Analysis and Prediction of Tire Traction Properties for Different Inflation Pressures Based on Vertical Deflection Control Method

The variation of inflation pressure has an important effect on the longitudinal slip characteristics of tires that can affect the braking performance of the vehicle, so the influence of inflation pressure should be taken into account in high-precision tire models. However, the effects of inflation pressure and vertical load on tire force and moment characteristics are usually coupled. When the inflation pressure is changing while keeping the load constant, the tire contact patch and carcass stiffness will change at the same time, so the contribution of tread and carcass to tire traction properties cannot be decoupled so that the tire design cannot be well guided. On the contrary, if the vertical loading method is changed, the vertical deflection control is used instead of load control. It is found that if the loaded radius of the tire is kept constant, the inflation pressure has little effect on the contact area between the tire and the road, it only changes the contact pressure. In this way, the contributions of tread and carcass to tire force and moment can be decoupled. Therefore, a tire traction test method with vertical deflection control is proposed in this article. Based on this method, an extended traction model is proposed to express the influence of tire inflation pressure.

Through experimental validation, it is found that compared with the method of vertical load control, the tire traction test based on vertical deflection control can better reveal the influence mechanism of inflation pressure on longitudinal slip stiffness and longitudinal friction coefficient, which is more conducive to the tire design. The proposed traction model is verified to be reliable. The predicted error index of the longitudinal force is less than 2%.