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A simplified evaluation method for cutting fluids has not been established to accurately estimate cutting performance. In this study, the friction coefficients of cutting fluids were calculated from the cutting force in micro feed end milling, defined as μ-MFM for the cutting performance index. For cutting conditions in which the finished surface roughness exceeded a largely theoretical value and the feed marks were hardly recognized, there was a high correlation between μ-MFM and the finished surface roughness in end milling of AISI 1045 compared with results from conventional friction tests. Moreover, the finished surface roughness in turning AISI 1045 and AISI 440C also increased with μ-MFM. The finished surface roughness in turning AISI 1045 and AISI 440C showed nearly theoretical values regardless of the cutting fluids when the cutting speed exceeded a certain speed. However, even if the cutting speed was high, the cutting edge transcription error on the finished surface in low-feed turning conditions increased with decreasing μ-MFM. It was possible that the difference in cutting edge biting performance for work material in cutting fluids had a substantial influence on the cutting edge transcription error for small uncut chip thicknesses on the finished surface formation area, such as the low-feed rate in turning. Therefore, cutting edge biting performance was evaluated using the cutting force instability rate CFIR, which was the quantitative value of the drifting cutting force in one end milling cutting with the feed rate based on the maximum uncut chip thickness on the finished surface formation area of the low-feed turning. As a result, the cutting edge transcription error in turning of AISI 1045 and AISI 440C under low-feed cutting conditions increased with CFIR. Therefore, there was a correlation between the CFIR and the cutting edge transcription error in turning at low-feed conditions.

In conventional friction tests, it is difficult to realize the high pressure and high temperature conditions of the tool-work contact area in cutting. In this study, the friction properties of machining fluids were evaluated using a friction coefficient calculated from the cutting force in micro feed end milling. The finished surface roughness in conventional end milling decreased with the friction coefficient of machining fluids obtained by this method. Also, the cutting speed dependence of the friction coefficient, and its influence on the biting property of the cutting edge can be evaluated by this method.

In this study, the difference of finished surface roughness and feed mark shape in lubricity of the cutting fluids were investigated in turning SUS440C. In the cutting speed of 20m/min, the oil having excellent oiliness caused the smallest finished surface roughness among the tested cutting fluids at the feed rate of 0.1mm/rev, while, the oil having high extreme pressure property was best at the feed rate of 0.2mm/rev. The feed marks were hardly recognized at any conditions. In the cutting speed more than 20m/min, the finished surface roughness in any lubricant conditions showed almost the same or slightly larger compared with that in dry conditions. The feed marks were recognized, and the transcription of cutting edges shape under wet conditions trended to be the same or worse than dry conditions.

Communication robots are expected to help elderly people that live alone. However, it is difficult for existing conversation systems to communicate smoothly. One reason for this is that the robot cannot recognize conversation breakdowns. To solve this problem, we tried to detect human motion characteristics when conversation is not established. The conversation experiment was conducted as a Wizard of Oz experiment. The behavior during the conversation was measured using an RGBD sensor, and the measured data analyzed through FFT analysis. The results showed that characteristic movement was found in head yaw movement.