METHOD AND DEVICE FOR DETERMINING A SIGNAL STATE OF A LIGHT SIGNAL SYSTEM

Abstract

A method for determining a signal state of a light signal system having several light signal emitters, wherein the light signal system comprises several signal states and a signal state is formed by means of one or more activated light signal emitters. The method includes: determining an object, which represents a signal state of a light signal system; saving a determined first object having a first identifier, if it is detected in a first video image that the first object represents a signal state of the light signal system; changing the identifier of the saved first object from the first identifier to a second identifier, if in a second video image the first object is no longer detected; deleting the saved first object having the second identifier, if a second object is determined in a further video image, which represents a different signal state of the light signal system.

Claims

1. A method for determining a signal state of a light signal system having several light signal emitters, wherein the light signal system has several signal states and a signal state is formed by one or more activated light signal emitters, the method comprising the following steps: determining an object representing the signal state of the light signal system; saving a determined first object having a first identifier when, in a first analysis cycle, it is detected that the first object represents the signal state of the light signal system; changing an identifier of the saved first object from the first identifier to a second identifier when the first object is no longer detected in a subsequent analysis cycle; deleting the saved first object having the second identifier, when a second object is determined in an analysis cycle, which represents a different signal state of the light signal system.

2. The method according to claim 1, further comprising: deleting the first object having the second identifier when a characteristic of the second object satisfies a defined condition, wherein the defined condition is that the signal state of the light signal system represented by the second object is a defined subsequent signal state with respect to the signal state of the light signal system represented by the first object.

3. The method according to claim 1, further comprising: deleting the first object having the second identifier when an age of the second object when an age of the second object is less than an age of the first object.

4. The method according to claim 1, further comprising: deleting the first object having the second identifier when a determined size of the second object corresponds to a determined size of the first object within a defined tolerance threshold.

5. The method according to claim 1, further comprising: defining a first environmental estimation area with respect to the first object having the second identifier, in which the first object is expected in a next analysis cycle.

6. The method according to claim 5, further comprising: defining a second environmental estimation area with respect to the first object having the second identifier, in which the second object is expected in a next analysis cycle, wherein the second environmental estimation area in which the second object is expected is defined, considering a current signal state of the light signal system represented by the first object and depending on a specific signal state subsequent thereto, which is represented by the second object.

7. The method according to claim 1, further comprising: deleting the first object having the second identifier when the second object is determined in a defined environmental estimation area with respect to the first object.

8. The method according to claim 1, further comprising the following step: saving the second object having a first identifier when the first object having the second identifier is deleted.

9. The method according to claim 1, further comprising: considering the saved object having the first identifier or the second identifier, in a further data evaluation.

10. The method according to claim 1, further comprising: determining the object representing the signal state of the light signal system within a defined environmental estimation area when the first object having the second identifier is saved.

11. A device configured to determine a signal state of a light signal system having several light signal emitters, wherein the light signal system has several signal states and a signal state is formed by one or more activated light signal emitters, the device configured to: determine an object representing the signal state of the light signal system; save a determined first object having a first identifier when, in a first analysis cycle, it is detected that the first object represents the signal state of the light signal system; change an identifier of the saved first object from the first identifier to a second identifier when the first object is no longer detected in a subsequent analysis cycle; delete the saved first object having the second identifier, when a second object is determined in an analysis cycle, which represents a different signal state of the light signal system.

12. A non-transitory computer-readable medium on which is stored a computer program for determining a signal state of a light signal system having several light signal emitters, wherein the light signal system comprises several signal states and a signal state is formed by one or more activated light signal emitters, the computer program, when executed by a computer, causing the computer to perform the following steps: determining an object representing the signal state of the light signal system; saving a determined first object having a first identifier when, in a first analysis cycle, it is detected that the first object represents the signal state of the light signal system; changing the identifier of the saved first object from the first identifier to a second identifier when the first object is no longer detected in a subsequent analysis cycle; and deleting the saved first object having the second identifier, when a second object is determined in an analysis cycle, which represents a different signal state of the light signal system.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] FIG. 1 shows a schematic representation of an example configuration of the present invention.

[0041] FIG. 2 shows a representation of the method steps of one example embodiment of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0042] FIG. 1 shows a schematic representation of a first embodiment of the present invention. In this case, a motor vehicle 1 is shown in surrounding area 10. The motor vehicle 1 has a video system 2. By means of the video system 2, image data of the area surrounding the motor vehicle 1 are recorded. This image data are evaluated by an evaluation device 3 by means of an evaluation software. In this case, signals are generated and forwarded to the driving assistance system 4. For example, the driving assistance system 4 may execute automated driving maneuvers, for example, automated braking or automated start-up. Also, if necessary, the driving assistance system 4 may communicate specific information to the driver. Further, a device 5 for determining a signal state of a light signal system having several light signal emitters can be configured as a stand-alone device. However, this device 5 can also be integrated into the evaluation device 3. Of course, integration directly into the video system 2 or into the driving assistance system 4 is also possible. Further, a digital memory 6 located in the motor vehicle 1 is shown. Detected objects are saved in the digital memory for a limited time. Additional information regarding the objects can also be saved herein, for example, whether an object is labelled (i.e. defined or identified) as “recognized” or as “estimated”.

[0043] Further, a light signal system 11 (e.g., a light signal system or traffic light) is shown in the surrounding area 10 of the motor vehicle 1. The light signal system 11 comprises three light signal emitters 12a, 12b, 12c. The upper light signal emitter 12a is a red light. The center light signal emitter 12b is a yellow light. The lower light signal emitter 12c is a green light. These light signal emitters 12a, 12b, 12c represent a defined signal state of the light signal system 11 when activated. Mostly four signal states (short: states) are defined. An activated light signal emitter 12c (green light) describes the state “traffic is allowed”. An activated light signal emitter 12b (yellow light) describes the state “wait in front of the intersection for the next signal”. An activated light signal emitter 12a (red light) describes the state “stop in front of the intersection”. Parallelly activated light emitters 12a and 12b (red and yellow lights) describe the state “prepare for onward driving”.

[0044] In FIG. 2 a representation of the method steps of an embodiment of the invention is shown. In this case, in a first step S1, the method is started. In a next step S2, the recording of the area surrounding the motor vehicle is carried out by means of a video camera—and thus at the same time the generation of video images as a starting point for the subsequent analysis.

[0045] In this case, using condition B1 it is checked whether a relevant object in a video image is identified. A relevant object is in particular an object that represents a signal state of a light signal system. For example, an activated red light of a traffic light detected in the video image may be such an object.

[0046] If the condition B1 is satisfied (Y branch), i.e., if a relevant object is determined in the data, a condition B2 or B4 is checked. The conditions B2 and B3 as well as the method step S3 are shown by dashed lines in the figure. This means that these are optional embodiment possibilities. If, on the other hand, the condition B1 is not satisfied (N branch), another condition B5 is checked.

[0047] By means of condition B2, it is checked whether an (for example, previously detected) object is already saved in a (for example, vehicle-internal) memory. If this condition B2 is not satisfied (N branch), the detected object is written to the memory in a next step S3, i.e., digitally saved. Further, the object receives a defined first identifier in the memory. By means of this defined first identifier, the information is saved that the object was actually detected in the last measurement cycle. In contrast to this, the information is saved by means of a defined second identifier that the object was detected in a previous measurement cycle, but was no longer detected in the last measurement cycle—and therefore its actual presence in the area surrounding the motor vehicle is only estimated.

[0048] If the condition B2 is satisfied (Y branch), i.e., if an object is already saved in the memory, a further condition B3 is checked whether the object detected in the current video image is identical to an object saved in the memory, to the extent that the saved object comprises the defined first identifier. If this is the case (Y branch), the object is kept in the memory and continues to retain the described first identifier. However, if this is not the case (N branch), i.e., if the detected object does not match a saved object having the first identifier (or if no object having a first identifier is saved in the memory), a condition B4 is checked whether the object detected in the current video image is identical to an object saved in the memory, to the extent that the saved object comprises the defined second identifier. If this is the case (Y branch), the object is kept in the memory and receives the defined first identifier again, because it has now been detected again. However, if this is not the case (N branch), i.e., if the detected object does not match a saved object having the second identifier, in a method step S7, the object saved in the memory is deleted to the extent that it bears the second identifier. That is, an object saved in the memory is not deleted if it bears the first identifier.

[0049] In a further method step S8, the newly detected object is saved in the memory together with the defined first identifier.

[0050] By means of condition B5, it is checked whether an object, which bears the defined first identifier, is already saved in the memory of the motor vehicle. If this is the case (Y branch), in a method step S4, the saved object is kept in the memory, but the identifier of the object is changed from the defined first identifier to a defined second identifier. In this way, the information is recorded that the previously detected object was no longer detected in the last measurement cycle. In a further method step S5, a definition of an environmental estimation area (so-called “predictor”) can be performed, in which a possible new detection in a next measurement cycle would be possible.

[0051] If, however, the condition B5 is not satisfied (N branch), a further condition B6 is checked whether an object is already saved in the memory of the motor vehicle, which bears the defined second identifier. If this is the case (Y branch), a counter is changed in a method step S6, which detects how often or how long the object once previously detected has not been detected any longer. Further, in this step, a further change of the environmental estimation area can be performed, in which a possible new detection in a next measurement cycle would be possible.

[0052] In a condition B7, it is checked whether a threshold value regarding the non-detected object is exceeded. In particular, whether a counter of allowed non-detection cycles has expired. If this is the case (Y branch), in a method step S7, the object saved in the memory with the second identifier is deleted.

[0053] In a condition B8, it is checked whether a termination criterion of the method is satisfied. If this is the case (Y branch), the method is ended in a method step S9.