Innovation-Based Fault Detection and Exclusion Applied to Ultra-WideBand Augmented Urban GNSS Navigation

Due to their ability to provide a worldwide absolute outdoor positioning, Global Navigation Satellite Systems (GNSS) have become a reference technology in terms of navigation technologies. Transportation-related sectors make use of this technology in order to obtain a position, velocity, and time solution for different outdoor tasks and applications. However, the performance of GNSS-based navigation is degraded when employed in urban areas in which satellite visibility is not good enough or nonexistent, as the ranging signals become obstructed or reflected by any of the numerous surrounding objects. For these situations, Ultra-Wideband (UWB) technology is a perfect candidate to complement GNSS as a navigation solution, as its anchor trilateration-based radiofrequency positioning resembles GNSS’s principle. Nevertheless, this fusion is vulnerable to interferences affecting both systems, since multiple signal-degrading error sources can be found in urban environments. Moreover, an inadequate location of the augmenting UWB transmitters can introduce additional errors to the system due to its vulnerability to the multipath effect. Therefore, the misbehavior of an augmentation system could lead to unexpected and critical faults instead of improving the performance of the standalone GNSS. Accordingly, this research work presents the performance improvement caused by the application of Fault Detection and Exclusion methods when applied to a UWB-augmented low-cost GNSS system in urban environments

Innovation-Based Fault Detection and Exclusion Applied to Ultra-WideBand Augmented Urban GNSS Navigation

Due to their ability to provide a worldwide absolute outdoor positioning, Global Navigation Satellite Systems (GNSS) have become a reference technology in terms of navigation technologies. Transportation-related sectors make use of this technology in order to obtain a position, velocity, and time solution for different outdoor tasks and applications. However, the performance of GNSS-based navigation is degraded when employed in urban areas in which satellite visibility is not good enough or nonexistent, as the ranging signals become obstructed or reflected by any of the numerous surrounding objects. For these situations, Ultra-Wideband (UWB) technology is a perfect candidate to complement GNSS as a navigation solution, as its anchor trilateration-based radiofrequency positioning resembles GNSS’s principle. Nevertheless, this fusion is vulnerable to interferences affecting both systems, since multiple signal-degrading error sources can be found in urban environments. Moreover, an inadequate location of the augmenting UWB transmitters can introduce additional errors to the system due to its vulnerability to the multipath effect. Therefore, the misbehavior of an augmentation system could lead to unexpected and critical faults instead of improving the performance of the standalone GNSS. Accordingly, this research work presents the performance improvement caused by the application of Fault Detection and Exclusion methods when applied to a UWB-augmented low-cost GNSS system in urban environments

AIOSAT - Autonomous Indoor & Outdoor Safety Tracking System

Even though satellite-based positioning increases rescue workers’ safety and efficiency, signal availability, reliability, and accuracy are often poor during fire operations, due to terrain formation, natural and structural obstacles or even the conditions of the operation. In central Europe, the stakeholders report a strong necessity to complement the location for mixed indoor-outdoor and GNSS blocked scenarios. As such, location information often needs to be augmented. For that, European Global Navigation Satellite System Galileo could help by improving the availability of the satellites with different features. Moreover, a multi-sensored collaborative system could also take advantage of the rescue personnel who are already involved in firefighting and complement the input data for positioning. The Autonomous Indoor & Outdoor Safety Tracking System (AIOSAT) is a multinational project founded through the Horizon 2020 program, with seven partners from Spain, Netherlands and Belgium. It is reaching the first year of progress (out of 3) and the overarching objective of AIOSAT system is to advance beyond the state of the art in tracking rescue workers by creating a high availability and high integrity team positioning and tracking system. On the system level approach, this goal is achieved by fusing the GNSS, EDAS/EGNOS, pedestrian dead reckoning and ultra-wide band ranging information, possibly augmented with map data. The system should be able to work both inside buildings and rural areas, which are the test cases defined by the final users involved in the consortium and the advisory board panel of the project

An enhanced integrity multisensor Fusion for a reliable seamless navigation.

Since its first applications in the late 20th century, GNSS technology has been deployed by the world’s technologically advanced countries in multiple fields, from fleet monitoring to sport-related topics. This massive deployment has led to new use cases that may not have been expected during the definition of said technology. Different error sources, such as interferences, jamming, signal attenuation due to indoor or urban canyon navigation, and signal-blocking objects may degrade the performance of GNSS-based navigation. Thus, standalone GNSS systems may not fulfil all the requirements a certain scenario might ask for. This has resulted in the research of alternative or supplementary methods to solve the aforementioned issues, such as multisensor navigation. This has become one of the main alternatives to GNSS standalone navigation, as it has been shown in the literature that it can result in an improvement in navigation in terms of availability or continuity, for example. Human-life involvement and high-cost freight transportation, among other factors, have attracted the attention of the users to the definition of a measure of trust that is placed in the correctness of the information supplied by the navigation systems; also called integrity. This concept is employed, among others, to enable the system to detect if it is trustable for navigation, provide warnings, and even act consequently. In this dissertation, we analyze, first, the design of an online multisensory navigation algorithm as a solution to the issues GNSS suffers especially in urban and indoor environments. Moreover, a two-stage integrity-ensuring method is analyzed, being this second algorithm a tailored complementary feature of the proposed navigation one.Desde sus primeras aplicaciones a fines del siglo XX, la tecnología GNSS ha sido implementada por los países tecnológicamente avanzados del mundo en múltiples campos, desde la monitorización de flotas hasta temas relacionados con el deporte. Este despliegue masivo ha dado lugar a nuevos casos de uso no contemplados durante la definición de dicha tecnología. Diferentes fuentes de error, como interferencias, atenuación de la señal debido a la navegación en interiores o en cañones urbanos y objetos que bloquean la señal pueden degradar el rendimiento de la navegación basada en GNSS. Por lo tanto, es posible que los sistemas basados únicamente en GNSS no cumplan con todos los requisitos que podría solicitar un determinado escenario. Esto ha dado lugar a la investigación de métodos alternativos o complementarios para solucionar los problemas antes mencionados, como la navegación multisensor. Ésta se ha convertido en una de las principales alternativas a la navegación autónoma GNSS, ya que se ha demostrado en la literatura que puede resultar en una mejora en la navegación en términos de disponibilidad o continuidad, por ejemplo. La afectación de la vida humana y el transporte de carga de alto costo, entre otros factores, han llamado la atención de los usuarios sobre la definición de una medida de confianza que se deposita en la exactitud de la información suministrada por los sistemas de navegación; también llamada integridad. Este concepto se emplea, entre otros, para que el sistema detecte si es fiable para la navegación, emita avisos e incluso actúe en consecuencia. En esta tesis analizamos, en primer lugar, el diseño de un algoritmo de navegación multisensorial online como solución a los problemas que sufre el GNSS especialmente en entornos urbanos e interiores. Además, se analiza un método de aseguramiento de la integridad en dos etapas, siendo este segundo algoritmo una característica complementaria a la medida del de navegación propuesto

A Review of the Evolution of the Integrity Methods Applied in GNSS

The use of GNSS technologies has been spreading over time up to a point in which a huge diversity of applications require their use. Due to this demand, GNSS has turned into a more reliable technology, as multiple aspects of it have evolved. Integrity has become a vital aspect of being considered when using GNSS. The following document gathers and shows different aspects of integrity in terms of GNSS. The paper mainly focuses on the description of different receiver autonomous integrity monitoring methods. For this purpose, basic concepts and possible GNSS error sources (and their corresponding solutions) are introduced. Afterward, an explanation and a classification of the integrity monitoring techniques is given, where the fault detection and exclusion methods and different protection level computation formulas are analyzed

Corrections to “A Review of the Evolution of the Integrity Methods Applied in GNSS”

In the above article [1], the authors forgot to properly acknowledgment the Shift2Rail Joint Undertaking

An enhanced integrity multisensor Fusion for a reliable seamless navigation.

Since its first applications in the late 20th century, GNSS technology has been deployed by the world’s technologically advanced countries in multiple fields, from fleet monitoring to sport-related topics. This massive deployment has led to new use cases that may not have been expected during the definition of said technology. Different error sources, such as interferences, jamming, signal attenuation due to indoor or urban canyon navigation, and signal-blocking objects may degrade the performance of GNSS-based navigation. Thus, standalone GNSS systems may not fulfil all the requirements a certain scenario might ask for. This has resulted in the research of alternative or supplementary methods to solve the aforementioned issues, such as multisensor navigation. This has become one of the main alternatives to GNSS standalone navigation, as it has been shown in the literature that it can result in an improvement in navigation in terms of availability or continuity, for example. Human-life involvement and high-cost freight transportation, among other factors, have attracted the attention of the users to the definition of a measure of trust that is placed in the correctness of the information supplied by the navigation systems; also called integrity. This concept is employed, among others, to enable the system to detect if it is trustable for navigation, provide warnings, and even act consequently. In this dissertation, we analyze, first, the design of an online multisensory navigation algorithm as a solution to the issues GNSS suffers especially in urban and indoor environments. Moreover, a two-stage integrity-ensuring method is analyzed, being this second algorithm a tailored complementary feature of the proposed navigation one.Desde sus primeras aplicaciones a fines del siglo XX, la tecnología GNSS ha sido implementada por los países tecnológicamente avanzados del mundo en múltiples campos, desde la monitorización de flotas hasta temas relacionados con el deporte. Este despliegue masivo ha dado lugar a nuevos casos de uso no contemplados durante la definición de dicha tecnología. Diferentes fuentes de error, como interferencias, atenuación de la señal debido a la navegación en interiores o en cañones urbanos y objetos que bloquean la señal pueden degradar el rendimiento de la navegación basada en GNSS. Por lo tanto, es posible que los sistemas basados únicamente en GNSS no cumplan con todos los requisitos que podría solicitar un determinado escenario. Esto ha dado lugar a la investigación de métodos alternativos o complementarios para solucionar los problemas antes mencionados, como la navegación multisensor. Ésta se ha convertido en una de las principales alternativas a la navegación autónoma GNSS, ya que se ha demostrado en la literatura que puede resultar en una mejora en la navegación en términos de disponibilidad o continuidad, por ejemplo. La afectación de la vida humana y el transporte de carga de alto costo, entre otros factores, han llamado la atención de los usuarios sobre la definición de una medida de confianza que se deposita en la exactitud de la información suministrada por los sistemas de navegación; también llamada integridad. Este concepto se emplea, entre otros, para que el sistema detecte si es fiable para la navegación, emita avisos e incluso actúe en consecuencia. En esta tesis analizamos, en primer lugar, el diseño de un algoritmo de navegación multisensorial online como solución a los problemas que sufre el GNSS especialmente en entornos urbanos e interiores. Además, se analiza un método de aseguramiento de la integridad en dos etapas, siendo este segundo algoritmo una característica complementaria a la medida del de navegación propuesto

On the Use of Ultra-WideBand-Based Augmentation for Precision Maneuvering

The limitations of the existing Global Navigation Satellite Systems (GNSS) integrated with Inertial Measurement Units (IMU) have presented significant challenges in meeting the stringent demands of precision maneuvering. The identified constraints in terms of accuracy and availability have required the development of an alternative solution to enhance the performance of navigation systems in dynamic and diverse environments. This paper summarizes the research regarding the integration of ultra-wideband (UWB) technology as an augmentation of the conventional GNSS+IMU system; it proposes an approach that aims to overcome the limitations of conventional navigation systems. By making use of UWB technology, the proposed low-cost UWB-augmented GNSS+IMU system not only fulfils the required performance standards but also offers the unique capability to navigate seamlessly across indoor and outdoor environments. The developed system was validated through comprehensive testing and analysis in both the automotive and maritime sectors. The obtained results highlight the system’s capacity as a dependable and resilient solution for precise navigation, and they promote its use within the domain of accurate maneuvering

Innovation-based fault detection and exclusion applied to ultra-wideband augmented urban GNSS navigation

Due to their ability to provide a worldwide absolute outdoor positioning, Global Navigation Satellite Systems (GNSS) have become a reference technology in terms of navigation technologies. Transportation-related sectors make use of this technology in order to obtain a position, velocity, and time solution for different outdoor tasks and applications. However, the performance of GNSS-based navigation is degraded when employed in urban areas in which satellite visibility is not good enough or nonexistent, as the ranging signals become obstructed or reflected by any of the numerous surrounding objects. For these situations, Ultra-Wideband (UWB) technology is a perfect candidate to complement GNSS as a navigation solution, as its anchor trilateration-based radiofrequency positioning resembles GNSS's principle. Nevertheless, this fusion is vulnerable to interferences affecting both systems, since multiple signal-degrading error sources can be found in urban environments. Moreover, an inadequate location of the augmenting UWB transmitters can introduce additional errors to the system due to its vulnerability to the multipath effect. Therefore, the misbehavior of an augmentation system could lead to unexpected and critical faults instead of improving the performance of the standalone GNSS. Accordingly, this research work presents the performance improvement caused by the application of Fault Detection and Exclusion methods when applied to a UWB-augmented low-cost GNSS system in urban environments

Residual based fault detection and exclusion methods applied to Ultra-Wideband navigation.

Global Navigation Satellite System (GNSS) has become the main technology in terms of navigation technologies, as it ensures a worldwide absolute outdoor positioning. The transportation sector employs this technology to obtain a position, velocity and time solution for the corresponding outdoor application. When talking about indoor positioning, nevertheless, GNSS becomes an unreliable navigation technology, as the below-noise signals get obstructed. In these cases, the Ultra-Wideband (UWB) technology can be used as a navigation solution, as its anchor trilateration based radiofrequency positioning resembles GNSS's principle and, depending on the anchor location, it can be used for indoor positioning. However, just like other radiofrequency based technologies, UWB is vulnerable to interferences and the multipath effect. With the aim of overcoming these drawbacks, this article discusses how to apply Fault Detection and Exclusion (FDE) techniques to avoid using faulty anchors when employing UWB in indoor/urban environments such as tunnels or train stations