Keywords: seat, vibration, model, nonlinear, human body, vehicle
Model identification for nonlinear automotive seat cushion structure
This paper presents the nonlinear characteristics of typical automotive seat cushion structures. The experimental transfer functions between the seat butt (upper surface of seat cushion) and the seat track show that the magnitude and frequency decrease as the excitation increases. This indicates that the structure has both nonlinear stiffness and nonlinear damping. This paper develops two nonlinear models for seat cushion structures. The linear and nonlinear terms are compared and analysed in both the models. A Recursive Least Squares (RLS) method is used to identify the nonlinear parameters. The transfer functions obtained by the analytical models compared very well with those obtained experimentally. Two typical seats, a sports car seat and a luxury car seat, are analysed. These two seats represent extreme choices of typical seat structures. The results presented here can be useful for both the analysts and seat cushion designers.