JFET_V2_N1_RP5 N. Suthanthira Vanitha Dr. V. Palanisamy M. Mani Journal on Future Engineering and Technology 2230 – 7184 2 1 50 56 Real Time Posture Tracking, Human Limb Segment, articulated body, MARG sensor This paper mainly deals with the software implementation of the quaternion filter algorithms and calibration algorithms for the sensors. Rigid body orientation may be determined without the aid of a generated source using a nine-axis Magnetic field, Angular Rate, and Gravity sensor containing three orthogonally mounted rate sensors, linear accelerometers and magnetometers. It describes a system designed to determine the posture of an articulated body in real-time. In the system the orientation of each segment relative to an Earth-fixed reference frame is individually determined through the use of an attached source less sensor. The orientations are used to set the posture of an articulated body model. Details of the fabrication of a prototype MARG sensor and a human body model designed to accept Earth-fixed reference orientation data are also described. Experimental results demonstrate the effectiveness of the tracking system and verify the correctness of the underlying theory. August-October 2006 Copyright © 2006 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=974