JP2007124097A - Vehicle periphery visual recognition device - Google Patents

Abstract

There is provided a vehicle periphery visual recognition device that allows an occupant to easily grasp an image captured in an oblique direction with respect to a longitudinal direction of a vehicle body. In addition, a vehicle periphery visual recognition device is provided that can reliably notify an occupant of an approaching obstacle with a simple configuration.
An auxiliary line 33 extending from a side end of a vehicle 10 is superimposed on a captured image 31 by an imaging unit 11 directed obliquely with respect to the longitudinal direction of the vehicle body of the vehicle 10 and displayed on a display unit 13. Based on the steering angle detected by the steering angle sensor 15, the entire range of the captured image 31 is switched to the distance measurement target area or only the vehicle 10 side from the auxiliary line 33 is switched to the distance measurement target area. The distance to the imaging target S reflected in the area is calculated by image processing. Based on the calculated distance to the imaging target S, the image processing unit 19A superimposes and displays a warning graphic on the predicted collision portion 61 displayed in the captured video 31, and the warning unit 17 also outputs a warning sound. Sound.
[Selection] Figure 3

Description

  The present invention relates to a vehicle periphery visual recognition device for visually recognizing the periphery of a vehicle so as to prevent the vehicle from colliding with another obstacle.

  2. Description of the Related Art Conventionally, a vehicle periphery visual recognition device that allows a vehicle to be safely operated by imaging a blind spot from a vehicle occupant with a camera device and displaying the image on a display device installed in a vehicle compartment has been put into practical use. .

  For example, as shown in FIG. 8, the camera periphery 8A to 8D has the optical axes of the camera devices 8A to 8D at the front end center portion and rear end center portion of the vehicle 81, and further at the left and right center portions such as door mirrors. 8a to 8d are installed in a direction parallel or perpendicular to the traveling direction of the vehicle.

  Then, by setting the angle of view of each of the camera devices 8A to 8D to a wide angle, an area 82 in the vicinity of the corner of the vehicle is, for example, a camera device 8A installed at the front center and a camera installed at the left center. An image is taken by the apparatus 8C (first prior art).

  In addition to the first prior art described above, the apparatus further includes a clearance sonar (not shown) having a detection range that overlaps the imaging range of the camera devices 8A and 8B, and notifies the occupant of the imaging target approaching the vehicle 81. Has been put into practical use (second prior art).

  In addition, a technique for calculating a distance to an imaging target or the like reflected in a captured image of a camera device by image processing has been proposed (third conventional technique).

  In the prior art as described above, since the area 82 is imaged at the end of the imaging range, it is expected that a vehicle corner camera having the area 82 as the center of the imaging range will be put into practical use in the future.

  However, the vehicle corner camera having the region 82 as the center of the imaging range has its optical axis set at an oblique angle with respect to the traveling direction of the vehicle 81. It is possible to grasp the positional relationship between an obstacle or the like and the vehicle 81, such as being reflected at the end of the imaging range and occupant's illusion as if another vehicle is located on the side of the vehicle 81. Have difficulty. Therefore, it is difficult to grasp the sense of distance between the obstacle and the vehicle 81 and has not yet been put into practical use.

  In addition, as in the second prior art described above, newly providing distance measuring means such as a clearance sonar to the vehicle 81 has a problem of increasing the weight and cost of the vehicle, which reduces the weight and cost of the vehicle. In view of what is desired, the application of the above-described third prior art is expected, but since the image processing is always performed on the entire surface of the captured image, the calculation load is large, and the practical application has not yet been achieved. .

  Therefore, an object of the present invention is to visually recognize the periphery of a vehicle that displays a captured image of a camera installed such that an optical axis of a vehicle corner camera or the like is oblique with respect to the front-rear direction of the vehicle. The object is to provide a device, and further to provide a vehicle periphery visual recognition device that can inform an occupant of an approaching imaging target or the like with a simple configuration.

  In order to solve the above problems, the present invention provides an imaging unit that images a peripheral region of a vehicle, a display unit that is installed in a vehicle interior of the vehicle and displays a captured image captured by the imaging unit, and the display unit A control unit that controls display of the captured image on the camera, and the imaging unit is installed such that an optical axis thereof is oblique with respect to a longitudinal direction of the vehicle body of the vehicle, and at an end of the imaging range. The front and rear direction of the vehicle of the vehicle is imaged, and the control unit includes an image processing unit that superimposes an auxiliary line extending the side end of the vehicle on the captured image and displays the auxiliary line on the display unit. .

  Preferably, the vehicle further includes a steering angle sensor that detects a steering angle of the vehicle, and the control unit includes a distance measuring unit that obtains a distance to an imaging target reflected in the captured image by image processing, The distance measuring unit sets the entire surface of the captured image as a distance measurement target area based on the steering angle detected by the steering angle sensor, or measures only the vehicle side from the auxiliary line in the captured image. The target area is switched, and the distance between the vehicle and the imaging target reflected in the distance measurement target area is calculated.

  More preferably, the image processing unit is displayed on the display unit when the distance between the vehicle and the imaging target calculated by the ranging unit is smaller than a predetermined first threshold value. A warning graphic is superimposed on the imaging target.

  More preferably, the image processing unit changes the warning graphic in accordance with a distance to the imaging target that is closer than the first threshold.

  The control unit further includes a warning unit that sounds a warning sound to the vehicle occupant, and the control unit calculates a distance between the vehicle and the imaging target calculated by the distance measuring unit from a predetermined second threshold value. If it is smaller, a warning sound may be generated from the warning unit.

  Furthermore, the control unit may change the warning sound according to a distance to the imaging target that is closer than the second threshold.

  According to the present invention, the imaging unit can obtain an image centered on the imaging range in the same direction by installing the optical axis in an oblique direction with respect to the longitudinal direction of the vehicle body of the host vehicle. The vehicle front-and-rear direction is imaged at the end of the vehicle, but the auxiliary line extending the side end of the vehicle is superimposed and displayed on the display unit by the image processing unit provided in the control unit. It is possible to easily grasp the positional relationship between the imaging target reflected on the captured image and the host vehicle using the auxiliary line as a guide. In addition, as long as the imaging target displayed on the opposite side of the vehicle with the auxiliary line as a boundary is traveling straight or turning in a direction away from the imaging target, there is no possibility of colliding with the host vehicle. It is possible to drive the vehicle safely by paying attention only to the imaging target displayed on the vehicle side with respect to the auxiliary line.

  Furthermore, if it has a distance measuring unit that obtains the distance to the imaging target reflected in the captured image by image processing, there is no need to provide a clearance sonar separately, which can reduce the weight and cost of the vehicle. It becomes. Further, the vehicle further includes a steering angle sensor that detects the steering angle of the vehicle, and the distance measurement unit sets the entire surface of the captured image as a distance measurement target area based on the steering angle detected by the steering angle sensor, or the captured image If the distance measurement unit can be switched to determine whether only the vehicle side of the auxiliary line is the distance measurement target area, there is no need to always calculate the distance for the entire captured image, and the calculation associated with the distance calculation The load can be reduced.

  Further, when the distance between the vehicle calculated by the distance measuring unit and the imaging target is smaller than a predetermined first threshold value, a warning graphic is superimposed on the imaging target displayed on the display unit. By doing so, it is possible to reduce an erroneous recognition of an imaging target that is an obstacle by the occupant.

  In addition, if the image processing unit changes the warning graphic according to the distance to the imaging target that is closer than the first threshold, the occupant may erroneously recognize the imaging target that is an obstacle. Further reduced.

  In addition, a warning unit that sounds a warning sound to a vehicle occupant is further provided, and the control unit calculates a distance between the vehicle and the imaging target that is an obstacle calculated by the ranging unit from a predetermined second threshold value. However, if the warning sound is emitted from the warning unit, it is further reduced that the occupant erroneously recognizes the imaging target.

  Further, if the control unit changes the warning sound according to the distance to the imaging target that is closer than the second threshold, it is further reduced that the occupant erroneously recognizes the imaging target that is the imaging target. Is done.

  FIG. 1 is a plan view showing a vehicle periphery visual recognition apparatus according to an embodiment of the present invention, and FIG. 2 is a block diagram thereof. As shown in FIG. 1, the vehicle periphery visual recognition device includes, for example, an imaging unit 11 installed at the left front end of the vehicle 10, and a display unit 13 installed in the passenger compartment and displaying captured images captured by the imaging unit 11. A steering angle sensor 15 that detects the steering angle of the vehicle 10, a warning unit 17 that emits a warning sound to the occupant of the vehicle 10, and a control unit 19 that controls display of the captured image on the display unit 13. It is configured.

  The imaging unit 11 is installed, for example, at the left front end of the vehicle 10 so that the optical axis 11a is oblique with respect to the longitudinal direction of the vehicle body of the vehicle 10, and the light from the imaging range 11A is converted into a lens system. An image is formed on an image pickup device (not shown) such as a CCD or a CMOS (not shown), and an image signal is transmitted to a control unit 19 described later.

  Specifically, for example, the imaging range 11 </ b> A of the imaging unit 11 installed at the left front end of the vehicle 10 has a horizontal viewing angle wider than a vertical viewing angle. It is possible to take a wide image in the left-right direction as the center.

  As a result, while the vehicle 10 is traveling, it is possible to visually recognize a blind spot region from the driver.

  The imaging unit 11 does not necessarily have to be installed at the left front end of the vehicle 10, and a plurality of imaging units 11 may be installed at the right front end, left and right rear ends, etc. In the embodiment, the case where it is installed at the left front end will be described as an example.

  The display unit 13 is also used as, for example, an LCD for displaying a screen of a car navigation device, and displays the captured image captured by the imaging unit 11 in real time.

  The steering angle sensor 15 detects, for example, the steering angle of the steering (not shown) of the vehicle 10, and transmits the detected steering angle to the control unit 19.

  The warning unit 17 alerts the occupant, and for example, emits a warning sound from a speaker (not shown) installed in the passenger compartment of the vehicle 10.

  The control unit 19 is a functional element that operates according to a predetermined software program in a general CPU in cooperation with a storage unit such as a ROM or a RAM. For example, as shown in FIG. 19A and a distance measuring unit 19B, which perform various information processing operations (including control operations) on the video signal transmitted from the imaging unit 11.

  For example, as illustrated in FIG. 3, the image processing unit 19 </ b> A superimposes an auxiliary line 33 that extends the side end of the vehicle 10 on the captured image 31 captured by the imaging unit 11 and displays the auxiliary line 33 on the display unit 13. The predetermined image processing is performed in accordance with the output from the distance measuring unit 19B. The auxiliary line 33 superimposed here is shifted by the distance between the front end of the imaging unit 11 and the side end of the vehicle body of the vehicle 10, unlike a straight line extending from the front end of the imaging unit 11 to the infinity point in the vehicle longitudinal direction. It is displayed at the position. Thereby, although the optical axis 11a of the imaging unit 11 is oblique with respect to the longitudinal direction of the vehicle body of the vehicle 10, it is possible to easily grasp the longitudinal direction of the vehicle body, and the vehicle 10 travels straight ahead. Alternatively, when making a right turn, it is possible to easily grasp that there is no possibility of a collision in the imaging target S displayed on the outer side of the vehicle 10 (left side of the auxiliary line 33) than the auxiliary line 33.

  The distance measuring unit 19 </ b> B uses the entire surface of the captured image 31 (captured images 31 </ b> L and 31 </ b> R) as a distance measurement target area based on the steering angle detected by the rudder angle sensor 15, or is more than the auxiliary line 33 in the captured image 31. It is switched whether only the vehicle 10 side (captured image 31R) is set as the distance measurement target area, and the distance between the vehicle 10 and the image capture target S reflected in the distance measurement target area is calculated.

  Specifically, for example, when the steering angle sensor 15 detects that the predicted course of the vehicle 10 is going straight or right when the vehicle 10 is moving forward, the imaging target S reflected in the captured image 31L Since there is no possibility of a collision, the distance measurement unit 19B uses only the captured image 31R displayed on the vehicle 10 side of the auxiliary line 33 as the distance measurement target area and captures the imaged object (not shown) in the captured image 31R. ) Is obtained by image processing. Further, for example, when the steering angle sensor 15 detects that the predicted course of the vehicle 10 is a left turn while the vehicle 10 is moving forward, all the imaging targets S in the captured image 31 can be obstacles. The distance unit 19B uses the entire surface of the captured video 31 (captured video 31L and 31R) as a distance measurement target area to obtain a distance to the captured image S reflected in the captured video 31 by image processing. Therefore, the calculation load can be reduced as compared with the case where the distance measurement is always performed on the entire captured image 31.

  Then, for example, when the distance between the vehicle 10 moving forward (including straight or turning right and left) and the imaging target S reflected in the captured video 31 is smaller than a predetermined first threshold, image processing is performed. The unit 19A is configured to superimpose a warning graphic on the closest part of the imaging target S shown in the captured video 31 and display the warning graphic on the display unit 13.

  Further, based on the steering angle detected by the rudder angle sensor 15, the expected course of the vehicle 10 is calculated, and the correspondence relationship (FIGS. 4A and 4B) stored in the storage means (not shown) is referred to. However, the degree of warning is changed stepwise according to the distance to the closest approach site of the imaging target S. 4A and 4B corresponds to the case where the imaging unit 11 is installed at the left front end of the vehicle 10, and the imaging unit 11 is connected to the right front end of the vehicle 10. If it is installed at the left and right rear ends, it must be stored separately.

  Specifically, for example, as shown in FIG. 5, the vehicle 10 based on the steering angle detected by the steering angle sensor 15 when the vehicle 10 tries to pass to the right near the other vehicle 50 that is stopped. When the predicted course of the vehicle is a straight or right turn, the distance measurement unit 19B uses only the captured image 31R on the right side of the auxiliary line 33 (see FIG. 3) as a distance measurement area, and the distance measuring unit 19B captures the image captured in the captured image 31R. The distance to the target (other vehicle 50) is calculated.

  Here, in the distance measuring unit 19B, for example, the imaging target S reflected in the captured image by performing image processing such as edge extraction on the captured images taken at two different times taken in time series. The amount of change in image height and angle of view (total or part) is calculated, and image pickup is performed based on the movement amount of the vehicle 10 and the focal length of the image pickup unit 11 while the image height and angle of view of the image pickup target S change. The distance to the target S is calculated.

  Then, for example, as shown in FIG. 4A, when the other vehicle 50 is in the position of the region a1 with respect to the vehicle 10, it is determined that the vehicle can pass through without paying special attention, and the image processing unit 19A Display without any warning graphic superimposed. Further, when the other vehicle 50 is in the position of the region a2 with respect to the vehicle 10, it is determined that the vehicle cannot pass through without paying some attention, and the image processing unit 19A displays, for example, in FIG. As shown, the predicted collision site 61 which is the closest approach site is surrounded and displayed by a yellow frame 63a as a warning graphic to alert the passenger. Further, when the other vehicle 50 is in the position of the region a3 with respect to the vehicle 10, it is determined that the possibility of a collision is very high, and the image processing unit 19A, for example, as shown in FIG. The predicted collision portion 61 is displayed by being surrounded by a red bent line 63b as a warning graphic to prompt the occupant to pay further attention. When the other vehicle 50 is in the position of the region a4 with respect to the vehicle 10, it is determined that a collision with the other vehicle 50 cannot be avoided even if the steering is rotated to the limit. As shown in FIG. 6C, the auxiliary line 33 is deleted, and a warning graphic 63c is superimposed on the entire display screen to prompt the occupant to stop the vehicle 10.

  Further, for example, as shown in FIG. 7, when the occupant of the vehicle 10 tries to turn left while looking at the other vehicle 70 that is stopped, the vehicle 10 based on the steering angle detected by the rudder angle sensor 15 is used. When the predicted course is a left turn, the distance measurement unit 19B calculates the distance to the imaging target (another vehicle 70) reflected on the entire surface of the captured video 31 using the entire captured image 31 as the distance measurement target area. .

  Then, for example, as shown in FIG. 4B, when the other vehicle 70 is in the position of the region b4 with respect to the vehicle 10, it is determined that it can be passed without paying special attention, and the image processing unit 19A Display without any warning graphic superimposed. Further, when the other vehicle 70 is in the position of the region b1 with respect to the vehicle 10, it is determined that there is a collision unless the expected course is changed, and the image processing unit 19A, for example, in the case of FIG. The video is displayed in a manner similar to that shown in FIG. Further, when the other vehicle 70 is at the position of the region b2 with respect to the vehicle 10, it is determined that a collision occurs when the steering is further rotated to the left, and the image processing unit 19A, for example, in the case of FIG. The video is displayed in a manner similar to that shown in FIG. When the other vehicle 70 is in the position of the region b3 with respect to the vehicle 10, it is determined that the collision with the other vehicle 70 cannot be avoided if the vehicle proceeds in this state, and the image processing unit 19A, for example, The video is displayed in the same manner as in the case of 6 (c) to prompt the occupant to stop the vehicle 10.

  At this time, the vehicle 10 moves forward (including straight or right / left turn) and the distance from the imaging target S displayed in the captured image 31 is a second threshold value (here, the same value as the first threshold value). ), The control unit 19 causes the warning unit 17 to sound a warning sound, and changes the warning sound according to the distance from the imaging target S.

  Specifically, for example, as shown in FIG. 4 (a) or (b), when an obstacle such as the other vehicle 50 or 70 exists at the position of the area a2 or b1, “pi, pi, pi, When a sporadic warning sound such as “pi, pi,...” Is sounded and an obstacle such as the other vehicle 50 or 70 exists at the position of the area a3 or b2, intermittently “pipipipi…” If there is an obstacle such as the other vehicle 50 or 70 at the position of the area a4 or b3, a continuous warning sound such as “Pee-e” is sounded. As a result, it is possible to further urge the occupant to pay attention to the obstacle.

  In the present embodiment, the first threshold value for superimposing the warning graphic and the second threshold value for sounding the warning sound are set to the same value, but different threshold values are set. Also good.

  As described above, the imaging unit 11 can obtain an image centered on the imaging range in the same direction by installing the optical axis 11a in an oblique direction with respect to the longitudinal direction of the vehicle 10. The vehicle body longitudinal direction of the vehicle 10 is imaged at the end of the range 11A, but the auxiliary line 33 extending from the side end of the vehicle 10 is superimposed by the image processing unit 19A provided in the control unit 19. Since it is displayed on the display unit 13, it is possible to easily grasp the positional relationship between the imaging target S reflected in the captured image 31 and the vehicle 10 using the auxiliary line 33 as a guide. Further, since the imaging target S displayed on the opposite side of the vehicle 10 with the auxiliary line 33 as a boundary is not likely to collide with the vehicle 10 as long as the vehicle 10 goes straight or turns right, the occupant can The vehicle can be safely operated by paying attention only to the imaging target S displayed on the vehicle 10 side.

  In addition, since the distance measuring unit 19B that obtains the distance to the imaging target S reflected in the captured image 31 by image processing is provided, there is no need to separately provide a clearance sonar and the like, and the vehicle is reduced in weight and cost. It becomes possible. Further, the steering angle sensor 15 for detecting the steering angle of the vehicle 10 is further provided, and the distance measuring unit 19B sets the entire surface of the captured image 31 as a distance measurement target area based on the steering angle detected by the steering angle sensor 15. Alternatively, since the distance measuring unit 19B can switch between the captured image 31 and the vehicle 10 side (captured image 31R) with respect to the auxiliary line 33 as the distance measurement target area, the distance calculation is always performed on the entire surface of the captured image 31. It becomes unnecessary, and it becomes possible to reduce the calculation load accompanying distance calculation.

  When the distance between the vehicle 10 calculated by the distance measuring unit 19B and the other vehicles 50 and 70 (imaging target S) that are obstacles is smaller than a predetermined first threshold value, the display unit 13 Since the warning graphic is superimposed and displayed on the predicted collision site of the other vehicles 50 and 70 displayed, it is reduced that the occupant misrecognizes the other vehicles 50 and 70 that become obstacles.

  In addition, the image processing unit 19A changes the warning graphic so as to increase the warning degree as the distance approaches the imaging target S closer to the first threshold, so that the occupant becomes an obstacle. Misrecognizing the vehicles 50 and 70 is further reduced.

  In addition, a warning unit 17 that sounds a warning sound to an occupant of the vehicle 10 is further provided, and the control unit 19 calculates the vehicle 10 calculated by the distance measuring unit 19B and other vehicles 50 and 70 that are obstacles (imaging target S). When the distance to the vehicle is smaller than the predetermined second threshold value, the warning unit 17 sounds a warning sound, so that it is further reduced that the occupant misrecognizes the other vehicles 50 and 70 that become obstacles. The

  In addition, since the control unit 19 changes the warning sound so as to increase the warning level as the distance gets closer to the imaging target S closer to the second threshold, the other vehicle in which the occupant becomes an obstacle The erroneous recognition of 50 and 70 is further reduced.

It is a top view which shows the vehicle periphery visual recognition apparatus which concerns on embodiment of this invention. It is a block diagram which shows the vehicle periphery visual recognition apparatus which concerns on embodiment of this invention. It is a figure which shows the example of a display of the vehicle periphery visual recognition apparatus which concerns on embodiment of this invention. (A) It is a reference figure which shows the positional relationship of the vehicle and imaging object when the estimated course of a vehicle goes straight or turns right. (B) It is a reference figure which shows the positional relationship of the vehicle and imaging object at the time of the expected course of a vehicle turning left. It is a top view which shows the motion of the vehicle carrying the vehicle periphery visual recognition apparatus which concerns on embodiment of this invention. (A)-(c) It is a figure which shows the example of a display of the vehicle periphery visual recognition apparatus which concerns on embodiment of this invention. It is a top view which shows the motion of the vehicle carrying the vehicle periphery visual recognition apparatus which concerns on embodiment of this invention. It is a top view which shows the conventional vehicle periphery visual recognition apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vehicle 11 Imaging part 11a Optical axis 13 Display part 15 Steering angle sensor 17 Warning part 19 Control part 19A Image processing part 19B Distance measuring part 33 Auxiliary line

Claims (6)

An imaging unit for imaging a peripheral region of the vehicle;
A display unit that is installed in a vehicle interior of the vehicle and displays a captured image captured by the imaging unit;
A control unit that controls display of the captured video on the display unit,
The imaging unit is installed so that the optical axis thereof is oblique with respect to the vehicle longitudinal direction of the vehicle, and images the vehicle longitudinal direction of the vehicle at the end of the imaging range,
The vehicle periphery visual recognition device, wherein the control unit includes an image processing unit that superimposes an auxiliary line extending from a side end of the vehicle on the captured image and causes the display unit to display the superimposed image. The vehicle periphery visual recognition device according to claim 1,
A steering angle sensor for detecting a steering angle of the vehicle;
The control unit has a distance measuring unit that obtains a distance to an imaging target reflected in the captured video by image processing,
The distance measuring unit sets the entire surface of the captured image as a distance measurement target area based on the steering angle detected by the steering angle sensor, or only the vehicle side of the auxiliary line in the captured image. A vehicle periphery visual recognition device, which switches whether to be a distance measurement target area and calculates a distance between the vehicle and the imaging target imaged in the distance measurement target area. The vehicle periphery visual recognition device according to claim 2,
When the distance between the vehicle and the imaging target calculated by the ranging unit is smaller than a predetermined first threshold, the image processing unit is configured to display the imaging target displayed on the display unit. A vehicle periphery visual recognition device characterized by superimposing a warning graphic thereon. The vehicle periphery visual recognition device according to claim 3,
The said image processing part changes the said warning figure according to the distance to the said imaging target nearer than the said 1st threshold value, The vehicle periphery visual recognition apparatus characterized by the above-mentioned. The vehicle periphery visual recognition device according to claim 2,
A warning section for blowing a warning sound to the vehicle occupant;
When the distance between the vehicle and the imaging target calculated by the distance measuring unit is smaller than a predetermined second threshold value, the control unit sounds a warning sound from the warning unit. A vehicle periphery visual recognition device. The vehicle periphery visual recognition device according to claim 5,
The vehicle periphery visual recognition device, wherein the control unit changes the warning sound according to a distance to the imaging target that is closer than the second threshold.

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