Active sensory feedback in manual machine tool operation -Effect of filtration in visual feedback of cutting force

Abstract

In some manual manufacturing processes, the human operator could perform its task well and swiftly, if it could acquire sensory information helpful to the performance effectively. In those situations, high frequency components contained in the sensory information (feedback signal to the operator) must be suppressed, because the operator cannot recognize and respond them. However, the filtering condition suitable for the suppression has never investigated so far. In this research, the cut-off frequency of low pass filter in active visual feedback system has been investigated. The objective manufacturing operation is to make a small-diameter hole onto an aluminum workpiece with a carbide drill. As the visual feedback device, see-through-see-around type head mounted display (HMD) was examined. The feedback information is cutting force and its magnitude is displayed by sector chart on HMD's screen. As the results, from the points of operating efficiency, workload and fatigue of the operators, it is found that the optimum cut-off frequency exists and it is related with operator's response characteristics measured separately.