Vehicle lane change safety check with graded sensor visibility ranges

Abstract

The invention relates to a system for checking a possible lane change for safety, wherein a computing unit (4) assesses, on the basis of data from a sensor unit (2), whether a respective detected road user (3) is located in a first region (5) or in a second region (6) and determines a distance thereof from the vehicle (1) and a speed, if the detected road user (3) is in the first region (5), and detects a safe lane change if no road users (3) are detected in the second region (6) and if all road users (3) detected in the first region (5) each have a combination of speed and distance from the vehicle (1) classified as safe.

Description

[0001] Safety testing of a vehicle lane change with graduated sensor visibility

[0002] The invention relates to a system for a vehicle for checking a possible lane change for safety, as well as a vehicle with such a system.

[0003] Particularly on a motorway with at least one carriageway and two or more parallel lanes traveling in the same direction, when overtaking a vehicle, the driver must at least temporarily change from a lane that is likely to be slower to a lane that is likely to be faster. When driving the vehicle, care must be taken to ensure that there is sufficient distance from any road user following behind the driver in the faster lane. This distance should be dependent, in particular, on the speed difference between the following road user and the driver's own vehicle, so that the driver's braking in response to the driver's own vehicle pulling out is avoided as far as possible.The dependence of the distance on the speed, which must be taken into account, arises from the fact that the shorter the distance and the higher the speed of the following road user from the own vehicle, the shorter the time until the following road user reaches the own vehicle for a given distance between them.

[0004] This relationship must be considered by a human driver when manually driving the vehicle. This circumstance must also be taken into account when developing and designing highly automated vehicles capable of performing such an overtaking maneuver as described above independently, i.e., through automated guidance. Just as visibility to the rear, against the main direction of travel, of rapidly approaching road users at a sufficient distance is often a limiting factor in the optimal implementation of these principles when manually driving, sensors with only a limited range are also available for automated vehicles. The desired ranges exceed the capabilities of current sensor systems. State-of-the-art methods are known to simplify such a vehicle course change for a manual driver:

[0005] In this context, DE 102013226 773 A1 relates to a device for assisting a course change of a vehicle, having the following features: a detection device for detecting a distance and a speed of at least one vehicle behind the vehicle; and a display device for displaying an indication of the detected distance and the detected speed of the vehicle behind.

[0006] It is an object of the invention to reduce the requirements for a sensor system for use by an automated vehicle in an overtaking scenario as described with parallel lanes and to be able to handle such a scenario better by means of a new driving strategy.

[0007] The invention is based on the features of the independent claims. Advantageous developments and refinements are the subject of the dependent claims.

[0008] A first aspect of the invention relates to a system for a vehicle for checking a possible lane change for safety, comprising a sensor unit and a computing unit, wherein the sensor unit is designed to detect road users and to transmit detection data to the computing unit, characterized in that the computing unit is designed to assess, based on the data from the sensor unit, whether a respective detected road user is located in a first area or in a second area, wherein the first area is closer to the vehicle than the second area and both the first area and the second area are located in an area opposite to the direction of travel of the vehicle, and to determine a distance of the respective road user from the vehicle and a speed of the respective road user if the detected road user is located in the first area,and to recognise a safe lane change if no road user is detected in the second area and all road users detected in the first area each have a combination of speed and distance from the own vehicle that is classified as safe, and to deny a safe lane change if there is at least one road user in the first area who has a combination of speed and distance from the own vehicle that is classified as unsafe.

[0009] The system is particularly advantageous when a vehicle equipped with the system is traveling on a single-way carriageway with two or more parallel lanes traveling in the same direction, for example on a motorway. The system is advantageously fully integrated into the vehicle itself; in particular, a sensor unit is arranged on the vehicle with its detection area directed backwards, against the main direction of travel of the vehicle, in order to be able to detect road users approaching from behind, i.e. from behind. However, the system can also be advantageously used on roads with only one lane in each direction in order to detect and assess road users already overtaking or approaching from behind.

[0010] The decision as to whether a potential lane change is considered safe is based on a combination of the distance between the road user approaching from behind and the driver's own vehicle, as well as the road user's speed. The road user's speed can be an absolute speed, but a relative speed of the road user relative to that of the driver's own vehicle is preferred with such a system, as this determines the time it takes for the road user to reach the driver's own vehicle, assuming they maintain their current speed, depending on the current distance between the road user and the driver's own vehicle.

[0011] Preferably, a predefined logic is used for decision-making that takes into account the distance and relative speed between road user and vehicle, for example by comparing the estimated time until collision described above with a predefined threshold. More complex metrics can also be applied and applied in the form of a table or analytically solvable equations. However, since it can be assumed that the system's sensor unit only has a limited range to be able to record the relative distance of a respective road user detected by it to the vehicle with the system, as well as the speed of the road user, a first range is defined within which the distance and speed of the road user are used.However, it has been shown that the basic presence of the other road user can be detected even at greater distances. For this purpose, a second area is defined, which extends behind the first area. Preferably, the second area and the first area are each limited laterally to the lateral extension of the directional carriageway with its multiple parallel lanes, in order to avoid, as far as possible, false detections of other objects that are mistakenly classified as road users.

[0012] If the road user is in the second area, i.e. at a greater distance from the vehicle than would be required to fall into the first area, they can be detected using the sensor unit, which in this case can be operated with fewer requirements than for a road user detected in the first area. Nevertheless, detections made by the sensor unit can be exploited without having to obtain precise information about the road user. Rather, only object detection itself counts, i.e. the fact that the existence of a road user in the second area can be detected. By using camera perception, for example, fewer pixels are needed to detect an object in the second area for a road user than to estimate the speed and, if applicable, the object class and, if applicable, the object size of a road user in the first area.

[0013] If only road users in the first zone are detected who have a respective combination of speed and distance from the host vehicle that is classified as safe with regard to a lane change initiated at the time of classification, a lane change can be initiated in the case of an automated vehicle, or a warning can be omitted in the case of a manually driven vehicle. If at least one road user in the first zone has a combination of distance and speed from the host vehicle that is classified as unsafe, the lane change will not be initiated in the case of an automated vehicle, and a warning will be issued in the case of a manually driven vehicle.Since there is a possibility that a road user outside the first zone is approaching the vehicle at very high speed and is about to enter the first zone, a safe lane change is only detected if there is no road user in the second zone.

[0014] This makes it possible to avoid determining a safe lane change in dangerous situations where, although all road users in the first area have sufficient distance and sufficiently low speed relative to the vehicle, a road user approaching very quickly from behind outside the first area poses an actual danger when executing the lane change.

[0015] If no road user is detected in either the first or second zone, a safe lane change is also recognized. Advantageously, the computing unit also limits the first and second zones to adjacent lanes, one of which is driven by the vehicle equipped with such a system.

[0016] According to an advantageous embodiment, the computing unit is designed to deny a safe lane change in the event that at least one road user is detected in the second area and to only allow its detection again once this road user has left the second area and at this time all road users detected in the first area each have a combination of speed and distance from the own vehicle that is classified as safe.

[0017] The system waits until a road user in the second zone enters the first zone, allowing the system to check their distance and speed relative to the vehicle. All other road users in the first zone must also maintain a safe combination of distance and speed relative to the vehicle. Only when this is met and no other road user is in the second zone can a safe lane change be detected.According to a further advantageous embodiment, the condition logic for checking the combination of a distance and a speed of a road user in the second area is dynamically adapted, for example depending on the speed of the own vehicle, weather conditions, road conditions, a mass of the own vehicle, a payload of the own vehicle, a current engine of the own vehicle, a charge state of the own vehicle's battery.

[0018] According to a further advantageous embodiment, the computing unit is designed to recognize a road user in the second area as such solely on the basis of a movement of the road user, without determining the speed of the road user relative to the own vehicle.

[0019] If the sensor unit has a camera, the road user in the second area can be detected with a relatively small number of pixels by identifying them as a moving object in the second area. Precise speed measurement of this road user and precise distance measurement from the vehicle itself are not necessary, and may not be possible in some cases.

[0020] According to a further advantageous embodiment, the computing unit is designed not to issue a warning to a driver of the vehicle and / or to initiate a lane change automatically when a safe lane change is detected by controlling an output unit of the system, and to issue a warning to the driver and / or to prevent the lane change from being initiated automatically when a safe lane change is denied.

[0021] According to a further advantageous embodiment, the warning to the driver of the vehicle comprises a plurality of warning levels, wherein the computing unit is designed to determine a warning level depending on the classification of a lane change as safe or unsafe and depending on the determined distance of a road user from the vehicle and / or the determined speed of the road user.

[0022] According to a further advantageous embodiment, the computing unit is designed to determine a respective dimension of at least one respective road user located in the first area from the data of the sensor unit and to dynamically adapt the combination of speed and distance required for a safe lane change to the respectively determined dimension.

[0023] The determined dimension can be used to adjust the extent of the first area and thus the positioning of the second area, as well as to adjust a condition as to whether a distance and speed of the road user relative to the own vehicle represent a safe combination.

[0024] According to a further advantageous embodiment, the second region adjoins the first region seamlessly.

[0025] According to a further advantageous embodiment, the computing unit is designed to adapt an extent of the first area and / or an extent of the second area depending on a current state of a predetermined situation parameter.

[0026] One possible situation parameter is a state variable of the current weather. Another possible situation parameter is the speed of the vehicle.

[0027] According to a further advantageous embodiment, the computing unit is designed to adapt an extension of the first area depending on the weather.

[0028] According to a further advantageous embodiment, the computing unit is designed to discard the definition of the second area when driving along a predetermined section of road and to use only the first area when checking the safety of a possible lane change.

[0029] Such a predefined route section or route section of a predefined category can be a country road. On country roads, the use of a second range may be unnecessary under certain circumstances, since the range of the sensor unit is typically sufficient compared to the road conditions and no high relative speeds are to be expected. A further aspect of the invention relates to a vehicle with a system as described above and below.

[0030] Advantages and preferred developments of the proposed vehicle result from an analogous and analogous transfer of the statements made above in connection with the proposed system.

[0031] Further advantages, features, and details will become apparent from the following description, which – where appropriate with reference to the drawings – describes at least one embodiment in detail. Identical, similar, and / or functionally equivalent parts are provided with the same reference numerals.

[0032] They show:

[0033] Fig. 1 : A road traffic situation on a single carriageway with two parallel lanes traveling in the same direction using a system for checking the safety of a lane change according to the state of the art.

[0034] Fig. 2: A road traffic situation on a one-way carriageway with two parallel lanes traveling in the same direction using a system for checking the safety of a lane change according to an embodiment of the invention.

[0035] Fig. 3: A vehicle with a system according to an embodiment of the invention.

[0036] The representations in the figures are schematic and not to scale.

[0037] Fig. 1 shows a situation in public road traffic on a one-way carriageway with two parallel lanes traveling in the same direction, i.e. a one-way carriageway of a motorway. In this situation, a vehicle 1 is traveling in the right-hand lane and is equipped with a state-of-the-art system for warning against a lane change due to excessive uncertainty. This system determines the distance and relative speed between road user 3 and the vehicle itself 1 using a sensor. A predefined conditional logic is used to determine whether the distance, given the relative speed between road user 3 and the vehicle itself 1, is sufficient to indicate a safe lane change. The distance and speed of the other road user 3 is determined using a sensor which naturally has a limited range.This range is effectively limited to the section of the directional lane indicated between two horizontally drawn dashed lines. Road user 3 in Fig. 1 is outside this range, which is why, in this state-of-the-art system, he or she is not analyzed with regard to his or her distance from the host vehicle 1 and his or her relative speed to it. However, if road user 3 is traveling at a very high speed, for example 300 km / h, while the host vehicle is traveling at, for example, 80 km / h shortly after leaving a driveway or following a slow-moving truck, dangerous situations can arise when the host vehicle 1 changes lanes, requiring road user 3 to brake sharply to avoid an accident.

[0038] Fig. 2, on the other hand, shows an exemplary system according to the invention which is installed in the vehicle 1 in order to avoid a dangerous situation as outlined in Fig. 1: The range of a sensor unit 2 of the system of the host vehicle 1 is still limited to a first area 5, within which a distance of a road user 3 from the host vehicle 1 and the relative speed of the other road user 3 relative to the host vehicle 1 can be determined; outside of the first area 5, however, this is not the case, or at least not reliably. The second area 6 adjacent to the first area 5 can still be detected by the sensor unit 2, but the distance and the relative speed of the other road user 3 from the host vehicle 1 cannot be determined, or cannot be determined reliably.Nevertheless, it can generally be detected by means of image recognition or other sensor metrics that another road user 3 is located in this second area 6, since this can be identified as a moving object in the second area 6 in the data from the sensor unit 2 after evaluation by the computing unit 4. Due to the limited precise sensor range of the sensor unit 2, the dimensions and kinematic data of the road user 3 cannot yet be determined. Therefore, the computing unit 4 of the system of the first vehicle 1 executes the following logic: If a road user 3 is detected in the second area 6, it is assumed that its speed and exact distance from the host vehicle 1 cannot yet be reliably determined. The system therefore waits until the road user 3 leaves the second area 6 and enters the first area 5.Once in the first area 5, road user 3 can determine an exact relative distance between themselves and their own vehicle 1, as well as a relative speed between road user 3 and their own vehicle 1. Using this information, it can be conventionally evaluated whether their current speed and their current distance from their own vehicle 1 represent a combination that allows the conclusion that their own vehicle 1 can safely change lanes from the right lane to the left lane. If a distance-dependent limit value for the speed or, alternatively, a speed-dependent limit value for the distance exceeds a respective limit condition, an unsafe lane change is assumed and, in the case of manual vehicle control, a warning is issued to the driver of their own vehicle 1.If the vehicle 1 is highly automated and capable of changing lanes independently and without human intervention, for example, to overtake a truck in front, the processing unit 4 prevents the automatic lane change. Otherwise, a warning to the driver can be omitted or a fully automatic lane change can be performed. If it is detected that a road user 3 is in the second zone 6, but enters the first zone 5 after a certain time, it can be assumed that the road user 3 is traveling at a correspondingly slow speed and does not pose a threat to a safe lane change for the host vehicle 1. Such an option can be additionally installed in the processing unit 4.The boundaries between the first area 5 and the second area 6 can also be designed flexibly, for example depending on the weather and in particular depending on the current maximum visibility. Weather influences such as fog can limit not only human visibility, but also, in particular, that of sensors of a sensor unit 2 of the host vehicle 1, such as an ultrasonic distance unit, to a certain extent radar waves, and in particular a camera unit. Accordingly, the boundaries of the first area 5 can be reduced in size according to the reduced detection range. The conditions of the road surface can also be taken into account. Furthermore, the extent of the first area 5 and thus the positioning of the adjoining second area 6 can be defined dynamically depending on the speed of the host vehicle 1.

[0039] Fig. 3 shows a vehicle 1 which is equipped with a system for checking the safety of a possible lane change. A rear-facing sensor unit 2 has at least one camera in order to be able to detect road users 3 traveling behind the vehicle 1 and to enable an assignment of the definition of a first area 5 and a second area 6 in an area opposite to the direction of travel of the vehicle 1, which definition is stored in a computing unit 4 of the vehicle 1. The computing unit 4 is shown in Fig. 3 as being arranged in the vehicle 1 by way of example, but can also be designed as a stationary central computing unit and used for a large number of vehicles 1.

[0040] Although the invention has been illustrated and explained in detail by preferred embodiments, the invention is not limited by the disclosed examples, and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention. It is therefore clear that a multitude of variations exist. It is also clear that exemplary embodiments are truly only examples and should not be construed as limiting the scope, possible applications, or configuration of the invention in any way.Rather, the preceding description and the description of the figures enable the person skilled in the art to implement the exemplary embodiments in concrete terms, whereby the person skilled in the art, with knowledge of the disclosed inventive concept, can make various changes, for example with regard to the function or the arrangement of individual elements mentioned in an exemplary embodiment, without departing from the scope of protection defined by the claims and their legal equivalents, such as further explanations in the description.

Claims

Patent claims 1. A system for a vehicle (1) for checking the safety of a possible lane change, comprising a sensor unit (2) and a computing unit (4), wherein the sensor unit (2) is designed to detect road users (3) and to transmit detection data to the computing unit (4), characterized in that the computing unit (4) is designed to assess, based on the data from the sensor unit (2), whether a respective detected road user (3) is located in a first area (5) or in a second area (6), wherein the first area (5) is closer to the vehicle (1) than the second area (6) and both the first area (5) and the second area (6) are located in an area opposite to the direction of travel of the vehicle (1), and to determine a distance of the respective road user (3) from the vehicle (1) and a speed of the respective road user (3).if the detected road user (3) is located in the first area (5), and to detect a safe lane change if no road user (3) is detected in the second area (6) and all road users (3) detected in the first area (5) each have a combination of speed and distance to the vehicle (1) that is classified as safe, and to deny a safe lane change if at least one road user (3) is located in the first area (5) who has a combination of speed and distance to the vehicle (1) that is classified as unsafe.

2. System according to claim 1, wherein the computing unit (4) is designed to determine a safe lane in the event that at least one road user (3) is detected in the second area (6). change and only to allow the detection of a safe lane change again as soon as this road user (3) has left the second area (6) and at this time all road users (3) detected in the first area (5) each have a combination of speed and distance to the vehicle (1) that is classified as safe.

3. System according to one of the preceding claims, wherein the computing unit (4) is designed to recognize a road user (3) in the second area (6) solely on the basis of a movement of the road user (3) as such, without determining its speed relative to the vehicle (1).

4. System according to one of the preceding claims, wherein the computing unit (4) is designed, when a safe lane change is detected, by controlling an output unit of the system, not to issue a warning to a driver of the vehicle (1) and / or to carry out the automatic initiation of a lane change, and, when a safe lane change is denied, to issue a warning to the driver and / or to prevent the automatic initiation of the lane change.

5. System according to claim 4, wherein the warning to the driver of the vehicle (1) comprises a plurality of warning levels, wherein the computing unit (4) is designed to determine a warning level depending on the classification of a lane change as safe or unsafe and depending on the determined distance of a road user (3) from the vehicle (1) and / or the determined speed of the road user (3).

6. System according to one of the preceding claims, wherein the computing unit (4) is designed to determine a respective dimension of at least one respective road user (3) located in the first area (5) from the data of the sensor unit (2), and to dynamically adapt the combination of speed and distance required for a safe lane change to the respectively determined dimension.

7. System according to one of the preceding claims, wherein the second region (6) adjoins the first region (5) seamlessly.

8. System according to one of the preceding claims, wherein the computing unit (4) is designed to adapt an extent of the first area (5) and / or an extent of the second area (6) depending on a current state of a predetermined situation parameter.

9. System according to claim 8, wherein the computing unit (4) is designed to adapt an extension of the first area (5) depending on the weather.

10. System according to one of the preceding claims, wherein the computing unit (4) is designed to discard the definition of the second area (6) when driving along a predetermined section of road and to use only the first area (5) when checking the safety of a possible lane change.

11. Vehicle (1) with a system according to one of the preceding claims.

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