FR2966924A1 - Reliable telematic location system for locating motor vehicle in case of failure or accident, has communication unit communicating with remote geolocation service for transmitting calculated current position of system - Google Patents

Abstract

The system has a global navigation satellite system receiver (1) providing geolocation signals (X-Z), and a dead reckoning navigation device (2) providing dead reckoning sensor signals (X'-Z'). A calculator (3) calculates current position (Xe-Ze) of system based on the signals received in correlation with cartographic data i.e. altitude data. The data identified in a cartographic base (5) is limited to geographic zones. A communication unit (4) i.e. mobile telephone, communicates with remote geolocation service i.e. emergency call and/or assistance service, to transmit the position. An independent claim is also included for a method for assisting a motor vehicle equipped with telematic system.

Description

FIELD OF THE INVENTION The present invention relates generally to a reliable location telematics system for calculating the current position of the system. More particularly, the present invention relates to the application of such a telematic system to a motor vehicle.

It is known in the prior art, in particular from WO 02/39063, a short-haul assisted positioning system. This document describes a road-assisted moving object positioning system using the information provided by a satellite positioning system, the information provided by a dead reckoning system and the information from a digital road map for calculate an estimate of the current position. This positioning system is integrated in a vehicle navigation device. Such a map-assisted positioning system nevertheless has some drawbacks, including the use of a digital road map used in conjunction with a navigation device, thereby requiring a large amount of information such as the type of lanes used. , railways, rivers, surfaces (agglomeration, countryside, etc.), administrative units, toponymy, speed limits, etc. as well as the absence of means of warning of the position of the vehicle in case of breakdown or accident. An object of the present invention is to meet the drawbacks mentioned above by providing a reliable location telematics system, in particular for assisting a vehicle in the event of a breakdown or accident, making it possible to remedy, on the one hand, poor location in case of difficult or disturbed reception of geolocation signals due to the environment, such as in the mountains, forests, tunnels, dense cities, canyon and urban canyon (city with narrow streets and high buildings) , or in the presence of trees, in the event of signal reflection (skyscraper with glazed surface, waterway) etc., while at the same time minimizing the necessary storage resources, in particular for the base of cartographic data, in order to reduce the costs of implementing such a system, and also to ensure the fastest possible support by a helpdesk or emergency service. case of breakdown or accident. Indeed, it has been shown in the context of the present invention that areas of difficult or disturbed reception (eg ravines, mountainous areas, desert areas) often correspond to areas of accident and where the quality of location is then essential to quickly find a broken or damaged vehicle. For this purpose, a first aspect of the present invention relates to a reliable location telematics system comprising a satellite positioning device capable of providing geolocation data, reckoning means capable of providing positioning data. relative to the received geolocation data, a map database and means for calculating a current position on the basis of the geolocation and positioning data received in correlation with the map data, characterized in that the listed map data in the base are limited to geographical areas where the geolocation data reception by the geographical positioning device is difficult or disturbed and in that the telematic system further comprises means of communication with a remote geolocation service for transmitting the geographical location device.current position calculated. Such a telematic system makes it possible to minimize the storage resources required by the use of a cartographic database limited to the places / regions where the reception of the geolocation data is difficult or disturbed, that is to say the level received signals is insufficient 3 (ie less than a determined threshold) to guarantee the integrity of the transmitted data, while nevertheless ensuring the obtaining of reliable location data and thus a reliable position transmission to the remote service of assistance or urgency with which the telematics system is connected. At the same time, the map database remains limited in volume as it only includes data for difficult reception areas, such as tunnels, forest roads, mountain roads, etc. According to an advantageous embodiment, the cartographic data listed in the database are simplified cartographic data allowing a cartographic correlation between the computed current position and the best projection on the map. The use of the altitude as cartographic data makes it possible to ensure good reliability of the projection on the navigable map of the current position while limiting the data necessary to perform such a correlation. According to an advantageous embodiment, the cartographic data listed in the database include elevation data covering the entire territory. This makes the location more reliable. According to another advantageous embodiment, the listed map data are updated incrementally via the communication means. The provision of such an incremental update system makes it possible to add or remove from the map database areas not covered by the satellite positioning device, to correct data related to a zone, and so on. According to another advantageous embodiment, the map database is stored on a removable digital medium.

The use of removable media allows the user to perform updates himself, for example by connecting to an Internet-like computer network. According to another advantageous embodiment, the telematic system further comprises means for receiving positioning data of a geostationary overlay navigation service and the means for calculating the current position are based on the positioning data received from the navigation service to correct the received geolocation data. The use of the data of a geostationary overlay navigation service makes it possible to correct the geolocation signals received by the satellite geographical positioning device in the event of insufficient reception. According to another advantageous embodiment, the telematic system comprises means for calibrating the dead reckoning means based on the geolocation data possibly corrected by the positioning data of the geostationary overlay navigation service and / or the map data of the database. The use of calibration means of the dead reckoning means makes it possible to increase the reliability of the determination of the current position, more particularly in the areas of difficult or disturbed reception of the geolocation signals. Advantageously, initial calibration parameters are transmitted via the communication means. According to another advantageous embodiment, in the event of good reception of the geolocation data and / or positioning data, means for identifying the errors of the cartographic data are activated, the identified errors being transmitted via the means Communication. Another object of the present invention is to ensure that the communication means of the telematic system can transmit the current position to the remote geolocation service. Indeed, it is essential that such communication can be established to be able to provide the required assistance in case of breakdown or accident. For this, according to another advantageous embodiment, the system comprises means for detecting and recording risk areas in which the reception signal of the communication means is insufficient to provide communication with the remote geolocation service. The recordings of these risk areas can then be used to enrich the knowledge of poor reception areas of the telecommunications network (eg GSM, 3G) in order to improve them. According to another advantageous embodiment, the remote geolocation service is an emergency call service and / or assistance. According to another advantageous embodiment, the communication means are mobile telephony means.

A second aspect of the present invention relates to a motor vehicle equipped with a telematic system according to the first aspect. A third aspect of the present invention relates to a method of assisting a motor vehicle equipped with a telematic system according to the first aspect, and comprising the steps of: (i) receiving geolocation and positioning data; (ii) correlate the location and location data received with simplified map data; (iii) calculate the current position of the vehicle based on the correlated received data; (iv) transmit the computed current position to a remote geolocation service. According to an alternative embodiment, the method comprises additional steps consisting in: (v) detecting and recording the risk areas in which the signal for receiving the communication means is insufficient to ensure communication with the remote geolocation service. Other features and advantages of the present invention will appear more clearly on reading the following detailed description of embodiments of the invention given as non-limiting examples and illustrated by the appended drawing, in which: FIG. 1 represents a telematic system according to an embodiment of the present invention. The invention will be described hereinafter only by way of non-limiting example in relation to FIG. 1. As mentioned in the introduction, one of the aims of the present invention is to find a good reliability of location of a vehicle in complement to satellite tracking systems, called GNSS (eg GPS or Galileo) and dead reckoning based on the use of gyro sensor, wheel motion signal, accelerometer, etc. Figure 1 shows a reliable location telematics system. The telematic system is intended more particularly to be integrated or used with a motor vehicle. The telematic system includes computing resources and sensors for positioning the vehicle on the one hand and means of communication with a remote infrastructure of assistance or emergency services on the other. In order to ensure a good quality of location, the system comprises a GNSS receiver 1 (eg GPS or Galileo) able to receive geolocation signals (X, Y, Z) and associated with a device for esteemed navigation. 2 used in cases of non-reception of the GNSS signals and able to receive signals of esteem sensors (X ', Y', Z '). A calculator 3 makes it possible to determine the current position (Xe, Ye, Ze) of the system on the basis of the received geolocation and / or dead reckoning data. Communication means 4 are provided for transmitting the current position (Xe, Ye, Ze) to a remote geolocation system (not shown) such as a helpline or emergency call service. The GSM network will preferably be used as communication means.

The dead reckoning device 2 requires, in order to be effective, a calibration phase specific to each vehicle and based on a good level of reception of the GNSS signals. In a certain number of cases where the GNSS information is noisy (eg satellite near the horizon), erroneous (in the case of signal reflection on a massive object) or absent (in the case of tunnels, canyons natural or urban), the position of the vehicle is then provided by the dead reckoning device. However, if the period of unavailability of the GNSS signal is too long and the calibration of the estimate could not be done correctly then a drift of the measured trajectory with respect to the real trajectory is observed (inaccuracy of the calculation model position by esteem). To remedy this, it is proposed to rely on a simplified 3D cartographic model to enable the activation of a cartographic correlation between the calculated position and its best projection on the navigable map. This cartographic base 5 is advantageously stripped of a maximum of attributes that have become useless for this application (eg type of path, surfaces, etc.). In addition, EGNOS geostationary navigation service data, if available, can also be used as input data for estimating to enhance the reliability of the computed position.

This onboard cartographic base 5 can be updated incrementally through the communication means 4 of the preference system according to a technique called "Over the Air" or OTA 6 of modifying the data of the database through a communication network, for example of the GSM type.

The internal storage of this database can be done on removable media type SDCARD to allow updates by the 8 client. For example, a capacity of 1 GB is more than enough to cover a continent like Europe with a great deal of detail: by restricting itself to areas where GNSS information is noisy or absent, the necessary capacity is then clearly lower, of the order of 10 to 100 MB). This cartographic base 5 can also be used as input data to make reliable and accelerate the convergence of the calibration phase of the algorithm of dead reckoning means, in addition to the data previously mentioned (estimation sensor, signal GNSS possibly corrected by EGNOS). Moreover, after the learning phase, if the confidence of the GNSS input data and / or estimation sensors is considered sufficient, the algorithm will be able to identify possible mapping errors aiming to enrich it in a second one. After verification by the supplier of this data, these errors can then be sent automatically by the telecommunications network according to the OTA technique. Similarly, the initial calibration parameters of the estimation data have a high diversity depending on the vehicle used (wheel development, axle size to use the ABS data for example). These parameters can be sent by the communication means and be corrected a posteriori if the calibration algorithm converges to different values. The on-board cartographic database 3 is optimized by limiting itself to risk areas and eliminating areas of very good GNSS reception. This base will include, for example, all tunnels, areas of poor GNSS reception in the mountains or in the forest, as well as very dense urban areas where the location is difficult to obtain ("urban canyon" or narrow street and roads on edge river or body of water). On the other hand, the altitude database will advantageously cover the entire territory to make the location generally reliable. It has furthermore been found that it is important to have a maximum coverage of the reception areas for the communication means 4 with the remote service of assistance or emergency call. Indeed, the emergency call and assistance services can not function if the signal of the transmitters of the telecommunications network is not sufficient (gray or white areas that is to say partially or not at all covered by the infrastructure). The precise mapping of these areas at risk (correlated to the road network) in Europe is not published. To improve the reliability of the system, it is planned to detect and record areas of poor GSM reception during the driving of vehicles equipped with the system to feed an external database of these risk areas, which can be communicated to the civil security or directly to telecommunication operators to improve it. Note that in the telematic system, the triggering threshold of the recording can be parameterized in particular according to the level of reception of the signal (GSM reception) which is recorded with its location in the on-board database and communicated to the infrastructure on client agreement either through the removable card that the client will load on his computer, either by remote update, or by diagnosis when the vehicle passes through the network review. The interest of providing a reliable localization for an improvement in the provision of emergency call or localized assistance in areas poorly covered by GNSS signals will be understood. Thus the location accuracy provided to the civil security will help to move the relief to the right place with a risk of accuracy error on the location minimized. In addition, the interest in database enrichment is to improve GSM coverage in order to eliminate call failure situations related to a lack of telecommunication infrastructure.

It will be understood that various modifications and / or improvements obvious to those skilled in the art can be made to the various embodiments of the invention described in the present description without departing from the scope of the invention defined by the appended claims.

Claims (15)

REVENDICATIONS1. Reliable location telematics system comprising a geographical positioning device (1) capable of providing geolocation data (X, Y, Z), dead reckoning means (2) capable of supplying positioning data (X ') , Y ', Z') with respect to the received geolocation data, a map database (5) and means (3) for calculating a current position (Xe, Ye, Ze) based on the geolocation data and positioning received in correlation with the map data, characterized in that the cartographic data listed in the database are limited to geographical areas where the reception of geolocation data by the geographical positioning device is difficult and in that the telematic system further comprises communication means (4) with a remote geolocation service for transmitting the calculated current position. 2. Telematic system according to claim 1, characterized in that the cartographic data listed in the database are simplified cartographic data allowing a cartographic correlation between the computed current position and the best projection on the map. 3. Telematic system according to claim 1 or 2, characterized in that the map data listed in the database include altitude data covering the entire territory. 4. Telematic system according to one of claims 1 to 3, characterized in that the listed map data are updated incrementally through the communication means. - 12 - 5. Telematic system according to one of claims 1 to 4, characterized in that the map database (5) is stored on a removable digital medium. 6. Telematic system according to one of claims 1 to 5, characterized in that it further comprises means for receiving positioning data of a geostationary overlay navigation service and in that the calculation means (3 ) of the current position are based on the positioning data received from the navigation service to correct the received geolocation data. 7. Telematic system according to one of claims 1 to 6, characterized in that it comprises means for calibrating the dead reckoning means based on the geolocation data possibly corrected by the positioning data of the service of navigation and / or cartographic data of the database. 8. Telematic system according to claim 7, characterized in that initial calibration parameters are transmitted via the communication means (4). 9. Telematic system according to claim 7 or 8, characterized in that in the event of good reception of the geolocation data and / or positioning data, means for identifying the errors of the cartographic data are activated, the errors identified being transmitted via the communication means (4). 10. Telematic system according to one of claims 1 to 9, characterized in that it comprises means for detecting and recording risk areas in which the reception signal of the communication means (4) is insufficient to ensure communication with the remote geolocation service. 11. Telematic system according to one of claims 1 to 10, characterized in that the remote geolocation service is an emergency call service and / or assistance. 2966924 - 13 - 12. Telematic system according to one of the preceding claims, characterized in that the communication means (4) are mobile telephony means. 13. A motor vehicle equipped with a telematic system according to any one of the preceding claims. 14. A method of assisting a motor vehicle equipped with a telematic system according to one of claims 1 to 12, comprising the steps of: (i) receiving geolocation and positioning data; (Ii) correlating the geolocation and positioning data received with simplified map data; (iii) calculate the current position of the vehicle based on the correlated received data; (iv) transmit the computed current position to a remote geolocation service. 15. Assist method according to claim 14, characterized in that it comprises additional steps consisting in: (v) detecting and recording the risk areas in which the reception signal of the communication means is insufficient to ensure the communication with the remote geolocation service.