The invention concerns a land vehicle positioning system (called LVPS) used in the land transporting mobile machines, such as cars, trucks, buses, motorcycles, trains, bicycles for navigation and determining the current geographic position of the vehicle.
There are different positioning systems based on the receipt of radio signals from different transmitters such as satellites (GPS, Galileo, COMPASS), beacons (LPE), cellular cells (CPS). The all listed above positioning systems have a common disadvantage, that they depend on the receipt of the radio signal, which in some conditions can not propagate (inside tunnels, between high buildings…etc.) and also can be jammed. Another disadvantage is that sometimes they need a long initial time to define the current geographic position.
The proposed LVPS does not receive any radio signals. It works is based on the fundamental physic laws and on powerful calculation algorithm. The main principle of work is the continuous measurement of the vehicle acceleration in all it forms: linear, tangential and centripetal and further integration its integration in the time, what results in the determining the current velocity vector, which once again integrated in the time determines the traveled distance.
The traveled distance S is calculated by the following formula:
S=DOUBLE_INTEGRAL((a dT) dT)
where a is the momentary acceleration, T is the travel time.
In parallel with the acceleration measurement, a process of continuous measurement of the geographic direction of travelling is going. Each angular change of the direction is sensed and sent as data to the main controlling microcomputer. Thus not only the acceleration, but also the movement direction is taken into account for the position calculations. The initial starting position is bound preliminary on the map, or as such position is taken the last calculated one. During the travel at some key points (curves, crossroads, etc.) possible correction of the current position is done. Thus, the current travel position is bound continuously on the map and calculated from the previous one.
The LVPS comprises a set of precise 3D accelerometer, used for continuous measurement of the acceleration; precise gyroscope, used to sense each change in the movement direction and for the linear acceleration measurement correction; magnetometer used as compass; microcomputer processing the data from the sensors, having in its memory the digitized geographic map.
For more complete description of the present invention and its advantages, reference is made to the following description, taken in conjunction with the accompanying drawing (Fig.1), in which the architecture of the LVPS with the internal inter-connections is shown.
An embodiment of the invention is presented in Fig.1. The land vehicle positioning system 100 comprises precise 3D accelerometer 1, gyroscope 2 and magnetometer 3. All these sensors are connected to the microcomputer 4, where the signals are processed; the current geographic position is calculated in real time and finally bound on the map. The microcomputer is connected to a physical memory medium 5, where the digitized geographic map is stored.