Context Adaptive GPS/GF-INS Integrated Navigation System

The environment in which a vehicle is operated and the behavior of the vehicle can be recognized from measurements of navigation sensors and navigation solutions. The navigation system is reconfigured according to the recognized environment and behavior in the context adaptive navigation system. When the context adaptive navigation system is used, performance of the conventional navigation system can be substantially improved. When the vehicle rotates with a high rate which cannot be measured by a gyroscope, the gyro-free inertial navigation system can be configured in order to provide navigation information of the vehicle using a gyro-free inertial measurement unit which consists of only accelerometers. However, when the angular velocity is near zero, the angular velocity cannot be accurately estimated. And, since the angular velocity of the vehicle is not always beyond the limit of gyroscope measurement, better navigation results can be obtained if the available gyroscope measurements are used. In this paper, a context adaptive GPS/GF-INS integrated navigation system is proposed, in which rotational motions are classified and the navigation system is reconfigured according to the classified rotational motion in order to have more accurate navigation results. Results of the proposed context adaptive GPS/GF-INS integrated navigation system are compared with those of the GPS/GF-INS integrated navigation system. The results show that the proposed context adaptive GPS/GF-INS integrated navigation system gives better navigation performance and angular velocity estimation performance.