New magnetostrictive type torque sensor for steering shaft

Abstract When measuring torque, there are many demands, such as non-contact to the shaft, a small size, and a simple installation. Other critical factors include, special processing in the shaft, which is not required, and being cost-effective. Therefore, we have proposed a new magnetostrictive type torque sensor [IEEE Trans. Mag. 35 (1999) 4503] (MTS) for a steering shaft using an inverse magnetostrictive effect. Generally, a magnetostrictive type torque sensor has a large hysteresis property. With this sensor, we have shown that the hysteresis can be drastically decreased, if the excitation magnetic field double the value or more of the coercive force of the shaft material is applied.