JP2015055966A - Rear lateral side alarm device for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rear lateral side alarm device for vehicles capable of preventing intermission of an alarm due to interruption of a detection state of a vehicle.SOLUTION: A vehicle rear lateral side alarm device 1 includes: a ranging sensor 10 for detecting a distance to another vehicle present at a rear lateral side of a self vehicle; a relative speed detection part 20 for detecting a speed of the other vehicle relative to the self vehicle; an escape time calculation part 22 that calculates an alarm object area escape time T required for the other vehicle to escape the alarm object area on the basis of respective detection results of the ranging sensor 10 and the relative speed detection part 20; and an alarm output part 30 that continuously outputs a prescribed alarm from when the other vehicle enters the alarm object area till when the alarm object area escape time T elapses.

Description

  The present invention relates to a vehicle rear side warning device that issues a warning when another vehicle approaches from the rear side of a running vehicle.

  Conventionally, other vehicles approaching from the rear side of the vehicle are detected by the distance measuring sensor, the vehicle speed is within a predetermined range, and within a predetermined time after the right-left turn movement is detected, and the rear side There is known a vehicular alarm device that issues an alarm when the distance to another vehicle is within an alarm distance (see, for example, Patent Document 1).

JP 2004-224254 A

  Incidentally, as a distance measuring sensor included in the vehicle alarm device disclosed in Patent Document 1 described above, a vehicle is detected based on an image captured by a camera, in addition to using a sensor such as a laser beam system or a radio wave system. There are cases. However, when a camera is used, there are the following problems.

  In general, when a vehicle is detected using an image captured by a camera, pattern recognition processing is performed on the obtained image to extract features such as a headlight on the front of the vehicle, a front grille, and wheels on the side. Vehicle identification and detection. Therefore, when a situation in which some of these characteristic portions are missing occurs due to a change in the angle of the vehicle included in the image, a vehicle traveling on the rear side of the own vehicle is not temporarily detected. Thus, the alarm lost state in which the alarm output temporarily stops occurs. In addition, even when reflected light from another vehicle or object is temporarily incident on the camera, a state in which the vehicle cannot be detected by the pattern recognition process temporarily occurs, and a similar temporary alarm loss occurs. It is not desirable for the alarm to be interrupted when the detection state of the vehicle is interrupted.

  In addition, such a phenomenon becomes remarkable when detecting the vehicle using the image of the camera, but it is the same when detecting the vehicle with other sensors such as other laser beams, such as the sensor mounting position. When a situation occurs in which the vehicle cannot be detected temporarily due to the above, a similar problem occurs.

  The present invention has been created in view of the above points, and an object of the present invention is to provide a vehicle rear side alarm device that can prevent an alarm from being interrupted due to an interruption of a vehicle detection state. There is to do.

  In order to solve the above-described problems, a vehicle rear side alarm device according to the present invention includes a distance measuring sensor that detects a distance to another vehicle existing behind the host vehicle, and other vehicles with respect to the host vehicle. Relative speed detection means for detecting the relative speed, and escape to calculate the alarm target area exit time required for another vehicle to exit the alarm target area based on the detection results of the distance measuring sensor and the relative speed detection means Time calculating means and alarm means for continuously outputting a predetermined alarm until the alarm target area exit time elapses after another vehicle enters the alarm target area.

  When another vehicle approaches the rear side of the host vehicle and enters the target area for warning, the time until it leaves this area is predicted and the alarm is output continuously. Even if the operation is interrupted, it is possible to prevent the alarm from being interrupted.

  In addition, the distance measuring sensor described above determines the presence or absence of other vehicles included in this image based on a camera that captures the rear side of the host vehicle including the alarm target area and an image obtained by imaging with the camera. And an image processing means for specifying a distance to the other vehicle when another vehicle is included. Further, the image processing means described above performs detection of another vehicle and identification of the distance to the other vehicle by extracting a characteristic image peculiar to the vehicle from images obtained by imaging with a camera. Yes. Thereby, even if the other vehicle based on the captured image of the camera cannot be temporarily detected due to the direction of the other vehicle, the reflected light, or the like, it is possible to reliably prevent the alarm from being interrupted. it can.

  Further, when it is confirmed that another vehicle is traveling in the alarm target area when the alarm target area escape time has elapsed based on the detection result of the distance measuring sensor described above, the escape time calculating means It is desirable that the area escape time is calculated again, and the alarm means continues to output the alarm until the recalculated alarm target area escape time elapses. As a result, even if the speed of the other vehicle slows down and the alarm target area escape time elapses, the alarm output can be continued even when the other vehicle is traveling in the alarm target area. It becomes.

  Further, the alarm means described above is based on the detection result of the distance measuring sensor, and when it is confirmed that there is no other vehicle in the alarm target area for a predetermined time or longer, before the alarm target area escape time elapses. It is desirable to stop the alarm output. As a result, it became clear that there was no other vehicle in the alarm target area before the alarm target area escape time elapses due to the speed of other vehicles increasing or leaving the other driving lane. In such a case, it is possible to stop outputting unnecessary alarms.

It is a figure which shows the structure of the vehicle rear side warning apparatus of one Embodiment. It is a figure which shows the relationship between the own vehicle, the installation position of a camera, and a warning object area | region. It is explanatory drawing which shows the calculation method of warning object area | region escape time T. FIG. It is a flowchart which shows the operation | movement procedure which gives an alarm when another vehicle approaches the own vehicle from the left and right rear sides. It is a flowchart which shows the operation | movement procedure of the modification which alerts when another vehicle approaches. It is a flowchart which shows the operation | movement procedure of the other modification which alerts when another vehicle approaches.

  Hereinafter, a vehicle rear side alarm device according to an embodiment to which the present invention is applied will be described with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a vehicle rear side alarm device according to an embodiment. As shown in FIG. 1, the vehicle rear side warning device 1 of this embodiment includes a distance measuring sensor 10, a relative speed detection unit 20, an escape time calculation unit 22, and a warning output unit 30. The vehicle rear side warning device 1 is installed in a vehicle and operates when a predetermined range on the left and right rear side that is a blind spot of the driver is set as a warning target region and another vehicle enters the warning target region. Alert the person.

  The distance measuring sensor 10 detects a distance to another vehicle existing behind the host vehicle. This distance measuring sensor 10 is based on the right camera 12 and the left camera 14 that image the rear side of the host vehicle including the alarm target area, and the image obtained by the imaging by the right camera 12 and the left camera 14. And an image processing unit 16 for determining the distance to the other vehicle when the other vehicle is included.

  FIG. 2 is a diagram illustrating the relationship between the host vehicle, the camera installation position, and the alarm target area. As shown in FIG. 2, the right camera 12 is attached to the right side surface (for example, the lower portion of the right door mirror) of the host vehicle G, and the left camera 14 is attached to the left side surface (for example, the lower portion of the left door mirror). The right alarm target area SR is set to the lane adjacent to the right side of the lane in which the host vehicle G is traveling, the same horizontal position as the B pillar of the host vehicle and a position behind the predetermined distance W. . The direction of the right camera 12 is set so that almost the entire right alarm target area SR is included in the visual field range. Similarly, the left alarm target area SL is set to the lane adjacent to the left side of the lane in which the host vehicle G is traveling, the same horizontal position as the B pillar of the host vehicle, and a position behind the predetermined distance W. Yes. The direction of the left camera 14 is set so that almost the entire left alarm target area SL is included in the visual field range.

  The image processing unit 16 extracts characteristic images peculiar to the vehicle from images obtained by imaging with the right camera 12 and the left camera 14 respectively, thereby detecting other vehicles and detecting other vehicles. Specify the distance. For example, images such as headlights on the front surface of the vehicle, front grille, and wheels on the side surfaces are extracted as characteristic portions by pattern recognition processing, and identification and detection of the vehicle and identification of the distance to the vehicle (vehicle position) are performed.

  The relative speed detector 20 detects the relative speed of another vehicle with respect to the host vehicle. Since the position of the other vehicle is specified by the image processing unit 16, the relative speed v of the other vehicle can be determined by observing the position of the other vehicle corresponding to each of the images captured at predetermined intervals. It becomes possible to detect. The detection of the relative speed v is performed before another vehicle enters the right alarm target area SR or the left alarm target area SL and is continued until the vehicle departs from the right alarm target area SR or the left alarm target area SL. The

  The escape time calculation unit 22 is based on the detection results of the distance measurement sensor 10 and the relative speed detection unit 20, and the alarm target region required for another vehicle to escape from the right alarm target region SR or the left alarm target region SL. The escape time T is calculated.

FIG. 3 is an explanatory diagram showing a method of calculating the alarm target region escape time T. In the example shown in FIG. 3, it is assumed that another vehicle H traveling in the lane on the right side of the traveling lane of the host vehicle G approaches from the rear and enters the right alarm target region SR at a relative speed v. The length of the right alarm target area SR is W. Assuming that the other vehicle H travels while maintaining the speed as it is, the alarm target region exit time T from entering the right alarm target region SR to leaving is:
T = W / v (1)
Can be calculated.

In addition, when the time from when the front end of another vehicle H enters the right alarm target region SR until the rear end leaves is the alarm target region exit time T, the approximate length of the vehicle is L. Then
T = (W + L) / v (2)
Can be calculated.

  The alarm output unit 30 continuously outputs a predetermined alarm until another alarm target area exit time T elapses after another vehicle enters the alarm target area. For example, the warning output unit 30 outputs a warning sound and displays a predetermined warning image indicating the direction in which another vehicle has approached.

  The relative speed detection unit 20 described above corresponds to the relative speed detection unit, the escape time calculation unit 22 corresponds to the escape time calculation unit, the alarm output unit 30 corresponds to the alarm unit, and the image processing unit 16 corresponds to the image processing unit.

  The vehicle rear side warning device 1 of this embodiment has such a configuration, and the operation thereof will be described next. FIG. 4 is a flowchart showing an operation procedure for issuing an alarm when another vehicle approaches the host vehicle G from the left and right rear sides.

  The relative speed detection unit 20 determines whether another vehicle has entered one of the right alarm target area SR and the left alarm target area SL based on the detection result of the distance measuring sensor 10 output at predetermined time intervals. Is determined (step 100). If the vehicle has not entered, a negative determination is made and this determination is repeated.

  Further, when another vehicle enters the right alarm target area SR or the left alarm target area SL from behind, an affirmative determination is made in the determination of step 100. Next, the relative speed detection unit 20 calculates the relative speed v of the entering vehicle with respect to the host vehicle based on the position of another vehicle output from the distance measuring sensor 10 at predetermined time intervals (step 102). . The escape time calculation unit 22 substitutes this relative speed v into the equation (1) or (2), and the time from when another vehicle enters the right alarm target region SR or the left alarm target region SL until it escapes. An alarm target area escape time T is calculated (step 104).

  Next, the warning output unit 20 outputs a warning notifying that another vehicle is approaching (step 106). In the above description, the alarm operation of step 106 is performed after the operation of step 104. However, actually, another vehicle has entered the right alarm target region SR or the left alarm target region SL. Since it is desirable to output an alarm when it is found, it is necessary to perform an alarm operation in step 106 in parallel with the operations in steps 102 and 104 after an affirmative determination is made in the determination in step 100.

  Next, the alarm output unit 30 determines whether or not the alarm target area escape time T has elapsed since the alarm output was started (step 108). If the time T has not elapsed, a negative determination is made, and the process returns to step 106 to continue the alarm output operation. If the time T has elapsed, an affirmative determination is made in the determination of step 108, and the alarm output unit 30 ends the alarm output operation (step 110). Thereafter, the process returns to step 100 and the operations after the entry determination of another vehicle are repeated.

  Thus, in the vehicle rear side warning device 1 of the present embodiment, when another vehicle approaches the rear side of the host vehicle and enters the right warning target area SR or the left warning target area SL, these Since it continues to output a warning by predicting the time until it leaves the area, even if the detection state of the vehicle by the distance measuring sensor 10 is interrupted, it is possible to prevent the warning from being interrupted.

  In particular, the distance measuring sensor 10 includes a right camera 12, a left camera 14, and an image processing unit 16, and detects other vehicles by image processing. Therefore, the direction and reflection of other vehicles are detected. Depending on the state of light or the like, there may occur a case where another vehicle cannot be detected temporarily based on the image captured by the right camera 12 or the left camera 14, but even in such a case, it is certain that the alarm is intermittent. Can be prevented.

  In addition, this invention is not limited to the said embodiment, A various deformation | transformation implementation is possible within the range of the summary of this invention. For example, in the above-described embodiment, the alarm target region escape time T is calculated on the assumption that other vehicles that have entered the right alarm target region SR or the left alarm target region SL at the relative speed v travel while maintaining the same relative speed. However, in practice, the relative speed v changes with time. Therefore, it is desirable to adjust the alarm output time according to the change in the relative speed v.

  FIG. 5 is a flowchart showing an operation procedure of a modified example in which an alarm is issued when another vehicle approaches. This operation procedure is different from the operation procedure shown in FIG. 4 in that an operation of Step 120 is added between Step 108 and Step 110. After the alarm target region escape time T has elapsed after the start of alarm output and an affirmative determination is made in the determination of step 108, the relative speed detector 20 determines that the other vehicle is on the right side based on the detection result of the distance measuring sensor 10. It is determined whether the vehicle is traveling in the alarm target area SR or the left alarm target area SL (step 120). When another vehicle slows down, it may remain in the right alarm target area SR or the left alarm target area SL even if the alarm target area escape time T elapses. It is necessary to maintain the alarm output. In this case, an affirmative determination is made in the determination of step 120, and the process returns to step 102 and the operations after the calculation of the relative speed v of the other vehicle are repeated. In the operation of Step 104 to be performed next, instead of calculating the alarm target region exit time T from when another vehicle enters the right alarm target region SR or the left alarm target region SL until it escapes, The operation of calculating the alarm target region exit time T until the vehicle exits the right alarm target region SR or the left alarm target region SL from the current position is performed. On the other hand, when the other vehicle is not traveling in the right alarm target area SR or the left alarm target area SL, a negative determination is made in the determination of step 120, and the process proceeds to step 110 to end the alarm output operation. .

  Thus, based on the detection result of the distance measuring sensor 10, it is confirmed that another vehicle is traveling in the right alarm target area SR or the left alarm target area SL when the alarm target area escape time T elapses. The alarm target area escape time T is calculated again, and the alarm output is continued until the alarm target area escape time T calculated again passes. As a result, even if the speed of the other vehicle slows down and the alarm target area escape time T elapses, the alarm output can be continued even when the other vehicle is traveling in the alarm target area. It becomes possible.

  FIG. 6 is a flowchart showing the operation procedure of another modified example in which an alarm is issued when another vehicle approaches. The operation procedure shown in FIG. 4 is different in that the operation of step 130 is added between step 108 and step 106. After the alarm output is started and the alarm target area escape time T has not elapsed yet, and a negative determination is made in the determination in step 108, the alarm output unit 30 determines whether or not the other detected vehicle has disappeared for a predetermined time. Is determined (step 130). When another vehicle is detected based on an image captured by the camera, even if the other vehicle actually travels within the imaging range, this vehicle is very short due to the direction of the vehicle, reflection of light, etc. It seems that the disappearance of is relatively easy. Therefore, the vehicle has actually escaped from the right alarm target region SR or the left alarm target region SL by confirming that the vehicle has disappeared for a predetermined time or more, rather than the disappearance of the vehicle in such a short time. It becomes possible to know. The length of the predetermined time is determined by measuring the time when the vehicle disappears in spite of the vehicle traveling in the right alarm target area SR or the left alarm target area SL. A longer value may be set.

  If the other vehicle has not disappeared for a predetermined time (if it has not disappeared at all or if it has disappeared but does not reach the predetermined time), a negative determination is made in the determination of step 130, and the process returns to step 106 to output an alarm. Operation continues. If another vehicle has disappeared for a predetermined time, an affirmative determination is made in the determination of step 130, and the process immediately proceeds to step 110 to end the alarm output operation.

  As described above, when it is confirmed that there is no other vehicle in the right alarm target area SR or the left alarm target area SL for a predetermined time or longer based on the detection result of the distance measuring sensor 10, the alarm target area escapes. Even before the time T elapses, the alarm output is stopped. As a result, there is no other vehicle in the alarm target area before the alarm target area exit time T elapses due to the speed of the other vehicle increasing or the other vehicle leaving the other driving lane. When it becomes clear, unnecessary alarm output can be stopped. Note that the operation of step 130 described above may be added between step 108 and step 106 in the flowchart shown in FIG.

  In the above-described embodiment, the distance measuring sensor 10 is configured using the right camera 12, the left camera 14, and the image processing unit 16. However, the distance measuring sensor is configured using a sensor such as a laser beam method or a radio wave method. You may do it.

  Further, in the above-described embodiment, the case where another vehicle enters the right alarm target area SR or the left alarm target area SL from behind is described, but also when another lane enters from the side of these areas. The present invention can be applied. In this case, since the approach point of another vehicle is not the tail of the right alarm target area SR or the left alarm target area SL shown in FIG. The timing to do this may be the time when another vehicle enters these areas. Even in this case, the calculation of the relative speed v and the calculation of the alarm target area escape time T are performed at the end of the right alarm target area SR or the left alarm target area SL (in practice, in the traveling lane of the host vehicle). On the other hand, in the two adjacent driving lanes, the position at which this tail is extended may be used as a reference.

  As described above, according to the present invention, when another vehicle approaches the rear side of the host vehicle and enters the warning target area, a warning is output by predicting the time until the vehicle leaves the area. Therefore, even if the detection state of the vehicle by the distance measuring sensor is interrupted, it is possible to prevent the alarm from being interrupted.

DESCRIPTION OF SYMBOLS 1 Vehicle rear side warning apparatus 10 Distance sensor 12 Right camera 14 Left camera 16 Image processing part 20 Relative speed detection part 22 Escape time calculation part 30 Alarm output part

Claims (5)

A distance measuring sensor that detects the distance to the other vehicle located behind the host vehicle;
A relative speed detecting means for detecting a relative speed of the other vehicle with respect to the own vehicle;
An escape time calculating means for calculating an alarm target area exit time required until the other vehicle exits the alarm target area based on detection results of the distance measuring sensor and the relative speed detection means;
Alarm means for continuously outputting a predetermined alarm until the alarm target area exit time elapses after the other vehicle enters the alarm target area;
A vehicle rear side warning device comprising: In claim 1,
The distance measuring sensor is
A camera for imaging the rear side of the host vehicle including the warning target area;
Based on the image obtained by imaging with the camera, the presence or absence of the other vehicle included in the image is determined, and the distance to the other vehicle is specified when the other vehicle is included. Image processing means;
A vehicle rear side warning device comprising: In claim 2,
The image processing means performs detection of the other vehicle and specification of a distance to the other vehicle by extracting a characteristic image specific to the vehicle from images obtained by imaging with the camera. A vehicle rear side warning device characterized by the above. In any one of Claims 1-3,
Based on the detection result of the distance measuring sensor, when it is confirmed that the other vehicle is traveling in the alarm target area when the alarm target area escape time has elapsed, the escape time calculating means The vehicle rear side warning device, wherein the alarm target area escape time is calculated again, and the warning means continues outputting the alarm until the recalculated alarm target area escape time elapses. In any one of Claims 1-4,
The alarm means escape time elapses when the alarm means confirms that there is no other vehicle in the alarm target area for a predetermined time or longer based on the detection result of the distance measuring sensor. A vehicle rear side warning device characterized by stopping output of a warning before.

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