The margin of error of a commercial GPS, such as those that are used in cars, is about 15 meters in an open field, where the receiver has wide visibility from the satellites. However, in an urban setting, the determination of a vehicle’s position can be off by more than 50 meters, due to the signals bouncing off of obstacles like buildings, trees, or narrow streets, for example. In certain cases, such as in tunnels, communication is lost, which hinders the GPS’s applications reaching Intelligent Transport Systems, which require a high level of security. “Future applications that will benefit from the technology that we are currently working on will include cooperative driving, automatic maneuvers for the safety of pedestrians, autonomous vehicles or cooperative collision warning systems,” the scientists comment.
However, in the case of the new prototype that they have developed they have managed to guarantee the position of the vehicle to within 1 or 2 meters in urban settings.
Low cost Inertial Measurement Unit (IMU) — three accelerometers and three gyroscopes
Unscented Kalman Filter