Magneto-Elastic Sensor, Load Pin, Ball-Joint And Tow Coupling Comprising This Sensor, Method Of Determining A Direction Of A Load Vector

The magneto-elastic sensor according to any of the preceding claims, wherein the member comprises a first magneto-elastically active region and a second magneto-elastically active region, which are directly or indirectly attached to or form a part of the member in such a manner that the mechanic stress is transmitted to the active regions, each active region comprising a magnetically polarized region, wherein the magnetic polarization of the first active region and the magnetic polarization of the second active region are substantially opposite to each other, and wherein the magnetic sensor means comprises a first pair of magnetic sensors comprising a first and a second magnetic field sensor being arranged approximate the first magneto-elastically active region for outputting a first signal corresponding to a stress-induced magnetic flux emanating from the first magnetically polarized region and the magnetic sensor means comprises a second pair of magnetic sensors comprising a first and a second magnetic field sensor being arranged approximate the second magneto-elastically active region for outputting a second signal corresponding to a stress-induced magnetic flux emanating from the second magnetically polarized region, wherein the magneto-elastic sensor further comprises a control unit, which is configured for determination of the stress applied to the member by performing a differential evaluation of the signals of the first pair of sensors and the second pair of sensors.

A method of determining a direction of a load vector, the method comprising the steps of:

• providing a magneto-elastic sensor comprising:
• a longitudinally extending shaft like member, which is subject to the load introducing mechanic stress in the member;
• at least one magneto-elastically active region directly or indirectly attached to or forming a part of the member in such a manner that the mechanic stress is transmitted to the active region, said active region comprising at least one magnetically polarized region such that the polarization becomes increasingly helically shaped as the applied stress increases;
• a magnetic field sensor means arranged approximate the at least one magneto-elastically active region for outputting a signal corresponding to a stress-induced magnetic flux emanating from the magnetically polarized region;
• wherein the magnetic sensor means comprises at least one direction sensitive magnetic field sensor, which is arranged to have a predetermined and fixed spatial coordination with the member,
• exposing the longitudinally extending shaft like member to the load,
• processing measurement data of the at least one direction sensitive magnetic field sensor so as to determine a shear stress and/or of a tensile or compressive stress, in particular so as to determine a direction of the load vector from the measurement data and the predetermined and known spatial coordination between the direction sensitive magnetic field sensor and the member.