Abstract:

In automobile navigation system, a dead reckoning system is used to solve the problem of GPS signal blocking in urban areas. In order to meet accuracy and reliability requirements, the gyroscope and compass,both of which have low accuracy, are integrated to determine the vehicle heading in DR system. Such integration has been achieved by a complementary filter. However, it has been pointed out that it has no effect in removing long term compass measurement errors resulting from long term magnetic anomalies. To deal with this problem, the use of a fuzzy filter to compensate for long term errors is presented. Furthermore, a complementary fuzzy filter is constructed to remove both short term and long term errors. It is shown through simulation results that application of this complementary fuzzy filter results in smaller heading errors and position errors .

Key words: fuzzy filter, complementary filter, dead reckoning system, compass, automobile navigation system