The tyre slippage in conventional tyre traction characteristics is termed as a loss of the linear velocity of the wheel center due to the integrated tyre longitudinal compression and soil compaction. Recent studies on agile tyre dynamics and mobility identified a necessity for a separate analysis of the tyre and soil contributions to the tyre slippage and, thus, their separate inputs to the tyre traction characteristic. In this regard, the paper presents a tyre traction characteristic that includes the peak friction coefficient and tyre characteristic slippage as parameters of this characteristic. A method is offered to determine the two parameters based on experimental data sets of the tyre slippage and the circumferential wheel force. A new method is proposed to split the tyre characteristic slippage into two components and, thus, to quantitatively characterize the contributions of the tyre and soil to the tyre slippage and the tyre traction characteristic.
The results of this study can be utilized to rank similar tires of different manufacturing companies with regard to the tyre slippage power losses in the same terrain conditions. The tyre and soil separate contributions are important for modelling and calibrating new tyre sensors to detect the tyre slippage components.