A Study on Optimal Voltage of Electromagnet for Precision Measuring Robot During Surface Roughness Measurement by Vibration Analysis

Abstract

In electric power stations, precision surface roughness measurements are performed for environmental loading reduction, quality assurance, and safety. These measurements are performed manually at high places, narrow places, uncomfortable environments, etc. Therefore, workers in power stations experience a lot of hardship and are exposed to danger. To solve these issues, this study researched and developed a crawler-type robot with high measurement accuracy. Conventionally, robots that supply workpieces for surface roughness instruments have been developed. However, to the best of our knowledge, robotization and self-propelled precision measurement instruments have not been developed. Usually, a precision measurement instrument is designed for increased stiffness and stability because high measurement accuracy is the highest priority. However, if the stiffness and stability of the robot are as high as those of the precision measurement instrument, a problem occurs in the robot operation. Therefore, we propose a precision measurement unit using electromagnets and a crawler-type self-propelled robot to equip the unit. In a previous study, vibration analysis experiments using the impulse response method were performed on a precision measuring robot. In this study, the relationships between the voltages applied to the electromagnet and the reductions in the vibration magnitudes were determined by analyzing the vibrations of the robot during measurement. Furthermore, an optimal voltage of the electromagnets of the precision measuring robot to reduce vibrations was determined. From the results of the vibration analysis, the authors demonstrated that the optimal voltages were 9 and 12 V, and the precision measurement unit confirmed the effectiveness and validity of vibration reduction and improved measurement accuracy.