Study On Lunar Rover Positioning And Parameter Estimation Algorithms Based On UWB

Study on Lunar Rover Positioning and Parameter Estimation Algorithms based on UWBLunar rover is the special vehicle traveling at the lunar surface which can study the moon and collect sample information of the moon. Development of the soft landing of lunar exploration is the second phase of project of our country's lunar plan, among which, lunar rover positioning is a key technology for soft-landing lunar exploration. The study of lunar rover positoning is an important part of lunar rover navigation and the prerequisite and basis for path planning. It has important practical significance for completing the planned scientific exploration tasks.Ultra-wideband (UWB) communication is a novel wideband short-range wireless communication technique, in which data are transferred using non-sinusoidal pulse with very short duration. To the UWB communication system, the data are transimited and received via narrow pulsed in or below the nanosecond level to get the GHz level bandwidth without the carrier used by the traditional communication systems. It has many characteristics, such as good radio penetration through structures, good security, high transmission rat, low power consumption , exceptional multi-path immunity and it provides precise positioning, it will become the hot research and the first choice of application in the future wireless positioning.For the lack of currently lunar rover positioning and navigation. In this paper, we make use of UWB wireless positioning technology onto lunar rover positioning, taking the lunar rover as the background, analyzing the topic research significance and the present situation, studying the UWB signal parameter estimation algorithm, including TOA and DOA estimation. We propose lunar rover positioning model based on UWB by combining the existing wireless positioning methods and study the lunar rover methods based on UWB. The study of this paper obtains the subsidization of science and technology research key project of Ministry of Education "the lunar rover positioning, navigation and control based on UWB technology" (number: 106059). This paper consists of six chapters. The concrete arrangements is as follows:In chapter one, we introduce the significance of lunar rover positioning, the advantage of positioning of lunar rover using UWB technology, the concept, characteristics and application of UWB signals, present situation of UWB positioning and existing problems.In chapter two, we introduce the technology of lunar rover, the basic math knowledges, the geometry principles of TOA, TDOA and AOA localization, the subspace method of wide-band signals and the pulse model of UWB signals, the traditional DOA estimation algorithm of wide band source.In chapter three, UWB signal TOA estimation methods have been studied, a Unitary-ESPRIT-based UWB signal time delay estimation algorithms are proposed. The the proposed methods are simulated, comparing to traditional ESPRIT algorithm to confirm its validity.In chapter four, we study the algorithm of ID and 2D DOA estimation for UWB signals based on unitary circuit array. In the view of the DOA estimation for DS-UWB signals, UCA-CSM-RB-MUSIC algorithm and UCA-CSM-ESPRIT algorithm are proposed. In the view of the DOA estimation for TH-UWB signals ID DOA estimation, UCA-DC algorithm is proposed.In chapter five, in the view of the several parameter estimation algorithm which are proposed in last two chapters, we study the lunar rover positioning respectively from the aspects of TOA positioning, TDOA positioning, AOA positioning. We propose four lunar rover positioning model and study the methods of lunar rover positioning including the two dimensional and three-dimensional coordinate positioning. We simulate the four models and analyzing the positioning accuracy.In chapter six, we summarize the whole paper, and show out some questions to be resolved in the reseaches of lunar rover positioning and UWB positioning in the future.This paper prime task and contribution are as follows: 1. Aiming at the defects thatthe existing TOA algorithms can 't estimate with high accuracy, we propose a new method to estimate TOA of UWB signals based on Unitary-ESPRIT. We simulate the the proposed algorithm and confirm its validity.2. Aiming at the defects of the DOA algorithm under ULA only can estimate 180 degree unfaintness angles, we propose three novel DOA estimation methods including: 1D/2D DOA estimation for DS-UWB signals based on UCA-CSM-RB-MUSIC algorithm, 2D DOA estimation for DS-UWB signals based on UCA-CSM-ESPRIT algorithm, ID DOA estimation for TH-UWB signals based on UCA-DB. The the proposed methods are simulated, from the simulation results, we see the validity of these algorithm.3. For locating the lunar rover and in the view of the several parameter estimation algorithm which are proposed in last two chapters, we study the lunar rover positioning respectively from the aspects of TOA positioning, TDOA positioning, AOA positioning. Then we propose four positioning models: a TOA/TDOA/AOA joint positioning under two-dimensional coordinate based on Unitary-ESPRIT TOA algorithm; a TOA positioning under three-dimensional coordinate based on Unitary-ESPRIT TOA algorithm; a AOA positioning under two-dimensional coordinate based on UCA-CSM-RB-MUSIC and UCA ID DOA estimation algorithm; a TOA/AOA joint positioning under three-dimensional coordinate based on Unitary-ESPRIT TOA and UCA-CSM-ESPRIT 2D estimation algorithm. We simulate the four models and confirm the validity.The main innovative work of this paper focus on the following three aspects:1. In order to improve the TOA estimation accuracy, a novel TOA estimation based on Unitary-ESPRIT algorithm is proposed. This algorithm reduces the complexity and the estimation precision has enhanced greatly.2. Because the angle estimation scope under UCA is as twice as that under ULA, at the basis of narrow band signals DOA estimation based on UCA, we first propose the UCA-CSM-RB-MUSIC algorithm and UCA-CSM-ESPRIT algorithm aiming at DS-UWB signals. Second, aiming at DOA estimation for TH-UWB signals, we propose the UCA-DC algorithm.3. We study respectively from the aspects of TOA positioning, DOA positioning and joint TOA/DOA positioning of UWB signals, then propose the positioning models and methods of lunar rover based on UWB, which can improve the localization accuracy efficiently.