Abstract
We have been developing a new aid vehicle, "Tread-Walk 2(TW-2)", which supports walking for elderly. TW-2 is controlled by the natural walking movement. But the user felt a sense of discomfort when the user started and stopped walking. This problem is caused by inaccurate estimation of the user's anteroposterior force. The estimation of the user's anteroposterior force is greatly related to inaccurate estimation of the vertical component of ground reaction force, which is approximated by the square waveform in the stance phase. This paper describes the new method to approximate the waveforms of the vertical forces as the isosceles trapezoidal waves depending on the walk phase and the gait cycle. By comparing the estimated anteroposterior force using the new method with the measured value using the force plate, the waveform pattern of the estimated force was found to be similar to that of the measured force.
