A step length estimation model for position tracking

Inertial Measurement Unit (IMU) is one option for the positioning system. Due to its independence and invulnerability, the IMU-based approaches could serve as an effective complementarity for the positioning systems applying communication networks, when the infrastructures are insufficient or unreliable. For pedestrians the Step and Heading System (SHS) is a practicable solution. With the length and heading of each step measured by the built-in inertial sensors in users portable device, the current location would be updated. A novel mathematical model for step length estimation is developed in this paper. In this model the relation among the step length, frequency and the variance of accelerations is revealed. Comparing with former models, not only the accuracy of step length estimation is improved substantially, but also the stabilization as well as robustness of the whole positioning system can be enhanced.