Design of Virtual Disturbance Feedforward Controller for Motion Sickness Mitigation

This study presents a virtual disturbance feedforward controller (VDFC) to mitigate motion sickness in vehicles equipped with active suspension systems. Because feedforward control is difficult to implement in practice owing to the limited availability of measurable or estimable road-disturbance information, a half-sine virtual disturbance (HSVD) corresponding to a bump input is introduced and incorporated into the feedforward controller design. The proposed VDFC is integrated with a feedback controller developed from quarter-car and half-car models using linear quadratic static output feedback (LQ SOF) control. Furthermore, to enhance the motion-sickness-mitigation performance of the VDFC, a simulation-based optimization framework is formulated and solved using a heuristic optimization technique. Simulations with bump inputs are carried out in a vehicle dynamics simulation environment using the LQ SOF controller together with the optimized VDFCs. A sensitivity analysis is also performed for the parameters of the optimized virtual disturbance. The results indicate that, under the bump-like excitation conditions considered, the proposed method can improve ride comfort and reduce motion-sickness-related response measures.