WO2021074494A1

WO2021074494A1 - Method for initializing a map database and associated computer

Info

Publication number: WO2021074494A1
Application number: PCT/FR2020/051607
Authority: WO
Inventors: Huynh Anh Vu; Huu Kim THAI; Francois Gratien; Nicolas PIQUARD
Original assignee: Psa Automobiles Sa
Priority date: 2019-10-17
Filing date: 2020-09-17
Publication date: 2021-04-22
Also published as: FR3102241B1; FR3102241A1

Abstract

The invention relates to a method for initializing, by means of a computing unit on board a vehicle, a map database stored in a dedicated memory, comprising steps of: - acquiring (31) a geographical position of the vehicle, - determining (32) a perimeter, comprising a plurality of elementary zones, on the basis of the acquired position, - selecting (33) an elementary zone belonging to the perimeter, - downloading (34) the selected elementary zone and storing the downloaded elementary zone in the map database, - checking (35) whether the dedicated memory is full, - if the dedicated memory is not full then repeating the steps of selecting (33) and of downloading (34) an elementary zone until the dedicated memory is full or all of the zones belonging to the perimeter have been downloaded.

Description

DESCRIPTION

Title: Method for initializing a cartographic database and associated calculator

Technical area

The invention relates to navigation aid in vehicles, and more specifically to the initialization of mapping data which is stored in storage units on board vehicles. Technological background

Such a navigation system is known, in particular from application FR 2941 526, which comprises a GPS (Global Positioning System) type receiver capable of determining the current position of the vehicle, storage means hosting a cartographic database, and a control interface that allows the driver to give instructions to the system.

The navigation system further comprises a control unit capable of determining a route from a place of departure to a place of destination.

The system also includes a display screen capable of displaying the visual guidance indications generated by the control unit, as well as an audio module making it possible to broadcast audio announcements indicating by voice synthesis said path.

Such navigation systems are usually preloaded with a map limited to one continent, for example Europe. But, when the vehicle is intended for a customer residing on another continent, for example Africa, the customer is found with inadequate mapping and a navigation system temporarily inoperable. The customer must then erase the preloaded map data and download map data in line with his place of residence.

Summary of the invention

An aim of the present invention is to remedy the aforementioned problem and in particular to allow the delivery to a customer of a vehicle equipped with a navigation system comprising map data relating to his place of use.

For this purpose, it proposes a method for initializing, by a calculation unit on board a vehicle, a cartographic database (21) stored in a dedicated memory (20), comprising steps of:

- acquisition (31) of a geographical position (50) of the vehicle,

- determination (32) of a perimeter (51), comprising a plurality of elementary zones, from the acquired position,

- selection (33) of an elementary zone belonging to the perimeter (51), - downloading (34) of the selected elementary zone and storage of the elementary zone downloaded in the cartographic database (21),

- check (35) whether the dedicated memory is full,

- if the dedicated memory is not full, then the repetition of the steps of selecting (33) and downloading (34) of an elementary zone until the dedicated memory (20) is filled or until all the zones are downloaded belonging to the perimeter (51).

By using the position of the vehicle, the invention enables the mapping database to be initialized with data relevant to the user of the vehicle, without increasing the memory space dedicated to storing the mapping. In addition, the invention makes it possible to better manage the memory space dedicated to mapping by limiting downloads according to the available memory.

Advantageously, the selection step determines an elementary zone closest to the position acquired and not yet downloaded.

Advantageously, each elementary zone of navigation data is organized into different building blocks each defined by navigation data of a specific type.

Advantageously, the elementary navigation data areas (23) are in N DS format. The invention also relates to a computer comprising at least one processor and at least one memory intended to store a cartographic database, characterized in that it is designed to implement the initialization method according to the invention.

The invention also relates to a vehicle characterized in that it comprises a computer according to the invention.

The invention also relates to a computer program product comprising instructions adapted for the execution of the steps of the method according to the invention, when the computer program is executed by at least one processor.

Brief description of the figures

Other characteristics and advantages of the invention will emerge from the description of the non-limiting embodiments of the invention below, with reference to the appended figures, in which:

[Fig 1] is a schematic view of an on-board vehicle navigation system according to the invention; and

[Fig 2] is a schematic view of the cartographic database integrated into the on-board navigation system of Figure 1.

[Fig. 3] schematically illustrates an initialization method, according to a particular embodiment of the present invention.

[Fig. 4] schematically illustrates an example of representation of cartographic data.

The on-board navigation system 1 for a motor vehicle shown schematically in FIG. 1 makes it possible to guide the driver to a destination that he has set according to a chosen route.

As illustrated in this FIG. 1, this navigation system 1 comprises a satellite geo-positioning information receiver 10, a non-volatile memory module 20 storing a cartographic database 21, a control unit 30, a control interface. control 40, a display screen 50 and audio broadcasting means 60.

The satellite geo-positioning information receiver 10 is preferably a GPS receiver (Global Positioning System) which captures the radio signals transmitted by at least four satellites of the GPS system and can, by calculating the propagation times of these signals between the satellites and itself, know its distance from them and, by trilateration, determine with an accuracy of a few meters the position of the vehicle placed in visibility of the satellites.

As a variant, the satellite geo-positioning receiver 10 uses a system different from the GPS, such as for example the EGNOS system (European Geostationary Navigation Overlay System), the GLONASS system or even the GALILEO system. The control unit 30 comprises a computer 31 able in particular to determine, from the cartographic database 21 stored in the non-volatile memory module 20 consisting for example of a hard disk or a flash memory, a route on the road network from a starting point defined by the user or corresponding to the current position of the vehicle, and to a destination selected by the user.

The control interface 40 allows the user to interact with the navigation system 1 and in particular to give it instructions such as in particular the places of departure and destination of the journey for which he wishes to obtain a guidance route. .

It may include a control keyboard, for example a physical keyboard integrated into the dashboard console under the display means 40, or else a displayable touch keyboard integrated into the display screen 50.

This control interface 40 may also include, in addition to or replacing such a control keyboard, a voice recognition module. The display screen 50, constituted for example by that of the vehicle infotainment device integrated into the dashboard, is able to display to the driver the visual guidance indications generated by the control unit 30 and indicating the path to take to reach the chosen destination.

The audio broadcasting means 60, consisting for example of the vehicle's speakers, making it possible to broadcast audio announcements generated by the control unit 30 and indicating by voice synthesis the actions to be performed by the driver.

The cartographic database 21 also comprises a plurality of modules elementary (also called elementary zones) of navigation data 23 superimposed on the base map and each being associated with a specific geographical zone corresponding to a department, a region or a state of a country, a country, or even a group neighboring countries with small areas such as for example the Benelux comprising Belgium, the Netherlands and Luxembourg.

Each elementary data module, advantageously in NDS (for Navigation Data Standard) format, is organized into different building blocks 24 each defined by navigation data of a specific type.

Such a building block 24 can for example include basic navigation data such as in particular routing data or even destination input data.

Each building block 24 may also include enhanced navigation data such as, but not limited to, points of interest (POI) data, digital road information channel (TMC) data, digital terrain models, ortho-images. , textual search modules, voice data, etc ...

The number of building blocks 24 making up an elementary navigation data module 23 may vary depending on the data provider.

The installation of these new elementary navigation data modules 23 can be carried out via wireless telecommunication means (downloading on a remote server) or by means for reading a data medium such as a USB key, a SD card or optical disc.

The method according to the invention is described below with reference to Figure 3 and illustrated using the example of Figure 4.

The method of initialization, by a calculation unit on board a vehicle, of mapping data, comprises a first step 31 of acquiring a geographical position of the vehicle.

The geographical position of the vehicle is for example obtained by the geo-positioning receiver 10 of the vehicle. As a variant, the position of the vehicle can be obtained by a download tool connected to the vehicle. This can be the case when the download takes place in a garage or car dealership, using a tool. diagnostic unit directly connected to the vehicle. In FIG. 4, the position of the vehicle is symbolized by the sticker 50.

The method also includes a step 32 of determining a perimeter, comprising a plurality of elementary zones, from the acquired position. The perimeter is determined for example by using a predetermined radius (for example 1000 km) around the position of the vehicle.

Other geometric shapes for the perimeter are possible, the shape used preferably being regular and centered on the position of the vehicle. In the example, the perimeter 51 is a circle centered on the position 50 of the vehicle.

The method then comprises the selection 33 of an elementary zone belonging to the perimeter.

According to one characteristic of the invention, the selection step 33 determines an elementary zone closest to the position acquired and not yet downloaded.

The first elementary zone loaded is the zone on which the position of the vehicle is located. In the example, the first elementary zone downloaded is the first elementary zone 41.

Once selected, the elementary zone is downloaded 34 and stored in the cartographic database.

The next step comprises a check 35 intended to check whether the memory dedicated to the storage of the mapping database is full following the downloading of the elementary zone.

By full memory is meant that no more memory space is available or that the available memory is below a predetermined threshold (for example a few kilobytes). Preferably, the predetermined threshold is defined so that the memory is considered to be full when the available memory is insufficient to contain the smallest of the elementary areas.

If there is still memory space available, then the steps for selecting 33 and downloading 34 of an elementary zone are repeated until the dedicated memory is filled or all the zones of the perimeter are downloaded.

The process therefore ends when all the elementary zones of the perimeter have been downloaded or when memory is full.

During successive iterations, the selection step 33 determines an elementary zone closest to the position acquired and not yet downloaded. The distance between the position of the vehicle and the basic zone can be calculated in different ways: for example by calculating the distance between the position and the barycenter of the basic zone or by calculating the distance between the position and a point on the perimeter of the zone elementary.

To determine if an elementary zone is in a given perimeter, several solutions are possible. In the example, it is assumed that all the elementary zones having at least a part inside the perimeter 51 belong to this perimeter. These are the first 41, the second 42, the third 43, the fourth 44 and the fifth 45 zone.

If it is assumed, to simplify the example that each of the elementary areas occupies 10 Megabytes and that the memory initially available for the cartographic database is 45 Megabytes, then the method according to the invention will successively download the first 41, the second 42 , the third 43 and the fourth 44 zone.

After downloading the fourth area 44, there is insufficient memory available to download a new area. The memory is considered full and the process stops.

Claims

1. Method for initializing, by a calculation unit on board a vehicle, a cartographic database (21) stored in a dedicated memory (20), comprising the steps of:

- acquisition (31) of a geographical position (50) of the vehicle,

- check (35) whether the dedicated memory is full,

2. The initialization method according to claim 1, wherein the selection step (33) determines an elementary area closest to the acquired position (50) and not yet downloaded.

3. Initialization method according to one of claims 1 or 2, characterized in that each elementary navigation data area (23) is organized into different building blocks (24) each defined by navigation data of the. a specific type.

4. Initialization method according to one of the preceding claims, characterized in that the elementary navigation data areas (23) are in N DS format.

5. Computer comprising at least one processor and at least one memory intended to store a cartographic database, characterized in that it is arranged to implement the initialization method according to one of the preceding claims.

6. Vehicle characterized in that it comprises a computer according to the preceding claim.

7. Computer program product comprising instructions adapted for the execution of the steps of the method according to one of claims 1 to 4, when the computer program is executed by at least one processor.