1. Field of the Invention
The present invention relates to a method and a system for determining a cornering angle of a tyre mounted on a vehicle, during running of such a vehicle.
2. Description of the Related Art
Information related to tyre conditions should be provided to a vehicle control system in order to control a vehicle. For example, such information may include the one relating to the load exerted on the tyres or to the length of the contact region between the tyre and the ground. For instance, U.S. Pat. No. 5,793,285 discloses a method and apparatus for monitoring tyres on a vehicle, by continuously measuring the distance between the associated vehicle axle (or a vehicle body part rigidity connected thereto) and the road, while the vehicle is in operation. From this measurement, the tyre deflection is determined. According to the authors, the measured tyre deflection represents a comparatively exact measure of the respective tyre load. When the tyre deflection determined leaves a predetermined desired range, a warning signal is transmitted.
PCT patent application no. WO 03/016115 discloses a method for determining the charge or load exerted on a tyre of a motor vehicle and/or for monitoring tyre pressure, wherein the pressure in each tyre is detected during operation of the vehicle and the rotational behavior of the individual wheels is observed. Load distribution parameters are also determined by comparing the rotational behavior and/or changes in said rotational behavior of the individual wheels during given driving states, taking into account preset and/or predetermined and/or learned variables. Tyre pressure and load distribution parameters are used to determine the load or charge exerted on the tyres and/or pressure loss. Furthermore, US patent application no. 2003/0058118 discloses a vehicle and vehicle tyre monitoring system, apparatus and method for determining the load-induced deflection or deformation of a vehicle tyre. Based thereon, deflection-related information, such as tyre load, molar air content total vehicle mass and distribution of vehicle mass, are provided.
U.S. Pat. No. 6,538,566 describes a process for the in-service monitoring of the condition of a tire of a wheel riding on a ground, the tire having a tread, the process comprising the steps of: providing in the tire, near the tread, a miniature sensor for sensing radial acceleration; monitoring the variations in the measurement from the sensor; detecting a decrease in the radial acceleration, said decrease corresponding to a zone of the tread in contact with the ground; and measuring a period of low radial acceleration phases and a fraction of this period during which the radial acceleration is low, said fraction within each period being related to a length of said zone where the tread is in contact with the ground, and thereby to the condition of the tire.
EP-0 887 211 relates to pneumatic tires for vehicles and in particular to a system for monitoring Ores by monitoring their deflection. The system comprises: a sensor device operatively arranged with respect to the tire to create an electrical pulse during the footprint pass corresponding to a deformation of the tire; means for calculating a ratio of the duration of said electrical pulse to the duration of one tire revolution; means for transmitting said ratio to an evaluating unit placed in the vehicle; wherein said sensor device is placed within the tread area of said tire in order that said electrical pulse presents a first maximum at the entrance and a second maximum at the leaving of said footprint pass.