Angle- and length measurement with sensors based on the Tunnel-Magnetoresistive (TMR) effect

The demand for mechatronic actuators is increasing in numerous application areas. The number of actuators applied is growing not only in the field of industrial automation, currently accelerated by Industry 4.0 initiatives, but also in the automotive and aerospace industries. "Decentralised motion control", "x-by-wire" or "more electric aircraft" are just some of the terms accompanying this trend in the different fields of technology. This trend is also leading to new requirements for the sensor technology used for measuring angular and linear movement. Angle- and length measurement systems based on magnetic principles have experienced particularly strong growth in recent years. Especially sensors based on the Magnetoresistive (MR) effect have been increasingly used for motion control applications, both in the industrial and automotive fields. MR sensors are not only used to control electromechanical actuators, but also for pneumatic and hydraulic actuators and can be used for both incremental and absolute measurement. This paper describes the basic technology and applications of a new generation of sensors based on the Tunnel-Magnetoresistive (TMR) effect, which is expanding the range of applications even further.