A new low-cost system for tyre-road force measurements: design and validation

The measurement of tyre-road contact forces is the first step towards the development of new control systems for the improvement of vehicle safety and performances. At present, tyre-road contact force measurement systems are very expensive and modify the non suspended vehicle inertia due to their high mass and rotational inertia moment. Thus, vehicle dynamics is significantly affected. The measured contact forces are therefore not fully representative of the contact forces that the tyres will experience during real working conditions. A new low-cost tyre-road contact force measurement system has been developed that is installable on any type of wheel. Its working principle is based on the measurement of three deformations of the wheel. Through a dynamic calibration of the instrumented wheel it is possible to reconstruct all three contact force and torque components once per wheel turn. These forces are then sent to the vehicle chassis and may be used by on-board active control systems to improve vehicle safety and performances. Validation tests were carried out with a vehicle having all four wheels equipped with the low-cost tyre-road contact force measurement system. It was possible to reconstruct contact forces once per wheel turn in any working condition with a precision that is comparable to that of existing high-cost measurement systems ([1], [2], [3], [4], [5])