Grasp Effort Evaluation Based on Muscle Activity

This paper proposes an estimation method of product usability based on tendon forces. The aim of this study is estimation of product usability using the tendon force during an object manipulation. Proposed method focuses on the forces of the tendons which are connected to the muscles. First, we explain the estimation method of product usability. The product usability is estimated quantitatively from the tendon forces. The tendon skeletal model of the index finger and the thumb is constructed to calculate the tendon forces. The tendon forces are calculated based on grasping information using a tendon skeletal model. Next, the cylinder pinching simulation using the proposed method is shown. The simulation result is compared with the human experimental result to evaluate the effectiveness of the proposed method. The sensory evaluation of the subjective grasp effort was conducted with five subjects. The calculated score of the simulation reflects the questionnaire survey result by the subjects. As an application, we show the evaluation results of the cell-phone button pushing. The calculated score by the simulation is also compared with the human questionnaire score. These results indicate that the proposed method can be used for the quantitative evaluation of the product usability.