JP6081250B2 - Driving support apparatus and control method for driving support processing - Google Patents

Description

  The present invention relates to a driving support apparatus that detects the approach of a three-dimensional object existing in the vicinity of a host vehicle and executes driving support processing, and a control method for driving support processing.

  In recent years, the development of systems for safe driving of vehicles has become active. As one of the developed technologies, a system for detecting a three-dimensional object (another vehicle, a pedestrian, etc.) around the host vehicle and notifying the driver is provided. Furthermore, a system for generating a warning by detecting a three-dimensional object approaching the host vehicle is also provided.

  As a technique for detecting a three-dimensional object around the host vehicle, there are many techniques that use an image obtained from a vehicle-mounted camera (for example, see Patent Documents 1 and 2). For example, there is a known system in which a rear camera equipped with a super-wide-angle lens such as a fisheye lens is used to capture a wide area behind the vehicle, and the captured image is analyzed to detect a three-dimensional object around the host vehicle and recognize the driver. It has been.

  In Patent Documents 1 and 2, a difference between two photographed images with different photographing times is taken, and a portion having a large difference value is detected as a three-dimensional object. Among these, in the technique described in Patent Document 1, a single camera captures peripheral images at different first and second points as first and second images that are time-sequentially parallaxed. . And the 4th image which carried out the projective transformation of the 1st image to the 2nd point is generated, and a solid thing is detected by the difference of the 4th image and the 2nd image. In the technique described in Patent Document 1, shooting is started when the vehicle moves backward.

  In the technique described in Patent Document 2, a solid object is detected from a difference between two captured images having different capturing times, and then an approach determination is performed using a density map. Specifically, each time the latest density map is created, the position of the latest three-dimensional object is detected and recorded as a history of the target to be tracked in a state associated with the detection time. Then, based on the recorded history of the target, the movement trajectory of the target is estimated, and it is determined whether or not the target corresponding to the movement trajectory is an approaching object.

  FIG. 3 is a diagram illustrating an example of a scene in which an alarm is generated by detecting a three-dimensional object approaching the host vehicle by analyzing an image behind the vehicle photographed by a rear camera. The example of FIG. 3 shows a scene where the host vehicle 100 moves backward in the parking lot. The other vehicle 200 parked exists behind the host vehicle 100, and the other vehicle 300 approaching the host vehicle 100 exists behind the right side of the host vehicle 100.

  Here, the parked vehicle 200 behind the host vehicle 100 approaches the host vehicle 100 when the host vehicle 100 moves backward, but since it is a parked vehicle, it is not necessary to generate an alarm. On the other hand, the approaching vehicle 300 located on the right rear side of the host vehicle 100 gradually approaches the host vehicle 100, and therefore it is necessary to generate an alarm as early as possible.

  FIG. 4 is a diagram schematically showing an image taken by the rear camera in the situation shown in FIG. In FIG. 4, three photographed images photographed by the rear camera while the host vehicle 100 is moving backward are shown in time series. The image 200 ′ of the parked vehicle 200 behind the host vehicle 100 moves outward from the center of the image along the time series as shown in FIGS. 4 (a) → (b) → (c). On the other hand, the image 300 ′ of the approaching vehicle 300 on the right rear side of the host vehicle 100 moves from the outside of the image toward the center along the time series as shown in FIGS. 4 (a) → (b) → (c). Yes.

  Using this property, when the three-dimensional object detected from the photographed image taken at each photographing time is moving from the outside of the image toward the center along the time series, the three-dimensional object is the host vehicle 100. It is determined that it is approaching. In this way, while the parked vehicle 200 that is actually approaching due to the backward movement of the host vehicle 100 is excluded from the alarm target, only the approaching vehicle 300 that is actually approaching from the right rear is the target of the alarm. Is possible.

Japanese Patent No. 3494434 JP 2012-174180 A

  However, as shown in FIG. 5, in a scene where forward and backward are repeated during parking, the vehicle is moving forward by inertia even if the gear shift is in the reverse position by switching the gear shift to the reverse position after moving forward. Sometimes. In such a case, as shown in FIG. 6, the image 200 ′ of the parked vehicle 200 behind the host vehicle 100 moves from the outside of the image toward the center along the time series, and thus approaches the host vehicle 100. There arises a problem that it is determined that the alarm has occurred and a false alarm is generated.

  The present invention has been made to solve such a problem, and a three-dimensional object is detected when a three-dimensional object detected from within a captured image is moving in time series from the outside of the image toward the center. When it is determined that the vehicle is approaching the host vehicle and an alarm is generated, an object of the present invention is to prevent a false alarm from occurring in a scene in which forward and backward are repeated during parking.

  In order to solve the above-described problems, in the present invention, when a three-dimensional object detected from a captured image is moving in time series from the outside of the image toward the center, the three-dimensional object approaches the host vehicle. If the vehicle speed is determined to be greater than the predetermined speed when it is detected that the gear shift of the vehicle is switched to the reverse position when executing the predetermined driving support process, Execution of processing is stopped.

  As described above, when the gear shift is switched to the reverse position and the vehicle speed is greater than the predetermined speed, the gear shift is switched to the reverse position while the vehicle is moving forward. It can be determined that the vehicle is moving forward due to inertia. In this case, since the three-dimensional object detected from the captured image moves from the outside of the image toward the center along the time series, it is erroneously determined that the three-dimensional object is approaching the host vehicle. Execution is stopped. Thereby, generation | occurrence | production of the unnecessary driving assistance process called a false alarm can be prevented.

It is a block diagram which shows the function structural example of the solid-object detection apparatus by this embodiment. It is a flowchart which shows the operation example of the driving assistance device by this embodiment. It is a figure which shows an example of the scene which detects the solid object which approaches the own vehicle, and generate | occur | produces an alarm. It is a figure which shows typically the image image | photographed with the rear camera in the situation shown in FIG. It is a figure for demonstrating the conventional problem. It is a figure for demonstrating the conventional problem.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram illustrating a functional configuration example of the driving support device 10 according to the present embodiment. As shown in FIG. 1, the driving support apparatus 10 of the present embodiment includes an image buffer 11, a predicted image generation unit 12, a movement amount calculation unit 13, a three-dimensional object detection unit 14, an approach determination unit 15, an alarm as its functional configuration. A generation unit 16, a vehicle speed determination unit 17, and a shift position detection unit 18 are provided. In addition, the driving support device 10 of the present embodiment is connected to the rear camera 20.

  Each function of the predicted image generation unit 12, the movement amount calculation unit 13, the three-dimensional object detection unit 14, the approach determination unit 15, the alarm generation unit 16, the vehicle speed determination unit 17, and the shift position detection unit 18 includes hardware, DSP (Digital (Signal Processor) and software can be used. For example, when configured by software, each of the functions 12 to 18 is actually configured by including a CPU, RAM, ROM, etc. of a computer, and a program stored in a recording medium such as RAM, ROM, hard disk, or semiconductor memory is stored. Realized by operating.

  The rear camera 20 includes a super wide-angle lens such as a fisheye lens, and captures a wide area of the area behind the host vehicle. Since a fisheye lens is used, the image captured by the rear camera 20 is a circular distortion around the imaging range.

  The image buffer 11 inputs a photographed image of the rear camera 20 and temporarily stores it for one frame period. The predicted image generation unit 12 converts the captured image of the rear camera 20 at the first capturing time stored in the image buffer 11 into a predicted image at a second capturing time after the first capturing time. Here, the first shooting time and the second shooting time are, for example, shooting times of two consecutive frames.

  In other words, the predicted image generation unit 12 predicts what kind of image the frame image captured at the first imaging time will change at the second imaging time after one frame time. Note that the time interval between the first shooting time and the second shooting time is not necessarily one frame interval. That is, the frame interval may be n (n is an integer of 2 or more). In this case, the image buffer 11 temporarily stores the captured image input from the rear camera 20 for an n frame period.

  As a specific method for generating a predicted image at the second shooting time from a shot image at the first shooting time, various methods can be applied. For example, the predicted image generation unit 12 converts a captured image at the first shooting time into a predicted image at the second shooting time based on the vehicle movement amount calculated by the movement amount calculation unit 13. Here, the moving amount calculation unit 13 inputs the moving amount of the vehicle in the time interval from the first shooting time to the second shooting time via an in-vehicle network (not shown) such as an in-vehicle LAN. Calculate from pulse.

  Specifically, the predicted image generation unit 12 sets the second object after one frame of the object in the captured image obtained during the first imaging time based on the vehicle movement amount calculated by the movement amount calculation unit 13. The position and size that would have moved during the shooting time are calculated. Then, an image in which an object is drawn according to the calculated position and size is generated as a predicted image at the second shooting time.

  Alternatively, the predicted image generation unit 12 can also convert the captured image at the first imaging time into the predicted image at the second imaging time as follows. That is, the predicted image generation unit 12 calculates the amount of change between the captured image obtained at the photographing time one frame before the first photographing time and the photographed image obtained at the first photographing time. . Then, by applying the calculated image change amount to the captured image obtained at the first imaging time, a predicted image at the second imaging time is generated.

  The three-dimensional object detection unit 14 is generated by the predicted image generation unit 12 from the captured image at the second imaging time input from the rear camera 20 and the captured image at the first imaging time stored in the image buffer 11. A difference from the predicted image at the shooting time of 2 is detected. And the area | region where the difference more than a fixed amount exists is detected as a solid object.

  The approach determination unit 15 determines whether or not the three-dimensional object detected by the three-dimensional object detection unit 14 is approaching the host vehicle. In the present embodiment, as described in FIG. 4, the approach determination unit 15 moves the solid object detected from the captured image by the three-dimensional object detection unit 14 from the outside of the image toward the center along the time series. It is determined that the three-dimensional object is approaching the host vehicle.

  The alarm generation unit 16 generates an alarm when the approach determination unit 15 determines that the three-dimensional object is approaching the host vehicle. The alarm may be performed by sounding an alarm sound or by displaying a frame on the approaching solid object on the display screen.

  The vehicle speed determination unit 17 detects the vehicle speed based on the vehicle speed pulse input via the in-vehicle network, and determines whether or not the detected vehicle speed is greater than a predetermined speed (for example, 1 km / h). The shift position detector 18 determines whether or not the gear shift of the host vehicle has been switched to the reverse position based on the shift position information input via the in-vehicle network. The shift position detector 18 also determines whether or not the gear shift is within a predetermined time (for example, 2 seconds) after the gear shift is switched to the reverse position.

  The alarm generation unit 16 described above, when the shift position detection unit 18 detects that the vehicle gear shift is switched to the reverse position, and the vehicle speed determination unit 17 determines that the vehicle speed is greater than the predetermined speed, Stop execution of alarm generation processing.

  If the vehicle speed is higher than the predetermined speed when the gear shift is switched to the reverse position, the gear shift is switched to the reverse position with the host vehicle 100 moving forward as described in FIG. Even if the vehicle enters, the vehicle 100 is moving forward due to inertia. In this case, the image 200 ′ of the parked vehicle 200 detected from the captured image by the three-dimensional object detection unit 14 moves from the outside of the image toward the center along the time series as shown in FIG. 6. Therefore, the approach determination unit 15 determines that the parked vehicle 200 is approaching the host vehicle 100. However, in this case, the execution of the alarm generation process by the alarm generation unit 16 is stopped, so that it is possible to prevent the occurrence of a false alarm related to the approach of the parked vehicle 200 that is not an alarm generation target.

  Further, the alarm generation unit 16 determines that the vehicle speed is not greater than a predetermined speed (for example, 1 km / h) by the vehicle speed determination unit 17 after stopping the execution of the alarm generation process, or the shift position detection unit 18. When it is determined that the vehicle gear shift is not within a predetermined time (for example, 2 seconds) after the vehicle gear shift is input to the reverse position, the alarm generation process is resumed. Here, the execution of the alarm generation process is resumed when it is determined that the vehicle speed is not higher than 1 km / h, but the execution of the alarm generation process is performed when the vehicle speed becomes zero (predetermined speed = 0). May be resumed.

  Here, when the vehicle speed is higher than the predetermined speed when the gear shift is switched to the reverse position, the alarm generation process of the alarm generation unit 16 is stopped. However, the present invention is not limited to this. For example, the approach determination process by the approach determination unit 15 may be stopped. Alternatively, the three-dimensional object detection process by the three-dimensional object detection unit 14 may be stopped.

  FIG. 2 is a flowchart showing an operation example of the driving support apparatus 10 configured as shown in FIG. In FIG. 2, when the vehicle speed is greater than a predetermined speed and the gear shift is within a predetermined time after being input to the reverse position, the processing by the three-dimensional object detection unit 14, the approach determination unit 15, and the alarm generation unit 16 is performed. An example of stopping is shown. The flowchart shown in FIG. 2 starts when the alarm generation function of the driving support device 10 is activated.

  First, the shift position detection unit 18 determines whether or not the gear shift of the host vehicle is input to the reverse position based on shift position information input via the in-vehicle network (step S1). If the shift position detector 18 determines that the gear shift is not input to the reverse position, the process proceeds to step S7.

  On the other hand, when the shift position detection unit 18 determines that the gear shift is input to the reverse position, the vehicle speed determination unit 17 detects the vehicle speed based on the vehicle speed pulse input via the in-vehicle network, and detects the detected vehicle speed. Is greater than a predetermined speed (1 km / h) (step S2). Here, when the vehicle speed determination unit 17 determines that the vehicle speed is not greater than the predetermined speed, the three-dimensional object detection unit 14, the approach determination unit 15, and the alarm generation unit 16 operate normally (step S3). Thereafter, the process proceeds to step S7.

  On the other hand, when the vehicle speed determination unit 17 determines that the vehicle speed is higher than the predetermined speed in step S2, the shift position detection unit 18 determines whether or not the gear shift is within a predetermined time (2 seconds) after the gear shift is input to the reverse position. Is determined (step S4). Here, when the shift position detection unit 18 determines that the gear shift is not within a predetermined time after being input to the reverse position, the three-dimensional object detection unit 14, the approach determination unit 15, and the alarm generation unit 16 operate as usual (step). S3). Thereafter, the process proceeds to step S7.

  On the other hand, when the shift position detection unit 18 determines that the gear shift is within a predetermined time after the gear shift is input to the reverse position in step S4, the processing of the three-dimensional object detection unit 14, the approach determination unit 15, and the alarm generation unit 16 is performed. Is stopped to suppress the generation of an alarm (step S5).

  Thereafter, the vehicle speed determination unit 17 determines whether or not the vehicle speed is greater than a predetermined speed (1 km / h) (step S6). If the vehicle speed determination unit 17 determines that the vehicle speed is still greater than the predetermined speed, the process returns to step S4. Thus, until it is determined in step S6 that the vehicle speed is not greater than the predetermined speed, or in step S4, it is determined that the vehicle shift is not within a predetermined time after the gear shift is input to the reverse position, the alarm generation is suppressed. Is maintained.

  On the other hand, when the vehicle speed determination unit 17 determines in step S6 that the vehicle speed is not greater than the predetermined speed, that is, the vehicle speed has decreased below the predetermined speed, the process proceeds to step S7. In step S7, the driving assistance device 10 determines whether or not the activation state of the alarm generation function has been canceled. If the activated state of the alarm generation function is not released, the process returns to step S1. On the other hand, when the activation state of the alarm generation function is canceled, the process of the flowchart shown in FIG. 2 ends.

  In the flowchart shown in FIG. 2, the example in which the process returns to step S4 when the vehicle speed determination unit 17 determines that the vehicle speed is higher than the predetermined speed in step S6 has been described, but the present invention is not limited to this. For example, the processing may be returned to step S5, and the alarm generation suppression state may be maintained when the vehicle speed is greater than a predetermined speed regardless of the elapsed time since the gear shift is input to the reverse position.

  As described above in detail, in the present embodiment, the three-dimensional object is approaching the host vehicle when the three-dimensional object detected from the captured image is moving in time series from the outside of the image toward the center. In executing the alarm generation process, when the gear shift is switched to the reverse position and the vehicle speed is determined to be greater than the predetermined speed, the execution of the alarm generation process is stopped. Thereby, in a scene where forward and backward are repeated during parking, it is possible to prevent the occurrence of a false alarm when the gear shift is input to the reverse position and the vehicle is moving forward due to inertia.

  In the above embodiment, an example of processing an image behind the host vehicle photographed by the rear camera 20 has been described. However, an image ahead of the host vehicle photographed by the front camera may be processed. In this case, when the shift position detection unit 18 detects that the gear shift is switched from the reverse position to the drive position, and the vehicle speed determination unit 17 determines that the vehicle speed is greater than the predetermined speed, the driving support process May be stopped.

  Moreover, although the said embodiment demonstrated the example which generate | occur | produces a warning to a driver | operator in the driving assistance apparatus 10, this invention is not limited to this. For example, the present invention can be applied to a collision avoidance system that avoids a collision with a three-dimensional object by automatic braking, an autonomous traveling system that performs automatic steering so as to avoid a three-dimensional object, and the like.

  In addition, each of the above-described embodiments is merely an example of implementation in carrying out the present invention, and the technical scope of the present invention should not be construed in a limited manner. That is, the present invention can be implemented in various forms without departing from the gist or the main features thereof.

DESCRIPTION OF SYMBOLS 10 Driving assistance apparatus 11 Image buffer 12 Prediction image generation part 13 Movement amount calculation part 14 Solid object detection part 15 Approach determination part 16 Alarm generation part 17 Vehicle speed determination part 18 Shift position detection part 20 Rear camera

Claims (9)

A three-dimensional object detection unit that takes a difference between two captured images taken sequentially by a camera mounted on the rear of the vehicle and has a difference of a certain amount or more as a three-dimensional object;
An approach for determining that the three-dimensional object is approaching the host vehicle when the three-dimensional object detected from the photographed image by the three-dimensional object detection unit is moving in time sequence from the outside of the image toward the center. A determination unit;
A driving support unit that executes driving support processing when the approach determination unit determines that the three-dimensional object is approaching the vehicle;
A vehicle speed determination unit that determines whether the speed of the vehicle is greater than a predetermined speed;
A shift position detector for detecting that the gear shift of the vehicle is switched to the reverse position,
The driving support unit determines that the vehicle speed is greater than a predetermined speed by the vehicle speed determination unit when the shift position detection unit detects that the gear shift of the vehicle is switched to the reverse position. In the case, the execution of the driving support process is stopped,
A driving support device characterized by that. The driving support unit starts the driving support process after a predetermined time has elapsed after stopping the execution of the driving support process.
The driving support apparatus according to claim 1. The driving support unit performs the driving support process when the vehicle speed determining unit determines that the vehicle speed is not greater than a predetermined speed within the predetermined time after the execution of the driving support process is stopped. The driving support device according to claim 2, wherein execution of the operation is started. The driving support apparatus according to claim 1, wherein the driving support unit is an alarm generation unit that generates an alarm for a driver. 2. The driving support unit is an autonomous traveling unit that automatically avoids a collision with a three-dimensional object determined to be approaching the vehicle by the approach determination unit by a brake operation or a handle operation. The driving assistance apparatus in any one of -4. A three-dimensional object detection unit that takes a difference between two captured images taken sequentially by a camera mounted in front of the vehicle and has a difference of a certain amount or more as a three-dimensional object;
An approach for determining that the three-dimensional object is approaching the host vehicle when the three-dimensional object detected from the photographed image by the three-dimensional object detection unit is moving in time sequence from the outside of the image toward the center. A determination unit;
A driving support unit that executes driving support processing when the approach determination unit determines that the three-dimensional object is approaching the vehicle;
A vehicle speed determination unit that determines whether the speed of the vehicle is greater than a predetermined speed;
A shift position detection unit that detects that the gear shift of the vehicle is switched to the drive position,
The driving support unit determines that the vehicle speed is greater than a predetermined speed by the vehicle speed determination unit when the shift position detection unit detects that the gear shift of the vehicle is switched to the drive position. In the case, the execution of the driving support process is stopped,
A driving support device characterized by that. A three-dimensional object detection unit that takes a difference between two captured images taken sequentially by a camera mounted on the rear of the vehicle and has a difference of a certain amount or more as a three-dimensional object, Whether or not the three-dimensional object is approaching the host vehicle depends on whether or not the three-dimensional object detected from the captured image by the three-dimensional object detection unit is moving from the outside of the image toward the center in time series. A driving support process in a driving support device comprising: an approach determining unit that determines; and a driving support unit that executes a driving support process when the approach determining unit determines that the three-dimensional object is approaching the vehicle. A control method,
A vehicle speed determination step in which the vehicle speed determination unit of the driving support device determines whether or not the speed of the vehicle is greater than a predetermined speed;
A shift position detecting step for detecting that the gear shift of the vehicle is switched to the reverse position, and the shift position detecting unit of the driving support device;
When the shift position detection unit detects that the vehicle gear shift is switched to the reverse position, and the vehicle speed determination unit determines that the vehicle speed is greater than a predetermined speed, A driving support process stop step for stopping execution;
A control method for driving support processing, comprising: A first driving support process start step for starting the driving support process after a predetermined time has elapsed after stopping the execution of the driving support process;
The control method for driving support processing according to claim 7, further comprising: After the execution of the driving support process is stopped, the driving support process is started when the vehicle speed determination step determines that the vehicle speed is not greater than the predetermined speed within the predetermined time. 2 driving support processing start step;
The driving support processing control method according to claim 8, further comprising:

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