碩士 / 國立臺灣大學 / 工程科學及海洋工程學研究所 / 107 / This study investigates the localization of underwater vehicles via the observability analysis using both inter-vehicle range and range-rate measurements. An instantaneous observability of the dynamic system is defined by taking the Gramian matrix of the Lie derivatives, in which the condition number of the observability Gramian matrix is a metric of the observability. Better observability is obtained when the condition number is reduced (the inverse of the condition number is increased). The condition number formula is derived with not only the range but also the range-rate measurements. The overall characteristics of the inverse of the condition number for including both measurements are similar to those for using only range measurements. With additional range-rate measurements, the improvement is observed when the angle between the relative velocity vector and the position vector is close to or . With increasing the inverse of the condition number, the trace of the Extended Kalman Filter (EKF) error covariance matrix is reduced.
The derived framework was demonstrated first using numerical simulations; Several routes including straight, circular, spiral and square paths were considered. Then a field experiment was conducted in WangHiXiang Bay, in 2017, with an Autonomous Underwater Vehicle (AUV) equipped with a compass, a tomographic sensor and a Doppler Velocity Log (DVL). The tomographic sensor transmits m-sequence signals, providing range and range-rate data simultaneously. The experiment results are consistent with the simulation results. Incorporating range-rate measurements improves the inverse of the condition number and therefore the localization of AUV.
| Identifer | oai:union.ndltd.org:TW/107NTU05345014 |
| Date | January 2018 |
| Creators | Yun-Ju Chan, 詹雲如 |
| Contributors | 郭振華 |
| Source Sets | National Digital Library of Theses and Dissertations in Taiwan |
| Language | zh-TW |
| Detected Language | English |
| Type | 學位論文 ; thesis |
| Format | 96 |
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