Integrated System for Heading Determination

The paper presents a design and a prototype of integrated system, designed for heading determination of land vehicles. The heading is an angle between the North direction (true or magnetic) and the direction of longitudal axis of a vehicle in the horizontal plane. In land vehicle positioning and navigation, for most of the time the heading can be considered the same as the direction of movement of the vehicle. Thus, it can be used, along with information about the linear displacement of the vehicle, for dead reckoning, i.e. calculation of current vehicle position by accumulating position increments from a known initial location. The determination of vehicle heading represents a key function of dead reckoning and significantly influences the accuracy of land vehicle positioning. Each of the angular sensors, commonly used for heading determination, has serious drawbacks and joint processing of data from several devices can be advantageous. The paper contains a short description of operation, properties and error characteristics of gyros and electronic compasses, which are frequently applied in heading determination application. Further part of the paper presents a design of integrated system, composed of the above mentioned devices. The system processes navigation data with use of a single complementary Kalman filter. A prototype of the designed system has been constructed and tested by the authors. The paper contains a detailed description of the prototype and chosen results of its testing.