A consumer tracking estimator for vehicles in GPS-free environments

The global positioning system (GPS) is a crucial component in navigation systems. Therefore, navigation systems usually malfunction in the outage cases of GPS signals. This paper proposes a consumer tracking estimator for vehicles in GPS-free environments. The proposed estimator exploits low-cost inertial measurement unit (IMU) and on-board diagnostics II (OBD-II) of the vehicle in order to achieve navigation data without any aid of GPS. The presented estimator is based on extended Kalman filter and linear Kalman filter for vehicle attitude and 3-D velocity estimations, respectively. For accurate estimations in GPS-free situations, the extended and linear Kalman filters achieve the inertial data and the vehicle speed from the IMU and the OBD-II, respectively. The proposed estimator tracks the vehicle trajectory velocity in GPS-free environments. Experiment results verify that the presented tracking estimator accurately tracks the vehicle trajectory without GPS. The results also exhibit that the proposed tracking estimator is superior to the conventional GPS-based estimators in the tracking performance.