Abstract
Keywords: Tyre, Tyre Contact Area, Cornering Stiffness, Fuzzy Model, Simulation
The problems of embedding real-time applications into the vehicle control systems using a tyre as one of control objects are acute. The reason is that many tyre parameters have high grade of uncertainty. One of the appropriate solutions in this area is the use of fuzzy sets in control algorithms.
The paper discusses the problems of fuzzy logic methods aimed at the evaluation of tyre dynamic parameters for the further application to automotive control systems. In this context, the three-leveled task system "Tyre - Surface", "Tyre - On-board automotive systems", "Tyre - Off-board transportation devices" can be proposed. This issue is illustrated in the paper by examples keeping the balance between the ease of problem handling and the feasibility of developed models. The developed fuzzy models have been tested using the MATLAB software.
The first example covers the fuzzy model of tyre contact area. A generalized model has been built to estimate the contact patch in relation to the normal wheel load and tyre inflation pressure. The data were obtained for test bench conditions on the basis of the visual processing of tread footprint. The testing programme has been developed for five tyre specimens from the different manufacturers and with the various blend of tyre rubber. The second instance is dedicated to the assessment of tyre lateral dynamics. The fuzzy model of cornering stiffness has been proposed with the use the tyre forces and slip angle as input variables. The developed procedure allows computing the tyre lateral force and can be applied to the fuzzy circuit processing the information from sensors of vehicle dynamics control systems.