主催: The Institute of Systems, Control and Information Engineers
会議名: 2022国際フレキシブル・オートメーション・シンポジウム
開催地: Hiyoshi Campus, Keio University, Yokohama, Japan
開催日: 2022/07/03 - 2022/07/07
p. 298-301
A large magnetic field must be generated by a recording medium and applied to a magnetic sensor to improve the signal-to-noise ratio of a magnetic encoder. A method for calculating the magnetic field generated by various recording media is required to efficiently design a magnetic encoder with a large applied magnetic field. Therefore, the purpose of this study is to develop a simulation method to calculate the magnetic field applied to a magnetic sensor in magnetic encoders using various recording media. Two types of samples are prepared. One is a coating-type magnet recording medium, which mainly contains Fe-Co alloy particles. The other is a Fe-Ni alloy sheet medium. The finite element method and medium magnetization model are used to consider recording conditions and the influence of the demagnetizing field of the recording medium. The actual recording medium is magnetized under the same recording conditions as those used in the simulation. The amplitude of the detection signal due to the applied magnetic field is measured. As the magnitude of the recording current is expected to strongly affect the amplitude of the applied magnetic field, the simulation and experiment are performed with several different recording currents. The errors between the simulated and measured amplitudes for the coating-type and alloy sheet recording media are 3 % and 7 %, respectively. This indicates that the proposed simulation method accurately calculates the amplitude of the applied magnetic field. In addition, the simulation and measurement results show similar effects of the recording current on the amplitude. This shows that the proposed method can predict the optimum value of the recording current. Using the simulation method, an optimum combination of material and recording current can be predicted more accurately to obtain the larger amplitude. The simulation method can also be used for analysis of self-demagnetization due to shape. These contribute to the efficient design of magnetic encoders.
