Linear Oscillatory Actuator Research Articles

A New Linear Oscillatory Actuator with Variable Characteristics Using Two Sets of Coils.

Nowadays, electromagnetic linear oscillatory actuators are used as vibration control devices because of their high controllability. However, there is a problem that thrust and vibration are small at a wide drive frequency range. In order to improve this problem, we propose a new linear oscillatory actuator that can easily change its own characteristics by using two sets of coils. Through finite element analysis, large vibration was observed at 100 Hz in a series connection, and large vibration and high thrust were observed at 70 Hz and 140 Hz in a parallel connection. From these results, we verified that the actuator had two different characteristics due to switchable connections, and could generate high thrust and large vibration by smaller currents at a wide drive frequency range.

Development of the Haptic Device using Linear Oscillatory Actuators

Development of the Haptic Device using Linear Oscillatory Actuators

リニア振動アクチュエータを用いた触覚提示システムの開発

リニア振動アクチュエータを用いた触覚提示システムの開発

Development of the Haptic Device Using Linear Oscillatory Actuators for the Disabled

Development of the Haptic Device Using Linear Oscillatory Actuators for the Disabled

モータ一体型リニア振動アクチュエータの実験的検証

We propose a linear oscillatory actuator that converts rotational motion into linear motion using brushed DC motors. In this study, we verify the operating principle and characteristics of this actuator through FEM analysis and dynamic simulation. Additionally, we verify the validity of the analysis results through experiments on a prototype.

Design and characteristics analysis of linear oscillatory actuator with ferrite permanent magnet for refrigerator compressor

Actuators using NdFeB permanent magnets (PMs) are widely used, but they are costly and are affected by unstable material supply. In this study, a linear oscillatory actuator (LOA) using a ferrite PM is designed for use in the compressor for refrigerators, instead of the NdFeB PM. In spite of benefits of ferrite PM, it has not been widely used because the residual magnetic flux density of the ferrite PM is normally 35% less than that of a NdFeB PM. To overcome this shortcoming, we analyze the mover features of the LOA using two types of the ferrite PMs: interior PM type and Halbach PM type. The LOA designed has the same outer stator outer radius and number of coil turns as a conventional LOA with the NdFeB PM. The validity of the designed model is verified by comparing the analysis results using the nonlinear finite element method.

Comparison and Dynamic Behavior of Moving-Coil Linear Oscillatory Actuator with/without Mechanical Spring driven by Rectangular Voltage Source

This paper deals with the comparison and dynamic behavior of a moving-coil linear oscillatory actuator (MCLOA) with/without a mechanical spring. On the basis of a dynamic simulation model, the dynamic characteristics such as a current and a stroke of the MCLOA without the spring are predicted for various values of frequency. And then, dynamic test results are given to confirm the dynamic simulations. Finally, this paper describes the influence of the spring on the dynamic behavior of the MCLOA from the dynamic experiments of the MCLOA with/without the spring.

Development of a Haptic Device Using a 2-DOF Linear Oscillatory Actuator

Mobile haptic devices are being studied extensively as they have a great potential to be used as information transfer devices. Amemiya and Maeda proposed a method for haptic feedback by a linear oscillator using asymmetrical drive. We have then proposed a small two degree-of-freedom oscillatory actuator for application as a haptic device. Using this actuator, we were able to reproduce asymmetric acceleration such as the one by Amemiya and Maeda. However, this waveform is dependent on the mechanical structure of the slider-crank mechanism and thus it is actually not necessary to use it for our actuator. In this paper, we propose a new waveform that is more suitable to the characteristics of our actuator. This compatibility with our actuator can be seen in the power consumption of our actuator, which is decreased by 35%.

Characteristics analysis of a haptic device using a 2-DOF linear oscillatory actuator

Characteristics analysis of a haptic device using a 2-DOF linear oscillatory actuator

Comparative investigation of permanent magnet linear oscillatory actuators used in orbital friction vibration machine

The paper describes the alternative designs and performances of a single-phase moving-magnet linear oscillating actuator (LOA) which has been developed for orbital friction welding. The influences of the pole ratio on the performance of the LOAs are investigated and the optimal parameters have been identified with reference to the thrust force characteristics. It can be illustrated that a quasi-Halbach magnetized LOA, in which the magnets are assembled on a nonmagnetic mover yoke, represents the best electromagnetic performances. Finally, the predicted thrust force-current characteristic of quasi-Halbach magnetized LOA is validated by measurements on a prototype actuator.

Dynamic Characteristics Analysis of Two‐DOF Oscillatory Actuator and Experimental Verification of Prototype

SUMMARYRecently, linear oscillatory actuators have been used in a wide range of applications. In particular, small linear oscillatory actuators are expected to be used in haptic devices by being extended to provide multi‐degree‐of‐freedom motion with arbitrary acceleration. In this paper, we propose a compact two‐DOF oscillatory actuator that can move in various directions on a plane. The static and dynamic characteristics of the actuator are determined by the 3D finite element method. The effectiveness of this method is shown through a comparison of the measured results with the experimental results from a prototype. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(1): 58–65, 2014; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22312

Optimization of 3-D Magnetic Circuit of Linear Oscillatory Actuator for Diaphragm Blower

The efficiency and materials cost of a linear oscillatory actuator (LOA) for a diaphragm blower depends on the design of magnetic circuit. Therefore, it is necessary to optimize the magnetic circuit in order to develop a high efficiency and low price LOA by employing the magnetic field analysis method and an optimization method. In this paper, the 3-D multi-objective optimization of LOA with large magnetic force and small magnet volume is carried out using the combined 3-D finite element method (FEM), evolution strategy (ES), and particle swarm optimization (PSO).

Proposal of a Two Movers Linear Oscillatory Actuator for Active Control Engine Mounts

Active control engine mounts employing linear oscillatory actuators are mounted onto automobiles to reduce the frame vibration and noise. In conventional ACMs, the electric power consumption is high, and we clarify the causes of the high electric power consumption by dynamic simulation. Moreover, we propose a new LOA with two movers. The operational principle is described and the effectiveness of the ACM is verified using dynamic simulation.

A Novel Transverse-Flux Moving-Magnet Linear Oscillatory Actuator

A novel transverse-flux moving-magnet linear oscillatory actuator (TMLOA) for a compressor is proposed and analyzed, which features a unique configuration composed of usual laminated stators and moving-magnet mover. It not only offers low manufacturing cost and great dynamic characteristics, but also provides high thrust force density for its transverse flux path. The magnetic field and thrust force are analyzed by three-dimensional finite-element model. The proposed model is also used for studying effects of the axial dimensions variation on the thrust force and stroke, and then the selection of axial parameters is obtained with reference to the amplitude and smoothness of thrust force. Finally, the measurements of a prototype validate the predicted results. It shows the proposed TMLOA is very suitable for linear reciprocating motion drive applications such as compressors and pumps.

Analysis of eddy current losses in cylindrical linear oscillatory actuator with Halbach permanent magnet array mover

This paper describes calculations and comparisons of eddy current losses in a cylindrical linear oscillatory actuator with a Halbach array permanent magnet mover for different voltage source waveforms. Using the magnetic vector potential and a two-dimensional cylindrical coordinate system, the paper presents an analytical procedure and obtains solutions for the eddy current losses using the Poynting theorem. To verify the proposed method, the eddy current losses obtained from the analytical solutions are compared with the results of a non-linear finite element method. Moreover, this paper shows that the eddy current losses are more significant when the actuator is driven by a square voltage waveform than when it is driven by a sinusoidal voltage waveform.

Performance Evaluation of Linear Oscillatory Actuator for Active Control Engine Mount

At present, we are studying active control engine mounts (ACMs) with linear oscillatory actuators (LOAs), mounted on automobiles to reduce frame vibration and noise. The basic construction of our ACM consists of two main parts: a hydraulic mount for passive vibration damping and an LOA for active vibration damping. In this study, we evaluate the active control performance of our improved LOA which has high thrust and good linearity against current, by a dynamic vibration simulation, in which 3-D FEM analysis is coupled with vibration and control analysis. Additionally, we clarify the effect of the control method and the resonance on the performance of the ACM.

Research on the Mathematics Model of a Permanent Magnet Linear Oscillatory Actuator with Moving Iron and Non-Salient Pole

A novel permanent magnet (PM) linear oscillatory actuator (LOA) of moving-iron and non-salient pole was presented on the basis of LOA research. The mathematical model of the LOA based on the magnetic circuit method was established, and derived the relationship between electromagnetic thrust and coil current, mover’s displacement. The thrust of LOA was simulated by the Finite Element Method (FEM). The corresponding experimental results verifies the electromagnetic thrust is direct proportional to coil current and reverse proportional to mover’s displacement during effective mover’s displacement. So the derived mathematical model based on the magnetic circuit method is correct. This conclusion provides a theoretical basis for the further calculation of thrust, the selection of control current and the design of controlling method.

Examination of vibration control of linear oscillatory actuator

AbstractLinear oscillatory actuators (LOAs) are widely used in linear motor shavers, electric toothbrushes, and mobile phone vibrators as high‐speed oscillatory driving devices. The maximum amplitude of the motor is obtained at a resonant frequency that is determined from the spring constant and the mass of the motor. However, there is a problem with these actuators: the amplitude decreases sharply when the driving frequency differs from the resonant frequency in a mechanical vibration system with minimal damping. In this paper, we propose a control method for the resonant frequency in which the thrust, which shows the characteristics of a spring, is generated on the basis of the displacement of the mover and the damping factor, in which the thrust, which shows the characteristics of damping, is generated based on the velocity of the mover. The proposed method assures that the resonant frequency always corresponds to the driving frequency and that rapid changes in the amplitude are avoided. © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(4): 55–62, 2012; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.21172

Analysis on electric power consumption characteristics of cylindrical linear oscillatory actuator with Halbach permanent magnet array mover under electromechanical resonance frequency

This paper deals with electric power consumption characteristics of cylindrical linear oscillatory actuator with Halbach permanent magnet array mover under electromechanical resonance frequency. The control parameters such as back-emf constant, torque constant, resistance, and inductance are obtained from characteristic equations and experimental results. Then, the voltage equation and mechanical motion equation after deriving control parameters are proposed by impedance modeling considering mechanical component, and theoretical resonance frequency is predicted by impedance modeling. Finally, dynamic simulation and experimental results are presented for drive characteristics such as current, power factor, and displacement according to the various values of frequency, and this paper find that the current and electric power consumed in linear actuator have the minimum value at the resonance frequency.

薄型二自由度振動アクチュエータの動作特性解析と試作機による実験検証

SUMMARY Recently, linear oscillatory actuators have been used in a wide range of applications. In particular, small linear oscillatory actuators are expected to be used in haptic devices by being extended to provide multi-degree-of-freedom motion with arbitrary acceleration. In this paper, we propose a compact two-DOF oscillatory actuator that can move in various directions on a plane. The static and dynamic characteristics of the actuator are determined by the 3D finite element method. The effectiveness of this method is shown through a comparison of the measured results with the experimental results from a prototype. © 2013 Wiley Periodicals, Inc. Electr Eng Jpn, 186(1): 58–65, 2014; Published online in Wiley Online Library (wileyonlinelibrary.com). DOI 10.1002/eej.22312