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.