DE102020118622A1 - control of a vehicle - Google Patents

Abstract

A method for determining an absolute map error of a geographic map for controlling a vehicle comprises the steps of scanning first sensors, each of which is set up to scan an area surrounding the vehicle; scanning at least one second sensor configured to receive signals from a radio navigation system; determining the position of the vehicle based on sensor values from the first and second sensors; validating the determined position using validators each associated with one of the first sensors; and determining an absolute map error at the determined position based on a distance between the determined position and a position determined based on the at least one second sensor.

Description

The invention relates to the control of a vehicle. In particular, the invention relates to determining a position of the vehicle.

A vehicle can be controlled depending on its geographic position and a geographic map that includes positions of objects in the area of the position. The vehicle's position can be determined, for example, by means of a receiver of a satellite-supported navigation system such as GPS. Correction signals (DGPS) can be used to improve position. In addition, objects around the vehicle can be determined, and the position can be determined based on positions of the objects in the map. Both methods can be combined with one another in order to increase the accuracy with which the position was determined. In addition, it can be examined how well the individual determinations fit together in order to exclude possibly erroneous sensor values from determining the position.

The map usually includes a lot of information and can be provided by a map manufacturer. A relative error of a mapped object can be small, for example, in the range of centimeters. Distances between registered objects may be close to actual distances between the corresponding real objects, respectively.

However, it is not uncommon to have a significant absolute map error, which can be in the range of a meter or more. Within a predetermined range, positions of all recorded objects can then have the same positional error. The position error may interfere with determining the geographic position of the vehicle. In particular, if the position only has to be determined on the basis of observations of objects in the area, the map error can be so great that the objects included in the map are offset by half the width of a traffic lane, for example, with respect to the determined position. Controlling the vehicle with such errors can be difficult or dangerous.

An object underlying the invention is to provide an improved technique for determining a map error of a geographic map on board a vehicle.

The invention solves the problem by means of the subject matter of the independent claims. Subclaims reflect preferred embodiments.

According to a first aspect of the present invention, a method for determining an absolute map error of a geographic map for controlling a vehicle comprises the steps of scanning first sensors, which are each set up for scanning an area surrounding the vehicle; scanning at least one second sensor configured to receive signals from a radio navigation system; determining the position of the vehicle based on sensor values from the first and second sensors; validating the determined position using validators each associated with one of the first sensors; and determining an absolute map error at the determined position based on a distance between the determined position and a position determined based on the at least one second sensor.

The method can be carried out on board the vehicle with little effort. In particular, the method can easily be integrated into an otherwise customary position determination of the vehicle. The determined absolute map error can be used to better determine positions of objects in the area of the determined position. An accuracy and/or an uncertainty of a certain position can be improved.

At least one of the first sensors can be set up to detect an object in the area surrounding the vehicle, it being possible for the position of the vehicle to be determined on the basis of a position of the object indicated on the map.

Objects noted on the geographic map may each have a relative position error that is less than a predetermined value. A relative position error occurs when the position of an object is incorrect relative to the position of another object in the same area. A map that gives positions of two real objects in such a way that a distance between them is 1.5 meters, when the actual distance between the objects is only 1 meter, has a relative position error of 50 cm at the point considered.

The absolute map error can be viewed as an absolute error affecting all objects of a predetermined area. For example, in the example above, the positions of the two objects on the map could each be offset by 3 meters in the same direction from their actual positions, regardless of their relative position errors. A relative position error is preferably substantially less than the map error. For example, the relative position error may be in the range of centimeters or decimeters, while the map error may be in the range of meters.

If a small relative position error of the objects can be assumed, then a map error can be transferred from one position to another in an improved manner. The map error determined at a first point can thus be transferred, for example, to a second point that has a predetermined maximum distance from the first position. The determined map error can also be transferred to another place in a sliding manner. The greater a distance between the points, the greater a deviation of the map error in the second point from the map error in the first point can be. The locations may be on different routes. The map can be corrected better as a result. Due to the transferability of a specific map error, the map error can also be determined for a point on the map at which the metrological prerequisites for a sufficiently precise or sufficiently reliable direct determination of the position of the vehicle are not given.

The determined map error can be averaged over a predetermined time. On the one hand, the determined map error can thereby be based on more measurements. On the other hand, a time-dependent influence on the determined position or on the determined map error can be reduced. For example, the radio navigation system can use a moving transmitter. The quality of a position determination can depend on a position of the transmitter and thus on time.

The absolute map error can be provided in a geographic map, from which a map error can then be read with respect to a position. The geographic map may be provided to another device, such as another vehicle. In one embodiment, the map error can also be indicated in the geographic map itself. The map can have multiple layers and the determined location dependent map error can be entered into one of the layers. This procedure can be particularly advantageous in connection with a map that is constantly or regularly updated on the basis of determinations of a fleet of vehicles. The map error can be given continuously for each position covered by the map or only for certain positions. On the vehicle side, the map error at a predetermined position can be interpolated between spotted map errors at other positions.

In particular, the absolute map error may be determined with respect to a plurality of positions determined within a predetermined area based on scans of multiple vehicles. For this purpose, if possible, every vehicle that determines a map error should have determined its own position with a high degree of certainty. This can be the case when all validators have positively validated a particular position. For example, the vehicles can be on the same road or on roads that are close to one another. Vehicle determinations are preferably collected and processed at a central location. An influence of a single determination on the determined map error can be reduced, so that the map error can be indicated more securely.

According to a further aspect, a device for use on board a vehicle is set up to determine an absolute map error of a geographic map and comprises first sensors for scanning an environment of the vehicle; at least one second sensor configured to receive signals from a radio navigation system; and a processing device. The processing device is set up to determine the position of the vehicle on the basis of sensor values from the first and second sensors; to validate the determined position using validators each associated with one of the first sensors; and determine an absolute map error at the determined position based on a distance between the determined position and a position determined based on the at least one second sensor.

The processing device can be set up to carry out a method described herein in whole or in part. For this purpose, the processing device can include a programmable microcomputer or microcontroller, and the method can be in the form of a computer program product with program code means. The computer program product can also be stored on a computer-readable data carrier. Features or advantages of the method can be transferred to the device or vice versa.

According to a further aspect of the present invention comprises a vehicle comprising a device described herein.

According to yet another aspect of the present invention, a system includes at least one vehicle having a device as described herein and an external entity configured to determine the map error based on a plurality of determinations by the at least one vehicle. The external site can also be set up to provide a specific map error at a predetermined position. For example, a vehicle can at least approximately determine its position and receive an indication from the external location of a map error to be assumed at this position. The position of the vehicle can then be determined in an improved manner, taking into account the map error.

According to yet another aspect of the invention, a method for controlling a vehicle comprises the steps of determining a geographic position of the vehicle based on received signals from a radio navigation system; determining an object in the vicinity of the vehicle based on a geographic map; taking into account an absolute map error of the map in the area of the determined position; and controlling the vehicle depending on the determined object.

In addition to being based on the signals of the radio navigation system, the position of a vehicle can also be determined on the basis of a scan of an environment if a position that can only be determined on the basis of the scan deviates by less than a predetermined amount from a position which can be determined based on the radio navigation system and the scan.

In other words, preference can be given to a position determined on the basis of received signals from the radio navigation system and detected objects in the surroundings if the observations can be positively validated. Otherwise, the position can be determined based on the received radio navigation signals. When controlling the vehicle with respect to an object recorded in the map, the map error in the area of the determined position of the vehicle can be taken into account.

• 1 ein System mit einem Fahrzeug;
• 2 ein Ablaufdiagramm eines ersten Verfahrens; und
• 3 ein Ablaufdiagramm eines zweiten Verfahrens

illustriert.The invention will now be described in more detail with reference to the accompanying drawings, in which:

• 1 a system with a vehicle;
• 2 a flowchart of a first method; and
• 3 a flowchart of a second method

illustrated.

1 10 shows a system 100 that includes a vehicle 105 and an optional location 110 external to the vehicle 105 . The vehicle 105 can have no drive or be designed as a motor vehicle, in particular as a motorcycle, passenger car, truck or bus. A device 115 is provided on board vehicle 105 which is set up to determine a position of vehicle 105 . Device 115 can also be set up to control vehicle 105 as a function of the determined position. The control may preferably include longitudinal or lateral control of the vehicle 105 .

Device 105 includes one or more first sensors 120 and one or more second sensors 125. First sensors 120 are set up to scan an area surrounding vehicle 105, in particular to detect an object 130. A first sensor 120 can include a camera, a radar sensor or a LiDAR sensor, for example. The object 130 is usually stationary and can also be referred to as a landmark. Example objects 130 include a building, street sign, structure, hill, or body of water. Positions of objects 130 in the area surrounding vehicle 105 can be noted on a locally available map. Based on positions of multiple objects 130, the position of the vehicle 105 can be determined. An unknown object 130 can be stored in the map and the position of a known object 130 in the map can be updated. Such a method is known under the name SLAM (simultaneous localization and mapping).

The second sensors 125 are set up to receive signals from a radio navigation system 135 . The radio navigation system 135 shown is satellite-based and includes a plurality of satellites 140, each of which emits signals based on which a position of the emitting satellite 140 with respect to the earth and a transmission time can be determined. Based on a reception timing and a propagation speed of the signals, a distance between the second sensor 125 and the satellite 140 can be determined. The position of the vehicle 105 can then be determined based on the distance and the position of the satellite 140 . This usually requires receiving signals from four or more satellites 140 simultaneously. A plurality of second sensors 125 can be provided, which can be assigned, for example, to different satellite-based navigation systems (GNSS: global navigation satellite system). A second sensor 125 can also be provided, which can receive signals from a number of navigation systems. Received satellite signals can be corrected on the basis of correction data, which can be provided by a DGPS (differential GPS) service, for example.

Furthermore, one or more third sensors 145 can be provided, which can provide further information for determining the position of the vehicle 105 . Such sensors can include, for example, an acceleration sensor, a yaw rate sensor or a rotation sensor for a wheel of vehicle 105 . These sensors 145 typically cannot be used for absolute position determination, but allow a position to be determined based on a previous position.

An optional data memory 150 can be provided for storing a geographic map. The geographic map preferably includes information related to the surroundings of vehicle 105 and includes features and/or positions of objects 130, for example. As will be explained in more detail later, the card can also include information about a card error. The card error can also be listed on a separate card. In both embodiments, the map error can be updated by the device 115.

A processing device 155 is provided for determining the position of the vehicle 105 . The processing device 155 is preferably in the form of a microprocessor and is connected to the sensors 120 , 125 and 145 and to the data memory 150 . A communication device 160 can also be provided in order to communicate with the external location 110 .

The external location 110 preferably comprises a communication device 165, a processing device 170 and an optional data memory 175 and is preferably set up, on the basis of information transmitted by one or more vehicles 105 or devices 115, to determine a card error in a card which covers an area where the vehicles 105 are located. Furthermore, the external station 110 can be set up to provide a map error with respect to a specific position, which a predetermined map has in the region of the position. Separate external locations 110 can also be provided for these two functionalities.

It should be noted that the determination of the map error may alternatively be performed by a vehicle 105 or by the external site 110 . Accordingly, in some embodiments of the present invention, the remote site and/or the communication device 160 may be omitted.

2 shows a flow chart of a first method 200 for determining a map error of a predetermined geographic map. Method 200 can run in particular on a processing device 155 on board vehicle 105 or on a processing device 170 at the external location. A distributed execution is also possible.

In a step 205 a first sensor 120 can be used to scan an area surrounding vehicle 105 . In a step 205 the surroundings can be scanned by means of a further sensor 120 . In the present example, two first sensors 120 are assumed. If more than two first sensors 120 are provided, further steps for scanning them can be provided accordingly. In addition, one or more third sensors 145 may be sampled.

In a step 215 at least one second sensor 125 can be scanned by receiving navigation signals from one or more transmitters of a radio navigation system 135 . Optionally, correction information can also be received, on the basis of which received signals can be corrected.

In a step 220, a position of the vehicle 105 can be determined on the basis of as many available sensor signals as possible. The sensor signals can be merged with one another to determine the position. The sensor signals on which the position is based can be validated in a step 225 separately from the determination of the position. A validator is preferably assigned to each first sensor 120, which is set up to determine how well the sensor signals of sensor 120 assigned to it match the specific position. Corresponding validators can also be used for third sensors 145 that are used.

If it is determined that sensor signals from a sensor 120 match the specific position better than a predetermined amount, they can be positively validated. If, on the other hand, it is determined that the sensor signals of a sensor 120 deviate from the determined position by more than the predetermined amount, then they can be validated negatively. In this case the position can be discarded or marked as unsafe.

If it was determined that all sensor signals match well enough, it can be assumed that the determined position could be determined with a very high degree of certainty. An accuracy of the determined position depends depending on the measure used by the individual validators. If the determination reliability is very high, a map error can be determined in that in a step 230 a further position is determined only on the basis of the sensor signals of the at least one second sensor 125. A map error only affects the position determined on the basis of the first sensors 120 and not the position determined using the second sensor 125 . A deviation between the positions determined in steps 220 and 30 can be determined as a map error in the range of the determined position.

The determined map error can be stored, preferably with reference to the determined position to which the determination relates.

3 shows a flow chart of a second method 300 for determining a position of a vehicle 105. Steps 305 to 325 correspond in pairs to steps 205 to 225 of the method 200 of FIG 2 . On the basis of the result of the validation of the sensor signals from the first sensors 120 in step 325, a decision can be made as to whether the determined position is sufficiently safe. This is usually the case when all of the sensor signals considered match each other sufficiently well.

Otherwise, if sensor signals from one or more first sensors 120 have been negatively validated, it can be decided that a position determined only on the basis of a second sensor 125 offers better accuracy and/or reliability. In a step 335 the position can be determined on the basis of the at least one second sensor 125 . In a step 340, a map error can be determined, which applies to the specific position and on which positions of objects 130 that are located in the vicinity of the specific position can be superimposed. In a first embodiment, the map error can be determined with respect to the determined position on the basis of local data stored in the storage device 150 . In another embodiment, the card error may be obtained from the external site 110. A corresponding request to the external body can include the specific position. In yet another embodiment, the card error can also be determined as a combination of external and internal determinations.

The vehicle 105 can be controlled in a step 345 . The control usually takes place depending on the positions of objects 130 in the environment, which can be corrected on the basis of the map error determined.

Reference List

100

system

105

vehicle

110

external location (server, service, cloud)

115

contraption

120

first sensor

125

second sensor

130

object (landmark)

135

radio navigation system

140

satellite

145

third sensor

150

data storage

155

processing facility

160

communication facility

165

communication facility

170

processing facility

175

data storage

200

first procedure

205

scan the environment

210

scan the environment

215

Receive navigation signals

220

determine position

225

Validate position

230

determine position

235

determine map errors

300

second procedure

305

scan the environment

310

scan the environment

315

Receive navigation signals

320

determine position

325

Validate position

330

determine position

335

determine position

340

determine map errors

345

control the vehicle

Claims (11)

Method (200) for determining an absolute map error of a geographic map for controlling a vehicle (105), the method (200) comprising the following steps: - scanning (205, 210) of first sensors (120), which are each set up to scan an area surrounding the vehicle (105); - Scanning (215) at least one second sensor (125) which is set up to receive signals from a radio navigation system (135); - determining (220) the position of the vehicle (105) on the basis of sensor values from the first (120) and second sensors (125); - validating (225) the determined position by means of validators each associated with one of the first sensors (120, 125); - determining (235) an absolute map error at the determined position based on a distance between the determined position and a position determined based on the at least one second sensor (125). Method (200) according to claim 1 , wherein a first sensor is set up to detect an object (130) in the area surrounding the vehicle (105), and the position of the vehicle (105) is determined on the basis of a position of the object (130) indicated on the map. Method (200) according to claim 2 , wherein objects (130) noted in the geographic map each have a relative position error that is less than a predetermined value. A method (200) according to any one of the preceding claims, wherein the determined map error is averaged over a predetermined time. A method (200) according to any one of the preceding claims, wherein the absolute map error is provided in a geographic map. A method (200) according to any one of the preceding claims, wherein the absolute map error is determined with respect to a plurality of positions determined within a predetermined area based on scans of a plurality of vehicles (105). Device (115) on board a vehicle (105), wherein the device (115) is set up to determine an absolute map error of a geographic map and the device comprises the following: - First sensors (120) for scanning an area surrounding the vehicle (105); - At least one second sensor (125) for receiving signals from a radio navigation system (135); - a processing device (155) which is set up to determine the position of the vehicle (105) on the basis of sensor values of the first and second sensors (120, 125); validate the determined position using validators associated with each of the first sensors (120); and determine an absolute map error at the determined position based on a distance between the determined position and a position determined based on the at least one second sensor (125). Vehicle (105) comprising a device (115). claim 7 . System (100) comprising at least one vehicle (105). claim 8 and an external site (110) configured to determine the map error based on a plurality of determinations by the at least one vehicle (105). Method (300) for controlling a vehicle (105), the method (300) comprising the following steps: - determining (335) a geographical position of the vehicle (105) on the basis of received signals from a radio navigation system (135); - Determining (305, 310) an object (130) in the vicinity of the vehicle (105) on the basis of a geographic map; - taking into account (340) an absolute map error of the map in the area of the determined position; and - Control (345) of the vehicle (105) depending on the specific object (130). Method (200) according to claim 10 , wherein the position is additionally determined on the basis of a scan (305, 310) of an environment if a position that can be determined only on the basis of the scan (335) deviates by less than a predetermined amount from a position that can be determined (320) based on the radio navigation system (135) and the scan.

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