Magnetic sensors have several advantages which make them attractive for automotive applications: they are contactless (there is no mechanical wear-out), insensitive to dirt and are relatively simple. MMT formerly developed a 360 deg through shaft angular position sensor technology using a probe which measures the magnetic field angle variation generated by a rotary diametrically magnetized magnet. Now, MMT is focusing on derived designs providing additional features like a multi-turn Output, an improved accuracy or a very low sensitivity to external magnetic fields. One of the targets is to meet the standard requirements for the automotive steering applications (the Electronic Stability Program legislation being one of the key drivers), and especially an accuracy of +/- 1 deg or below. Another aim is to provide an absolute multi-turn output in a compact embodiment. In this paper, after presenting the basics of our 360 deg through shaft solution we will introduce a generic principle to improve the sensor linearity and provide prototype measurement results. Then, we will present absolute multi-turn sensor concepts including again prototype design and measurement results. In this paper, we have introduced a generic, efficient and simple solution to achieve high accuracies in a through shaft 360 deg sensor. Further steps will be now to apply it to specific applications like steering wheel sensor for ESP or electric motor shaft absolute position sensor. We also have introduced solutions for absolute multi-turn sensing. In that area, next steps will be to study integration with torque sensor for combined functions related to steering system and to pursue on the path toward a simple, reliable (and possibly contactless) multi-turn sensor.
Multiturn and high precision through-shaft magnetic sensors
Magnetische 360-Grad Präzisionssensoren
2009
6 Seiten, 16 Bilder, 11 Quellen
Conference paper
English
European Patent Office | 2017
|European Patent Office | 2017
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