Adaptive step length estimation algorithm using optimal parameters and movement status awareness.

An adaptive step length estimation algorithm operating with optimal parameters and a movement status awareness algorithm are proposed. The proposed algorithm was developed as a means for increasing the accuracy in estimating walking distances. The algorithm was applied to pedestrian navigation system, ubiquitous health monitoring systems, and so forth. The algorithm's optimal parameters were derived after measurement errors were taken into consideration. The movement status awareness algorithm was designed using a walking characteristic called the acceleration variance. After estimating a subject's walking distance using the proposed algorithm, the measured error was 4.8% with respect to actual walking distance. Alternatively, estimating a subject's walking distance without the algorithm yielded an error of 20% with respect to actual walking distance.