Measurement of positions, mechanical displacements and rotations and stresses of bodies

A method for measuring an alignment between two bodies comprising at least two magnetic field sensors mounted on one body and at least one permanent magnet mounted on another body, the method comprising:

• generating, by the at least one permanent magnet, a magnetic field Hmeasurement at positions xi of the at least two sensors;
• measuring, by the at least wo sensors, at least one component of the generated magnetic field Hmeasurement;
• calculating a magnetic theoretical field Htheory, the magnetic theoretical field Htheory generated by the at least one permanent magnet at the positions xi for a given position and a given alignment ymagnet of the at least one permanent magnet,
• determining a difference d between the magnetic theoretical field and the measured magnetic field Hmeasurement such that d(ymagnet)=Htheory(ymagnet)−Hmeasurement, and
• determining a position and alignment ymagnet of the at least one permanent magnet in such a way that a mathematical norm of the difference d is minimized and thus the position and alignment ymagnet of the at least one permanent magnet relative to the field sensors is determined.