Signal synthesis for magnetoresistive speed sensors based on field simulations combined with measured sensor characteristic diagrams

Magnetic sensors based on the AMR-effect are widely used as sensors in automotive applications. The wheel speed sensor signal is used by the Anti-Lock-Brake-System (ABS) and other electronic stability programs. These systems require very high availability of the wheel speed information and consequently the sensor function demands very strict reliability. The electrical output signal is the combination of a complex magnetic system and the nonlinear behaviour of the magnetoresistive sensor. Small deviations from the optimal sensor position in front of the encoder wheel cause signal distortions in the electrical output signal.