D. Bétaille - Academia.edu (original) (raw)
Papers by D. Bétaille
![Research paper thumbnail of Special Issue on IEEE IV 2012 Workshops: Part 1 of 2 [Guest Editorial]](https://attachments.academia-assets.com/95169759/thumbnails/1.jpg)
](IEEE Intelligent Transportation Systems Magazine, 2013
Survey Review, 1999
ABSTRACT This paper presents a series of tests that could be used to assess the performance of an... more ABSTRACT This paper presents a series of tests that could be used to assess the performance of any real-time kinematic GPS system. Criteria including accuracy, speed of ambiguity recovery, ability to maintain lock and signal tracking sensitivity are considered and typical test results presented. System performance is examined using both static and truly kinematic applications, under both benign and high-multipath environments.
… précise pour les …, 2009
... Robosoft, Technopole d'Izarbel, 64210 Bidart {eric.lucet,damien ... Pi+1|i = FiPi|i ... more ... Robosoft, Technopole d'Izarbel, 64210 Bidart {eric.lucet,damien ... Pi+1|i = FiPi|i FT i + JuiPUi JT ui + Q PUi is the covariance of the input dynamic noises ... standard deviation 0.0044 0/s DGPS measure standard deviation 0.4 m Maximum velocity 10.0 m/s Minimum velocity −2.0 m ...
Navigation, 2016
GNSS localization in an urban environment remains a key issue that must be solved in order to ena... more GNSS localization in an urban environment remains a key issue that must be solved in order to enable innovative driver assistance systems or cooperative applications. This key issue exists not only in terms of accuracy but also in terms of integrity. Actually, one aims at reducing as much as possible the error mainly due to multipath on buildings and provide in the mean time a certain guarantee on the user position exactness. This article shows how a simple geometric modeling, named 'Urban Trench', of the city environment can improve significantly the positioning accuracy. Authors also propose an algorithm for computing an urban trench protection level, with a much higher reliability compared to conventional protection level whose open sky assumption is violated. Experimental results are given in the cities of Nantes, Paris, and Toulouse, France.
2012 15th International IEEE Conference on Intelligent Transportation Systems, 2012
Mobility pricing based on GNSS is bound to become a significant tool for both traffic control and... more Mobility pricing based on GNSS is bound to become a significant tool for both traffic control and infrastructure funding, compared to geofencing roadside technologies. But GNSS positioning in cities remains challenging, because of the poor satellite visibility and of the occurrence of many satellite signal reflections (multipath), that in the best case combine with the direct signal, but, when the direct signal is obscured, create significant biases of several tens of meter in the pseudo-range measurements and consequently on the computed position. The method proposed here is based on a simplified 3D model of buildings at both sides of streets, named "Urban Trench" for that reason, which can benefit in the process of satellite visibility check and GNSS positioning. Homogeneous street sections are described with three parameters: width, building height and transversal position of the vehicle. These parameters allow to identify the satellites in direct visibility and to compute the estimated additional range brought by the reflections. It has been proved that, in some environments such as the Grands Boulevards in Paris, the position computed by a least squares method can be improved by a factor of 70% after application of our visibility check and multipath bias correction, without degrading the availability..
Global Navigation Satellite Systems (GNSS), such as GPS, are more and more playing a key role in ... more Global Navigation Satellite Systems (GNSS), such as GPS, are more and more playing a key role in the development of new traffic applications and services, such as those making use of “Geofencing” techniques, electronic tolling systems being the most famous among them. Geofencing needs geopositioning and, in most of the case, geopositioning with a certain level of quality, in particular in terms of integrity for the liability-critical applications. The EGNOS system is the European Wide Area Augmentation System for GPS and has been built, upon air transport specifications, to increase the accuracy, but mainly the integrity of GPS system. The French Ministry in charge of Transport, the MEEDDM, has funded a specific study, called “EGNOS-On-The-Road”, to assess, thanks to full-scale experiments in real-life conditions, the improvements that can be expected from EGNOS for road applications, compared to GPS. The authors first describe the experimental test bench, the GNSS sensors and the data processing that have been used. Then they present the results, in terms of availability, accuracy, integrity an in terms of adequacy to the application needs, for several types of sensors: stand-alone GPS receivers or EGNOS/GPS receivers, used with internal and external antennas. The paper ends with a conclusion and high-level recommendations.
Satellite positioning performances are critical for transport liability applications such as road... more Satellite positioning performances are critical for transport liability applications such as road user charging, or pay per use assurance. The scientific community has focused for several years on environments with favorable conditions (aviation, maritime, rural) and is now addressing transport applications including urban areas. This is the case of this paper that presents the result of a study co-financed by the National French Space Agency (CNES). This study aimed first to collect the positioning data in urban area of several GPS/EGNOS receivers (more than 1.5 millions of positions) in addition to their associated satellite raw data and the reference positions. Its goal was secondly to assess the performance using classical positioning algorithms and last to propose and assess improved algorithms. The authors present first how to obtain the true trajectory necessary for the performance assessments. The instrumentation they set-up on board a test vehicle is based on IXSEA LandINS inertial measurement unit hybridized with kinematics GPS and odometry. The reference trajectory obtained is analyzed, with the aim of qualifying its accuracy. Based on these measurements, the authors then present the performance improvements obtained using different techniques, in particular 2D techniques to improve availability in difficult area such as narrow streets, smoothing technique to optimize the filtering and local error modeling technique to assess in particular disturbing multipath effects. Thanks to the ground truth obtained in this benchmark, the authors demonstrate that these techniques bring a significant improvement to position data performances, enlarging that way the spectrum of liability-critical road transport applications in urban areas.
Integrity is an attribute of the quality of performance of a positioning technology that is getti... more Integrity is an attribute of the quality of performance of a positioning technology that is getting crucial for many Intelligent Transportation Systems dealing with safety. Managing the confidence in estimated locations is difficult when operating in complex outdoors environments, particularly for Global Navigation Satellite Systems (GNSS). A common integrity process consists in removing outliers amongst the measurements using Fault Detection and Exclusion (FDE) algorithms and then to compute Protection Levels (PL) that quantify the integrity zone. This snapshot paradigm is applicable mainly to the aerospace domain where high pseudo-ranges redundancy exists, which is not the case for land applications. In this paper, a new approach to localization integrity for land mobile robot is proposed by combining vehicle and GNSS data, stored within a short-term memory, called data horizon. This formulation allows for the application of FDE algorithms on the combined data set. It also leads to a gain of redundancy that enables PLs to be reduced and to increase the availability of integrity algorithms. Results from evaluation tests are included to demonstrate the validity of the approach.
Les travaux de recherche rapportes ici concernent la faisabilite de la localisation 2D de vehicul... more Les travaux de recherche rapportes ici concernent la faisabilite de la localisation 2D de vehicules specialises pour l'auscultation des routes, par traitements en temps differe de mesures de plusieurs capteurs embarques: DGPS, odometre et differents gyrometres. Les techniques mises en oeuvre combinent filtrages et lissages. Le probleme se pose de localiser en continu l'AGR, alors que le GPS est sujet a masquage. L'etude s'appuie sur le formalisme de Kalman. Plusieurs techniques classiques de lissage ont ete eprouvees sur des essais reels. Une combinaison de l'une d'entre elles avec un lisseur concu assez intuitivement (a partir de similitudes geometriques en zones de masquage) a conduit au meilleur resultat, proche de la precision metrique specifiee. Une utilisation originale de donnees cartographiques avec un filtre de Kalman est presentee afin d'ameliorer la localisation pendant les masquages prolonges du GPS. Des experimentations ont eu lieu sur la piste de reference du LCPC, parfaitement degagee, et les zones de masquage etaient simulees lors du traitement en temps differe. La reference pour le chemin "reellement" parcouru etait fournie par un recepteur DGPS cinematique de precision centrimetrique. (A).
This paper describes the system approach for a future positioning system to be developed for the ... more This paper describes the system approach for a future positioning system to be developed for the European CVIS project (www.cvisproject.org) that deals with an increased transport safety and efficiency using advanced positioning, mapping and communication technologies. Positioning and mapping functions will be provided by the sub-project POMA, where new methods for the combination of several positioning components will be developed. The whole positioning system setup of CVIS will then be deployed at DLR in Berlin. This setup will not only cover onboard components but also infrastructure based sensors and sensor networks together with enhanced positioning algorithms. This new approach shall enable high accuracy and reliability for the following field trials spread over Europe
Multipath signals have a strong effect on position estimates; these are studied intensely theoret... more Multipath signals have a strong effect on position estimates; these are studied intensely theoretically and experimentally. In this paper a domain oriented perspective is presented, passenger vehicles traversing dense urban areas. The purpose is to examine the effects of multipath on pseudo-ranges and Doppler measurements. The approach combines a theoretical formulation with extensive testing. The experiment includes the acquisition of measurements provided by a low-cost automotive GPS receiver on-board a vehicle in real traffic conditions. In addition, the vehicle trajectory was measured precisely to allow for the quantification of measurement errors. Two approaches are used in the experimental part to determine the pseudo-range and Doppler errors: Vehicle on-board measurements plus post-processing; vehicle onboard measurements, data from an external GPS reference station and post-processing. The results enable the identification of satellites whose signals are corrupted by multipath, to plot the results with respect to the trajectory so as to provide contextual information that facilitates understanding. It was also possible to establish the discontinuous relationship between signal to noise ratio and pseudo-range & Doppler errors.
This paper tackles the problem of precise car localization for Advance Driver Assistance System a... more This paper tackles the problem of precise car localization for Advance Driver Assistance System applications. Localization is performed by loosely coupling proprioceptive data with exteroceptive perceptions. Two localization systems were designed, one based on Differential GPS and the other on Real Time Kinematic GPS. In both cases, sensor latencies were precisely measured and taken into account to minimize their effects. Track experimentations were carried out with two vehicles at different speeds. A methodoly based on a comparison with a Post-Processed Kinematic GPS reference is presented to evaluate performances of the two systems.
2009 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2009
For mobile robots to navigate autonomously, knowing with certainty their location is fundamental.... more For mobile robots to navigate autonomously, knowing with certainty their location is fundamental. However, this is difficult when operating in complex outdoors environments, and often results are inaccurate. To guarantee the certainty of the location estimates, the notion of integrity is used. This is a measure of the degree of confidence that provides a guaranteed location zone. The process consists in removing outliers amongst the measurements using Fault Detection and Exclusion (FDE) algorithms and then to compute Protection Levels (PL) that quantify the integrity zone. This is applicable mainly to Global Navigation Satellite Sytems (GNSS) in the aerospace domain where data redundancy exists and few multipath, which is not the case for land applications. In this paper, a new approach to localization integrity for land mobile robots is proposed by combining vehicle and GNSS data, stored within a short-term memory, the data horizon. This formulation allows for the application of FDE algorithms on the combined data set. It also leads to a gain of redundancy that enables PLs to be reduced and to increase the availability of integrity algorithms.
IEEE Intelligent Transportation Systems Magazine, 2013
Survey Review, 1999
ABSTRACT This paper presents a series of tests that could be used to assess the performance of an... more ABSTRACT This paper presents a series of tests that could be used to assess the performance of any real-time kinematic GPS system. Criteria including accuracy, speed of ambiguity recovery, ability to maintain lock and signal tracking sensitivity are considered and typical test results presented. System performance is examined using both static and truly kinematic applications, under both benign and high-multipath environments.
… précise pour les …, 2009
... Robosoft, Technopole d'Izarbel, 64210 Bidart {eric.lucet,damien ... Pi+1|i = FiPi|i ... more ... Robosoft, Technopole d'Izarbel, 64210 Bidart {eric.lucet,damien ... Pi+1|i = FiPi|i FT i + JuiPUi JT ui + Q PUi is the covariance of the input dynamic noises ... standard deviation 0.0044 0/s DGPS measure standard deviation 0.4 m Maximum velocity 10.0 m/s Minimum velocity −2.0 m ...
Navigation, 2016
GNSS localization in an urban environment remains a key issue that must be solved in order to ena... more GNSS localization in an urban environment remains a key issue that must be solved in order to enable innovative driver assistance systems or cooperative applications. This key issue exists not only in terms of accuracy but also in terms of integrity. Actually, one aims at reducing as much as possible the error mainly due to multipath on buildings and provide in the mean time a certain guarantee on the user position exactness. This article shows how a simple geometric modeling, named 'Urban Trench', of the city environment can improve significantly the positioning accuracy. Authors also propose an algorithm for computing an urban trench protection level, with a much higher reliability compared to conventional protection level whose open sky assumption is violated. Experimental results are given in the cities of Nantes, Paris, and Toulouse, France.
2012 15th International IEEE Conference on Intelligent Transportation Systems, 2012
Mobility pricing based on GNSS is bound to become a significant tool for both traffic control and... more Mobility pricing based on GNSS is bound to become a significant tool for both traffic control and infrastructure funding, compared to geofencing roadside technologies. But GNSS positioning in cities remains challenging, because of the poor satellite visibility and of the occurrence of many satellite signal reflections (multipath), that in the best case combine with the direct signal, but, when the direct signal is obscured, create significant biases of several tens of meter in the pseudo-range measurements and consequently on the computed position. The method proposed here is based on a simplified 3D model of buildings at both sides of streets, named "Urban Trench" for that reason, which can benefit in the process of satellite visibility check and GNSS positioning. Homogeneous street sections are described with three parameters: width, building height and transversal position of the vehicle. These parameters allow to identify the satellites in direct visibility and to compute the estimated additional range brought by the reflections. It has been proved that, in some environments such as the Grands Boulevards in Paris, the position computed by a least squares method can be improved by a factor of 70% after application of our visibility check and multipath bias correction, without degrading the availability..
Global Navigation Satellite Systems (GNSS), such as GPS, are more and more playing a key role in ... more Global Navigation Satellite Systems (GNSS), such as GPS, are more and more playing a key role in the development of new traffic applications and services, such as those making use of “Geofencing” techniques, electronic tolling systems being the most famous among them. Geofencing needs geopositioning and, in most of the case, geopositioning with a certain level of quality, in particular in terms of integrity for the liability-critical applications. The EGNOS system is the European Wide Area Augmentation System for GPS and has been built, upon air transport specifications, to increase the accuracy, but mainly the integrity of GPS system. The French Ministry in charge of Transport, the MEEDDM, has funded a specific study, called “EGNOS-On-The-Road”, to assess, thanks to full-scale experiments in real-life conditions, the improvements that can be expected from EGNOS for road applications, compared to GPS. The authors first describe the experimental test bench, the GNSS sensors and the data processing that have been used. Then they present the results, in terms of availability, accuracy, integrity an in terms of adequacy to the application needs, for several types of sensors: stand-alone GPS receivers or EGNOS/GPS receivers, used with internal and external antennas. The paper ends with a conclusion and high-level recommendations.
Satellite positioning performances are critical for transport liability applications such as road... more Satellite positioning performances are critical for transport liability applications such as road user charging, or pay per use assurance. The scientific community has focused for several years on environments with favorable conditions (aviation, maritime, rural) and is now addressing transport applications including urban areas. This is the case of this paper that presents the result of a study co-financed by the National French Space Agency (CNES). This study aimed first to collect the positioning data in urban area of several GPS/EGNOS receivers (more than 1.5 millions of positions) in addition to their associated satellite raw data and the reference positions. Its goal was secondly to assess the performance using classical positioning algorithms and last to propose and assess improved algorithms. The authors present first how to obtain the true trajectory necessary for the performance assessments. The instrumentation they set-up on board a test vehicle is based on IXSEA LandINS inertial measurement unit hybridized with kinematics GPS and odometry. The reference trajectory obtained is analyzed, with the aim of qualifying its accuracy. Based on these measurements, the authors then present the performance improvements obtained using different techniques, in particular 2D techniques to improve availability in difficult area such as narrow streets, smoothing technique to optimize the filtering and local error modeling technique to assess in particular disturbing multipath effects. Thanks to the ground truth obtained in this benchmark, the authors demonstrate that these techniques bring a significant improvement to position data performances, enlarging that way the spectrum of liability-critical road transport applications in urban areas.
Integrity is an attribute of the quality of performance of a positioning technology that is getti... more Integrity is an attribute of the quality of performance of a positioning technology that is getting crucial for many Intelligent Transportation Systems dealing with safety. Managing the confidence in estimated locations is difficult when operating in complex outdoors environments, particularly for Global Navigation Satellite Systems (GNSS). A common integrity process consists in removing outliers amongst the measurements using Fault Detection and Exclusion (FDE) algorithms and then to compute Protection Levels (PL) that quantify the integrity zone. This snapshot paradigm is applicable mainly to the aerospace domain where high pseudo-ranges redundancy exists, which is not the case for land applications. In this paper, a new approach to localization integrity for land mobile robot is proposed by combining vehicle and GNSS data, stored within a short-term memory, called data horizon. This formulation allows for the application of FDE algorithms on the combined data set. It also leads to a gain of redundancy that enables PLs to be reduced and to increase the availability of integrity algorithms. Results from evaluation tests are included to demonstrate the validity of the approach.
Les travaux de recherche rapportes ici concernent la faisabilite de la localisation 2D de vehicul... more Les travaux de recherche rapportes ici concernent la faisabilite de la localisation 2D de vehicules specialises pour l'auscultation des routes, par traitements en temps differe de mesures de plusieurs capteurs embarques: DGPS, odometre et differents gyrometres. Les techniques mises en oeuvre combinent filtrages et lissages. Le probleme se pose de localiser en continu l'AGR, alors que le GPS est sujet a masquage. L'etude s'appuie sur le formalisme de Kalman. Plusieurs techniques classiques de lissage ont ete eprouvees sur des essais reels. Une combinaison de l'une d'entre elles avec un lisseur concu assez intuitivement (a partir de similitudes geometriques en zones de masquage) a conduit au meilleur resultat, proche de la precision metrique specifiee. Une utilisation originale de donnees cartographiques avec un filtre de Kalman est presentee afin d'ameliorer la localisation pendant les masquages prolonges du GPS. Des experimentations ont eu lieu sur la piste de reference du LCPC, parfaitement degagee, et les zones de masquage etaient simulees lors du traitement en temps differe. La reference pour le chemin "reellement" parcouru etait fournie par un recepteur DGPS cinematique de precision centrimetrique. (A).
This paper describes the system approach for a future positioning system to be developed for the ... more This paper describes the system approach for a future positioning system to be developed for the European CVIS project (www.cvisproject.org) that deals with an increased transport safety and efficiency using advanced positioning, mapping and communication technologies. Positioning and mapping functions will be provided by the sub-project POMA, where new methods for the combination of several positioning components will be developed. The whole positioning system setup of CVIS will then be deployed at DLR in Berlin. This setup will not only cover onboard components but also infrastructure based sensors and sensor networks together with enhanced positioning algorithms. This new approach shall enable high accuracy and reliability for the following field trials spread over Europe
Multipath signals have a strong effect on position estimates; these are studied intensely theoret... more Multipath signals have a strong effect on position estimates; these are studied intensely theoretically and experimentally. In this paper a domain oriented perspective is presented, passenger vehicles traversing dense urban areas. The purpose is to examine the effects of multipath on pseudo-ranges and Doppler measurements. The approach combines a theoretical formulation with extensive testing. The experiment includes the acquisition of measurements provided by a low-cost automotive GPS receiver on-board a vehicle in real traffic conditions. In addition, the vehicle trajectory was measured precisely to allow for the quantification of measurement errors. Two approaches are used in the experimental part to determine the pseudo-range and Doppler errors: Vehicle on-board measurements plus post-processing; vehicle onboard measurements, data from an external GPS reference station and post-processing. The results enable the identification of satellites whose signals are corrupted by multipath, to plot the results with respect to the trajectory so as to provide contextual information that facilitates understanding. It was also possible to establish the discontinuous relationship between signal to noise ratio and pseudo-range & Doppler errors.
This paper tackles the problem of precise car localization for Advance Driver Assistance System a... more This paper tackles the problem of precise car localization for Advance Driver Assistance System applications. Localization is performed by loosely coupling proprioceptive data with exteroceptive perceptions. Two localization systems were designed, one based on Differential GPS and the other on Real Time Kinematic GPS. In both cases, sensor latencies were precisely measured and taken into account to minimize their effects. Track experimentations were carried out with two vehicles at different speeds. A methodoly based on a comparison with a Post-Processed Kinematic GPS reference is presented to evaluate performances of the two systems.
2009 IEEE/RSJ International Conference on Intelligent Robots and Systems, 2009
For mobile robots to navigate autonomously, knowing with certainty their location is fundamental.... more For mobile robots to navigate autonomously, knowing with certainty their location is fundamental. However, this is difficult when operating in complex outdoors environments, and often results are inaccurate. To guarantee the certainty of the location estimates, the notion of integrity is used. This is a measure of the degree of confidence that provides a guaranteed location zone. The process consists in removing outliers amongst the measurements using Fault Detection and Exclusion (FDE) algorithms and then to compute Protection Levels (PL) that quantify the integrity zone. This is applicable mainly to Global Navigation Satellite Sytems (GNSS) in the aerospace domain where data redundancy exists and few multipath, which is not the case for land applications. In this paper, a new approach to localization integrity for land mobile robots is proposed by combining vehicle and GNSS data, stored within a short-term memory, the data horizon. This formulation allows for the application of FDE algorithms on the combined data set. It also leads to a gain of redundancy that enables PLs to be reduced and to increase the availability of integrity algorithms.