Development of a CSGPS/DR Integrated System for High-precision Trajectory Estimation for the Purpose of Vehicle Navigation

Abstract

In this study, a carrier smoothed global positioning system / dead reckoning (CSGPS/DR) integrated system for high-precision trajectory estimation for the purpose of vehicle navigation was proposed. Existing code-based GPS has a low position accuracy, and carrier-phase differential global positioning system (CPDGPS) has a long waiting time for high-precision positioning and has a problem of high cost due to the establishment of infrastructure. To resolve this, the continuity of a trajectory was guaranteed by integrating CSGPS and DR. The results of the experiment indicated that the trajectory precision of the codebased GPS showed an error performance of more than 30cm, while that of the CSGPS/DR integrated system showed an error performance of less than 10cm. Based on this, it was found that the trajectory precision of the proposed CSGPS/DR integrated system is superior to that of the code-based GPS.Keywords: GPS, carrier phase, dead-reckoning, integrating, filter using this is linked with image and road information, it can be applied as a technology for lane keeping and lateral control.I n m o s t v e h i c l e n a v i g a t i o n s y s t e m s , t h e c o d e measurement of global positioning system (GPS) is utilized. However, the code measurement of GPS has a problem of low trajectory precision. As an alternative to this, a carrier-phase differential global positioning system (CPDGPS) technique using the carrier phase measurement of GPS can be used to obtain a position solution with an accuracy of several centimeters. However, to apply the CPDGPS technique, integer ambiguity included in carrier phase measurement needs to be determined. For this, measurement needs to be collected for several minutes in a stationary state. Also, a reference station with correction information and a communication infrastructure need to be established. Thus, it has disadvantages of distance limitation and a lot of cost.To resolve this, a carrier smoothed global positioning 124 JPNT 4(3), 123-130 (2015) http://dx.doi.org/10.11003/JPNT.2015.4.3.123 system (CSGPS) technique can be used to obtain a highprecision trajectory with a precision of less than 30 cm and to obtain continuous relative position and attitude. For this, a study on the use of the Hatch filter was performed (Hatch 1982). The Hatch filter combines the carrier phase measurement including a noise of less than 1 cm and integer ambiguity and the code measurement with a noise of 1~2 m based on the complementary Kalman filter, and utilizes the advantages of the two measurements. However, this method cannot guarantee the continuity of a trajectory because the bias included in a position solution could change in case of the change in visible satellites.On the other hand, dead reckoning (DR) navigation can obtain continuous relative position and attitude for a short time, but has a problem of accumulating position and attitude error element characteristics. Thus, in DR navigation, it is important to determine initial position and attitude, and to correct the error...