Vibration Synthesis and Seat Dynamics Compensation for Single-Axis Seat Vibration in Driving Simulators

Realistic seat vibration reproduction is essential for delivering authentic haptic cues and enhancing driver immersion in driving simulators. Unlike direct playback of road recordings, simulator applications require vibration synthesis that responds interactively to driver inputs and vehicle dynamics. Reproducing these vibrations at the seat is complicated by actuator bandwidth, cross-axis coupling, and the dynamic behavior of the seat structure, which can alter the intended target response. This work presents vibration synthesis and seat dynamics compensation methods implemented on a dual-axis seat vibration reproduction system equipped with horizontal and vertical actuators. Frequency Response Functions (FRFs) were measured to characterize the system dynamics under both single-axis and dual-axis excitations, capturing direct responses as well as cross-axis effects. Run-up, coast-down, and combined excitation tests were then used to evaluate performance under more operational conditions. Several seat dynamics compensation strategies were compared, including direct inverse of the FRF, energy-based, and manual equalization of the signal. Single-input single-output (SISO) methods reproduced the target response with good accuracy under independent excitation, while simultaneous dual-axis operation revealed correlated responses and inaccuracies due to cross-axis coupling. To address this, a matrix-inverse method based on the full FRF matrix was implemented. The research presents results comparing these methodologies, highlights their respective challenges and limitations, and includes perceptual assessments to evaluate how the reproduced vibrations were perceived by participants.