Abstract
Safety of automobiles is increasingly demanded. To prevent burst of tires, smart tires are currently under development The embedded sensor enables highly precise measurement of road surface friction, and the precise friction measurements make more efficient anti-blocking-system (ABS). In a previous study, the authors proposed a new wireless strain monitoring method that adopts the tire itself as a sensor, with an oscillator circuit. This method is very simple and useful, but it requires a battery to activate the oscillator circuit. In the present study, the previous method for wireless tire monitoring is improved to produce a passive wireless sensor. The capacitance change of tire causes changes of the tuning frequency. This change of the tuned radio wave enables us to measure the applied strain of the specimen wirelessly, without any power supply from outside. This new passive wireless method is applied to a specimen and the static applied strain is measured.
