Combined heading technology in vehicle location and navigation system

As an important parameter in vehicle location and navigation system, heading measurement requires a higher precision. The paper aims at the research on fusion of heading information obtained through magnetic compass, angular rate gyro and GPS. Firstly, a integrated filter model has been designed to adapt the error characteristics of gyroscope, magnetic compass and GPS. Then, considering loss of GPS, a Preposed Detection Link (PDL) is adopted to inhibit the low-frequency magnetic interference of magnetic compass and to improve the accuracy of information integration. Simulation with gyroscope, magnetic compass and GPS shows that not only the high-frequency magnetic interference and the accumulation of errors can be inhibited, but the low-frequency interference for long time can also be inhibited by the integrated filter, and the PDL-based compensation filter can provide higher accurate heading value for vehicles as an aided plan when GPS signal quality is not good.