In this paper, we propose a new position and direction measurement method of rock bolt hole with a cross line laser. A combination of the light-sectioning method and a hole detection in an image is used to estimate a hole position and direction. Experimental results in a tunnel under construction show that the proposed method can measure positions and directions with high accuracy.

Semiconductor manufacturing equipment requires improvement of the accuracy by a linear encoder in a short measurement range. The error in the short range involves the interpolation error and other errors. Improvement in the interpolation error had already achieved in existing research. In contrast, this paper describes the development of a grid interferometer-type linear encoder using a hologram scale with excellent accuracy in a short measurement range. The developed encoder can achieve the error excluding interpolation error less than 10^-6 magnitude per measurement range of 50 μm. In the development, error factors in the short-range measurement were examined. An equipment to identify the accuracy in this short-range measurement with high resolution and accuracy was then developed. Error analysis by the developed accuracy measurement equipment made it possible to improve a linear encoder accuracy. As a result, the accuracy of grid interferometer type linear encoder was able to reach at ±20 pm in the measurement range of 50 μm.

The purpose of this study is to develop an absolute track recording method to develop a higher accuracy magnetic absolute encoder. Shortening the magnetic pole distance is effective to achieve higher accuracy, but the absolute position misdetection due to attenuation and interference of the magnetic signal on the absolute track decrease the accuracy. Therefore, a magnetic pole array and its decoding method are developed to solve the problems of magnetic signal attenuation and interference by increasing the magnetic pole spacing without allowing three or more identical magnetic poles in succession. When the magnetic pole distance is shortened, the magnetic signal of the absolute track of the developed method detects the absolute position with a larger sensor gap than the existing method. At the magnetic pole distance realized by the developed method, interpolation errors are reduced, confirming the high accuracy of the magnetic absolute encoder.

Core pin driving method in the injection mold was proposed, in which core pins were installed in the runners located on both sides of the flow front meeting area, and internal melt flow was generated at the meeting part by the up-and-down movement of the core pins. In this paper, using a new mold in which the installation position of the core pin was changed inside the cavity, first, a simple method for estimating the internal melt flow caused by the drive of the core pin was proposed. Then, by this method, the internal melt flow, glass fiber orientation, tensile strength and fracture modes of the molded product were investigated. As a result, the area of flow front meeting face changes due to the forced melt flow driven by the core pin, and the area affects the joying strength of the meeting face, so that the tensile strength of the molded product changes. As described above, the molding phenomenon of the core pin driving method and the molded product characteristics were clarified.