A Study on Machine Instability Feedback During Digging Operation in Teleoperated Excavators

The construction industry in Japan has a shortage of workers and skilled operators because of the decrease in the working population due to the low birth rate and aging population. The number of operators of hydraulic excavators, which account for the largest proportion of construction machinery, is also decreasing and it has become difficult to employ operators with expert skills. Teleoperated hydraulic excavators can address this problem. It is difficult, however, to carry out safe and efficient construction work using a teleoperated excavator because of the lack of information available to the operator, such as the posture of the machinery and condition of the work object, in comparison with operating an actual excavator. Therefore, we propose a machine instability feedback system that calculates the attachment posture and digging reaction force and feeds the hydraulic excavator power margin directly back to the operator. This becomes an index of the margin until the excavator body, not the attachment, starts to move by the digging reaction force. We conducted a subject study using an excavator simulator to verify the effect of presenting the machine instability information to the operator. The results confirm that the operator could safely carry out digging work with acceptable work efficiency when machine instability information was provided.