GPS/INS/Odometer Integrated Navigation Algorithm with Prior Velocity in Land Vehicle System

When GPS outages occur in a land vehicle navigation system,INS navigation error will be cumulated quickly. In this paper,the Odometer observations are added to the measurement equation to improve the system observability and navigation accuracy based on prior velocity. And a new method is implemented for position modification. By calculation,it is shown that compared with INS navigation,the velocity accuracy is improved with prior velocity. And with applying the new position modification method,the position accuracy is improvedgreatly. After the Odometer observations are added to the measurement equation,both position accuracy and velocity accuracy are improved further.