CMP process used to polish glass substrates for hard disk drives and sapphire substrates for LEDs is rarely automated, and the success or failure of this process is depended on the skilled technician. In this study, the prediction of the removal rate and friction coefficient was conducted using only the real-time data output from the motors on the polisher. Multiple regression analysis was performed using the acquired training data set with the motor load current as the objective variable and the removal rate and friction coefficient as explanatory variables. The results showed that the predicted removal rate was approximately 1 μm/h lower than the experimental value. Therefore, we performed multiple regression analysis again after compensating for mechanical characteristics by conducting a low pressure polishing test. Multiple regression analysis was also performed by changing from the slurry free introducing method to the circulation method. As a result, it was found that the compensation process can improve the prediction accuracy and it can be applied to monitoring system the consumable condition by real-time prediction.

Rolling bearings are important mechanical elements used for rotating systems in various industrial machineries. Failures such as flaking by steel fatigue, may eventually occur if the bearings are used for a long period without any measures. A common practice is to replace the bearings even if they have not failed. For this reason, accurate failure prediction may allow the usage of bearings just before failure and contribute to the saving of natural resources. Various methods for evaluating fatigue damage of bearings have been studied. Rolling contact fatigue causes microstructural change in the bearing steel, which is quantified by X-ray diffraction method. It is known that fatigue damage can be estimated from the amount of microstructural change utilizing X-ray, however, this is a destructive method. Therefore, a non-destructive and simple diagnostic method to estimate the remaining life of bearings using Eddy current testing has been developed. This based on the fact that rolling contact fatigue causes a change in magnetic properties and microstructures of steel.

It is experts’ common knowledge that vibration measurements in the high-frequency band of several kHz to 10 kHz are necessary for precise diagnosis in CBM to detect the damages of rotating elements such as ball or roller bearings. Some cheaper digital output MEMS accelerometers with relatively low maximum sampling frequency may have insufficient anti-alias filtering effects and generate alias noise. However, there is a possibility to utilize the data with alias noise to detect the damage of bearing by frequency analysis from the envelope of the vibration waveform obtained by “under sampling”. If this is true, precision diagnosis of bearings by using inexpensive sensor system can be realized. To confirm this, vibrations in three axial directions were measured at the same timing by digital output MEMS accelerometers （wireless 3D sensor） with a maximum sampling frequency of 3.2kHz, and frequency analysis was performed on the composite waveform. The experimental results show that abnormalities （wound on the raceway of bearings） could be detected with sufficient sensitivity. Furthermore, by using the 3D envelope FFT, the measurement can be performed without concern for the mounting direction of the vibration sensor. This may greatly reduce man-hours and costs for equipment maintenance and enlarge the application of CBM.

Vibration and sound are widely used in the diagnosis of rotating machinery failures. While this method has the advantage of simplicity and high accuracy, it has the disadvantage of requiring high measurement frequency. Therefore, we have developed a method for vibration-based fault diagnosis with a measurement frequency that is a few hundredths of the frequency required by the sampling theorem, by performing signal reconstruction using compressed sensing. In this paper, we report the results of the evaluation of the parameter setting method based on the measurement results of propeller drive sound in the laboratory. We also report the results of applying the method to the vibration of a rotating machine in a real environment and evaluating its noise resistance performance.

In recent years, a method for evaluating the performance of sound absorbing material by parametric speaker has been proposed. However, this evaluation method is limited to experimental research, and sufficient theoretical research has not been conducted. Therefore, in this study, we theoretically examine the 2-microphone method, which is a previous study as a sound absorption coefficient measurement method, when using a parametric speaker. Furthermore, as a new sound absorption performance evaluation method based on this research, the sound absorption coefficient is derived from the sound pressure displacement of two points of ultrasound and one point of sound pressure displacement of audible sound generated from a parametric speaker. Then, the validity of proposed method is confirmed by numerical calculation.

In order to save labor in patrol inspections of power plants, the application of sensing technology to replace the five senses is under consideration. Use a 360° camera instead of visual inspection to record the site images, a technology has been developed to estimate and record patrol inspection routes using Visual-SLAM technology that uses 360° camera images. For example, if an abnormal noise occurs in the rotating machine, because we are checking the sound while moving during the patrol inspection, it is important to record the position. Therefore, we recorded video and audio data using a 360° camera, and linked the results of self-localization using Visual-SLAM technology with the results of time-frequency analysis of the audio data, we have developed a technology to easily identify the location where the acoustic data has changed.

Toward the realization of net zero in the future, the progress of lubricant diagnosis by color, which is important as a technology to support net zero is reported. Diagnosis of colored lubricant is possible with the color sensor method. In addition, it was confirmed that the color of lubricant had a high correlation with Ruler score.

This study focuses on the vibration tests of concrete materials to evaluate their dynamic characteristics including damping property. The vibration tests are conducted based on the impact excitation using an impulse hammer. The vibration response of an object is measured by a laser Doppler vibrometer. Frequency spectra are analyzed by a spectrum analyzer from the measured time history responses. This vibration test approach is applied to several specimens with different dimensions and water-cement ratios. Damping ratio of each mode for a specimen is calculated by half-width method with the measured frequency responses. The vibration test results confirmed that it is possible to extract differences in natural frequencies and damping ratios due to differences in the dimensions and water-cement ratios of the specimens. The measured natural frequencies were compared to those calculated by finite element analysis, resulting in good agreement between them. It is verified from the experiments that the present vibration test approach for the concrete materials can evaluate their dynamic properties and is effective to develop concrete structures with a desired damping in future.