Development of a Multibody Dynamic Model of a Seated Occupant to Evaluate More Realistic ISO-Standard Motion Sickness Dose Value 2023-01-0853

It is estimated that the share of autonomous vehicles in the market will reach an important point between 2050s and 2060s. Some major benefits of autonomy in ground vehicles can be regarded as reducing traffic, saving fuel and reducing emissions. Accordingly, it is anticipated that autonomous vehicles (AVs) will prevent driver error from happening, which is the primary cause of 90% of traffic accidents. However, it is a prerequisite that the AVs are accepted by the public, and be used regularly in daily life. AVs obliges everyone to be a passenger, thereby occupants will lose authority on the vehicle and have to deal with non-driving tasks during an automated ride. This will increase the lack of situational awareness, leading occupants to be more sensitive to motion sickness, where the major reasons of motion sickness are conflict between vestibular and visual senses, lack of control, unable to predict the direction of movement. Increase in motion sickness reduces comfort and can adversely affect people's attitude towards AVs. In this study, a Simscape Multibody dynamic model is developed based on a 6 DOF biodynamics model including the vertical and fore-aft motion of the whole body. The multibody model is then integrated with vestibular system dynamics to evaluate the ISO2631-1 standard motion sickness dose value (MSDV). This study aims to develop a realistic multibody simulation model to be used in comfort analyses of AVs in terms of motion sickness. This paper also demonstrates the impact of using biodynamics models in evaluating motion sickness for simulation environment. Results are quantified by using Simulink Vehicle Dynamics Blockset by comparing MSDV with and without the multibody model for several case scenarios (i.e. double lane change test, constant radius, increasing steer).