Star selection strategy using measurement coupling matrix in starlight Doppler-based integrated navigation system

The high precision positioning and navigation of underwater vehicles is one of the key technologies for deep-sea exploration and ocean exploration, the underwater localization systems can be categorized into two main types: Inertial Navigation System (INS) and acoustic positioning system. INS is widely used in underwater navigation on account of its autonomy, however, without the information aiding from additional sensors, the errors of inertial measurement units accumulate with time passes. The acoustic positioning system can be divided into three types: Long Base Line (LBL), Short Base Line (SBL) and Ultra Short Base Line (USBL). They are defined according to the distance between transponders. The short baseline (SBL) positioning system includes more than 3 transponders to form an acoustic array, and the formation of the array is normally triangle or quadrilateral. The distance between the transponder is accurately measured and generally more than 10m. The acoustic array coordinate system is built based on the transponder and its relationship with the carrier coordinate system of the vehicle is determined by conventional method, the main disadvantage of the SBL positioning system is that the baseline length is relatively large in order to achieve high accuracy in deep-water measurement. However, as the lateral length of the vehicles is small, it is difficult to make sure the transponders be placed way from each other, meanwhile it is difficult to calibrate multiple transponders and avoid noise. To solve this problem, this paper present an inertial navigation system and single range navigation system (SRNS) based on one acoustic transponder, the navigation system consist of an acoustic transponder, a pressure transponder and inertial sensors mounted on the vehicle and an answering device transponder which is laoid out at tens of meters deep straight under the buoy. This paper studies the measurement equation's nonlinearity effect of the INS/SRNS, establishes state equation and measurement equation of the INS/SRNS integrated system. To deal with the nonlinear noise problems of transponders, meanwhile, in view that fault detection based on traditional state chi-square hypothesis testing cannot determine the specific cause of the fault, and could only determine the validity of measure information, a new fault detection algorithm based on dual-state method is adopted. The application of this method on underwater integrated navigation system demonstrates that the algorithm can rapidly and accurately detecting and identify the faults in the system. Experiments on QIANDAO Lake show that the proposed method restrains the divergence trend error of the integrated system's navigation, which verify the effectiveness of the single range integrated navigation.

In connection with the increasing complexity of aircraft navigation support, with growing demands placed on them, it is increasingly necessary to develop integrated navigation data processing system by solving synthesis problems based on optimal filtering methods. One of the promising ways to improve aircraft navigation support is to create an integrated navigation system (INS). In this work the triadic structure of a promising integrated navigation system based on inertial and satellite technologies is proposed. Combining nautical meters as part of the triad concept allows the flexible use of various navigation data processing algorithms and trajectory optimization ones at different stages of flight. Based on optimal filtering theory methods the integrated navigation data processing algorithm, which is an extended Kalman filter, is synthesized. A distinctive feature of the algorithm is that the variables of the state vector which are to be measured, are the errors in the determination of appropriate navigation and timing parameters. Priori information about the dynamics of errors is more reliably known than the one about aircraft motion variables. It is shown that the use of the proposed navigation system as a navigation aid for problem solving of highly accurate aircraft position indication satisfies the requirements for navigation and timing data accuracy. The imitating statistical modeling of optimal filtering algorithm of the triad integrated system is carried out. The accuracy characteristics of subsystems for different operating configurations of the constellation are given. Analysis of the results of the accuracy characteristics study of INS in various operating conditions has showed that the positioning accuracy in the navigation computer is up to date satellite navigation receivers.

High-precision navigation of the underground excavating machine is the core of realizing safe excavating and autonomous control, but it is difficult to realize high-precision navigation for the underground excavating machine. The integration of GNSS and inertial navigation system are generally adopted for the high-precision navigation of the ground equipment, which can provide high-precision navigation for a long time. However, the GNSS signals cannot be used in underground operation, so the navigation scheme applied to the ground cannot be used underground. At the same time, the velocity of the underground excavation machine is very slow and the operation time is very long, which makes it impossible to use pure inertial navigation scheme for navigation. Because the inertial navigation error accumulates with time, if the operation time is too long, the navigation accuracy cannot be guaranteed. The integration of inertial navigation and odometer is considered as a reliable scheme, but simulation and experimental analysis show that the traditional integration of inertial navigation and odometer cannot meet the operation requirements of the underground excavating machine in the presence of serious slipping and measurement noises. This paper proposes an integration of fully damped inertial navigation/odometer to provide long-term high-precision orientation navigation information for mining equipment. The advantage of the fully damped inertial navigation/odometer integration approach is that it can maintain high accuracy of orientation measurement in one week or longer under the condition of sensor drift error and odometer measurement error. Simulation and field tests are carried out to validate the performance of the proposed approach.

A new integrated navigation system designed for small size Unmanned Aerial Vehicles (UAVs) is presented. The proposed system is based on a number of low-cost avionics sensors, including Global Navigation Satellite Systems (GNSS), Micro-Electro-Mechanical System (MEMS) based Inertial Measurement Unit (IMU) and Vision Based Sensors (VBS). The use of an Aircraft Dynamics Models (ADMs) to provide additional information to compensate for the shortcomings of Vision Based Navigation (VBN) and MEMS-IMU sensors in high-dynamics attitude determination tasks is also considered. Additionally, the research concentrates on the potential of carrier-phase GNSS for Attitude Determination (GAD) using interferometric techniques. The main objective is to design a compact, light and relatively inexpensive system capable of providing the required navigation performance (position and attitude data) in all phases of flight of small UAVs, with a special focus on precision approach and landing, where VBN techniques can be fully exploited in a multi-sensor data fusion architecture. An Extended Kalman Filter (EKF) is developed to integrate the information provided by the different sensors and to provide estimates of position, velocity and attitude of the UAV platform in real-time. Three different integrated navigation system architectures are implemented. The first architecture uses VBN at 20 Hz and GNSS at 1 Hz to augment the MEMS-IMU running at 100 Hz. The second mode also includes the ADM (computations performed at 100 Hz) to provide augmentation of the attitude channel. The third fusion architecture uses GNSS based attitude values. The simulations are carried out on the AEROSONDE UAV performing high-dynamics manoeuvres repre-sentative of the UAV operational flight envelope. Simulation of the VBN-IMU-GNSS (VIG) integrated navigation system shows that the system can attain position, velocity and attitude accuracies complying with Category Two (CAT II) precision approach requirements. Simulation of the VBN-IMU-GNSS-ADM (VIGA) system also shows promising results, since the achieved attitude accuracy is higher using the ADM-VBN-IMU than using VBN-IMU only. However, due to rapid divergence of the ADM virtual sensor, there is a need for frequent re-initialisation of the ADM data module, which is strongly dependent on the UAV flight dynamics and the specific manoeuvring transitions performed. In the simulation of the third integrated navigation system, the VIG system is augmented by employing the GAD, forming the VIG-GAD (VIGGA) system architecture. The performances achieved with the VIG, VIGA and VIGGA integrated Navigation and Guidance System (NGS) are presented and are in line with the International Civil Aviation Organization (ICAO) precision approach requirements.

In this paper, an adaptive and robust Kalman filter algorithm based on the maximum correntropy criterion (MCC) is proposed to solve the problem of integrated navigation accuracy reduction, which is caused by the non-Gaussian noise and time-varying noise of GPS measurement in complex environment. Firstly, the Grubbs criterion was used to remove outliers, which are contained in the GPS measurement. Then, a fixed-length sliding window was used to estimate the decay factor adaptively. Based on the fixed-length sliding window method, the time-varying noises, which are considered in integrated navigation system, are addressed. Moreover, a MCC method is used to suppress the non-Gaussian noises, which are generated with external corruption. Finally, the method, which is proposed in this paper, is verified by the designed simulation and field tests. The results show that the influence of the non-Gaussian noise and time-varying noise of the GPS measurement is detected and isolated by the proposed algorithm, effectively. The navigation accuracy and stability are improved.

This video provides a step-by-step guide for performing the hybrid endoscopic thoracic discectomy using navigation and robotic arm for addressing high migrated calcified disc herniation. With the development of techniques, endoscopic spine surgery has emerged as a reliable treatment for thoracic myelopathy. This approach offers high-resolution, off-axis visualization of the surgical field. The field is poised to advance further as endoscopic instruments are refined, becoming less invasive and more precise through the integration of navigation and robot-assisted systems. A 62-year-old woman presented to us with chief complaints of both legs weakness. She had difficulty standing and walking after squatted due to weakness in her legs and her Oswestry Disability Index score was 66. On examination her both side knee extension and ankle dorsiflexion were grade 4 without dysesthesia. The imaging examination confirmed the diagnosis of thoracic myelopathy caused by a highly migrated calcified disc herniation at T5-6 level. The patient underwent an endoscopic thoracic discectomy using robotic arm and navigation for addressing highly migrated calcified disc herniation, resulting in an excellent outcome. The continuous development of navigation and robotic systems in endoscopic thoracic surgery enhanced accuracy in surgical incisions and instrument placement, as well as improved efficiency in locating pathology and achieving precise decompression. Endoscopic thoracic discectomy combines full-endoscopy and unilateral biportal endoscopic (UBE) techniques to leverage the benefits of both approaches, including the cross-viewing of full-endoscopy cannula and the use of larger Kerrison rongeurs under UBE.

As part of our recent research to assess the potential of low-cost navigation sensors for Unmanned Aerial Vehicle (UAV) applications, we investigated the potential of carrier-phase Global Navigation Satellite System (GNSS) for attitude determination and control of small size UAVs. Recursive optimal estimation algorithms were developed for combining multiple attitude measurements obtained from different observation points (i.e., antenna locations), and their efficiencies were tested in various dynamic conditions. The proposed algorithms converged rapidly and produced the required output even during high dynamics manoeuvres. Results of theoretical performance analysis and simulation activities are presented in this paper, with emphasis on the advantages of the GNSS interferometric approach in UAV applications (i.e., low cost, high data-rate, low volume/weight, low signal processing requirements, etc.). The simulation activities focussed on the AEROSONDE UAV platform and considered the possible augmentation provided by interferometric GNSS techniques to a low-cost and low-weight/volume integrated navigation system (presented in the first part of this series) which employed a Vision-Based Navigation (VBN) system, a Micro- Electro-Mechanical Sensor (MEMS) based Inertial Measurement Unit (IMU) and code-range GNSS (i.e., GPS and GALILEO) for position and velocity computations. The integrated VBN-IMU-GNSS (VIG) system was augmented using the inteferometric GNSS Attitude Determination (GAD)sensor data and a comparison of the performance achieved with the VIG and VIG/GAD integrated Navigation and Guidance Systems (NGS) is presented in this paper. Finally, the data provided by these NGS are used to optimise the design of a hybrid controller employing Fuzzy Logic and Proportional-Integral-Derivative (PID) techniques for the AEROSONDE UAV.

Celestial navigation system (CNS) is a completely autonomous navigation technology with strong anti-interference ability and high navigation accuracy, which has a great application prospect. Aim at defect of traditional integrated navigation system using attitude angle measurement celestial navigation system and strapdown inertial navigation system (SINS), which can only correct of strapdown inertial navigation system’s gyro drift. This paper proposes an improved integrated navigation system that add double-star positioning celestial navigation to traditional SINS/CNS integrated navigation system, meanwhile, introduces the fault detection technology based on statistical distance to solve the problem that inaccuracy of measurement information leads to the integrated navigation system’s performance degradation. By analyzing the simulation results, the improved navigation system can inhibit divergence of system and obtain high accurate and stable navigation information.

New progress of navigation and positioning technology, especially satellite navigation and positioning technology is reviewed in this paper. Development trend and direction of satellite navigation technology after GPS is discussed. Compatibility and interoperability of multi-mode satellite navigation system, integration and complementarity of satellite navigation with ground mobile network, and the integration of navigation and communication technology are introduced respectively in the first place. Then the inbound satellite positioning and communication system and bi-directional satellite positioning communication system are proposed. Finally, the possibility of the integration of navigation signal and function into the communication link is looked into the future.

The constraints of weight, volume and power for Small unmanned air vehicle (UAV) restrict the application of sensors with heavy and good performance and powerful processors. This paper presents a real-time solution of autonomous flight navigation and its results for small UAV by applying small, cheap, low precision and low-power integrated navigation system, which includes Strap-down Inertial Navigation System (SINS) based on Micro-electro-mechanical system (MEMS) inertial sensors, Global Positioning System (GPS) receiver and magnetometer. The Square-Root Unscented Kalman filter (SR-UKF) for data fusion using in this MEMS-SINS/GPS/ magnetometer integrated navigation system provides continuous and reliable navigation results for the loops of guidance and control for the small UAV with autonomous flight. The whole integrated navigation system algorithm is implemented within low-power embedded microprocessors. The real-time flight test results show that the MEMS-SINS/GPS/magnetometer integrated navigation system is effective and accurate.

As the battle environment becomes more complicated, the demand for higher accuracy and better anti-jam capacity of navigation has been increasing. The conventional JTIDS/INS/GPS integrated navigation cannot meet the demands of certain situations such as precision strike and formation flight. A new system that introduces the differential GPS into JTIDS/INS/GPS integration system is proposed to improve the navigation performance in the modern combined operations. In this system, the differential information of DGPS is transmitted through the communication data link of Link-16. As a result, the system resources are efficiently utilized and the controllability and anti-jam performance of the system are significantly enhanced. A hybrid slot allocation protocol (HSAP) that combines a static slot allocation algorithm and a dynamic slot allocation algorithm and the corresponding source-chosen mechanisms are proposed. The performance of the JTIDS/INS/GPS integration navigation using the differential GPS information from one or multiple base stations is studied and compared with that of the system without using the differential GPS information. Furthermore, the performance of the integration navigation using HSAP is compared with that of the system using static slot allocation algorithm. We show that navigation accuracy based on the differential GPS is improved, and using HSAP also leads to higher localization accuracy.

<div class="htmlview paragraph">In future lunar and Mars exploration missions the ability to provide the crewmember navigation information will be critical. Exploration demands that Extravehicular Activity (EVA) astronauts be provided the capability to operate with greater autonomy in accomplishing complex EVA missions than has been the case previously. Robust crew information interfaces and navigation support integral to the EVA spacesuit system are expected to be minimum requirements. Navigation support must allow the EVA crew to determine their position relative to EVA target locations, satellite imagery and maps and assist them in walking or riding to the desired targets on the planetary surface. Together, these needs suggest a requirement for an integrated system that combines data and voice communications, a high performance visual display, and navigation support in a design that is compatible with spacesuit environmental and packaging restrictions and with unique EVA crew interface demands. Unlike current Earth surface operations, lunar and Mars missions will require that these capabilities be provided with a minimum of infrastructure and without the availability of an extensive network of satellites like the Global Positioning System (GPS).</div> <div class="htmlview paragraph">NASA has included crew information interface experiments in its Desert Research and Technology Studies (RATS) to better understand the detailed requirements for such a system and has evolved a test platform called the Communications Avionics and Informatics (CAI) pack to support those studies. During 2006, Hamilton Sundstrand and Raytheon have worked with NASA to integrate a ground based navigation system developed for military uses into this test environment for a preliminary assessment of feasibility and utility. The results show significant promise and the potential for near term development of a more fully integrated test system. This paper describes the test systems, test activities and results and discusses possible future experimentation.</div>

High dynamic aircraft is a very attractive new generation vehicles, in which provides near space aviation with large flight envelope both speed and altitude, for example the hypersonic vehicles. The complex flight environments for high dynamic vehicles require high accuracy and stability navigation scheme. Since the conventional Strapdown Inertial Navigation System (SINS) and Global Position System (GPS) federal integrated scheme based on EKF (Extended Kalman Filter) is invalidation in GPS single blackout situation because of high speed flight, a new high precision and stability integrated navigation approach is presented in this paper, in which the SINS, GPS and Celestial Navigation System (CNS) is combined as a federal information fusion configuration based on nonlinear Unscented Kalman Filter (UKF) algorithm. Firstly, the new integrated system state error is modeled. According to this error model, the SINS system is used as the navigation solution mathematic platform. The SINS combine with GPS constitute one error estimation filter subsystem based on UKF to obtain local optimal estimation, and the SINS combine with CNS constitute another error estimation subsystem. A non-reset federated configuration filter based on partial information is proposed to fuse two local optimal estimations to get global optimal error estimation, and the global optimal estimation is used to correct the SINS navigation solution. The χ 2 fault detection method is used to detect the subsystem fault, and the fault subsystem is isolation through fault interval to protect system away from the divergence. The integrated system takes advantages of SINS, GPS and CNS to an immense improvement for high accuracy and reliably high dynamic navigation application. Simulation result shows that federated fusion of using GPS and CNS to revise SINS solution is reasonable and availably with good estimation performance, which are satisfied with the demands of high dynamic flight navigation. The UKF is superior than EKF based integrated scheme, in which has smaller estimation error and quickly convergence rate.

In this article, a mode composite ridged substrate integrated coaxial line (MCRSICL) is proposed for concurrent multichannel operation. The TEM and TE10 modes of the MCRSICL are excited simultaneously with high isolation. Consequently, the operation frequency band of the ridged substrate integrated coaxial line (RSICL) is expanded without necessitating additional physical space. The transmission performance and design principle of the MCRSICL are studied. Based on the low-temperature co-fired ceramic (LTCC) technology, an MCRSICL prototype is designed and fabricated to enable parallel TEM and TE10 operations. The measurement results show that the TEM and TE10 channels operate from dc to 40 and from 18 to 40 GHz, respectively, and the crosstalk between the two channels is below −35 dB. Besides, a multichannel high-speed signal transmission system is designed based on the MCRSICL prototype for high-speed interconnect applications, and the measured output signals exhibit good eye diagrams with 25- and 10-Gb/s pseudorandom binary sequence (PRBS) input signals. Subsequently, a dual-band bandpass filter (BPF) is proposed based on the MCRSICL, whose two channels operate at 5.7 and 29 GHz in a large frequency ratio of 5.1. In addition, a reconfigurable RF front end is designed using the MCRSICL BPF operating in both the sub-6G and Ka bands for an integrated communication and navigation system. The innovative MCRSICL establishes a novel platform for multichannel interconnect and component, characterized by compact dimension, simple transition, versatile design flexibility, and weak coupling between channels.

In this paper, we integrate the high-precision inertial navigation system (INS) with the GPS precise point positioning (PPP) by using the tightly-coupled architecture, which aims to obtain the preferable attitude and positioning information in the remote marine applications. The structure of INS/PPP tightly-coupled integrated navigation is presented firstly in the paper. Then, the observation model in the local geographic frame (ENU frame) is derived, where the Extend Kalman filter (EKF) is used for the information fusion. Finally, a real shipborne marine test is conducted to test the performance of INS/PPP tightly coupled integration. The experimental results show that the positioning accuracy of the integrated navigation system can be better than 10cm in the horizontal axis and 20cm for the vertical channel, and the attitude estimation error can be smaller than 1 arcsec. Besides this, the performance the tightly-coupled integration can be maintained during 100s simulated signal outages, while that performance of loosely-coupled integration will degrade significantly in such a case.