Analyzing the influences of bus driver seat's suspension system on driver's comfort level and stability.

This article focuses on analyzing the influence of the seat suspension damping ratio (ξ_se) on bus driver comfort and vertical stability using a three-degree-of-freedom (3DOF) quarter-vehicle model. Experimental measurements of a nonlinear air spring’s parameters were integrated into the model to simulate driver acceleration responses under random excitation (ISO 8608 standard) and transient excitation (IRC 99-1988 standard). Results indicate that increasing ξ_se improves comfort by reducing frequency-weighted acceleration (a_w) at low speeds (10–20 km/h) and enhances vertical stability by lowering the ratio of driver acceleration to gravitational acceleration (a/g) during bump impacts, with stability effects varying across vehicle speeds. The study highlights the importance of incorporating nonlinear air spring behavior and kinematic effects of the guiding mechanism for accurate seat suspension system modeling in bus driver environments.