DE102021114528A1 - UPDATING INITIAL MAP DATA STORED IN A MEMORY - Google Patents

Abstract

A method is provided for updating initial map data stored in memory for a moving motor vehicle. The initial map data correspond to an initial area around the motor vehicle, divided into initial sub-areas, in the center of which the motor vehicle is initially located. The initial map data are stored separately in the memory for each of the initial sub-areas together with an initial position of the respective sub-area relative to the motor vehicle. The method includes updating the initial map data when a distance of the motor vehicle from a first outer limit of the initial area falls below a predetermined minimum distance. Updating includes overwriting the initial map data corresponding to initial sub-areas that are within the initial area and adjoining a second outer boundary with further map data that correspond to further sub-areas that are outside of the initial area and are adjacent to the first outer boundary . The updating also includes overwriting the respective initial position with a respective current position of the initial sub-areas that are not overwritten and of the further sub-areas relative to the motor vehicle at a point in time when the minimum distance is not reached.

Description

The present invention relates to a method for updating initial map data stored in a memory for a moving motor vehicle, a method for locating the motor vehicle and a control system which is designed to carry out at least one of the methods.

When using large spatial data sets, which are available with a LIDAR-based localization of motor vehicles, the map displays regularly have a high memory requirement, i.e. a comparatively large amount of map data is required.

Conventionally, there are essentially two approaches for loading new map data while the motor vehicle is driving. In a first of the two approaches, a new and up-to-date, mostly rectangular map section (so-called tile) is loaded, which is centered around the current position of the motor vehicle, with the previous tile in the memory being overwritten. Also known is the loading of map data along a previously known route, which ensures an adequate forecast.

Reloading centered tiles overwrites useful information in memory, i.e. parts of the map that are still relevant but have moved elsewhere. In addition, the rewriting of the map in the memory must be done in an order of reading the map data in locating the automobile, which introduces a delay. The latter can be circumvented by simultaneously writing to a second block of memory, switching after the write is complete, and then reading the old card. However, this doubles the storage space requirement.

Loading along a route can reduce the amount of data to be loaded, but may not be practical in applications where dynamic rerouting is required in response to unanticipated traffic situations.

Against the background of this prior art, the object of the present invention is to specify a device and/or a method which is/are suitable for overcoming at least the above-mentioned disadvantages of the prior art.

The problem is solved by the features of the independent claim. The dependent claims relate to preferred developments of the invention.

According to this, the object is achieved by a method for updating initial map data stored in a memory for a moving motor vehicle.

The initial map data correspond to an initial area around the motor vehicle, divided into initial sub-areas, in the center of which the motor vehicle is initially located.

The initial map data are stored separately in the memory for each of the initial sub-areas together with an initial position of the respective sub-area relative to the motor vehicle.

The method includes updating the initial map data when a distance of the motor vehicle from a first outer limit of the initial area falls below a predetermined minimum distance.

Updating includes overwriting the initial map data corresponding to initial sub-areas that are within the initial area and adjoining a second outer boundary with further map data that correspond to further sub-areas that are outside of the initial area and are adjacent to the first outer boundary .

The updating also includes overwriting the respective initial position with a respective current position of the initial sub-areas that are not overwritten and of the further sub-areas relative to the motor vehicle at a point in time when the minimum distance is not reached.

In other words, the mapped area around the motor vehicle is divided into sub-areas or map sections, in particular of the same size. The area can be a two-dimensional or three-dimensional area. The map data is available separately for each of the sub-areas to disposal. This means that the map data that describe the mapped area are stored separately in the memory according to the sub-areas, so that each sub-area is assigned its own memory address.

The map data of the subregions can be stored anywhere in memory and does not have to be stored in the correct spatial order.

In order to enable map data of a sub-area in the memory to be assigned to the actual position of the sub-area in the area around the motor vehicle, the position of each of the sub-areas relative to the motor vehicle is stored in addition to the map data.

If the motor vehicle moves, after a certain time it will fall below a minimum distance from an outer limit or side of the mapped area, i.e. it will come too close to an area that is no longer mapped.

When this happens, the map data of sub-areas on the car-far side of the area can be deleted and replaced with map data of sub-areas on the car-near side, so that the car after the replacement or overwriting is again in the middle of the newly created or replaced area updated area.

It is conceivable that the mapping of the sub-areas or the respective position of the sub-areas is changed during updating faster than the overwriting or loading of the map data is or can be carried out. The loading can take place before, in parallel with and/or after the updating of the respective position of the sub-areas.

The relevant tiles or sub-areas that are overwritten can be blocked for functions that access this map data, such as a driver assistance system and/or a localization function for the motor vehicle, until a point in time at which they are fully loaded or overwritten will. The additional map data, ie the map data of the sub-areas that are not overwritten and for which only or exclusively the mapping is updated, can also continue to be accessed while the map data of the new sub-areas are being loaded.

If several sub-areas are updated, their loading processes can be carried out in parallel and/or sequentially or one after the other.

The solution proposed here consequently enables map data to be written and read at the same time with little additional memory requirement, can guarantee adequate forecasting and maintain flexibility in the event of unexpected changes in the direction of travel and diversions, without the motor vehicle leaving the loaded map area.

The method may include determining the distance of the motor vehicle to the first outer boundary based on a distance to the center of the initial range and/or determining whether the motor vehicle has left a maximum range extending around the center of the initial range.

The first outer limit can be opposite the second outer limit relative to the center of the initial area and/or the second outer limit can be that outer limit of the initial area that is furthest away from the motor vehicle when the distance falls below the minimum distance.

Overwriting can include loading the additional map data that is stored in a memory in the motor vehicle and/or in a cloud.

The first and second map data can be stored in a first memory area and the position of the respective sub-area relative to the motor vehicle can be stored in a second memory area, the first and second memory areas being separate from one another.

The minimum distance can be selected in such a way that if the distance falls below the minimum distance, there is more than one initial sub-area between the motor vehicle and the first outer boundary.

It can thereby be ensured that the motor vehicle remains within the mapped area and that there is a sufficient preview for locating the motor vehicle, even while the map data close to the second outer border is being deleted or overwritten.

The sub-areas can form a grid in the area around the motor vehicle. It is conceivable that the sub-areas have a quadrilateral shape, in particular a square shape. It is also conceivable that the sub-areas are cuboid, in particular cube-shaped. For example, a grid can be provided with 4x4 sub-areas for a two-dimensional area or with 4x4x4 sub-areas for a three-dimensional area.

After the update, the motor vehicle can again be essentially in the middle of an area formed by the initial sub-areas that have not been overwritten and the further sub-areas.

Furthermore, a method for locating a motor vehicle is provided, wherein the above reference to the method for updating stored in a memory initial map data for a moving motor vehicle also applies to the method for locating the motor vehicle and vice versa.

The method for locating the motor vehicle includes providing current map data using the method described above for updating initial map data stored in a memory for a moving motor vehicle.

The method for locating the motor vehicle also includes locating the motor vehicle based on the current map data and current sensor data, which are provided by sensors installed on the motor vehicle and correspond to an environment of the motor vehicle.

It is conceivable that the sensor data are provided in the form of a point cloud from at least one LIDAR sensor installed on the motor vehicle.

The approach described above with reference to the method for updating initial map data stored in a memory for a moving motor vehicle can therefore be part of a localization implementation, in particular for automated or autonomous motor vehicles.

A high-resolution map can be used for the map data. The map data can be located on a (backend) server, a hard disk on a control device on which the localization is calculated and/or on another control device.

The control device on which the localization is calculated can have a main memory or RAM and an associated processor or an associated CPU, by means of which the localization is calculated.

In this case, the loading process of the map data required for updating includes reading this map data from the respective hard drive and/or requesting and receiving this map data from the server, transferring this map data via the on-board network, as well as unpacking and writing this map data to the R.A.M.

If the localization solution is calculated on a graphics card having a graphics processor or a GPU with associated main memory, the map data required for updating are additionally copied from the main memory of the processor into the main memory of the GPU.

However, since the map data required for updating is minimized by the method described above, the loading and thus the updating of the map data and the localization of the motor vehicle based on the current map data can be more efficient in relation to a required computing power and/or computing time compared to conventional methods be performed.

Furthermore, a control system for a motor vehicle is provided, wherein what is described above with reference to the methods also applies to the control system and vice versa.

The control system is configured to carry out at least one of the methods described above.

The control system can be installed in an automated motor vehicle, in particular an automobile.

The following is an embodiment related to 1 and 2 and Tables 1 and 2 (see end of description).

Table 1 shows a table to illustrate an occupancy of a memory with initial map data, which correspond to an initial area divided into initial sub-areas around a motor vehicle, in the middle of which the motor vehicle is initially located,
1 schematically shows the motor vehicle in the middle of the initial area,
Table 2 shows a table to illustrate an occupancy of a memory with updated map data, which is divided into an initial sub-areas and further sub-areas in an updated area
Motor vehicle, in the middle of which the motor vehicle is, correspond, and
2 shows schematically the motor vehicle in the center of the updated area.

In 1 and Table 1 shows an initial state in which the motor vehicle 17 is located at a center of an initial area extending around the motor vehicle 17 .

The initial area, which has predefined outer borders, can also be referred to as the first and/or mapped area.

The initial area comprises initial sub-areas 1 - 16 arranged in a grid pattern, dividing the initial area into 4×4 squares.

Initial map data, which correspond to the initial sub-areas 1-16, are stored in a memory (not shown), which is located in the motor vehicle 17 in the present case. That is, each of the initial sub-areas 1-16 is represented by a set of initial map data, which is stored in the memory in the form shown in Table 1.

This means that, as can be seen from Table 1, a memory location with its own memory address 0×0-0×F is provided for each of the sub-areas 1-16.

In addition, as can also be seen from Table 1, position information is stored for each of the sub-areas, which makes it possible to determine to which sub-area 1-16 the initial map data stored under the respective memory address 0×0-0×F correspond.

Thus, the initial map data for each of the initial sub-areas 1 -16 are stored separately in the memory together with an initial position of the respective sub-area relative to the motor vehicle 17 .

The initial map data is stored in a first memory area and the position of the respective sub-area relative to the motor vehicle is stored in a second memory area, with the first and second memory areas being separate from one another.

In the present case, the position information is the number of the respective sub-area 1-16, with the sub-areas 1 to 16 always being arranged at the same or predetermined position relative to the motor vehicle 17.

Based on the number of the sub-area 1-16 stored as position information, it can thus be determined which data is stored in the associated memory address.

A separate memory area is therefore used to enable an association between map data of a sub-area 1-16 in the memory and its position in the mapped area around the motor vehicle for applications that have access to the map data and the position information.

As a result, the map data corresponding to one of the sub-areas 1-16 can be stored in the memory as desired and do not have to be stored in the correct spatial order.

The above related to 1 What is described in Table 1 and 1 is the initial state on which the method for updating the initial map data stored in the memory is based.

The method includes updating the initial map data when a distance from the moving motor vehicle 17 to an outer limit of the initial area falls below a predetermined minimum distance.

In the present case, this minimum distance is considered to have been fallen short of if the motor vehicle 17 moves outside a maximum range 18, as is the case in 1 is shown.

The square maximum area 18 here has the same center point as the initial area divided into the initial sub-areas 1-16 and in the present case has the same size as one of the initial sub-areas 1-16.

This means that the distance from motor vehicle 17 to the outer limits of the initial area is determined based on a distance from motor vehicle 17 to the center of the initial area.

In the present case, the motor vehicle 17 leaves the maximum area 18 to the right (see Fig. 1 ).

Since the motor vehicle 17 exceeds the maximum range 18 to the in 1 leaves the right side, the minimum distance to the right outer border of the initial area is undershot and the initial map data is updated.

Updating the initial map data in memory essentially involves two steps.

In a first step, initial map data are overwritten, which correspond to initial sub-areas 1, 5, 9, 13, which lie in the initial area and (from the inside) border on the left outer border (left column in 1 ).

In the present case, only the initial map data is overwritten that is in the memory with the memory addresses (see Table 1) 0×2 (for sub-area 13), 0×3 (for sub-area 1), 0×5 (for sub-area 9 ) and 0×C (for sub-area 5) are stored. During overwriting, these memory areas are blocked for data access (see lock in Table 2).

The card data that correspond to the initial sub-areas that are in the initial area to the in 1 adjoin the left outer limit of the initial area, ie adjoin the outer limit that lies opposite the right outer limit relative to the center of the initial area and that is farthest away from motor vehicle 17 when the distance to the right outer limit is less than the minimum.

This initial map data is overwritten with further or newly loaded map data that correspond to further or new sub-areas 4', 8', 12', 16' that lie outside the initial area and (from the outside) to the right-hand outer border of the border the initial area (see right column in 2 ).

Depending on the storage location of the additional map data, overwriting can include loading the additional map data from a memory in the motor vehicle and/or from a cloud.

Since the minimum distance is selected in such a way that when the minimum distance is not reached, more than one initial sub-area, here an outer half of the initial sub-areas 3, 7, 11, 15 not to be overwritten and the initial sub-areas 4, 8, 12, 16 , are located between the motor vehicle 17 and the right-hand outer border, the motor vehicle 17 is also sufficiently far inside in the mapped and already loaded area that is available for data access while the initial sub-areas 1, 5, 9, 13 are being overwritten.

Another advantage of the method is that the initial map data of the initial sub-areas 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16 that are not to be overwritten are not reloaded for updating the initial map data have to.

This is the case because in a second step, the respective initial position is overwritten with a respective current position of the non-overwritten initial sub-areas 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16 and of the further or newly loaded sub-areas 4', 8', 12', 16' relative to the motor vehicle at a point in time when the distance falls below the minimum.

This means that the initial sub-areas 2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16 that are already loaded and are not to be overwritten retain their respective memory address and only their position relative to motor vehicle 17 updated (see synopsis from 1 and 2 and Tables 1 and 2). This saves time and computing power when updating the map data.

The first and the second step here start at the same time, with the overwriting of the position requiring less computing power than the loading.

After updating, the motor vehicle is again in the middle of an area 1, 2, 3, 4', 5, 6, 7, 8', 9, 10, 11, 12' formed by the non-overwritten initial sub-areas and the further sub-areas. , 13, 14, 15, 16'.

0×3 4 - Laden

0×4 6 0×5 12 - Laden

0×6 1 0×7 15 0×8 7 0×9 10 0×A 14 0×B 2

0×C 8 - Laden 0×D 5 0×E 3 0×F 11 The method described above can be part of a method for locating the motor vehicle 17 which, as a first step, comprises providing current map data using the method described above for updating initial map data for the moving motor vehicle 17 stored in the memory. In a second step, the motor vehicle 17 is localized based on the current map data and current sensor data, which are provided by sensors (not shown) installed on the motor vehicle 17 and correspond to an environment of the motor vehicle 17 . Table 1 memory address Position relative to the motor vehicle 0×0 14 0×1 10 0×2 13 0×3 1 0×4 7 0×5 9 0×6 2 0×7 16 0×8 8th 0×9 11 0×A 15 0×B 3 0×C 5 0×D 6 0×E 4 0×F 12 Table 2 memory address Position relative to the motor vehicle 0×0 13 0×1 9 0×2 16 - store

0×3 4 - loading

0×4 6 0×5 12 - store

0×6 1 0×7 15 0×8 7 0×9 10 0×A 14 0×B 2

0×C 8 - loading 0×D 5 0×E 3 0×F 11

Reference List

1 - 16

initial sub-areas

4', 8', 12', 16'

further sub-areas

17

motor vehicle

18

maximum range

Claims (10)

Method for updating initial map data stored in a memory for a moving motor vehicle (17), - the initial map data relating to an initial sub-area (1 - 16) subdivided into the initial area around the motor vehicle (17), in the middle of which the motor vehicle is (17) initially located, and - the initial map data for each of the initial sub-areas (1 - 16) together with an initial position of the respective sub-area (1 - 16) relative to the motor vehicle (17) being stored separately in the memory, characterized in that the method comprises: - updating the initial map data when a distance from the motor vehicle (17) to a first outer limit of the initial area falls below a predetermined minimum distance, the updating comprising: - overwriting the initial map data belonging to the initial sub-areas (1, 5, 9, 13) that are in the initial range and adjoin a second outer border, with further map data corresponding to further sub-areas (4', 8', 12'16') which lie outside the initial area and border on the first outer border, - overwriting the respective initial position with a respective one Current position of the initial sub-areas (2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16) that are not overwritten and of the further sub-areas (4', 8', 12', 16') relative to the motor vehicle (17) at a time when the minimum distance is not reached. procedure after claim 1 , characterized in that the method includes determining the distance of the motor vehicle (17) to the first outer boundary based on a distance to the center of the initial area and/or determining whether the motor vehicle (17) has left a maximum area (18) extending around the middle of the initial area. procedure after claim 1 or 2 , characterized in that the first outer limit of the second outer limit is opposite relative to the center of the initial area and/or the second outer limit is that outer limit of the initial area which is furthest away from the motor vehicle (17) when the distance falls below the minimum distance. Method according to one of the preceding claims, characterized in that the overwriting comprises loading the further map data which are stored in a memory in the motor vehicle (17) and/or in a cloud. Method according to one of the preceding claims, characterized in that the first and second map data are stored in a first memory area and the position of the respective sub-area relative to the motor vehicle (17) is stored in a second memory area, the first and second memory areas being separate from one another . Method according to one of the preceding claims, characterized in that the minimum distance is selected in such a way that when the minimum distance is not reached, there is more than one initial sub-area (3, 4, 7, 8, 11, 12, 15, 16) between the motor vehicle (17 ) and the first outer border. Method according to one of the preceding claims, characterized in that the sub-areas (1 - 16, 4', 8', 12', 16') form a grid in the area around the motor vehicle (17). Method according to one of the preceding claims, characterized in that after the update the motor vehicle (17) is again in the middle of a sub-area (2, 3, 4, 6, 7, 8, 10, 11, 12, 14, 15, 16) and the further sub-areas (4', 8', 12', 16') is located in the area formed. Method for locating a motor vehicle (17), characterized in that the method for locating comprises: - providing current map data by means of a method for updating initial map data stored in a memory for a moving motor vehicle (17) according to one of Claims 1 until 8th , and - the localization of the motor vehicle (17) based on the current map data and current sensor data provided by sensors installed on the motor vehicle (17) and corresponding to an environment of the motor vehicle (17). Control system for a motor vehicle (17), characterized in that the control system is designed to use a method according to one of Claims 1 until 9 to execute.

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