JP2006185431A - Vehicle circumference monitoring device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To extract a pedestrian exactly discriminatingly from an artificial structure on an infrared image. <P>SOLUTION: The plurality of first search areas Mask_U1(I) adjacent each other is provided in a lower side from a lower end of a binarized object OB, and the first search areas Mask_U1(I) in the lowermost end position brought into Idn1(I)-ΔdI<prescribed threshold value DISP_TH or (dn1(I)-Δd)≥DISP_TH is detected by a parallex dn1(I) of the first search areas Mask_U1(I) and a parallex Δd of the binarized object OB. When (dn1(I)-Δd)≥DISP_TH is satisfied, a height delta_H of other object O1 is calculated from a lower end position D_F_y of the first search areas Mask_U1(K) in the lowermost end position having the parallex substantially same to that of the binarized object OB, and estimates a vertical width O_delta_H of the binarized object OB shielded by the other object O1. A lower end position Ob_min_y of a gray scale area is expressed as D_F_yP+O_delta_H. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a vehicle periphery monitoring apparatus that extracts an object by binarization processing of an image photographed by an infrared camera.

Conventionally, an object such as a pedestrian who may collide with the own vehicle is extracted from an infrared image around the own vehicle obtained by photographing with an infrared camera, and information on the object is transmitted to the driver of the own vehicle. A display processing device to be provided is known (for example, see Patent Document 1).
In this display processing device, binarization processing is performed on the infrared image to search for a region where the bright portion is concentrated (binarization target object), and the aspect ratio and sufficiency ratio of the binarization target object, as well as the actual area And the distance calculated by the center of gravity position on the infrared image, it is determined whether or not the binarized object is a pedestrian's head. Then, from the distance of the pedestrian's head region from the infrared camera and the average height of the adult, the height of the pedestrian on the infrared image is calculated, and a body region including the pedestrian's body is set, By displaying the body region and the body region separately from other regions, the driver's visual assistance for the pedestrian is performed.
Also, binarization processing is performed on the infrared image to search for a region (binarization target object) where bright portions are concentrated, and an image that is at the same distance as the binarization target object in the vertical direction of the binarization target object. A technique is known in which an area is extracted, the height of the object is calculated from the binarized object and the image area at the same distance as the binarized object, and the object is recognized as a pedestrian. (For example, refer to Patent Document 2).
Japanese Patent Laid-Open No. 11-328364 JP 2003-216937 A

By the way, in the display processing device according to an example of the above prior art, since the pedestrian is detected based on the shape determination for the head region and the body region on the infrared image, the shape of the pedestrian, particularly the head There is a risk that it may be difficult to distinguish a pedestrian from an artificial structure having a size and height similar to the shape of the heat generating and generating heat.
Moreover, in the said patent document 2, the height of a target object is calculated based on the image area which is the same distance as a binarization target object in the up-down direction of a binarization target object and a binarization target object on an infrared image, Since only pedestrian recognition is performed, when an obstacle exists in front of the binarized object, an area of the same distance as the binarized object can be detected below the binarized object. Therefore, it may be difficult to accurately detect the actual height of the object, and it may be difficult to recognize a pedestrian.
The present invention has been made in view of the above circumstances, and an object thereof is to provide a vehicle periphery monitoring device capable of accurately distinguishing and extracting a pedestrian and an artificial structure on an infrared image.

  In order to solve the above problems and achieve the object, the vehicle periphery monitoring device according to the present invention is obtained by imaging by infrared imaging means (for example, the infrared cameras 2R and 2L in the embodiment). A vehicle periphery monitoring device that extracts an object existing outside the host vehicle as an object based on the obtained image, and binarized object from image data obtained by binarizing the grayscale image of the image Between the binarized object extracting means (for example, step S7 in the embodiment), the infrared imaging means, and the binarized object extracted by the binarized object extracting means. If there is an obstacle in the determination result of the obstacle determination means (for example, step S34 in the embodiment) for determining whether or not there is another object to be an obstacle, and the determination result of the obstacle determination means. If determined, A height calculating means for calculating a height dimension of the binarized object based on a height dimension of the obstacle on the gray scale image (for example, also serves as step S34 in the embodiment); Object type determining means for determining the type of the object based on the height dimension of the binarized object calculated by the height calculating means (for example, also serving as step S34 in the embodiment). It is a feature.

  According to the vehicle periphery monitoring device described above, since the obstacle exists between the infrared imaging means and the binarized object, the lower end of the binarized object cannot be directly detected. Even when there is a possibility that the height dimension of the binarized object is erroneously detected, by calculating the height dimension of the binarized object based on the height dimension of the obstacle on the grayscale image The occurrence of false detection of the height dimension can be prevented. For example, the height calculation means is based on the height dimension of the obstacle on the gray scale image, the distance from the infrared imaging means to the obstacle, and the distance from the infrared imaging means to the binarized object. It is obtained by estimating the height dimension of the part of the binarized object shielded by the object, and adding the estimated height dimension and the height dimension of the binarized object that is directly detected. This value is newly set as the height dimension of the binarized object. Thereby, the accuracy of the height dimension of the binarized object can be improved, and the type of the binarized object can be accurately determined according to the height dimension.

  Further, the vehicle periphery monitoring device according to the present invention described in claim 2 exists in the external environment of the host vehicle based on an image obtained by imaging by infrared imaging means (for example, infrared cameras 2R and 2L in the embodiment). A vehicle periphery monitoring device that extracts an object as an object, and a binarized object extracting unit that extracts a binarized object from image data obtained by binarizing the grayscale image of the image (for example, Step S7) in the embodiment, and a plurality of adjacent pixels having a predetermined height width below the binarized object extracted by the binarized object extracting means on the grayscale image. First search area setting means for setting the first search area (for example, the first search area Mask_U1 (I) in the embodiment) (for example, also serving as step S34 in the embodiment), and the binarization Target The binarized object distance (for example, the parallax Δd in the embodiment) that is a state quantity related to the distance between the binarized object extracted by the extracting unit and the infrared imaging unit, and the first First search area distance (for example, parallax dn1 (I) in the embodiment) which is a state quantity related to the distance between each of the plurality of first search areas set by the search area setting means and the infrared imaging means ) And a new first search area corresponding to the first search area distance shorter than the binarized object distance is newly set as a second search area (for example, the second search area Mask_U2 in the embodiment). (I)) is set as the second search area setting means (for example, step S34 in the embodiment also) and the second search area set by the second search area setting means is the binarization target. Placed in sequence Continuity determination means for determining whether or not (for example, step S34 in the embodiment also serves) and the continuity determination from the lower end of the binarized object extracted by the binarized object extraction means The distance to the lower end of the second search area located at the lowest position among the second search areas determined to be continuously arranged on the binarized object by the means (for example, in the embodiment A value obtained by adding a height (for example, vertical width O_delta_H in the embodiment) to the vertical width of the binarized object according to the height delta_H) is obtained. The height calculation means (for example, step S34 in the embodiment) set as a dimension and the type of the object based on the height dimension of the binarized object calculated by the height calculation means. Object type determination means for determining (for example, It is characterized in that it comprises a step S34 also serves as the) in the embodiment.

  According to the above vehicle periphery monitoring device, there is a relatively large object (for example, a wall or the like) between the infrared imaging means and the binarized object, and in the image obtained by imaging by the infrared imaging means, Even when the binarized object exists so as to protrude upward from the upper end of the object, the height dimension of the object can be detected with high accuracy, and further, the height dimension of the object can be detected. By calculating the height dimension of the binarized object based on the above, occurrence of erroneous detection of the binarized object height dimension can be prevented. That is, by determining whether or not there is a series of second search regions arranged so as to be adjacent to the binarized object in the vertical direction by the continuity determining unit, It is possible to accurately detect the height dimension of the object existing on the near side. Further, the height calculation means shields the object based on the height dimension of the object on the gray scale image, the distance from the infrared imaging means to the object, and the distance from the infrared imaging means to the binarized object. The height dimension of the portion of the binarized object thus obtained is estimated, and a value obtained by adding the estimated height dimension and the height dimension of the binarized object directly detected is obtained. , Newly set as the height dimension of the binarized object. Thereby, the accuracy of the height dimension of the binarized object can be improved, and the type of the binarized object can be accurately determined according to the height dimension.

  Furthermore, in the vehicle periphery monitoring apparatus according to the third aspect of the present invention, the continuity determination means is the second search area existing within a predetermined distance from the binarized object or the appropriate second search area. Is determined to be the second search region arranged continuously.

  According to the vehicle periphery monitoring device described above, for example, by setting a relatively short value (for example, a distance that includes the adjacent second search region) as the predetermined distance, the adjacent second search region is accurately determined. For example, by setting a relatively long value (for example, a distance that includes at least a plurality of adjacent second search areas) as the predetermined distance, the local distance due to a detection error or the like is set. Even if it is impossible to extract the second search area, it can be determined that the second search area is actually arranged continuously. It is possible to accurately detect the height dimension of an existing object.

  Furthermore, the vehicle periphery monitoring apparatus according to the present invention described in claim 4 includes pedestrian recognition means (for example, step S35 in the embodiment) for recognizing a pedestrian existing in the outside of the host vehicle based on the image. The pedestrian recognition means is characterized in that a pedestrian recognition process is performed on the object determined to be a pedestrian other than an artificial structure by the object type determination means.

  According to the vehicle periphery monitoring device, in addition to the object determined to be a pedestrian, walking is performed by performing a pedestrian recognition process on the object determined to be other than an artificial structure. The recognition accuracy of the person can be improved.

  Furthermore, the vehicle periphery monitoring device of the present invention according to claim 5 is an alarm output means for outputting an alarm to the object determined to be a pedestrian other than an artificial structure by the object type determining means. (For example, step S19 in the embodiment).

  According to the above vehicle periphery monitoring device, in addition to the object determined to be a pedestrian, an alarm is output for an object determined to be other than an artificial structure. It is possible to prevent an unnecessary alarm from being output.

As described above, according to the vehicle periphery monitoring device of the present invention described in claim 1, the height dimension of the binarized object is calculated based on the height dimension of the obstacle on the gray scale image. Therefore, it is possible to prevent occurrence of erroneous detection of the height dimension.
Furthermore, according to the vehicle periphery monitoring device of the present invention as set forth in claim 2, there is a case where a relatively large object (for example, a wall or the like) exists between the infrared imaging means and the binarized object. In addition, the height dimension of the object can be accurately detected, and the height of the binarized object is calculated by calculating the height dimension of the binarized object based on the height dimension of the object. Occurrence of erroneous dimension detection can be prevented.
Furthermore, according to the vehicle periphery monitoring device of the present invention as set forth in claim 3, it is possible to accurately detect the height dimension of an object existing in front of the binarized object in accordance with a predetermined distance. Can do.
Furthermore, according to the vehicle periphery monitoring device of the present invention as set forth in claim 4, the recognition accuracy of a pedestrian can be improved.
Furthermore, according to the vehicle periphery monitoring device of the present invention described in claim 5, it is possible to prevent an unnecessary alarm from being output to the artificial structure.

Hereinafter, a vehicle periphery monitoring device according to an embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, for example, the vehicle periphery monitoring device according to the present embodiment includes an image processing unit 1 including a CPU (central processing unit) that controls the vehicle periphery monitoring device, and two infrared rays that can detect far infrared rays. Cameras 2R, 2L, a yaw rate sensor 3 for detecting the yaw rate of the host vehicle, a vehicle speed sensor 4 for detecting the traveling speed (vehicle speed) of the host vehicle, a brake sensor 5 for detecting presence or absence of a brake operation by the driver, and a speaker 6 and a display device 7, for example, the image processing unit 1 is detected by an infrared image around the host vehicle obtained by photographing with two infrared cameras 2R and 2L, and sensors 3, 4 and 5. It is possible to detect a moving body such as a pedestrian or an animal ahead of the traveling direction of the host vehicle from a detection signal related to the traveling state of the host vehicle, and contact between the detected moving body and the host vehicle may occur. When it is determined that there is sex, and outputs an alarm via a loudspeaker 6 or the display device 7.
For example, the display device 7 is a display device integrated with instruments that display various travel state quantities of the host vehicle, a display device of a navigation device, and various information at a position that does not obstruct the driver's front view in the front window. HUD (Head Up Display) 7a and the like are displayed.

  The image processing unit 1 includes an A / D conversion circuit that converts an input analog signal into a digital signal, an image memory that stores a digitized image signal, a CPU (central processing unit) that performs various arithmetic processing, and a CPU RAM (Random Access Memory) used to store data during computation, ROM (Read Only Memory) that stores programs, tables, maps, etc. executed by the CPU, driving signals for the speaker 6, HUD 7a, etc. And an output circuit for outputting a display signal and the like. The signals output from the infrared cameras 2R and 2L and the sensors 3, 4 and 5 are converted into digital signals and input to the CPU. Yes.

For example, as shown in FIG. 2, the infrared cameras 2 </ b> R and 2 </ b> L are disposed at the front portion of the host vehicle 10 at a substantially target position with respect to the center in the vehicle width direction of the host vehicle 10. The optical axes of the cameras 2R and 2L are fixed so that they are parallel to each other and the heights from both road surfaces are equal. The infrared cameras 2R and 2L have a characteristic that the output signal level increases (that is, the luminance increases) as the temperature of the object increases.
Further, the HUD 7a is provided so that the display screen is displayed at a position that does not obstruct the driver's front view of the front window of the host vehicle 10.

The vehicle periphery monitoring apparatus according to the present embodiment has the above-described configuration. Next, the operation of the vehicle periphery monitoring apparatus will be described with reference to the accompanying drawings.
Below, the operation | movement of target object detection, such as a pedestrian, and alarm output in the image processing unit 1 is demonstrated.
First, in step S1 shown in FIG. 3, the image processing unit 1 acquires infrared images that are output signals of the infrared cameras 2R and 2L.
Next, in step S2, the acquired infrared image is A / D converted.
Next, in step S3, a grayscale image including halftone information is acquired and stored in the image memory. Here, the right image is obtained by the infrared camera 2R, and the left image is obtained by the infrared camera 2L. Moreover, since the horizontal position on the display screen of the same target object is shifted in the right image and the left image, the distance from the own vehicle 10 to the target object is calculated based on this shift (that is, parallax). Can do.

Next, in step S4, the right image obtained by the infrared camera 2R is used as a reference image, and binarization processing of this image signal, that is, a region brighter than the predetermined luminance threshold ITH is set to “1” (white), and a dark region Is set to “0” (black).
In addition, the process of the following step S4-step S9 is performed about the reference | standard image (for example, right image) obtained by the binarization process.
Next, in step S5, image data obtained by performing binarization processing on the infrared image is converted into run-length data. In the run-length data, an area that has become white by binarization processing is displayed as a line at the pixel level, and each line has a width of one pixel in the y direction and an appropriate number of pixels in the x direction. Is set to

Next, in step S6, the object is labeled in the image data converted into run-length data.
Next, in step S7, the object is extracted according to the labeling of the object. Here, among the lines in the run-length data, when the lines including the equivalent x-direction coordinates are adjacent in the y direction, the adjacent lines are regarded as constituting a single object.
Next, in step S8, the center of gravity G, the area S, and the aspect ratio ASPECT of the circumscribed rectangle are calculated.

Here, the area S is the run length data of the object of the label A (x [i], y [i], run [i], A) (i = 0, 1, 2,..., N−1; If N is an arbitrary natural number), the length (run [i] -1) of each run-length data is calculated by integrating the same object.
The coordinates (xc, yc) of the center of gravity G of the object of label A are the length (run [i] -1) of each run-length data and the coordinates x [i] or y [i] of each run-length data. ] (Ie, (run [i] −1) × x [i] or (run [i] −1) × y [i]) obtained by multiplying the same object. The value is calculated by dividing by the area S.
Further, the aspect ratio ASPECT is calculated as a ratio Dy / Dx between the length Dy in the vertical direction and the length Dx in the horizontal direction of the circumscribed rectangle of the object of label A.
Since the run length data is indicated by the number of pixels (number of coordinates) (= run [i]), the actual length needs to be “−1” (= run [i] −1). Further, the coordinates of the center of gravity G may be replaced by the center of gravity coordinates of a circumscribed rectangle.

Next, the process of step S9 and step S10 and the process of step S11-step S13 are performed in parallel.
First, in step S9, tracking of a target object between times, that is, recognition of the same target object at every sampling period is performed. In this inter-time tracking, k is a time obtained by discretizing time t as an analog quantity with a sampling period. For example, when objects A and B are extracted at time k, the objects C and D extracted at time (k + 1) are extracted. And the objects A and B are determined. If it is determined that the objects A and B and the objects C and D are the same, the labels of the objects C and D are changed to the labels of the objects A and B, respectively. Then, the position coordinates (for example, the center of gravity, etc.) of each recognized object are stored in an appropriate memory as time series position data.

  Next, in step S10, the vehicle speed VCAR detected by the vehicle speed sensor 4 and the yaw rate YR detected by the yaw rate sensor 3 are acquired, and the yaw rate YR is integrated over time to calculate the turning angle θr of the host vehicle 10.

On the other hand, in steps S11 to S13 executed in parallel with the processes of steps S9 and S10, a distance z between the object and the host vehicle 10 is calculated. Since the process of step S11 requires a longer calculation time than the processes of step S9 and step S10, the cycle is longer than that of steps S9 and S10 (for example, about three times the execution cycle of steps S1 to S10). Etc.).
First, in step S11, one object is selected from a plurality of objects tracked on image data obtained by binarizing a reference image (for example, the right image). The entire region surrounding the object with a circumscribed rectangle is extracted from the reference image (for example, the right image) as the search image R1.

  Next, in step S12, a search area for searching for an image (corresponding image) R2 corresponding to the search image R1 from an image (for example, the left image) corresponding to the reference image (for example, the right image) is set and correlated. An operation is executed to extract the corresponding image R2. Here, for example, a search area is set in the left image according to each vertex coordinate of the search image R1, and the luminance difference sum C (a, b) indicating the level of correlation with the search image R1 in the search area. And the region where the total value C (a, b) is minimum is extracted as the corresponding image R2. This correlation calculation is performed not on the image data obtained by the binarization process but on the gray scale image. In addition, when there is past position data for the same object, the search area can be narrowed based on the past position data.

  Next, in step S13, the centroid position of the search image R1, the centroid position of the corresponding image R2, and the parallax Δd in units of the number of pixels are calculated, and the distance between the vehicle 10 and the object, that is, an infrared camera. The distance (object distance) z (m) between the 2R and 2L lenses and the object is the camera base length, that is, the center position of each image sensor of the infrared cameras 2R and 2L, for example, as shown in the following formula (1). Based on the horizontal distance D (m) between them, the camera focal length, that is, the focal length f (m) of each lens of the infrared cameras 2R and 2L, the pixel pitch p (m / pixel), and the parallax Δd (pixel). calculate.

In step S14, after the calculation of the turning angle θr in step S10 and the calculation of the distance z in step S13, for example, as shown in the following formula (2), the object on the image data is calculated. The coordinates (x, y) and the distance z are converted into real space coordinates (X, Y, Z).
Here, the real space coordinates (X, Y, Z), for example, as shown in FIG. 2, are set with the origin O as the midpoint position of the attachment positions of the infrared cameras 2R, 2L at the front of the host vehicle 10, The coordinates on the image data are set with the center of the image data as the origin and the horizontal direction as the x direction and the vertical direction as the y direction. Also, the coordinates (xc, yc) are the coordinates (x, y) on the reference image (for example, the right image) based on the relative positional relationship between the mounting position of the infrared camera 2R and the origin O in the real space. This is a coordinate obtained by converting the origin O of the real space and the center of the image data into coordinates on a virtual image obtained.

  Next, in step S15, the turning angle correction for correcting the positional deviation on the image due to the turning of the host vehicle 10 is performed. In this turning angle correction, when the host vehicle 10 turns, for example, to the left by the turning angle θr during the period from time k to time (k + 1), the image data on the image data obtained by the infrared cameras 2R and 2L This is a process for correcting that the range is shifted in the x direction by Δx. For example, as shown in the following formula (3), corrected coordinates (Xr, Yr) obtained by correcting real space coordinates (X, Y, Z) , Zr) are newly set as real space coordinates (X, Y, Z).

Next, in step S16, from the real space position data forming N (for example, about N = 10) time-series data after the turning angle correction obtained within the monitoring period of the predetermined time ΔT for the same object, An approximate straight line LMV corresponding to the relative movement vector between the object and the vehicle 10 is calculated.
In this step S16, the latest position coordinates P (0) = (X (0), Y (0), Z (0)) and the position before (N−1) samples (that is, before a predetermined time ΔT). Coordinate P (N-1) = (X (N-1), Y (N-1), Z (N-1)) is corrected to a position on the approximate straight line LMV, and the corrected position coordinate Pv ( 0) = (Xv (0), Yv (0), Zv (0)) and Pv (N−1) = (Xv (N−1), Yv (N−1), Zv (N−1)). calculate.
Thereby, a relative movement vector is obtained as a vector from the position coordinates Pv (N−1) to Pv (0).
In this way, by calculating an approximate straight line that approximates the relative movement locus of the object with respect to the host vehicle 10 from a plurality of (for example, N) real space position data within the monitoring period of the predetermined time ΔT, the relative movement vector is obtained. It is possible to reduce the influence of the position detection error and accurately predict the possibility of occurrence of contact between the host vehicle 10 and the object.

Next, in step S17, it is determined whether or not the detected object is an alarm target in an alarm determination process according to, for example, the possibility of contact between the detected object and the host vehicle 10 or the like. .
If this determination is “NO”, the flow returns to step S 1 to repeat the above-described steps S 1 to S 17.
On the other hand, if this determination is “YES”, the flow proceeds to step S18.
In step S18, for example, it is determined whether or not an alarm output is necessary in an alarm output determination process according to whether or not the driver of the host vehicle 10 is performing a brake operation based on the output BR of the brake sensor 5. To do.
When the determination result of step S18 is “NO”, for example, when the acceleration Gs generated when the driver of the host vehicle 10 performs a brake operation (deceleration direction is positive) is greater than the predetermined threshold GTH. Determines that the occurrence of contact is avoided by the driver's brake operation, determines, returns to step S1, and repeats the processing of steps S1 to S18 described above.
On the other hand, when the determination result of step S18 is “YES”, for example, when the acceleration Gs (deceleration direction is positive) generated when the driver of the host vehicle 10 performs a brake operation is equal to or less than the predetermined threshold GTH. Alternatively, if the driver of the host vehicle 10 is not performing a brake operation, on the other hand, if the determination result in step S18 is “YES”, it is determined that the possibility of contact is high, and step S19 Proceed to
The predetermined threshold GTH corresponds to a state in which the host vehicle 10 stops when the distance between the object and the host vehicle 10 is equal to or less than the predetermined distance Zv (0) when the acceleration Gs during the brake operation is maintained. The value to be

In step S19, the driver generates an audible alarm such as a sound via the speaker 6, a visual alarm such as a display via the display device 7, or a predetermined tension on the seat belt, for example. A tactile alarm is output by applying a tactilely perceptible tightening force or by generating vibration (steering vibration) that can be perceived by the driver tactilely on the steering wheel.
Next, in step S20, for example, image data obtained by the infrared camera 2R is output to the display device 7, and a relatively approaching object is displayed as an emphasized image.

Hereinafter, the alarm determination process in step S17 described above will be described with reference to the accompanying drawings.
For example, as shown in FIG. 4, the alarm determination process includes a collision determination process, a determination process as to whether or not the vehicle is within the approach determination area, an approach collision determination process, an artificial structure determination process, and a pedestrian determination process. This is a process for determining the possibility of occurrence of contact between the host vehicle 10 and the detected object. In the following, referring to a case where there is an object 20 moving at a speed Vp in a direction substantially orthogonal to the traveling direction of the host vehicle 10 (for example, the Z direction), for example, as shown in FIG. explain.

First, in step S31 shown in FIG. 4, a collision determination process is performed. In this collision determination process, for example, in FIG. 5, the object 20 approaches the distance Zv (0) from the distance Zv (N−1) along the direction parallel to the traveling direction of the host vehicle 10 during the predetermined time ΔT. In this case, the relative speed Vs in the Z direction of the host vehicle 10 is calculated, and when it is assumed that the host vehicle 10 and the object 20 move within the predetermined ground height H while maintaining the relative speed Vs, It is determined whether or not the host vehicle 10 and the object 20 come into contact within the margin time Ts.
If this determination is “NO”, the flow proceeds to step S 37 described later.
On the other hand, if this determination is “YES”, the flow proceeds to step S32.
The margin time Ts is a time for determining the possibility of occurrence of contact at a timing earlier than the predicted contact occurrence time by a predetermined time Ts, and is set to about 2 to 5 seconds, for example. Further, the predetermined ground height H is set to a value that is about twice the vehicle height of the host vehicle 10, for example.

Next, in step S32, it is determined whether or not the detected object exists within a predetermined approach determination area. In this determination process, for example, as shown in FIG. 6, in the area AR <b> 0 that can be monitored by the infrared cameras 2 </ b> R and 2 </ b> L, it is an area before the position Z <b> 1 ahead of the host vehicle 10 by a distance (Vs × Ts). An area of a predetermined ground height H having a width (α + 2β) obtained by adding a predetermined width β (for example, about 50 to 100 cm) to both sides of the vehicle width α of the host vehicle 10 in the vehicle lateral direction (that is, the X direction). If AR1, that is, the object continues to exist, it is determined whether or not the object exists in the approach determination area AR1 where the possibility of occurrence of contact with the host vehicle 10 is extremely high.
If this determination is “YES”, the flow proceeds to step S 34 described later.
On the other hand, if this determination is “NO”, the flow proceeds to step S33.

And in step S33, the approach collision determination process which determines whether a target object enters into an approach determination area | region and may contact with the own vehicle 10 is performed. In this approach collision determination process, for example, as shown in FIG. 6, objects existing in the entry determination areas AR2 and AR3 of a predetermined ground height H existing outside the approach determination area AR1 in the vehicle lateral direction (that is, the X direction). It is determined whether there is a possibility that the object moves and enters the approach determination area AR1 and contacts the host vehicle 10.
If this determination is “YES”, the flow proceeds to step S 36 described later.
On the other hand, if this determination is “NO”, the flow proceeds to step S 37 described later.

And in step S34, the artificial structure determination process which determines whether a target object is an artificial structure is performed. In this artificial structure determination process, as described later, for example, when a feature that is impossible for a pedestrian is detected, it is determined that the target object is an artificial structure, and is excluded from the alarm target.
If this determination is “NO”, the flow proceeds to step S35.
On the other hand, if this determination is “YES”, the flow proceeds to step S 37.
And in step S35, the pedestrian determination process which determines whether there exists a possibility that a target object is a pedestrian is performed.
If the determination result of step S35 is “YES”, the process proceeds to step S36.
On the other hand, when the determination result of step S35 is “NO”, the process proceeds to step S37 described later.

In step S36, if the object may enter the approach determination area and come into contact with the host vehicle 10 in step S33 described above (YES in step S33), or in step S35, the artificial structure If it is determined that the object determined not to be a pedestrian (YES in step S35), it is determined that contact between the detected object and the vehicle 10 may occur, and the object Is determined to be an alarm target, and a series of processing ends.
On the other hand, in step S37, when there is no possibility that the host vehicle 10 and the object come into contact with each other within the predetermined margin time Ts in step S31 described above (NO in step S31), or the object approaches in step S33. When there is no possibility of entering the determination area and coming into contact with the host vehicle 10 (NO in step S33), or when it is determined in step S34 that the object is an artificial structure (YES in step S34), Alternatively, if it is determined in step S34 that the object determined not to be an artificial structure is not a pedestrian (NO in step S35), there is a possibility of occurrence of contact between the detected object and the host vehicle 10. It is determined that there is no object, it is determined that the object is not an alarm target, and the series of processing ends.

  In the following, when the artificial structure determination process in step S34 and the pedestrian determination process in step S35 described above are recognized such that a plurality of objects overlap each other on the image data, Processing for calculating the height dimension (vertical width) will be described.

In this artificial structure determination process, first, the lower end position of the gray scale region (that is, the region where the object exists on the gray scale image) is calculated.
First, as shown in FIG. 7, for example, on a reference image (for example, the right image obtained by the infrared camera 2R), a predetermined vertical width (height) adjacent to each other downward from the lower end of the binarized object OB. A plurality of first search areas Mask_U1 (I) (I is an appropriate positive integer) having a width (dyP) and a horizontal width dxP are set.
Here, the predetermined horizontal width dxP is, for example, a value obtained by developing a predetermined horizontal width MASK_W in real space (for example, a value larger than the shoulder width of a pedestrian, such as 70 cm) on the image (= focal length f × predetermined horizontal width MASK_W). / Object distance z) or a predetermined value (for example, binarized object width Wb + 2 × predetermined value M_W; where predetermined value M_W is 2 pixels or the like), whichever is larger is set.
Further, the predetermined vertical width dyP is, for example, a value obtained by developing a predetermined vertical width MASK_H (for example, 10 cm) in real space on an image (= focal length f × predetermined horizontal width MASK_H / object distance z), or a predetermined vertical width DYP Of the minimum values, the larger value is set.

Then, for each first search area Mask_U1 (I) continuously arranged in the binarized object OB, each first search area is calculated by calculating the sum of the right image and the left image (Sum of Absolute difference). The parallax dn1 (I) of Mask_U1 (I) is calculated, and based on the parallax dn1 (I) and the parallax Δd calculated in step S13 described above,
| Dn1 (I) −Δd | <predetermined threshold DISP_TH, or
(Dn1 (I) −Δd) ≧ predetermined threshold DISP_TH
The first search area Mask_U1 (I) at the lowest end position is detected.

Here, when | dn1 (I) −Δd | <predetermined threshold DISP_TH, that is, when the parallax between the binarized object OB and the first search area Mask_U1 (I) at the lowest end position is substantially equal, Based on the coordinates (xP1 (I), yP1 (I)) of the upper left vertex UL1 (I) of one search area Mask_U1 (I), the lower end position Ob_min_y of the grayscale area is, for example, as shown in FIG.
Ob_min_y = yP1 (I) + dyP
It becomes.
In FIG. 7, the binarized object OB is represented by the coordinates (xb, yb) of the circumscribed rectangle of the circumscribed rectangle of the binarized object OB, the width Wb of the circumscribed rectangle, and the height Hb of the circumscribed rectangle. The lower end position (yb + Hb) and the lateral (x direction) position (xb + Wb / 2) of the gravity center of the binarized object OB are shown.

Further, (dn1 (I) −Δd) ≧ predetermined threshold DISP_TH, that is, another object O1 (for example, a wall or the like) at a position in front of the binarized object OB, for example, as shown in FIGS. Is present, the lower end position D_F_yP of the first search area Mask_U1 (K) (K is an appropriate integer) at the lowermost end position having substantially the same parallax as the binarized object OB, The height delta_H of the object O1 (for example, a wall or the like)
delta_H = yP1 (I) + dyP / 2−D_F_yP,
The vertical width O_delta_H of the binarized object OB shielded by the other object O1 is set to the ground height Cam_H of the infrared cameras 2R and 2L and the distance d from the infrared cameras 2R and 2L to the other object O1. Based on
O_delta_H = (delta_H-d_Cam_H) + z_Cam_H
And In addition,
d_Cam_H = f × Cam_H / d, z_Cam_H = f × Cam_H / z
It is.
Thus, the actual height dimension (vertical width) of the binarized object OB is obtained by adding the vertical width O_delta_H to the apparent vertical width of the binarized object OB detected on the grayscale image. The lower end position Ob_min_y of the gray scale area is
Ob_min_y = D_F_yP + O_delta_H
It becomes.

Next, when calculating the upper end position of the gray scale region, a predetermined vertical width (height width) adjacent to each other upward from the upper end of the binarized object OB corresponding to the case of calculating the lower end position. ) A plurality of search areas Mask_U (I) (I is an appropriate positive integer) having dyP and width dxP are set.
Here, the predetermined horizontal width dxP is, for example, a value obtained by developing a predetermined horizontal width MASK_W in real space (for example, a value larger than the shoulder width of a pedestrian, such as 70 cm) on the image (= focal length f × predetermined horizontal width MASK_W). / Object distance z) or a predetermined value (for example, binarized object width Wb + 2 × predetermined value M_W; where predetermined value M_W is 2 pixels or the like), whichever is larger is set.
Further, the predetermined vertical width dyP is, for example, a value obtained by developing a predetermined vertical width MASK_H (for example, 10 cm) in real space on an image (= focal length f × predetermined horizontal width MASK_H / object distance z), or a predetermined vertical width DYP Of the minimum values, the larger value is set.

Then, for each search area Mask_U (I) continuously arranged on the binarized object OB, each search area Mask_U (I) is calculated by a calculation (Sum of Absolute difference) between the right image and the left image. The parallax dn (I) is calculated, and based on the parallax dn (I) and the parallax Δd calculated in step S13 described above,
| Dn (I) −Δd | <predetermined threshold DISP_TH
The search region Mask_U (I) at the uppermost end position is detected.
From the coordinates (xP (I), yP (I)) of the upper left vertex UL (I) of the search area Mask_U (I) of the uppermost position, the upper end position Ob_max_y of the grayscale area is
Ob_max_y = yP (I)
It becomes.
Thereby, the gray scale region is set as a region having a vertical width and a horizontal width dxP from the upper end position Ob_max_y to the lower end position Ob_min_y.

As described above, according to the vehicle periphery monitoring device according to the present embodiment, the obstacle (the other object O1) exists between the infrared cameras 2R and 2L and the binarized object OB. Even when the actual lower end of the binarized object OB cannot be directly detected and there is a possibility that the height dimension of the binarized object OB is erroneously detected, Based on the height dimension (height delta_H) of the obstacle (other object O1), the height dimension (vertical width O_delta_H) of the binarized object OB shielded by the obstacle (other object O1) By calculating, it is possible to prevent occurrence of erroneous detection of the actual height dimension of the binarized object OB.
And when the height dimension (vertical width) of the binarized object calculated by the process mentioned above is a value of the range permitted as a pedestrian, the binarized object is a pedestrian. If the height dimension (vertical width) of the binarized object calculated is outside the range allowed as a pedestrian, the binarized object is determined to be an artificial structure. be able to.

In the above-described embodiment, when another object (for example, a wall or the like) is present in front of the binarized object OB, (dn1 (I) −Δd) ≧ predetermined threshold DISP_TH The first search region Mask_U1 (I) at the lowermost position is detected, but the present invention is not limited to this. For example, as shown in FIG. 10, for each first search region Mask_U1 (I), (dn1 ( I) −Δd) ≧ predetermined threshold DISP_TH (that is, it is determined that there is another object O1 that is an obstacle between the infrared cameras 2R and 2L and the binarized object OB), which are substantially mutually One or a plurality of first search areas Mask_U1 (I) having the same parallax may be newly set as the second search areas Mask_U2 (I).
In this case, it is determined whether or not the set second search region Mask_U2 (I) is continuously arranged on the binarized object OB, and the binarized objects have substantially the same parallax. The second search area Mask_U2 (I) at the lowermost position is detected from one or a plurality of second search areas Mask_U2 (I) continuously arranged in the OB, and is abbreviated as the binarized object OB. The lower end position D_F_yP of the first search area Mask_U (I) at the lowermost position and the second search area Mask_U2 (I at the lowermost position, which have the same parallax and are continuously arranged on the binarized object OB ) May be calculated based on the lower end position Ob_min_y of the gray scale region.
Furthermore, in this case, when determining whether or not the second search area Mask_U2 (I) is continuously arranged on the binarized object OB, the second search areas Mask_U2 (I The second search region Mask_U2 (I + j) (j is an arbitrary integer) existing within a predetermined distance from the second search region Mask_U2 (I) may be determined.

It is a block diagram which shows the structure of the vehicle periphery monitoring apparatus which concerns on embodiment of this invention. It is a figure which shows the vehicle carrying the vehicle periphery monitoring apparatus shown in FIG. It is a flowchart which shows operation | movement of the vehicle periphery monitoring apparatus shown in FIG. It is a flowchart which shows the alarm determination process shown in FIG. It is a figure which shows an example of the relative position of the own vehicle and a target object. It is a figure which shows an example of area | region divisions, such as an approach determination area set ahead of a vehicle. It is a figure which shows an example of 1st search area Mask_U1 (I) set when detecting the lower end position of a gray scale area | region. It is a figure in the real space which shows an example in case the other target object O1 (for example, wall etc.) exists in the position before the binarized target object OB. It is a figure on an image which shows an example when the other target object O1 (for example, wall etc.) exists in the position before this binarization target object OB. It is a figure which shows an example of 1st search area Mask_U1 (I) and 2nd search area Mask_U2 (I) set when detecting the lower end position of the gray scale area which concerns on the modification of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image processing unit 2R, 2L Infrared camera 3 Yaw rate sensor 4 Vehicle speed sensor 5 Brake sensor 6 Speaker 7 Display apparatus 10 Own vehicle step S7 Binarization object extraction means step S19 Alarm output means step S34 Obstacle judgment means, height calculation Means, object type determination means, first search area setting means, second search area setting means, continuity determination means Step S35 Pedestrian recognition means

Claims (5)

A vehicle periphery monitoring device that extracts an object existing in the outside of the host vehicle as an object based on an image obtained by imaging by an infrared imaging means,
Binarization object extraction means for extracting a binarization object from image data obtained by binarizing the grayscale image of the image;
Obstacle determining means for determining whether or not there is another object that is an obstacle between the infrared imaging means and the binarized object extracted by the binarized object extracting means. When,
The height for calculating the height dimension of the binarized object based on the height dimension of the obstacle on the gray scale image when it is determined in the determination result of the obstacle determination means that the obstacle exists. A calculation means;
A vehicle periphery monitoring device comprising: an object type determining unit that determines a type of the object based on a height dimension of the binarized object calculated by the height calculating unit. A vehicle periphery monitoring device that extracts an object existing in the outside of the host vehicle as an object based on an image obtained by imaging by an infrared imaging means,
Binarization object extraction means for extracting a binarization object from image data obtained by binarizing the grayscale image of the image;
A first search for setting a plurality of first search areas adjacent to each other having a predetermined height below the binarized object extracted by the binarized object extracting means on the gray scale image. Region setting means;
The binarized object distance, which is a state quantity related to the distance between the binarized object extracted by the binarized object extracting means and the infrared imaging means, and the first search area setting means The first search region distance, which is a state quantity related to the distance between each of the plurality of first search regions set and the infrared imaging means, is compared, and the first shorter than the binarized object distance. A second search area setting means for newly setting the first search area corresponding to the search area distance as a second search area;
Continuity determining means for determining whether or not the second search area set by the second search area setting means is continuously arranged on the binarized object;
The second search area determined by the continuity determination unit to be continuously arranged on the binarization target from the lower end of the binarization target extracted by the binarization target extraction unit The value obtained by adding the height according to the distance to the lower end of the second search region located at the lowest position to the vertical width of the binarized object is the height of the binarized object. A height calculating means to set as a height dimension;
A vehicle periphery monitoring device comprising: an object type determining unit that determines a type of the object based on a height dimension of the binarized object calculated by the height calculating unit. The continuity determining means is the second search area in which the binarized object or the second search area existing within a predetermined distance from the appropriate second search area is the second search area continuously arranged. The vehicle periphery monitoring device according to claim 2, wherein the determination is made. Pedestrian recognition means for recognizing pedestrians existing in the external world of the vehicle based on the image,
The pedestrian recognition means performs a pedestrian recognition process on the object that is determined to be other than an artificial structure or a pedestrian by the object type determination means. Item 3. The vehicle periphery monitoring device according to Item 2. 4. The apparatus according to claim 1, further comprising an alarm output unit that outputs an alarm to the object that is determined to be other than an artificial structure or a pedestrian by the object type determining unit. The vehicle periphery monitoring device according to one.

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