Real-Time Vehicle Seat Surface Displacement Control System for Mitigating Whole-Body Vibration Under Low-Frequency Conditions

Abstract Purpose This study aims to mitigate the adverse health effects and discomfort from whole-body vibration (WBV) in vehicles, focusing on low-frequency vibrations below 10 Hz. We developed a Vehicle Seat Surface Displacement Control (VSSDC) system to enhance occupant ride comfort. Methods The VSSDC system uses a real-time feed-forward digital signal processing (DSP) controller and a compact DC linear actuator. It controls the vertical displacement of the seat surface that directly contacts the occupant. A state-space model, identified with the N4SID algorithm, was used to predict seat surface displacement from road inputs. The system was tested on a general passenger vehicle under varying conditions, and its effectiveness was evaluated using objective vibration data and subjective feedback from six participants. Results The VSSDC system successfully reduced seat vibration and WBV, especially for frequencies below 3 Hz. The system achieved an average WBV reduction of up to 25%, with an 18% reduction in vibrations under 3 Hz. The subjective evaluation indicated that reducing vibrations below 3 Hz provided a smoother and more comfortable experience for occupants, particularly softening the impact from road irregularities. Conclusion The VSSDC system offers a practical and scalable solution for mitigating low-frequency WBV by addressing the under-seat space and power constraints of general passenger vehicles. The combination of a compact linear actuator and an enhanced feed-forward control mechanism proved effective in improving ride comfort. Future research should involve a larger, more diverse participant group and explore optimization for multi-directional vibrations.