Device and method for determining the speed of a wheeled terrestrial vehicle from measurements of a magnetic field

摘要: A device for measuring the speed of movement a wheeled terrestrial vehicle is characterized in that it comprises magnetometer (2) intended to take measurements magnetic field and positioned so as be sensitive variations caused by rotation at least one partially metallic wheel, such, capable delivering corresponding signal (20), means (3) processing said are establishing frequency spectrum thereof, determining, from spectrum, wheel deducing therefrom, on basis information representative radius vehicle. Application particular tachometers motor vehicles.