Abstract
Besides primary driving task, we used to have additional actions, for example, pushing some buttons and looking for something. Such secondary actions have been the major cause of traffic accidents. We refer to such body movements as physical workloads(PWL) and analyze a driver behavior to clarify the influence of the physical workloads on the driving performance. It is known that an internal force of closed loop mechanism affects stiffness of the mechanism. If drivers maintain the body posture according to the PWL, the internal force to a steering wheel increases. In this paper, we analyzed stiffness of a steering wheel according to the body movement.
