Development of a simplified human body dynamics model for motion control on a vehicle

Abstract

This study aims to create a system that can be used to evaluate vehicle characteristics while simultaneously controlling human body behavior through numerical simulations. The proposed system consists of a vehicle model, a human body dynamics model, and a musculoskeletal model. In the present paper, a human body dynamics model using multibody dynamics is proposed. However, attempting to implement a whole-body model would necessitate dealing with multiple degrees of freedom and give rise to problematic phenomena. Furthermore, the influences of human motion are uncertain and difficult to parameterize. Accordingly, in the present research, the human model is limited to the head and trunk of a human body riding inside a vehicle. This human body dynamics model is composed of an internal model and an external model. The internal model incorporates a motion control model. The internal model, which is composed of an inverse model and a forward model, generates commands to control body motion, while the external model simulates the actual body motion. Then, in order to identify the parameters of the motion control model, the motion of maintaining posture is measured using a simple experimental device that can simulate horizontal acceleration applied to a subject. In order to demonstrate the effectiveness of the proposed human body dynamics model, a simple human dummy model (which simulates the experimental model used for experiments such as automobile collisions) that consists of only a spring and a damper was created. Comparing this dummy model with the human body dynamics model reveals that the human body dynamics model can simulate details of human motion that the simple dummy model cannot.

Keywords

• human model
• vehicle
• simulation
• multibody dynamics
• motion control