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Tyre friction remote sensor using giant magneto-impendance

The aim of the project is to develop a remote interrogated
sensor system to monitor the frictional conditions between
the tyre and the roadway in order to enhance active vehicle
safety.

The aim of the proposed research is the development of a sensor system to monitor the frictional conditions between the tyre and the roadway in order to enhance the active vehicle safety. In vehicles having wheels with rubber tyres, the deformation and forces that occur in the tyre material give a great deal of information about the driving status of the vehicle. In particular, it is possible to monitor current frictional conditions between the tyre and the roadway. This information can be used to calculate the force transmission that takes place between tyre and roadway and for registration of the so-called 'slip position', which indicates the loss of gripping power even before the tyre begins to slip. Consequently, this sensor can be implemented for the development of new tyres with improved force transmission under different driving conditions and the development of an improved ABS (anti-blocking system). The proposed system will also be able to detect critical conditions of the tyre itself such as insufficient pressure or overheating and therefore prevent tyre explosion and reduce maintenance costs and environmental impact by increasing tyre's life. In the USA, around 250,000 accidents a year can be traced to insufficient tyre pressure. 75% of all flat tyres are the result of insufficient pressure or gradual loss of pressure due to leakage. A 10% drop in pressure cuts tyre service-life by 15%. (Source: SCHRADER-BRIDGEPORT INTERNATIONAL). To gain a broad acceptance of this technique the system has to be reliable, inexpensive, and simple to integrate in existing concepts of the automotive industry. These requirements can be fulfilled by a new class of wireless, interrogated, passive stress sensors that will be embedded directly into the tyre rubber. It has been shown that the stress measured at suitable positions on the tyre can be analysed to give information on the frictional coefficient, the roadway condition, and the tyre inflation. The sensor to be investigated in this project is principally based on a combination of magnetostriction and magnetoimpedance. In it, the stress produces a change of the permeability in a magnetoelastic element. Thus the skin depth of this element is altered leading to a change in the electrical impedance resulting in amplitude variations measured by an radio frequency link between the sensor and a stationary antenna. Initial experiments have been carried out on wires of magnetoelastic material to demonstrate that the concept of combination of magneto-striction and magnetoimpedance is entirely feasible. Their physical characteristics allow to present the sensors as very simple sensitive elements such as thin wires, ribbons or sputtered films and make them ideal for radio-based remote measurement of mechanical stress such as pressure, torque, friction or temperature in the harsh environments of automotive or road transport more generally. Due to their small size and weight these devices do not modify or interfere with the tyre's other features. Keywords: sensor, tyre, remote interrogation.
Acronym: 
TYRESENSE
Project ID: 
2 375
Start date: 
01-07-2000
Project Duration: 
60months
Project costs: 
1 890 000.00€
Technological Area: 
Sensor Technology related to measurements
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.