Assessment of optimal passive suspensions regarding motion sickness mitigation in different road profiles and sitting conditions

Abstract

Automated vehicles (AVs) are expected to lead the evolution of mobility. Motion sickness, known as car sickness, is one of the main issues AVs will face, and could jeopardise their wide impact. However, a limited work has been done on how the optimisation of suspension dynamics could contribute. In this direction, this paper explores the mitigation of car sickness and the improvement of ride comfort through the optimisation of passive suspension systems. More specifically, a half car model, which represents a passenger vehicle from IPG/CarMaker, is used to optimise front suspension system for minimising comfort, but also maintaining vehicle handling while the vehicle is driving over two different road classes. The evaluation of comfort is conducted using the common standardised metric suggested by ISO-2631. After having obtained the optimum design solutions, the optimal solutions are simulated using IPG/CarMaker by assigning the road profiles on a 23 km long countryside road path. Then, vehicle accelerations are transferred to the occupant's head using appropriate models from the literature for both back-on and back-off sitting conditions. Afterwards, car sickness and ride comfort are further assessed to explore in detail how the tuning of the suspension systems through optimisation has minimised the first and enhanced the latter. For the assessment of car sickness, a three dimensional detailed biomechanical human model is used. The results imply that the pitch velocity seems more suitable, as a cost function for optimising the suspension systems with regards to motion sickness mitigation. Therefore, it should be considered either on its own or in combination with metric suggested by ISO-2631.

Integrated Active Seat Suspension for Enhancing Motion Comfort

“…In this work, the vehicle acceleration measurements (ẍ, ÿ, z, r, φ and θ) from the Xsens IMU are transmitted to the occupants' head (ẍ h , ÿh , zh , rh , φh and θh ) using a multidimensional human body model [20]. This takes into account…”

Effects of seat back height and posture on 3D vibration transmission to pelvis, trunk and head

“…Particularly in automated vehicles, motion comfort is essential (Kyriakidis, Happee and de Winter, 2015) as these vehicles are intended for spending time on work and leisure activities. Assessment of postural stabilization and comfort can be used in seat design (Papaioannou, Jerrelind, Drugge and Shyrokau, 2021) and in motion planning (Zheng, Shyrokau and Keviczky, 2021) of automated vehicles, potentially resulting in higher comfort levels.…”

Simulating 3D Human Postural Stabilization in Vibration and Dynamic Driving

“…Deeper knowledge of postural stabilization and its relationship to motion comfort is particularly relevant for motion planning [2] and active suspension control [3]. Future (automated) vehicles shall accommodate these new requirements with the design of seats [4] and interiors [5].…”