Tyres, also known as “tires” in American-English, are critical components in road vehicles. Contemporary tyres not only ensure adhesion of their associated road vehicles to road surfaces in widely varying weather conditions, but also perform vibration and shock isolation functions. Moreover, during their operating lifetime, tyres are required to survive potentially up to several thousand or even millions of deformation cycles without exhibiting work-hardening failure, and yet exhibit a relatively modest degree of energy dissipation therein as a result of viscous dampening effects. As an additional operating requirement, contemporary tyres need to be robust against scuffing and objects impacting thereonto. Yet further, tubeless tyres are required to robustly grip onto their associated wheel hubs even when subject to considerable stresses, for example during emergency braking. In response to these aforementioned requirements for contemporary tyres, the tyres are constructed from elastic synthetic rubber, natural rubber and/or plastics material reinforced by meshes of metal wire, carbon fibre and similar. Modern tyres are therefore to be respected as highly optimized and advanced products.
Tyre failure during operation can potentially result in immobilization of an associated vehicle or even accident. Moreover, tyres operated at unsuitable pressures can adversely influence associated vehicle fuel economy; fuel economy is becoming increasingly pertinent in view of increases in fuel costs as well as in view of carbon dioxide generation and its perceived impact on World climate change.
It is known to mount sensors onto automobiles to monitor characteristics such as tyre pressure and acceleration in one or more orthogonal axes, and to convey information representative of these characteristics via wireless communication links to electronic control units (ECU) forming parts of data management systems of the vehicles. By employing such arrangements, it is possible to warn drivers of a need to inflate one or more tyres of their vehicles in order to improve driving quality and safety.
In a published Japanese patent no. JP 2003211924 (Mazda Motor), there is a disclosed a pneumatic sensor device suitable for use with a tyre of a vehicle for detecting tyre pressure and generating corresponding tyre pressure information. The device includes a transmitter for transmitting the pressure information together with an identification code for distinguishing the sensor device from other such sensor devices simultaneously included on other wheels of the vehicle. A control unit of the vehicle is operable to receive the transmitted pressure information and its associated identification code. The received pressure information is stored in a memory of the control unit. The control unit is operable to raise an alarm in an event that tyre pressure is not correct pursuant to predefined criteria.
In a published United Kingdom patent application no. GB 2385931 A, tyre monitors are described which are mounted adjacent to tyres near their tyre inflation valve stems. The tyre monitors include sensors to measure pressure, temperature and rotation direction of their respective tyres. Moreover, the monitors are operable to communicate measured sensor signals via transmitters to their respective receiver for subsequent processing and eventual presentation on a display unit. A vehicle mounted controller in communication with the receiver is operable to determine whether pressure information is associated with a front tyre or a rear tyre based on the strength of the wireless signal received at the receiver, and whether pressure data is associated with a right tyre or left tyre based on associated rotation direction data.
On account of tyre condition being an important factor influencing vehicle operating economy and safety, a technical problem is therefore how to provide more advanced wheel and tyre monitoring. When a fleet operator has many vehicles in its fleet, ensuring quality of wheel and tyre maintenance for all the vehicles in the fleet is paramount. Such quality can at least partially be ensured by following rigorous manual maintenance routines, for example by performing regular vehicle inspections and systematically changing tyres after a predefined number of traveled kilometers. However, it is still feasible that tyres and wheels undergo events which escape the attention of such rigorous maintenance routines and can therefore represent a potential hazard. For example, wheels are potentially exchanged between vehicles either without authorization of respective vehicles owners which can thereby circumvent such rigorous maintenance routines or by way of theft. Moreover, wheel hubs are susceptible over their operating lifetime to being provided with numerous replacement tyres.
As elucidated in the foregoing, tyre monitors are known. In order to measure tyre condition and detect unauthorized tampering with tyres, for example when wheels are temporarily removed from their associated vehicles, for example when exchange from winter tyres to summer tyres in Northern Europe and Canada, more advanced tyre and wheel monitors are required. However, there then arises a technical problem regarding how to manage complex configurations of tyre and wheel monitors, especially when tyres are replaced at mutually different times and wheels and their tyres are susceptible to being retained in storage over periods when exchanging between summer and winter tyres.
The present invention seeks to address the aforementioned technical problems.