New approaches for linear position measurement

Konferenz: Sensoren und Messsysteme - 19. ITG/GMA-Fachtagung
26.06.2018 - 27.06.2018 in Nürnberg, Deutschland

Tagungsband: ITG-Fb. 281: Sensoren und Messsysteme

Seiten: 3Sprache: EnglischTyp: PDF

Persönliche VDE-Mitglieder erhalten auf diesen Artikel 10% Rabatt

Voss, Andreas; Bartos, Axel; Gayrard, Fabien (TE Sensor Solutions GmbH, Hauert 13, 44227 Dortmund, Germany)

Magnetic field sensing devices are widely used for contactless position measurements in a broad range of technical fields, such as automotive, industry, agricultural machines and consumer applications. Many of such measurement systems are based on detecting the position of a movable element along a measurement path by sensing the magnetic field created by the sensing magnet attached to the movable element. For instance, magnetic sensors are frequently employed for measuring the linear displacement of pistons in pneumatic and hydraulic cylinders or for level measurements of fluids in containers, such as in industrial ink tanks. Typically, an array of magnetic sensors is used to solve these tasks. The response of the magneto-resistive (MR) sensors not only depend on the applied magnetic field but also depend on the sensor temperature. Temperature effects may change the sensing signal and therefore may reduce the precision of the position measurement, if the actual sensor temperature is not known. The situation becomes even more difficult if a temperature gradient is present along the sensor array. As not all sensors of the used sensor-chain are directly influenced by the magnet at one time, a pre-processed compensation algorithm can be used to minimize the temperature effects which will lead to more accurate position results.