Motion monitoring based on a finite state machine for precise indoor localization

This paper presents a precise stance detection method for accurate personal localization using a foot-mounted inertial measurement unit. The exact classification of the stance phases of the foot is realized with a finite state machine (FSM), which separates the human gait circle in different sub-states. The FSM-based approach provides high accurate and robust detections of Zero Velocity Updates (ZUPTs) which can be applied to the navigation filter. We use a constraint stochastic cloning (SC) Kalman filter to show the performance of the high precise ZUPT intervals with real world sensor data including forward, backward and staircase motion. Even for the movement type running and the signals of an ultra-low cost inertial measurement unit we achieve with our motion monitoring system a position estimation with an average error of less than 1.5% of the travelled distance.