A simple calibration for upper limb motion tracking and reconstruction

This paper extends the work of inertial sensor based upper limb motion tracking by introducing a simple calibration method to automatically construct a global reference frame and estimate arm length. The method has effectively eliminated the requirement of manually aligning the sensors´ local reference frames when multiple sensors are used to track the movements of the individual arm segments. The capacity of arm length estimation also makes it possible to reconstruct position trajectories of the elbow and the wrist joints in a reference frame with the shoulder joint as the origin. Verification of the algorithm has been done by comparing the estimated arm length with the Kinect captured pseudo ground truth. Effectiveness of the algorithm can be observed by visualizing the reconstructed position trajectories of the arm joints.