Performance evaluation of a Pedestrian Navigation System based on an objective experimental method

摘要

The ability to estimate the distance covered and the orientation of a person, regardless from where he or she is located, is an important aspect in various research areas and in particular in Pedestrian Navigation Systems (PNS) for emergency responders. In this paper we present a PNS based on a wearable wireless device attached to the instep of the pedestrian. The implemented real time algorithm, is able to identify pedestrian's strides, estimating theirs length and direction by using information provided from an embedded Inertial Measurement Unit (IMU). The proposed device is also equipped with MicroSD slot and Bluetooth module for data storage and for sending information in real time. The proposed system has been tested through an objective experimental method in which ten volunteers were walking along three different tracks, five times each, keeping the IMU attached to the instep. In the first trial subjects walked along a straight path that is 90m long, in the second they walked twice along a rectangular path with long side equal to 15m and short side equal to 7.5m and in the last they walked 400m along a standard athletics track. For each test we computed absolute and average error. The results show that the average error is 3.52% for the straight track, 1.09% for the rectangular track and 3.71% for the elliptic track.