Research On Integrated Navigation Algorithm Of The Pedestrian Navigation System Based On MIMU/GPS

What this paper research is Pedestrian Navigation (PNS),which mainly used to provide speed and position information of walking people. This would be very helpful to fireman and soldiers as they doing their duty.The subject we research is Micro Inertial Measurement Unit (MIMU). With the development of micro electrical technology, it is possible for us to integrate inertial measurement unit to a small chip, which can be carry by people.Inertial navigation can be divided into two kinds: gimbaled inertial navigation system and strapdown inertial navigation system. We have no ability to build a stabilized platform ,so we use the strapdown inertial navigation system. Strapdown inertial navigation system build a platform in math. We can get position,speed and attitude by updating the strapdown matrix.Integrated navigation is one of the most important way to improve the accuracy of navigation system . This paper also use integrated navigation to improve positioning accuracy . We use GPS to assist our navigation system . To build our navigation system we would use loose coupled and deep coupled system .In terms of the character that MIMU keep a high accuracy in a short time and its error increase by time, we would use zero velocity update to restrain the error . According to zero velocity detector , we come up with generalized likelihood rate test. We come up with three kinds of simplified generalized likelihood rate test, including acceleration-moving variance detector, acceleration-magnitude detector and angular rate energy detector. As we know , it is difficult to detect the error of z axial. So we come up with zero angular rate update , heuristic heading reduce and compass heading reduce to correct the heading error.This paper analysis the character of the error of GPS and build error equation of GPS.According to the error equation of GPS, we build loose coupled system and deep coupled system.To combine INS and GPS data, we use Extended Kalman Filter , which do well in non-liner system . And we come up with innovation to detect work state of GPS . We use innovation vector as the standard of changing navigation project.According to the content of different navigation project, we designed different experiment . The experiment proved that: angular rate energy detector have the best effect,GPS would improve positioning accuracy of our navigation system and heading reduce project really work well without GPS.