Correlation between Subjective and Objective Evaluations of Steering Performance of Passenger Vehicles

The relationship between subjective and objective evaluations on the steering performance of passenger vehicles is investigated to realize the subjective evaluation with objective measurement and to completely replace the objective measurement by subjective evaluation. The subjective evaluation uses steering performance as the study point, and objective evaluation focuses on angle pulse, wheel, snaking, and central tests. The subjective and objective evaluation systems are established, which consist of 7 subjective evaluation indicators (inherent steering characteristics, steering transient response, yawing response, and others) and 17 objective evaluation indicators (formant frequency, average steering angle, yaw velocity gain, et al.). A total of 7 groups of subjective evaluation score and 17 groups of objective evaluation score are obtained by evaluating 4 vehicles. The functional relationship between subjective and objective evaluations is established through regression analysis. Result shows that a 1D binary linear relationship exists between subjective and objective evaluation indicators under a small sample condition. Most of the subjective evaluation indicators have a negative relationship with formant level within the linear function. The formant level is a critical indicator that influences the steering performance of passenger vehicles on the basis of hypothesis testing and dynamic analysis. The lower the formant level is, the higher the subjective evaluation score will be.