Abstract
The Doppler-assisted error provided by a low-precision microelectromechanical system (MEMS) strapdown inertial navigation system (SINS) increases rapidly. Therefore, the bandwidth of the tracking loop for a global positioning system (GPS)/MEMS-SINS ultra-tight integration system is too narrow to track Doppler shift. GPS measurement error is correlated with the MEMS-SINS velocity error when the Doppler-assisted error exists, leading to tracking loop lock loss. The estimated precision of the integrated Kalman filter (IKF) also decreases. Even the integrated system becomes unstable. To solve this problem, an innovative GPS/MEMS-SINS ultra-tight integration scheme based on using high-precision carrier phase measurements as the IKF measurements is proposed in this study. By assisting the tracking loop with time-differenced carrier phase (TDCP) velocity, the carrier loop noise bandwidth and code correlator spacing are reduced. The tracking accuracies of the carrier and code are increased. The navigation accuracy of GPS/MEMS-SINS ultra-tight integration is further improved.
Highlights
The error characteristics of global positioning systems (GPSs) and strapdown inertial navigation systems (SINSs) are highly complementary
The dynamic performance of the GPS receiver is improved by reducing dynamic stress, and its loop thermal noise is restrained by reducing the loop bandwidth [6]
GPS, ρis rate thecalculated pseudo-range the phase pseudo-range, difference of the receiver pseudo-random code, ρDLL is the by the receiver loop, and ρ is the pseudo-range rate for aiding estimated by the receiver aidloop, δρ is the pseudo-range error between the GPS measurement and receiver loop estimation, f Phase lock loop (PLL) is the carrier loop tracking aiding frequency, δτ is the phase difference of the receiver pseudo-random code, ρ delay lock loop (DLL) is the pseudo-range rate calculated by the receiver loop, and ρ aid is the pseudo-range rate for aiding DLL
Summary
The error characteristics of global positioning systems (GPSs) and strapdown inertial navigation systems (SINSs) are highly complementary. Integrating high-precision carrier phase measurements and the MEMS-SINS velocity error. Integrating high-precision GPS carrier phase measurements and would improve the accuracy of the GPS/MEMS-SINS integration. To improve the accuracy of GPS/MEMS-SINS ultra-tight integration, by assisting assisting tracking loopvelocity, with TDCP velocity, an innovative ultra-tight ultra-tight the trackingthe loop with TDCP an innovative integration scheme integration scheme based on high-precision carrierasphase measurement asisthe. System; IF: intermediate frequency; K:switch; PLL: phase lock loop; IMU: inertial measurement unit; The proposed scheme adopts TDCP velocity and CSP as the IKF measurements to estimate the state vector and to correct SINS errors. Considering the configuration of the federated filter, the innovative GPS/MEMS-SINS ultra-tight integration isolates the measurement noise of the CSP and TDCP velocity to take advantage of the high-precision measurement. In this study, based on the above literature, TDCP was used to improve the speed measurement accuracy, CSP was used to improve the pseudo-distance measurement accuracy, a system solution was created on the basis of low-cost and low-precision MEMS/SINS, and a laboratory semi-physical simulation experiment and land vehicle experiment were conducted to further verify the feasibility of the scheme
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
