Computational Prediction of Subjective Sense of Force Based on Muscle Activity Estimation

We feel the effort during manipulation of a product. The effort takes a key role in the subjective product usability. It is known that muscle activity correlates with the subjective effort. Knowing the muscle activity is useful to predict one’s subjective sense. In this paper, we propose a computational prediction method of subjective sense of force based on the estimation of muscle activity. In this study, we make a hypothesis the subjective sense of force changes according to the amount of the muscle activity. To validate the hypothesis, we developed a three dimensional musculoskeletal model, and estimated the muscle activity during a weight holding task. We also defined the perception change ratio based on the measurement of the relationship between the quantitative applied force and the subjective perceived force. In the experiment, the subjective sense of force was predicted by using the perception change ratio that depends on the muscle activity. The experimental results confirmed the feasibility of the proposed computational prediction method of subjective sense of force.