The non-contacting models feature clock spring-free and Hall Effect (HE)-based technology, which allows measurement without the constraints of a connecting cable for the transmission of power and output signals.
The torque-only sensor (TOS) measures the relative shift angle between two rotating shafts linked by a torsion bar. This angular data is converted into a voltage output and is fed to the EPAS electronic control unit (ECU) to determine how much power assistance is required. This sensor is ideal for applications where a steering angle sensor is already discretely fitted to the column electronic architecture or mounted below the airbag housing. It is particularly useful for column EPAS applications that benefit from the elimination of the connecting cable.
The torque angle sensor (TAS) has the ability to collectively measure torque, steering wheel angle and speed with a number of steering wheel turns. The upper portion of the sensor contains components for differential torque measurement, and the lower housing uses a set of satellite gears to measure the rate and number of steering wheel turns. The steering angle sensor output is absolute and offers true power-off capability. This sensor is an optimal solution for vehicles that require both torque and steering angle feedback. The TAS sensor design effectively replaces the need to fit two discrete devices.
The torque index sensor (TIS) offers a cost-effective solution that features an additional HE switch that functions by counting the number of turns of the steering shaft for comparative analysis with an EPAS motor. A motor position sensor (MPS) obtains the relative value of angles from the steering assist motor and by comparing this information; the TIS sensor can accurately determine the absolute value of the steering angle without the use of a discrete steering angle sensor.