Vehicle State and Tyre Force Estimation Based on Four-Wheel Vehicle Model Compared to Bicycle Model

As an alternative to the very simple linear single track vehicle model for model-based vehicle state and tyre force estimation, the use of a four-wheel vehicle model including suspension kinematics is investigated in this contribution. Both models are compared based on experimental reference data. The largest potential advantage of using the four-wheel vehicle model is that relevant additional quantities of interest can be estimated in a coupled fashion without the need for enriching the core vehicle model with extra models, e.g., to derive the (individual) longitudinal, lateral, or vertical tyre forces. One of the core questions that this contribution is trying to answer is regarding the achievable estimation result accuracy when employing the four-wheel vehicle model instead of the bicycle model. We will initially assess test track conditions, while future investigations may expand to open road driving conditions.