Rotational Speed Sensor for High Temperature

Abstract:
A new sensor concept for future wheel speed applications in trucks based on a series resonant circuit with a sensor coil is proposed. This sensor is not only able to cover the full rotational speed range beginning at standstill but also the temperature range up to more than 200deg C. In addition a digital current interface, self-diagnosis-capability and additional information about airgap and temperature is feasible in order to enhance the reliability of the system. With this sensor concept it is possible to replace the currently used inductive sensors with rotational symmetry (TIM: Twist Insensitive Mounting) and a diameter smaller than about 10 mm. All this can be achieved with the help of signal processing.