碩士 / 國立臺灣海洋大學 / 通訊與導航工程學系 / 100 / In this paper, the two-stage Kalman filter (TKF) for the tracking loop design of the GPS receiver for the ultra-tightly coupled (UTC) GPS/INS integration is carried out. The primary advantage of the UTC configuration is a significant reduction of the tracking loops bandwidth, as the Doppler signal derived from INS aids the tracking loop to remove the dynamics from the GPS signals. The UTC structure reveals many benefits, e.g., disturbance and multipath rejection capability, improved tracking capability for dynamic scenarios and weak signals, and reduction of acquisition time.
The unknown random biases degrade the tracking performance of the Kalman filter estimation. Multipath effect, ionospheric delay and tropospheric delay are the main contributing sources of bias errors in GPS position determination. In many practical situations, there are unknown random biases in the system model, essentially caused by the multipath, ionospheric delay and tropospheric delay. The GPS tracking loops may lose lock due to the signals being weak, subjected to excessive dynamics or completely blocked. Traditional GPS tracking loop can be replaced by the vector tracking loop (VTC) for solving some of the problems. In high dynamic situations, the Doppler frequency changes faster with time, and it is therefore the carrier tracking loop of GPS receiver requires a wide bandwidth to track a carrier signal in high dynamic situations. As a specific configuration of the VTC, The ultra-tightly coupled (UTC) GPS/INS integrated navigation integrates the signals from the tracking loops of the GPS receiver with the position and velocity obtained from the INS. To treat the biases of the measurement and system models, the TKF is employed to estimate the signal parameters in the GPS receiver’s signal tracking loop.
The proposed method demonstrates the superior capability on improvement of the tracking performance as an alternative estimator for dealing with the low quality signal and high dynamic environments for the tracking loop design of the UTC integration system.
| Identifer | oai:union.ndltd.org:TW/100NTOU5300035 |
| Date | January 2012 |
| Creators | Yan-Chu Chen, 陳彥竹 |
| Contributors | Dah-Jing Jwo, 卓大靖 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 74 |
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