We designed a tightly-coupled integration between GNSS and inertial navigation systems (INS) where we modify the update step of a classical Extended Kalman Filter (EKF) to consider different robust estimators (such as M-estimators). We consider different faulty scenarios where the pseudoranges contain one or several non-modeled biases. The tightly-coupled GNSS/INS robust Kalman filter performance in the presence of biases is compared with the classical EKF and with a loosely-coupled Robust-GNSS/INS approach. The robust tightly-coupled version is able to minimize more efficiently the biases effect thanks to the direct redundancy of the inertial sensor within the robust estimator.
There is little doubt in the benefit gained from cooperative modes of road transport, as agents working together generally perform better. In simple terms, this is the holistic idea that the whole is greater than the sum of its parts, commonly known as synergy. On top of this clear advantage, the complex systems theory of emergence suggests that novel strategies will develop from the as-yet-undefined patterns and structures. It is clear, however, that to facilitate this development certain technological advances need to be achieved. In this case, individual road agents need to accurately identify their location, and communicate easily and safely with other agents. This is a shift away from protective and passive systems toward preventative and active transport safety.
A component of most GPS receiver front-ends, the automatic gain control (AGC) can flag potential jamming and spoofing attacks. The detection method is simple to implement and accessible to most GPS ...
Researchers at the university of Colorado have successfully used radio frequency record-and-playback systems (RPS) have gathered importance commercially because it offers the best way to test hardw ...
This article describes how combining radio frequency identification (RFID) tracking chips and Global Positioning System (GPS)-enabled handheld reader terminals can lead to improved precision in the tracking of international goods. It presents a Supply Chain Management Implementation System that allows for both indoor and outdoor tracking, offers a unique tag identifier that provides identification, updated time, and updated position, offers worldwide tracking, and uses a combination of GNSS and RFID technologies. The article discusses the equipment, system, and methodology integrating identification, communication, and position/time functions.
This article describes a study of travel behaviors with a quantitative data set acquired through the use of household Global Positioning System Automated Travel Diaries (GPS-ATD). Data collected from GPS-ATD promises to be useful in developing models for travel patterns and demand, estimating travel modality decision-making, evaluating regional transportation trends, predicting travel changes due to contingencies, and predicting trip generation per capita in terms of demographics, location, and socioeconomics. Upon describing some issues related to earlier versions of GPS-ATD devices and their drawbacks, researchers explain how the system specifications for the proposed GPS-ATD are an improvement. Such improvements include its readiness for mass production, component selection, integration with on-board features in vehicles, and the embedded software. The user interface and system testing is also described. The article also notes that the system is capable of supporting the upcoming 2010 California Statewide Household Travel Survey.
In this article the author discusses the feasibility of replacing traditional odometers on vehicles with one based from data collected from a Global Navigation Satellite System (GNSS) such as the Global Positioning System (GPS) or its European or Russian cognates. Such information is usefully distributed en masse to road authorities, company executives, and insurance companies as well as for monitoring driving patterns to aid in traffic logistics. The author explains that, if such a device can be produced economically, it will offer substantial advantages over existing odometers. Benefits include fewer moving parts with GNSS-based odometers, no sensitivity to tire pressure, road surface, or vehicle load, tamper-proof, and easy installation in both old and new vehicles. The author demonstrates the feasibility of a GNSS odometer, which would require that four percent accuracy be achieved.
Automatic Dependent Surveillance-Broadcast (ADS-B) is a cooperative surveillance system that uses a data communication protocol with the automatic broadcast of parameters such as identification, position, and velocity. This article describes results from trade studies which examined the availability of Global Positioning System (GPS) combined with receiver autonomous integrity monitoring (RAIM) into systems that can meet the various future requirements of ADS-B applications. Included in this study were the following most significant system parameters: user location, GPS receiver awareness of selective availability, GPS satellite constellation, satellite failure probability assumptions, and satellite masking angle assumptions. Various combination of the parameters were then compared with the most recent version of planned ADS-B requirements. This would then allow for any changes to current airplane designs that might be needed in order to meet the ADS-B requirements.
This article describes an integrated multisensor approach to navigation technology that combines complementary features from different navigation technologies. The result is accurate and reliable navigation capabilities for urban scenarios. In the article, the author takes earlier developments in the fields of inertial navigation system (INS)/laser scanner and Global Positioning System (GPS) laser scanner integration. These efforts are then extended by combining GPS, laser scanner, and inertial data into a single multisensor integrated solution. Potential applications for the described technique can be found in the guidance and control of autonomous ground and aerial vehicles.
In this article the authors discuss the development and field testing of a new implementation of a combined Global Positioning System (GPS) receiver, wireless data link, and processor as outfitted on automobiles for applications in pedestrian detection. The device called is known as a pedestrian alert system (PAS), and it is designed to detect pedestrians in all weather and non-line-of-sight situations, allow for the classification of pedestrian collision types, provide an effective means of alerting drivers to the presence of detected pedestrians, and reduce or eliminate missed detections and false alerts. Field tests are described that evaluate the PAS system's efficacy. The features examined include adequate driver interface, a robust communications link, accurate differential GPS (DGPS), and accurate prediction of velocity and position vectors in 8 second anticipation. The provided proof of concept PAS was deemed to satisfy the given parameters.
This article looks at the difficulities of Global Positioning System (GPS)-based positioning for pedestrians in urban areas. Urban canyons create degradation in the accuracy and integrity of GPS ranging. They can also increase the geometric dilution of receiver precision. The article describes a novel approach involving a geographic information system (GIS) database containing the geometrical description of buildings in the area. The approach involves restricting the area of possible locations, mitigating multipath effects, matching the environment with GPS measurements, and employing models to compute accurate fixes. The intrinsic freedom of the pedestrian is maintained. The article then describes how this new method was implemented using GIS products which enabled the concept to be used as light middleware on mass market terminals such as personal navigation devices or personal digital assistants (PDAs). Results from tests conducted in several cities reveal significant improvements in the accuracy of GPS-based positioning.
This article describes new methods to improve the integrity of Global Positioning System (GPS) for applications in aviation. Focus is on addressing integrity monitoring, time-to-alert (TTA), and the necessary constellation strength. The article references the Federal Aviation Administration’s (FAA) GPS Evolutionary Architectural Study (GEAS) which was initiated with the goal of creating an architecture capable of bringing airplanes within 200 feet of the ground. It discusses the implications that the architecture will have on the Wide Area Segmentation Systems (WAAS) and Local Area Augmentation Systems (LAAS) programs. Techniques such as Receiver Autonomous Integrity Monitoring (RAIM) and relative (RRAIM) and absolute (ARAIM), which are used for Lateral Navigation (LNAV), and integrity determination, are described. The article evaluates the advantages of these architectures and their implications for constellations and satellite strength.
