Keeping a grip
Sep 3rd 2009
From The Economist print edition
Transport: A new type of tyre, equipped with built-in sensors, can help avoid a skidand could also improve fuel-efficiency
FEW sensations of helplessness match that of driving a car that unexpectedly skids. In a modern, well-equipped (and often expensive) car, electronic systems such as stability and traction control, along with anti-lock braking, will kick in to help the driver avoid an accident. Now a new tyre could detect when a car is about to skid and switch on safety systems in time to prevent it. It could also improve the fuel-efficiency of cars to which it is fitted.
The Cyber Tyre, developed by Pirelli, an Italian tyremaker, contains a small device called an accelerometer which uses tiny sensors to measure the acceleration and deceleration along three axes at the point of contact with the road. A transmitter in the device sends those readings to a unit that is linked to the braking and other control systems.
The accelerometers in the Cyber Tyre contain two tiny structures, the distance between which changes during acceleration, altering the electrical capacitance of the device, which is measured and converted into a voltage. Powered by energy scavengers that exploit the vibration of the tyre, the device encapsulating the accelerometers and the transmitter is about 2.5 centimetres in diameter and about the thickness of a coin.
Constantly monitoring the forces that tyres are subjected to as they grip the road could help reduce fuel consumption by optimising braking and suspension. Moreover, it could promote the greater use of tyres with a low rolling-resistance, which are often fitted to hybrid vehicles. These save fuel by reducing the resistance between the tyre and the road but, to do so, they have a reduced grip, especially in the wet. If fitted with sensors, such tyres could be more closely monitored and controlled in slippery conditions.
Pirelli believes its new tyre could be fitted to cars in 2012 or 2013, but this will depend on getting carmakers to incorporate the necessary monitoring and control systems into their vehicles. As with most innovations, these are expected to be available in upmarket models first, and cheaper cars later. But if the introduction in 1973 of Pirellis steel-belted Cinturato radial tyre is any guide, devices that make cars safer will be adopted rapidly.
SOURCE http://www.economist.com/sciencetechnology/tq/displaystory.cfm?story_id=E1_TQNJJGSQ
Sep 3rd 2009
From The Economist print edition
Transport: A new type of tyre, equipped with built-in sensors, can help avoid a skidand could also improve fuel-efficiency
FEW sensations of helplessness match that of driving a car that unexpectedly skids. In a modern, well-equipped (and often expensive) car, electronic systems such as stability and traction control, along with anti-lock braking, will kick in to help the driver avoid an accident. Now a new tyre could detect when a car is about to skid and switch on safety systems in time to prevent it. It could also improve the fuel-efficiency of cars to which it is fitted.
The Cyber Tyre, developed by Pirelli, an Italian tyremaker, contains a small device called an accelerometer which uses tiny sensors to measure the acceleration and deceleration along three axes at the point of contact with the road. A transmitter in the device sends those readings to a unit that is linked to the braking and other control systems.
The accelerometers in the Cyber Tyre contain two tiny structures, the distance between which changes during acceleration, altering the electrical capacitance of the device, which is measured and converted into a voltage. Powered by energy scavengers that exploit the vibration of the tyre, the device encapsulating the accelerometers and the transmitter is about 2.5 centimetres in diameter and about the thickness of a coin.
Constantly monitoring the forces that tyres are subjected to as they grip the road could help reduce fuel consumption by optimising braking and suspension. Moreover, it could promote the greater use of tyres with a low rolling-resistance, which are often fitted to hybrid vehicles. These save fuel by reducing the resistance between the tyre and the road but, to do so, they have a reduced grip, especially in the wet. If fitted with sensors, such tyres could be more closely monitored and controlled in slippery conditions.
Pirelli believes its new tyre could be fitted to cars in 2012 or 2013, but this will depend on getting carmakers to incorporate the necessary monitoring and control systems into their vehicles. As with most innovations, these are expected to be available in upmarket models first, and cheaper cars later. But if the introduction in 1973 of Pirellis steel-belted Cinturato radial tyre is any guide, devices that make cars safer will be adopted rapidly.
SOURCE http://www.economist.com/sciencetechnology/tq/displaystory.cfm?story_id=E1_TQNJJGSQ
