Yoshimi Kikuchi

Study on high accuracy optical encoder with 30 bits

This paper describes a fabrication method for a high accuracy disk which has a higher accuracy than a drawing system of an original disk pattern, and development of an optical rotary encoder with a resolution of 30 bits. High accuracy disk technology is the most significant technology regarding fine angular sensors, and it has an accuracy of less than 0.5 /spl mu/m and 1 sec as it reaches its limitation. However, concerning the disk for an angular sensor it is necessary to obtain a higher accuracy. And then, this study has enabled the creation of a higher accuracy disk and encoder by rejecting disk error which measured at repeatable errors. By using the studied technology, it was possible to make the high a resolution and high accuracy optical encoder with the resolution of 30 bits.

Reduction method of external magnetic field effect on VR resolver

This paper deals with an angle accuracy of Variable Reluctance resolver to detect an angle of rotor about hybrid electric vehicle motor. Magnetic field effect was reduced by setting to long distance from t he motor exciting coi1, conventionally. However, it was found that magnetic field effect reduction method was accomplished by increasing of a back yoke thickness on the VR resolver stator by using finite element method.

5 NRAD high-resolution and multi-functional angle sensor for nanotechnology

In recent years nanotechnology control systems have required a high-resolution and high-precision angle sensor. Technology for the manufacture of a high-precision disk and measurement evaluation technology using an angle calibration system were developed. A high-resolution optical angle sensor with. high precision and a self-accuracy calibrating function was also developed. The resolutions of the measuring instrument and the angle sensor were aimed at 1 ms (0.001 s). The component engineering for realizing 1 ms measurement consisted of eight types of technology: (1) the mechanism section by a disk realization highly precise for 0.3 s; and (2) CAE (computer aided engineering) analysis technology and high-precision coupling technology; (3) the signal dividing technology for an ultra high-resolution signal; (4) the accuracy compensation technology by ROM; (5) the self-accuracy calibrating technology; (6) the angle calibration system technology with 1 ms of resolution; (7) the high-speed serial bi-directional synchronous bus communication technology; and (8) speed signals and an angular-acceleration signal achieved within a sensor. Using these component engineering technologies, a 30-bit resolution high-precision and multi-functional angle sensor was studied. In order to develop an ideal angle sensor, high-precision composition parts were developed. In addition, the development of an evaluation measuring instrument, accuracy compensation technology, signal dividing technology for high-resolution, and wireless high-speed signal communication technology were achieved. Thus, a 30-bit high-resolution and high-precision multi-functional angle sensor was developed.