A Study on the Effect of Steering Input Frequency on Transient Lateral Dynamics of Four-Wheeled Passenger Vehicles 2019-26-0070
Vehicle lateral dynamic response parameters such as yaw velocity, lateral acceleration, roll angle, etc. depend on the nature of steering input. Response parameters vary with the amplitude and frequency of steering input. This paper deals with developing insights into the effect of steering input frequency on transient handling dynamics. For the purpose three different SUV segment vehicles with similar curb weight are considered. Vehicles are given continuous sinusoidal inputs as recommended in ISO 7401:2011. Steering inputs of the amplitudes corresponding to 4m/sec^2 lateral acceleration are given using a Steering Robo (ABD SR30) for three different frequencies as recommended in ISO 7401:2011. Variation in lateral acceleration, yaw rate, roll angle and roll rate responses as well as gains are studied for different steering input frequencies. Additionally, a pulse and a multi-frequency sine sweep input (0.2-2Hz) are given and the corresponding responses are studied to obtain yaw natural frequency, yaw damping and coherence of mentioned output variables with steering inputs. Paper discusses the relationship of steering input frequency with important transient handling parameters in both time and frequency domain. Several insights are developed, adding to the understanding of transient lateral dynamics and its relationship with steering input.