Yasuyoshi Asai

Dynamic Analysis Method of Linear Resonant Actuator With Multimovers Employing 3-D Finite Element Method

This paper proposes the dynamic analysis method of a linear resonance actuator with multimovers under PWM (Pulse Width Modulation) feedback control employing the 3-D finite element method (FEM). The effectiveness of this method is shown by the comparison with the experimental results. Furthermore, the effect of a link-spring on each mover motion is clarified.

Amplitude Control Method of Linear Resonant Actuator by Load Estimation From the Back-EMF

This paper proposes a feedback control method for a linear resonant actuator (LRA), in which an external load estimated from two signals of the back-EMF is used as a target voltage in PID control. From the estimated load, it becomes possible to obtain an arbitrary amplitude of the mover. The effectiveness of this method was verified through FEM analysis.

3-D finite element analysis of linear resonance actuator under PID control

This paper proposes a numerical method to analyze dynamic characteristics on a linear resonant actuator when it is operated under PID control in PWM feedback control by the back-EMF detecting from a coil. The effectiveness of this method is clarified through the measurement of a prototype.

PID feedback control method for Linear Resonant Actuator using an estimated external load from the back-EMF as a target voltage

This paper proposes a feedback control method for a Linear Resonant Actuator (LRA), in which an external load estimated from two signals of the back-EMF is used as a target voltage in PID control. The effectiveness of this method was verified through the FEM analysis in which the magnetic field equation is coupled with electric circuit equation, control method, and motion equation. As a result, it was found to be possible to maintain arbitrary amplitude responded to the estimated load.

Dynamic Characteristics of Novel Two-DOF Resonant Actuator by Vector Control

This paper proposes a two degree-of-freedom (DOF) resonant actuator and clarifies its dynamic characteristics. The feature of this two-DOF actuator is that the movement of each x- and z-axis is independently controlled by vector control. In this paper, dynamic characteristics of the actuator were confirmed through 3-D finite-element method and measurement. In single axis drive, it was found that amplitude of each x and z-axis was independently controlled by vector control. On the other hand, the amplitude of each axis is almost equal to single axis drive without mutual interference in biaxial drive. The measured results agree well with analyzed one. From these results, the effectiveness of the proposed two-DOF resonant actuator was verified.

Simplified Position Estimation Using Back-EMF for Two-DoF Linear Resonant Actuator

This paper proposes a simplified position estimation method and clarifies the dynamic characteristics of the two-degree-of-freedom (DoF) resonant actuator under sensorless control. The feature of this two-DoF actuator is that movement in the x- and z-axis can be independently controlled by vector control. In this paper, we extrapolate the mover position from the zero crossing time and amplitude of the back electromotive force. During both single and biaxial drives, it was found that the amplitude of the x- and z-axis could be independently controlled without using position sensors. The measured results agree well with the analyzed results. From these results, the effectiveness of the proposed estimation method was verified.

Experimental verification of disturbance compensation control of linear resonant actuator

Linear resonant actuators (LRAs) have been used in a wide range of applications because of their high efficiency. However, the amplitude of LRAs severely decreases when external loads are applied. As a solution to this problem, this paper proposes a disturbance compensation control using sensor-less load estimation. First, we propose a load device which is able to evaluate the dynamic characteristics of an actual LRA mounted on an electric shaver. Next, we verify the effectiveness of the proposed control through measurement using 1-mover LRA and voice coil motor. As a result, measurement using this load device validates the effectiveness of the proposed control.

A disturbance compensation control for linear resonant actuator based on the law of energy conservation

Linear resonant actuators (LRAs) have been used in a wide range of applications [1] because they can reciprocate in a comparatively short stroke in spite of their compact size and light weight.

Proposed of novel linear oscillating actuator's structure using topology optimization

This paper proposes a novel magnetic structure of a linear oscillating actuator (LOA). The higher efficient magnetic structure is necessary for reduction in size and weight of an LOA. In a conventional optimization method using a genetic algorithm, it depends on an initial shape hard, and it is difficult to get a novel magnetic structure. In this paper, the topology optimization method which does not need the initial shape is applied to an LOA. The unguessed magnetic structure with magnetization direction and ferromagnetic shape is computed, and the validation of calculated structure is confirmed through the measured results.

A novel linear resonant actuator with 3-D structural magnetic circuit

In this paper, we propose a novel linear resonant actuator (LRA) with a 3-D structural magnetic circuit to improve its thrust characteristics . The effectiveness of the proposed actuator is verified through finite element method (FEM) analysis in which the magnetic field equation is coupled with the electric circuit equation, control method, and motion equation .