Michio Matsunami

A combined method for the global optimization using radial basis function and deterministic approach

The present paper proposes a combined method for the global optimization of realistic engineering problems using radial basis functions and a deterministic approach. A die mold model for orientation of magnetic powder is optimized to show the effectiveness of the proposed method.

Static torque characteristics of permanent magnet type stepping motor with claw poles

This paper analyzes static torque characteristics of a permanent magnet type stepping motor with claw poles. The analysis of this motor is a truly three-dimensional problem, and thus is performed by using three-dimensional finite element method with edge elements. We clarify detent torque characteristics by changing the magnetic situation in permanent magnets and by changing the shape of stator teeth.

Optimization of electromagnetic devices using artificial neural network with quasi-Newton algorithm

The paper proposes a method for the design optimization of electromagnetic devices. It utilizes an artificial neural network with the quasi-Newton algorithm. The proposed method can determine optimal weights and biases in the neural network more rapidly than the conventional method. A simple electromagnetic device is optimized by using this method. The paper reviews several optimization techniques for learning in multilayer neural networks. From the results of comparative numerical simulations, it proposes a method to construct the nonlinear mapping function more rapidly than the conventional algorithm, that is, the error back-propagation proposed by Rumelhart et al. (1986).

Finite element analysis of permanent magnet type stepping motors

This paper analyzes the static characteristics of a permanent magnet-type stepping motor with claw poles. The analysis of this motor is a truly three-dimensional problem. First, the authors clarify the distribution of magnetic flux density in the motor. Then, they calculate static torque characteristics of the motor and show the good agreement between calculated results and measured data. Moreover, they show the difference of torque characteristics developed by two types of magnetic situation of the permanent magnet.

Analysis of Thrust and Core Loss of Linear Motor with Magnetic Powder Core

This paper analyzes the thrust and core loss of a linear motor made of magnetic powder core, that is, soft magnetic composite material. The magnetic field is calculated by using axial symmetric finite element method and boundary element method. The difference of the thrust and core loss of the motor with magnetic powder core from those with laminated core is clarified quantitatively

Basic design and dynamic analysis of the small-sized flywheel energy storage system - application of Lorentz force type magnetic bearing -

Lead batteries are used mainly for energy storage. However, they are using chemicals and heavy materials, which will affect to environment badly. Therefore, clean energy storage systems are under development using magnetic bearing. However, eddy current causes serious rotational loss for energy storage. Therefore, Lorentz force type magnetic bearing is proposed. Rotational losses are expected to be negligible due to constant flux in airgap. To confirm operation of proposed magnetic bearing, an experimental setup is fabricated and basic characteristics are measured. Rotor could run-up to 3000 min−1. Moreover, new 5 DOF control type small sized energy storage flywheel is designed circumstantially.

Analysis of PWM Inverter Fed Linear Permanent Magnet Motor Using MATLAB/Simulink Coupled with FEM

A PWM inverter fed linear permanent magnet motor is analyzed by using MATLAB/Simulink coupled with the finite element method, which is fully integrated into a drive system. An axial symmetric FEM code is developed considering permanent magnet and eddy current in order to couple with MATLAB/Simulink. The stator current, thrust and displacement of the motor drive system are analyzed

Optimal design of thrust characteristics of permanent magnet type linear motor using orthogonal table and multiregression analysis

This paper proposes an optimization method using the orthogonal table of experimental design method and multiregression analysis coupled with 2-D FEM. A linear synchronous motor with permanent magnets (PMLSM) is designed to develop a large thrust and a small force ripple.

Generation of music scale from brushless DC motor with surface permanent magnets

The authors propose a method for generating a music scale from a brushless DC motor with surface permanent magnets by introducing d-axis current with a desired frequency. The paper begins by theoretically verifying the proposed method by analyzing the vibration emitted from the motor, which is the cause of an acoustic noise and/or musical sounds. The calculated results approximately agree with the measured ones. Moreover, the vibration characteristics are clarified by changing the desired frequency, the motor speed and the output power. Finally, this paper shows a method of generating desired musical sounds by sequentially emitting the musical scales.

Current-based detection of eccentric load coupled to brushless DC motor

This paper proposes a new diagnosis method for the eccentric load coupled to a brushless DC motor, which utilizes the amplitude of two-phase current. The experiment verifies that the Fourier analysis and the Wavelet analysis of the amplitude of two-phase current are effective. Especially, the Fourier analysis of the amplitude of two-phase current is proportional to the load torque with the coefficient of the inverse of torque constant at a low speed. The proposed method is very useful to estimate the amount of eccentric load using the stator current.