Method for automatically controlling longitudinal vehicle motion

Abstract

The present invention relates to a method for automatically controlling the longitudinal movement of a vehicle (1), in which the surroundings of the vehicle (1) and the objects therein are detected with reference to detection signals of a surrounding sensor device (5) and the state of the traffic lights (3, 4) of an intersection (K) that the vehicle (1) must take into account in order to pass through the intersection (K) regulated by traffic lights is determined. According to the present invention, when the vehicle (1) approaches the intersection (K), it is recognized that the view of the surrounding sensor device (5) of the traffic lights (3, 4) may be blocked by the vehicle (2) in front, and, once it has been recognized that the view of the surrounding sensor device (5) may be blocked by the vehicle (2) in front, a minimum distance (xv) of the vehicle (1) to the vehicle (2) in front, which is to be the basis for the automatic control of the longitudinal movement, is determined depending on the current relative position of the vehicle (1) in relation to the traffic lights (3, 4) and the vehicle (2) in front.

Description

[Technical Field]

[0001] The present invention relates to a method for automatically controlling the longitudinal movement of a vehicle, in which the surroundings of the vehicle and objects therein are detected with reference to detection signals from a surrounding sensor device, and the status of traffic signals at an intersection regulated by traffic lights is determined so that the vehicle takes the traffic signals into account when passing through the intersection. [Background technology]

[0002] From WO 2012 / 166170 A1 a method for controlling a vehicle in an autonomous operating mode is known, which method comprises: - controlling the operation of the vehicle by the processor based on the first control strategy; - a step in which a sensor field is identified based on the field of view of one or more sensors of the vehicle; - receiving sensor data for one or more selected sensors; - identifying a change in sensor sensitivity of one or more sensors based on the sensor data, the change in sensor sensitivity comprising a reduced ability to recognize objects within the sensor field; - determining a second control strategy based on the change; - controlling the operation of the vehicle by the processor based on the second control strategy. Summary of the Invention [Problem to be solved by the invention]

[0003] SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for automatically controlling the longitudinal movement of a vehicle. [Means for solving the problem]

[0004] This problem is solved according to the invention by a method having the features set forth in claim 1.

[0005] Advantageous embodiments of the invention are the subject of the dependent claims.

[0006] A method for automatically controlling the longitudinal movement of a vehicle includes detecting the surroundings of the vehicle and objects therein with reference to detection signals from a surrounding sensor device, and determining the state of a traffic signal at an intersection that the vehicle should take into account in order to pass through the intersection regulated by the traffic signal. According to the present invention, when a vehicle approaches an intersection, it is recognized that the surrounding sensor device's view of the traffic signal may be obstructed by a preceding vehicle, and when it is recognized that the surrounding sensor device's view of the traffic signal may be obstructed by the preceding vehicle, a minimum distance of the vehicle from the preceding vehicle that the vehicle will not fall below is determined, which is used as the basis for automatic control of the longitudinal movement, depending on the current position of the vehicle relative to the traffic signal and relative to the preceding vehicle.

[0007] By applying this method, it is possible to virtually eliminate the obstruction of the view of the surroundings sensor device of a vehicle, particularly when traveling in automated driving operations, to traffic lights by a preceding vehicle, for example a truck.

[0008] In particular, the method provides an optimized response to particularly tall and / or wide vehicles ahead that are present in the intersection area and cast a shadow on the sensor, blocking the view of the traffic light. In such cases, the minimum vehicle distance to the preceding vehicle is adapted so that a traffic light that appears relatively suddenly from the sensor's shadow is not unexpected for the vehicle and does not require sudden braking. Therefore, a traffic light that appears suddenly from the sensor's shadow is a calculated risk when applying the method.

[0009] In an embodiment of the method, the minimum distance is determined such that when the minimum distance between the vehicle and the vehicle ahead is reached, the surroundings sensor device has an open view of the traffic signal that is not obstructed by the vehicle ahead, i.e. the vehicle either drives while maintaining the minimum distance to the vehicle, or stops behind the vehicle while respecting the minimum distance so that the surroundings sensor device has an open view of the traffic signal and can react to the traffic signal accordingly.

[0010] In a further development of the method, the sensor shadow cast by the preceding vehicle on the vehicle's surroundings sensor device is determined, and with reference to this sensor shadow, it is determined whether the sensor device has an open view of the traffic light, where the sensor shadow is understood to be a view obstruction for the surroundings sensor device.

[0011] Furthermore, a possible embodiment of the method contemplates that the most probable location of the traffic signal within the shadow of the sensor is determined as a hypothesis, in particular as a worst-case scenario, in order to determine the minimum distance that would allow a vehicle to react relatively comfortably if the traffic signal were actually present there.

[0012] In another possible embodiment, the state of the traffic light in the most likely position is assumed to be red, particularly as a worst case for the vehicle, allowing the vehicle to stop at the traffic light with a comfortable stopping maneuver.

[0013] For this purpose, one development provides for a hypothetical determination of a comfortable stopping distance for the vehicle depending on the current driving speed, and this stopping distance is set as a minimum distance for the most likely position of the traffic light, in particular a stopping distance that would require the vehicle to react quickly to a traffic light that is showing red, thereby virtually eliminating the possibility of a sudden braking operation that would endanger the safety of the vehicle's occupants.

[0014] In a possible embodiment of the method, if the position of the traffic signal relative to the vehicle is known, for example with reference to existing map data, the minimum distance is limited to this known position of the traffic signal, i.e. no further determination is made in such a case, and the longitudinal movement is controlled in accordance with this minimum distance with respect to the known position of the traffic signal.

[0015] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. [Brief explanation of the drawings]

[0016] [Figure 1] 1 shows a schematic representation of a traffic situation including a vehicle and a traffic light being blocked by a vehicle ahead. [Figure 2] 3A and 3B show schematic diagrams of another traffic situation including a vehicle having a determined minimum separation to a vehicle ahead. [Figure 3] 10 is a schematic diagram showing an outline of determination of the minimum interval. DETAILED DESCRIPTION OF THE INVENTION

[0017] In all the drawings, the same reference numerals are used to designate corresponding parts.

[0018] FIG. 1 shows a traffic situation at an intersection K, with a vehicle 1 and a leading vehicle 2, embodied for example as a truck 2, traveling in front of it.

[0019] FIG. 2 shows another traffic situation in which a vehicle 1 has a determined minimum distance xv to a vehicle 2 in front, and FIG. 3 shows an overview of the determination of the minimum distance xv.

[0020] The intersection K is regulated by traffic lights, with a traffic light 3 standing at the edge of the roadway and another corresponding traffic light 4 suspended from a so-called lamppost.

[0021] The vehicle 1 is traveling in an automated driving mode, and the surroundings of the vehicle 1, particularly the surroundings located in front of the vehicle, and objects therein are detected with reference to the detection signals of the surroundings sensor device 5, which is shown in a greatly simplified manner as an example.

[0022] With reference to the detection signals of the surrounding sensor device 5, the states of the traffic signals 3, 4 that should be taken into consideration when passing through the intersection K are recognized.

[0023] In the embodiment shown in FIGS. 1 to 3, a vehicle 1 is traveling behind a relatively large vehicle 2, which may be a bus, toward an intersection K regulated by traffic lights.

[0024] As shown in Fig. 1, when vehicle 1 is traveling behind vehicle 2 in front with a gap a that is too narrow, vehicle 2 in front blocks the view of traffic signals 3 and 4 from surrounding sensor device 5. In this case, vehicle 2 in front may block the view of not only traffic signal 3 at the edge of the roadway but also another traffic signal 4 above, and the view-blocking portion S, also called the sensor shadow S, is shown by the hatched surface in Figs. 1 and 2.

[0025] As a result, a situation may arise in which vehicle 1 approaches red traffic lights 3, 4 at a relatively high driving speed, while vehicle 2 in front is still able to pass through intersection K. This may force vehicle 1 to initiate dynamic braking, i.e. relatively strong braking, to stop vehicle 1 at red traffic lights 3, 4, particularly in automated driving operations, which may surprise and / or injure the occupants of vehicle 1.

[0026] It may also happen that when the traffic light 4 emerges from the view blockage S of the preceding vehicle 2, the angle between the surroundings sensor device 5 and, in particular, another traffic light 4 is too large, so that the other traffic light 4 is also outside the detection range of the surroundings sensor device 5.

[0027] In such a situation, a method for controlling the longitudinal movement of the vehicle 1 will be described below so that the vehicle 1 can generally perform a relatively comfortable automated driving operation.

[0028] In this method, when a vehicle 1 approaches an intersection K that is regulated by traffic lights and the vehicle 1 must take into account the state of traffic lights 3 and 4 when passing through the intersection K, each time the vehicle 1 approaches the intersection K, it is recognized whether a vehicle 2 in front is blocking the view of the surrounding sensor device 5 of the traffic lights 3 and 4.

[0029] When it is recognized that the surroundings sensor device 5's view of the traffic lights 3, 4 is blocked by the vehicle 2 ahead, the minimum distance xv of the vehicle 1 from the vehicle 2 ahead is determined depending on the current relative position of the vehicle 1 from the traffic lights 3, 4 and from the vehicle 2 ahead, as shown in detail in Figure 3.

[0030] To enable the traffic light 3 to be within the detection range of the surrounding sensor device 5 and thereby to detect the state of the traffic light 3, it is necessary that the ratio between the first section ys and the second section xs is greater than the ratio between the third section yv and the fourth section xv.

[0031] In this case, the first section ys represents the distance between the center line of the vehicle 2 in front and the inside corner of the traffic light 3, while the second section xs represents the straight-line distance between the surrounding sensor device 5 of the vehicle 1 and the extension of the first section ys.

[0032] The third section yv extends from the surroundings sensor device 5 to the outer corner of the leading vehicle 2, and the fourth section xv represents the minimum distance xv between the vehicle 1 and the leading vehicle 2.

[0033] This approach is equally applicable to the additional traffic signal 4 located above and to the left, not shown. For the additional traffic signal 4 located on a lamppost, the minimum height of the additional traffic signal 4 is important, since in the worst case this lower-hanging additional traffic signal 4 would be blocked, for example, by a semi-trailer.

[0034] The relative position of the traffic light 3 can be derived by a high-resolution map or by prior visual recognition of the traffic light 3. Furthermore, the relative position and driving speed of the vehicle 2 ahead are calculated by the assistance system through radar-, lidar- and / or camera-based detection signals, i.e. the minimum distance xv to be respected is greater than / equal to yv*xs / ys, and the vehicle 1 is then accelerated or decelerated accordingly.

[0035] Such a high-resolution map contains the positions of the traffic lights 3, 4 with high accuracy, and the position of the vehicle 1 is likewise determined. From there, the visibility beam of the surroundings sensor device 5 can be calculated, with which it should be possible to detect the relevant traffic light 3, 4. When this calculated visibility beam hits the vehicle 2 ahead, or when this visibility beam intersects with the vehicle 2 ahead or its predicted position, assuming that the vehicle 2 ahead continues to behave in the same way as it does now, particularly with regard to speed and acceleration, the vehicle 1 can react accordingly, so that the visibility beam detects the relevant traffic light 3, 4.

[0036] With respect to the vehicle 2 ahead, the view obstruction S, ie the sensor shadow S that the vehicle 2 ahead casts on the surroundings sensor device 5 of the vehicle 1, is determined by the vehicle 1 and in particular calculated.

[0037] Next, the most likely location of a potential traffic light 3 within the sensor shadow S is determined and this is used as the worst-case assumption since the vehicle 1, i.e., the vehicle's system, has no evidence that there is no traffic light 3 there.

[0038] Furthermore, it is assumed that the traffic light 3 is red, since this situation is also the worst-case scenario for the vehicle 1. The surroundings sensor device 5 of the vehicle 1 can then recognize the hypothetically nearest traffic light 3 when it is no longer blocked by the vehicle 2 ahead and moves out of the sensor's shadow S. Then, when the traffic light 3 shows its red light, the vehicle 1 can stop in front of the traffic light 3 with a relatively comfortable stopping maneuver. To be able to do this, the vehicle 1 must know the stopping distance to the traffic light 3 depending on its speed, and must adjust this stopping distance as a minimum distance xv in relation to the control of its longitudinal movement. In this way, it is possible to largely avoid situations in which the vehicle 1 gets too close to the vehicle 2 ahead and is surprised by the sudden appearance of the red traffic light 3.

[0039] If the position of the traffic lights 3, 4 relative to the vehicle 1 is known, for example with reference to map data present on the vehicle side, the range of assumptions can be limited to that position based on the map data of the traffic lights 3, 4.

[0040] In addition, the recognition of intersecting roads can also be used as an indicator of intersection K to similarly limit the range of assumptions.

[0041] A navigation map in which an intersection K with traffic lights 3, 4 is entered enables the vehicle 1, even without the precise location of the individual traffic lights 3, 4, to comply early with the appropriate minimum distance xv from a preceding vehicle 2 that may at least partially block the view of the surroundings sensor device 5 before reaching the intersection K, thus enabling an open view of the surroundings sensor device 5 at least to the traffic light 3.

[0042] The method can be applied equally well in the absence of map information: if the vehicle 1 is at a relatively large distance from the traffic lights 3, 4 and its visibility is unobstructed but is lost due to the approach of the vehicle 2 ahead, the previously estimated position of the vehicle 1 can be used to calculate the visibility beam in the same way as in the presence of highly accurate map data. [Prior art documents] [Patent documents]

[0043] [Patent Document 1] WO 2012 / 166170(A1)

Claims

1. A method for automatically controlling the longitudinal movement of a vehicle (1), comprising: detecting the surroundings of the vehicle (1) and objects therein with reference to detection signals from a surroundings sensor device (5); and determining the state of traffic signals (3, 4) at an intersection (K) regulated by traffic lights that the vehicle (1) should take into account in order to pass through the intersection (K), comprising: It is recognized that when the vehicle (1) approaches the intersection (K), the view of the surroundings sensor device (5) to the traffic signals (3, 4) may be blocked by a preceding vehicle (2); When it is recognized that the view of the surroundings sensor device (5) with respect to the traffic signal (3, 4) may be obstructed by the vehicle (2) ahead, a minimum distance (xv) of the vehicle (1) with respect to the vehicle (2) ahead, which is to be the basis for automatic control of longitudinal movement, and which must not be exceeded by the vehicle (1), is determined depending on the current relative position of the vehicle (1) with respect to the traffic signal (3, 4) and with respect to the vehicle (2) ahead; a sensor shadow (S) cast by the preceding vehicle (2) on the surroundings sensor device (5) of the vehicle (1) is determined; The most probable position of the traffic light (3) within the determined shadow (S) of the sensor is determined as a hypothesis; The state of the traffic light (3) in the most likely location is assumed to be red. A method characterized by:

2. 2. The method according to claim 1, characterized in that the minimum distance (xv) is determined so that the surroundings sensor device (5) has an open view of the traffic lights (3, 4) that is not obstructed by the vehicle (2) ahead when the minimum distance (xv) between the vehicle (1) and the vehicle (2) ahead is reached.

3. 2. The method according to claim 1, characterized in that the vehicle (1) determines a comfortable stopping distance depending on the assumption depending on the current driving speed, and this stopping distance is set as the minimum distance (xv) to the most likely position of the traffic light (3).

4. 4. The method according to claim 1, wherein if the position of the traffic signal (3) relative to the vehicle (1) is known, the minimum spacing (xv) is limited to this known position of the traffic signal (3).

5. A method for automatically controlling the longitudinal movement of a vehicle (1), comprising: detecting the surroundings of the vehicle (1) and objects therein with reference to detection signals from a surroundings sensor device (5); and determining the state of traffic signals (3, 4) at an intersection (K) regulated by traffic lights that the vehicle (1) should take into account in order to pass through the intersection (K), comprising: It is recognized that when the vehicle (1) approaches the intersection (K), the view of the surroundings sensor device (5) to the traffic signals (3, 4) may be blocked by a preceding vehicle (2); When it is recognized that the view of the surroundings sensor device (5) with respect to the traffic signal (3, 4) may be obstructed by the vehicle (2) ahead, a minimum distance (xv) of the vehicle (1) with respect to the vehicle (2) ahead, which is to be the basis for automatic control of longitudinal movement, and which must not be exceeded by the vehicle (1), is determined depending on the current relative position of the vehicle (1) with respect to the traffic signal (3, 4) and with respect to the vehicle (2) ahead; a sensor shadow (S) cast by the preceding vehicle (2) on the surroundings sensor device (5) of the vehicle (1) is determined; The most probable position of the traffic light (3) within the determined shadow (S) of the sensor is determined as a hypothesis; The vehicle (1) determines a comfortable stopping distance depending on the current driving speed according to the assumption, and this stopping distance is set as the minimum distance (xv) to the most likely position of the traffic light (3). A method characterized by:

6. 6. The method according to claim 5, characterized in that the minimum distance (xv) is determined so that the surroundings sensor device (5) has an open view of the traffic lights (3, 4) that is not obstructed by the vehicle (2) ahead when the minimum distance (xv) between the vehicle (1) and the vehicle (2) ahead is reached.

7. 7. The method according to claim 5 or 6, characterized in that if the position of the traffic signal (3) relative to the vehicle (1) is known, the minimum spacing (xv) is limited to this known position of the traffic signal (3).

8. A method for automatically controlling the longitudinal movement of a vehicle (1), comprising: detecting the surroundings of the vehicle (1) and objects therein with reference to detection signals from a surroundings sensor device (5); and determining the state of traffic signals (3, 4) at an intersection (K) regulated by traffic lights that the vehicle (1) should take into account in order to pass through the intersection (K), comprising: It is recognized that when the vehicle (1) approaches the intersection (K), the view of the surroundings sensor device (5) to the traffic signals (3, 4) may be blocked by a preceding vehicle (2); When it is recognized that the view of the surroundings sensor device (5) with respect to the traffic signal (3, 4) may be obstructed by the vehicle (2) ahead, a minimum distance (xv) of the vehicle (1) with respect to the vehicle (2) ahead, which is to be the basis for automatic control of longitudinal movement, and which must not be exceeded by the vehicle (1), is determined depending on the current relative position of the vehicle (1) with respect to the traffic signal (3, 4) and with respect to the vehicle (2) ahead; If the position of the traffic signal (3) relative to the vehicle (1) is known, the minimum distance (xv) is limited to this known position of the traffic signal (3). A method characterized by:

9. The minimum distance (xv) is determined so that the surroundings sensor device (5) has an open view of the traffic lights (3, 4) that is not obstructed by the vehicle (2) ahead when the minimum distance (xv) between the vehicle (1) and the vehicle (2) ahead is reached.

9. The method according to claim 8.

10. 9. A method according to claim 8, characterized in that the sensor shadow (S) cast by the preceding vehicle (2) on the surroundings sensor device (5) of the vehicle (1) is determined.

11. 11. The method according to claim 10, characterized in that within the determined shadow (S) of the sensor, the most probable position of the traffic light (3) is determined as a hypothesis.

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