Design Of Navigation System Research Articles

基于MPU6050的航姿演示系统设计

基于MPU6050的航姿演示系统设计

Magneto-Inertial Integrated Navigation System Design Incorporating Mapping and Localization Using Concurrent AC Magnetic Measurements

A new artificially generated magnetic-field-based alternative navigation technique is investigated for achieving seamless navigation in non-line-of-sight (NLOS) environments where satellite navigation is unavailable, and where vision, lidar, and other sensors that make use of signals of opportunity cannot provide reliable estimation. Unlike the previously reported multilateration methods, which make use of the magnetic receiver coil's voltage model, the proposed method first extracts three-dimensional field vectors from concurrent ac magnetometer measurements, then establishes the spatial representation model of magnetic vectors for localization purpose. It does so by separating each frequency component and developing a geometric matching procedure using the interpolated data from the grid map in order to achieve a pose estimation. This study further presents an integrated navigation algorithm that associates an inertial measurement with the estimated pose information to secure a continuous navigation solution at a high output rate, where the extended Kalman filter (KF) formulation is typically employed. Finally, in order to validate the estimation performance of the proposed method, a small-scale trajectory experiment in 70cm × 70cm × 50 cm test platform was performed, by which the integrated navigation was verified as possessing an average position accuracy in the sub-cm range as well as a heading angle error in the sub-degree range.

Development and Validation of Linear Covariance Analysis Tool for Atmospheric Entry

Entry guidance is a fundamental element of atmospheric entry missions. However, during the atmospheric entry, there are many uncertainties that cannot be predicted and ultimately lead to trajectory dispersions. Linear covariance analysis, widely used for navigation system design and analysis, is a technique that can also be used to assess guidance, navigation, and control (GN&C) system performance. In this paper, linear covariance analysis is used to predict and analyze the dispersions and dispersion error budgets for atmospheric entry. Uncertainties, including atmospheric density, aerodynamic axial and normal force coefficients, sensor measurement errors, and winds, are modeled as exponentially correlated random variables. The closed-loop dispersion covariance propagation and update equations of an augmented system are formulated using linear covariance theory, and a series of simulations are carried out to show that linear covariance analysis can be used for trajectory dispersion analysis for a closed-loop GN&C atmospheric entry system. It is shown that the linear covariance analysis can provide accurate Monte Carlo–like results in a fraction of the time to predict trajectory dispersions and produce dispersion budgets to assess the effects of individual uncertainties.

Алгоритмічне забезпечення високоточної системи визначення просторової орієнтації

Мета: У статті розглянуто особливості алгоритмічного забезпечення високоточної систем визначення просторової орієнтації, що можуть бути застосовані у високоточних застосуваннях, наприклад, навігації морських рухомих об’єктів. Головною метою є створення алгоритмічного забезпечення, спрямованого на забезпечення функціонування багаторежимної навігаційної системи. Методи дослідження: Для розв’язання зазначеної проблеми використовуються методи інерціальної навігації, теорії автоматичного управління, включаючи слідкувальні системи та статистичної обробки інформації. Результати: Розроблене алгоритмічне забезпечення високоточної системи визначення просторової орієнтації з урахуванням наявності різних режимів системи та взаємозв’язків між ними. Отримано основні вирази для алгоритмічного забезпечення високоточної багаторежимної системи визначення просторової орієнтації. Представлено узагальнену блок-схему алгоритму функціонування системи. Висновки: Представлено результати розробки алгоритмічного забезпечення високоточної системи визначення просторової орієнтації з урахуванням наявності декількох експлуатаційних режимів. Отримані результати можуть бути корисними для проектування високоточних навігаційних систем рухомих об’єктів широкого класу.

Design and experimental study of MEMS personal navigation system

Design and experimental study of MEMS personal navigation system

Cross-Cultural User Experience of Luxury Hotel Websites: A Conjoint Analysis

The website of luxury hotel brands is regarded as a great platform for marketers to create positive brand identity. The underlying architecture of information, as well as the design of graphics, navigation system, and user interface could have an influence on user experience with a hotel brand. Utilizing a conjoint design, this research assessed user preferences of three website design factors: background/font color, human image use, and navigation system. The preferences of two cultural groups—that of the Chinese and American consumers—were compared and contrasted. The findings of this study suggest that users from both the US and Chinese cultures have similar tastes for hotel website design features. They both prefer photos with no human images, dark background with light font, and a linear navigation system. The convergent tendencies of the two cultural groups and practical implications for the luxury hotel industry were discussed.

Design of Sensor Data Fusion Algorithm for Mobile Robot Navigation Using ANFIS and Its Analysis Across the Membership Functions

Design and development of autonomous mobile robots attracts more attention in the era of autonomous navigation. There are various algorithms used in practice for solving research problems related to the robot model and its operating environment. This paper presents the design of data fusion algorithm using Adaptive Neuro Fuzzy Interface (ANFIS) for the navigation of mobile robots. Detailed analysis of various membership functions (MFs) provided in this paper helps to select the most appropriate MF for the design of similar navigation systems. The combined use of fuzzy and neural networks in ANFIS makes the measured distance value of the residual covariance consistent with its actual value. The data fusion algorithm within the controller of the mobile robot fuses the input from ultrasonic and infrared sensors for better environment perception. The results indicate that the data fusion algorithm provides minimal root mean square error (RMSE) and mean absolute percentage error (MAPE) when compared with that of the individual sensors.

Ship Trajectory Tracking Control System Design Based on Sliding Mode Control Algorithm

Abstract The paper reports the design and tests of the planar autopilot navigation system in the three-degree-of-freedom (3-DOF) plane (surge, sway and yaw) for a ship. The aim of the tests was to check the improved maneuverability of the ship in open waters using the improved nonlinear control algorithm, developed based on the sliding mode control theory for the ship-trajectory tracking problem of under-actuated ships with static constraints, actuator saturation, and parametric uncertainties. With the integration of the simple increment feedback control law, the dynamic control strategy was developed to fulfill the under-actuated tracking and stabilization objectives. In addition, the LOS (line of sight) guidance system was applied to control the motion path, whereas the sliding mode controller was used to emulate the rudder angle and propeller rotational speed control. Firstly, simulation tests were performed to verify the validity of the basic model and the tracking control algorithm. Subsequently, full scale maneuverability tests were done with a novel container ship, equipped with trajectory tracking control and sliding mode controller algorithm, to check the dynamic stability performance of the ship. The results of the theoretical and numerical simulation on a training ship verify the invariability and excellent robustness of the proposed controller, which: effectively eliminates system chattering, solves the problem of lateral drift of the ship, and maintains the following of the trajectory while simultaneously achieving global stability and robustness.

A quantum mechanical interpretation of gravitational redshift of electromagnetic wave

It had been observed that electro-magnetic waves can undergo a frequency shift in a gravitational field. This effect is important for satellite communication and astrophysical measurements. Previously, this redshift phenomenon was interpreted exclusively as a relativistic effect. Here we found this effect can also be explained based on a quantum mechanical consideration. We propose that, due to the quantum nature of the photon, its effective mass is not zero. In a gravitational field, the total energy of the photon includes both its quantum energy and its gravitational energy. Then, the condition of energy conservation will require a frequency shift when the photon travels between two points with different gravitational potentials. This result suggests that the gravitational redshift effect of a photon is essentially a quantum phenomenon. This new understanding can be helpful for the future design of satellite navigation systems and other astrophysical applications.

Theoretical and experimental assessments of accuracy of nonorthogonal mems sensor arrays

The paper deals with theoretical and practical assessments of nonorthogonal configurations of MEMS sensors based on both the uniaxial gyroscopes and the triaxial inertial measuring units. The main goal of the paper is research of the possibility to use nonorthogonal redundant configurations in navigation applications. Methods of inertial navigation, analytical mechanics, mathematical statistics and simulation were used in the research. Analysis of nonorthogonal redundant configurations of uniaxial MEMS sensor arrays including matrices of directional cosines has been carried out. Description of nonorthogonal redundant MEMS sensor array based on inertial measuring units (MPU-6050) is represented. Tables of directional cosines for nonortogonal redundant MEMS arrays based on inertial measuring units with such constructive elements as triangular and tetragonal pyramids are obtained. The mutual location of measuring axes for these configurations is given. Features of dynamic test including equipment possibilities and technique of random errors determination are described. Using of the three-degree-of-freedom test bench provides the simulation of the developed MEMS sensor arrays in conditions close to the real operation. The theoretical assessment of accuracy of nonorthogonal redundant MEMS sensor arrays based on both the uniaxial gyroscopes and the triaxial inertial measuring units is carried out. The assessment is implemented using correlation matrices of errors. The experimental assessment of the MEMS array based on triaxial inertial measuring units is determined based on the results of the dynamic analysis. The appropriate graphical dependences including graphs of relative variances and histograms of the random errors distribution are presented. Comparative analysis of the obtained assessments is given. The results can be useful for the design of navigation systems, for example, unmanned aerial vehicles or rockets for the launch of satellites into orbit.

Design and implementation of Autonomous navigation system for localization and mapping using SLAM technique

Design and implementation of Autonomous navigation system for localization and mapping using SLAM technique

ORB-SLAM based humanoid robot location and navigation system

Aiming at the indoor location and navigation problem of humanoid biped robot with complex motion structure, a humanoid biped robot localization and navigation system based on ORB-SLAM is designed. Firstly, the working principle of ORB-SLAM is analyzed, and it is improved to realize the function of missing map reading and generating dense point cloud map. Secondly, the dense point cloud map is converted to octomap, and then the conversion of 3D map to 2D map is completed. The SBPL planning library is improved to carry out the path planning of the robot, and the path planning based on the boundary exploration is realized. Finally, the experimental verification is carried out on the biped robot to verify the effectiveness of the location and navigation system design in the indoor environment.

Preliminary Design of Nano Satellite for Regional Navigation System

A Low cost Regional Navigation Satellite System employing constellation of nano satellites has been proposed for Indonesian coverage. The constellation of Low Earth Orbit nano satellites off course will not be able to give better position fixed to the GPS. However, the design of navigation system has much lower in cost compare to the current navigation system. This paper tells about preliminary design of the proposed regional navigation satellite system. The results of our satellite design has 3 kg on its weight, 10 W on power requirement at the peak condition, and 2.7 years of lifetime. Payload communication of the satellite will use UHF and TT&C communication will use VHF. Total area of solar panel will be 0.11 m2.

Identificación de Parámetros de Desempeño de un UAV a Través de Vuelos de Prueba

The design and implementation of a autonomous navigation and control system for UAV, mandates simulating the system before in-flight testing. These simulations require a computational model of the aircraft, that can be obtained from the computation of aerodynamic parameters such as the drag polar. In this paper we present the identification of these parameters using two methods: one by flight testing techniques; the other by a combination of semi-empirical methods and computational fluid dynamics, dubbed the hybrid method. The hybrid method, which produces a parabolic polar drag, had the same qualitative trend compared to experiments. However, a detailed analysis of the parameters that shapes the polar drag, had significant differences, particularly in the parasite drag. This is probably due to propeller effects, low Reynolds Number and limitations of the piloting technique.Keywords: Drag polar, flight testing, parasite drag, UAV, VLM

A General Euler Angle Error Model of Strapdown Inertial Navigation Systems

Attitude error models play an important role in analyzing the characteristics of navigation error propagation for the design and operation of strapdown inertial navigation systems (SINS). However, the majority of existing attitude error models focus on misalignment, rather than Euler angle errors. Misalignment cannot directly describe attitude error propagation, which is an indirect measurement. To solve the problem, a general Euler angle error model of SINS is proposed. Based on Euler angle error propagation analysis, relative Euler angle errors, and convected Euler angle errors are introduced to compose the general Euler angle error model. Simulation experiments are carried out to verify the proposed model.

Particle filter based integrated navigation for quadrotors

In this work, in order to achieve increased positioning accuracy, a particle filter based integrated navigation system is designed for a rotary wings unmanned aerial vehicle (UAV). As the navigation problem has highly non-linear characteristics on the system and measurement models, the designed algorithm which is based on particle filter works more effectively with respect to Kalman filter-based algorithms which have strict linearity assumptions. In order to verify the proposed algorithm, firstly the designed navigation system is tested with a flight scenario planned in an only simulation environment. After that, the designed algorithm is tested with the data acquired on a real rotary wings system in the laboratory for a different number of particles separately and it has been shown to produce satisfactory results. In this study, an integrated navigation solution having high accuracy and reliability was calculated for a quadrotor having six degrees of freedom.

Particle filter based integrated navigation for quadrotors

In this work, in order to achieve increased positioning accuracy, a particle filter based integrated navigation system is designed for a rotary wings unmanned aerial vehicle (UAV). As the navigation problem has highly non-linear characteristics on the system and measurement models, the designed algorithm which is based on particle filter works more effectively with respect to Kalman filter-based algorithms which have strict linearity assumptions. In order to verify the proposed algorithm, firstly the designed navigation system is tested with a flight scenario planned in an only simulation environment. After that, the designed algorithm is tested with the data acquired on a real rotary wings system in the laboratory for a different number of particles separately and it has been shown to produce satisfactory results. In this study, an integrated navigation solution having high accuracy and reliability was calculated for a quadrotor having six degrees of freedom.

一种辅助船舶入港的发光二极管导航系统设计与实现

一种辅助船舶入港的发光二极管导航系统设计与实现

Shupe effect of fiber sensing coils in multidimensional thermal field

Optical fibers have a wide range of applications and constitute the core of fiber-optic gyroscope which is revolutionizing the ancient inertial rotation detection. However, fiber coils in these instruments are susceptible to surrounding physical quantities, which can seriously deteriorate their accuracy. And the thermally induced parasitic effect is one of the most critical factors leading to the bias drift. This drift error is due to the nonreciprocity phase shift in the counter-propagating optical loops when a thermal gradient passes through the fiber coil as described by Shupe. The quadrupole winding patterns along with other coiling schemes have been proposed to reduce the Shupe effect by maintaining fiber parts at equal distances from the coil center beside each other. Many researchers have investigated the thermal effect on this drift on the assumption that the temperature transient propagates only radially along the fiber coil, while little attention has been paid to the case of the multidimensional thermal field. This can hardly satisfy completeness of the theory, and be applied to certain complicated working conditions. In this paper, we develop theoretical models that describe drift signals caused by radially, axially and circumferentially transmitted thermal effects on the quadrupole winding fiber coil. The obtained findings indicate that the bias error excited by the thermal flow in radial and axial directions is proportional to the weighted sum of the difference in temperature changing rate between outer and inner sides of the fiber ring. And the share of the sum linearly grows when approaching to the top surface near the input and output end (I/O end) of the fiber. Thus, it is suggested that it should be avoided to place heat sources in the neighboring area. For the circumferentially distributed temperature field, the drift depends on the symmetry of the thermal gradients on both sides of the centerline connecting the fiber midpoint and the I/O end. This circumferential thermal effect can be dominant, since it tends to cover a larger spatial scale than its counterparts in radial and axial directions. And besides making a good symmetrical design of the temperature distribution with respect to the centerline, it can be suppressed by arranging the nonuniformity of the thermal field in the opposite direction of the fiber coil to the I/O end, which is also beneficial to reducing its sensitivity to the angular change. Our results can help better understand the mechanisms for the thermal error formation and guide us in optimizing and facilitating the thermo-structure design of both fiber gyroscopes and navigation systems.

Моделювання високоточної системи визначення просторової орієнтації під дією збурень зовнішнього середовища

Мета: У статті розглянуто проблеми моделювання робастних високоточних систем визначення просторової орієнтації, які можуть використовуватися у навігації морських рухомих об’єктів. Головною метою є створення математичної моделі, пристосованої для моделювання збуреної системи, та моделей збурень зовнішнього середовища. Методи дослідження: Для розв’язання даної проблеми було використано теорію робастних систем управління, теорію фільтрації та теорію ймовірностей. Результати: Представлено модель збуреної системи визначення просторової орієнтації, створеної за допомогою засобів Simulink. Запропоновано вираз для визначення моменту збурення. Виконано аналіз можливих збурень зовнішнього середовища для системи досліджуваного типу. Отримано моделі збурень зовнішнього середовища на основі теорії фільтрації. Виконано порівняння двох підходів до розробки моделей зовнішнього середовища. Висновки: Представлено результати моделювання високоточної системи визначення просторової орієнтації рухомих об’єктів з урахуванням збурень зовнішнього середовища. Отримані результати можуть бути корисними для проектування високоточних навігаційних систем рухомих об’єктів.