and control strategies of a Linear Switched Reluctance Actuator (LSRA). The introduction of various type of linear electromagnetic actuators (LEA) are compared and the advantages of LSRA over other LEA are discussed together with the type of actuator configurations and topologies. The SRA provides an overall efficiency similar to induction actuator of the similar rating, subsequently the friction and windage losses are comparable but force density is better. LSRA has the advantage of low cost, simple construction and high reliability compare to the actuator with permanent magnet. However, LSRA also has some obvious defects which will influence the performance of the actuator such as ripples and acoustic noise which are caused by the highly nonlinear characteristics of the actuator. By researching the design variables of the actuator, the influences of those design variables are introduced and the detail comparisons are analyzed in this paper. In addition, this paper also reviews on the control strategies in order to overcome the weaknesses of LSRA.

Design of a Coaxially Magnetic-Geared Linear Actuator for Electric Power Steering System Applications

This paper will present the designs and feasibility assessments of a linear electromagnetic actuator that can directly provide the electric power steering (EPS) forces for an economy sized vehicle. Within the physical and operational constraints, a tubular device being composed by a linear permanent magnet motor and a magnetic gears set will be systematically designed to form the coaxially magnetic-geared linear actuator. Determinations of the optimized geometrical compositions of the motor and the gears set based on the fluxes and thrust forces will be assessed in detail. For practical considerations, the dynamic performances of the proposed EPS system and the corresponding radii of turning circles will also be evaluated at various driving speeds. It is thus confirmed that the adoptions of such electromagnetic systems for those common EPS systems are technically feasible.

Compound Control of Electromagnetic Linear Actuator Based on Fuzzy Switching

Due to the motion control system of electromagnetic linear actuator (EMLA) is a nonlinear system with poor controllability, single control strategy has been difficult to meet the requirements of its control. A compound control strategy based on inverse system control (ISC) and proportional-integral (PI) is designed in this paper. Switching between two algorithms, which is based on the fuzzy rules, prevents the control algorithm to jitter and jump. System model is build under Matlab/Simulink to do simulation analysis. The designed controller is integrated into the system simulation model and the system software of digital signal processor (DSP) controller. Simulation and test results show that the compound control strategy using fuzzy switching rules achieves the smooth transition of two control algorithms, and the goal of any position location, and continuous adjustment in 0~4mm lift. Positioning accuracy is up to ± 0.02mm, while the response time is less than 10ms.

The Influence of Pulsed Linear Electromagnetic Actuator Magnetization History on Precision and Impact Energy Stability

The influence of pulsed magnetization history in pulsed electromagnetic actuator on system output mechanical parameters has been discussed. Hysteresis behavior of pulsed linear electromagnetic actuators considerably degrades the precision and stability of impact energy system's performance. In this paper, a method is developed to provide stability for the dosed impact energy in pulsed linear electromagnetic actuators. Theoretical conclusions and experimental results have been provided.