The measurement of displacement with the use of MEMS sensors : accelerometer, gyroscope and magnetometer

The paper presents the method of determining the global orientation of links of the measuring arm by gauging the angles of the links relative to the vector of the gravitational and magnetic field using inertial sensors. A method of using Kalman filter to average the results is presented as a test on two-links measuring arm equipped with accelerometers and magnetometers placed on each of the links and analysis of measurement results in terms of repeatability. There was demonstrated the ability of creating kinematic chain. Instead of determining the position of the final link on the basis of the measurement of angles in relation to the previous links from the end to the base of the arm, it is possible to define links global orientation by measuring angles of links in reference to the vectors of the gravity field and the magnetic field, in global coordinate system.