ITS based on EGNOS for enhancing the safety of dangerous goods transportconfidence in the GNSS positionning

摘要

TheL location is an increasingly important element increasingly important for all ITS applications. With the advent of cooperative systems, knowledge at lane levels foron roads affected by an event becomes essential in order to transmit relevant information to oncoming vehicles in the area to enable alerting the drivers if the launch of an emergency braking procedure emergency becomes necessary. Based solely on the use of low cost GPS receivers, the position obtained is subject to many factors that limit theits accuracy and the confidence itone can have in this position. Indeed, several factors disrupt the entire information chain of information that leads to the calculation of the WGS84 coordinates of the event or the vehicle. These factors are divided into several families. One, addressed in this paper, concerns factors related to the satellite constellation and signal transmission in the atmosphere. WhichThese factors are the variation of satellites orbits, variations in reference clocks on board satellites, disturbance and refractions through the different layers that form the terrestrial atmosphere. In the framework of work on the introduction of telematics in the legislation of land transport of hazardous materials, the Telematics Working Group of the UNECE/OTIF (Joint meeting for Dangerous Goods regulation for inland transport) raised the question of the reliability of positions obtained from low-cost GNSS receivers. This working group left it to the SCUTUM project, s’est interrogé sur la confiance qui peut être mise dans les positions obtenues par des récepteurs GNSS bas co?ts. Ce groupe de travail a laissé le soin au projet SCUTUM which integrated a work package to prepare a CEN Workshop Agreement (CWA), to define the minimum set of data needed to be provided by a GNSS receiver to calculate the “area” of confidence associated to the position. This CWA opens the way to accessing the row data and offers the capability to implement solutions to help the end user to adapt his behaviour in accordance with the confidence he can have in the given position. Datex Ⅱ principles are used for modelling .the introduction of telematics introduction into dangerous goods transport and the result of the CWA. Datex Ⅱ is now a CEN standard under the CEN/TS 16157 series from the CENT/TC 278. It is already used for the exchange of road traffic information between road operators and service providers. Some research projects, such as COVEL a FP7 project driven by the GSA, have demonstrated the capability to connect road roadside units with traffic control centres by using Datex Ⅱ such as COVEL a FP7 project driven by the GSA. This extension for location can be used by ITS actors and that coultd help many applications to give the position andas well as the confidence in itthat position. This communication will show the way to use it and the added value for traffic managers and other users. The Datex Ⅱ principles are also used by the Telematics Working Group of the UNECE/OTIF Joint meeting for Dangerous Goods regulation for inland transport. This group faces the needs of location by GNSS and parallely the confidence which can be given to the position calculated by systems based on GNSS positioning. Telematics Working Group established a link with SCUTUM which integrated a work package to prepare a CEN Workshop Agreement to define the minimum set of data needed to be provided by a GNSS receiver to calculate the “area” of confidence associated to the position. In the location referencing package of Datex Ⅱ, several location referencing systems are able to be used. Due to the fact that all of them have note the same level of precision one attribute is proposed to define the level of precision which could be expected by the end user. With EGNOS, this attribute could be calculated for location provided by satellite positioning and associates with the coordinates. Two extensions could be used therefore