Evaluation system for product usability using human mimetic robot hand

The quantitative evaluation of product usability is important for product design. In this paper, we propose an evaluation system for product usability using a human mimetic robot hand with a tendon skeletal model. The proposed system enables us to evaluate product usability of a physical object, such as a prototype. To realize the system, we developed a robot hand which has a human mimetic structure. The design concepts of the robot hand are to imitate the human finger size, degree of freedom and fingertip structure. Ease of control is also characteristic of the robot hand. We propose to use tendon forces to evaluate the product usability. The joint torques during manipulation of the product are obtained from sensors on the robot hand. The tendon forces are calculated from the joint torques using the tendon skeletal model. Precise imitation of human finger structure makes the sensed joint torques similar to those of humans. The obtained joint torques are expected to be similar to those of humans. To evaluate the effectiveness of the proposed system, we conduct the experiments where the robot finger pushes cell phone button to evaluate its usability. The experimental result is verified by comparing with the existing questionnaire results from Ikeda [1]. The calculation score of the proposed system reflects the questionnaire result. These results indicate that the proposed system can quantitatively evaluate the actual product usability.