JPH0980165A - Apparatus and method for detecting object - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost apparatus and a method for detecting an object with a simple structure which facilitates the maintenance and management of the side of the object to be detected and without necessity of a high grade image processor. SOLUTION: A retroreflecting material of a predetermined pattern for retroreflecting the light of a near infrared wavelength band is previously provided at an object to be detected. An emitting unit 1 emits a light of a near infrared wavelength band in a monitoring area. A CCD camera 2 is so exposure regulated to make it possible to discriminate the image of high luminance light. The camera 2 images only the image of the monitoring area by the light of the near infrared wavelength band. The image signal from the camera 2 is binarized by a binarizer 3, and the binary image data is stored in an image memory 4. A discriminator 5 discriminates whether the retroreflecting material is present in the monitoring area or not based on the binarized image data.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an object detecting apparatus and method for detecting whether or not a predetermined object (including a person) exists within a predetermined monitoring area.

[0002]

BACKGROUND OF THE INVENTION In various applications, it is required to detect whether a given object is within a given surveillance area. For example, when a visually impaired person enters the surveillance area, in order to give an alarm or guide the current position,
It is required to detect whether or not a visually impaired person exists within a predetermined area.

Conventionally, based on such a request, for example, a detecting device shown in FIG. 8 has been devised. This detection device is for detecting that the visually impaired person 1 has entered the monitoring area 2, and is installed above the monitoring area 2 and a transmitter 3 which is carried by the visually impaired person 1 and emits weak radio waves. The receiver 4 includes a receiver 4 that receives the weak radio wave emitted from the transmitter 3, and a determination unit (not shown) that determines whether the receiver 4 receives the weak radio wave. Monitoring area 2
Is determined by the level of the weak radio wave emitted from the transmitter 3 and the receiving sensitivity of the receiver 4. In addition, visually impaired person 1
Has a cane 5 for the visually impaired.

According to the detection apparatus shown in FIG. 8, when the transmitter 3 enters the monitoring area 2, the receiver 4 receives the weak radio wave emitted from the transmitter 3, and the reception state is determined by the determination unit. If it is determined that the visually impaired person 1 is in the monitoring area 2 and there is no transmitter 3 in the monitoring area 2, the receiver 4 does not receive the weak radio wave, and the state in which the weak radio wave is not received is the determination. It is determined by the section that the visually impaired person 1 is not in the monitoring area 2.

[0005]

However, in the above-mentioned conventional detecting device, it is premised that the visually impaired person 1 carries the transmitter 3, and the transmitter 3 is out of order or the battery serving as its power source has a long life. Since it does not work when it runs out, the visually impaired person 1 has to periodically replace the battery and check the operation at relatively short time intervals, and it is troublesome to maintain the transmitter 3. In addition to being troublesome, there is a drawback in that the detection device is not likely to operate because the maintenance is easy to neglect. Further, since the transmitter 3 is relatively expensive and the number of visually impaired persons 1 is large, the conventional detection device has a drawback that the entire system is expensive.

Under such circumstances, not only the detection device for detecting whether or not the visually impaired person is in the monitoring area, but also the detection for detecting whether or not various other objects are present in the monitoring area. The same applies to the device.

The present invention has been made in view of the above circumstances, and it is not necessary to provide an expensive transmitter or the like to an object to be detected, maintenance of the object to be detected can be easily performed, and high-level It is an object of the present invention to provide an object detection apparatus and method that does not require a special image processing circuit or the like, has a simple configuration, and is inexpensive.

[0008]

In order to solve the above-mentioned problems, an object detecting device according to a first aspect of the present invention is an irradiation unit for irradiating a predetermined monitoring region with light of a predetermined wavelength region, and the irradiation unit. Based on the image signal obtained from the image pickup means, which is arranged in the vicinity and picks up the image of the monitoring area by only the light of the predetermined wavelength area, a predetermined pattern provided in advance on the object to be detected. A retroreflective material that is a retroreflective material that retroreflects light in the predetermined wavelength region,
And a determining means for determining whether or not it exists in the monitoring area.

The pattern of the retroreflective material includes the shape, the size, the number of the retroreflective material, the positional relationship when there are a plurality of retroreflective materials, the mutual spacing, and the like.

An object detecting apparatus according to a second aspect of the present invention is the object detecting apparatus according to the first aspect, in which the retroreflective material having the predetermined pattern has a different pattern depending on a direction of the object, It further comprises direction determining means for determining the orientation of the retroreflective material existing in the monitoring area based on the image signal obtained from the means.

An object detecting apparatus according to a third aspect of the present invention is an irradiation unit for irradiating a predetermined monitoring region with light in a predetermined wavelength region, and is arranged in the vicinity of the irradiation unit, and uses only light in the predetermined wavelength region. An image pickup means for picking up an image of the monitoring area, and a retroreflective material having a predetermined pattern provided in advance on an object to be detected based on image signals obtained temporally before and after the image pickup means, And a traveling direction determining means for retroreflecting light in a predetermined wavelength region and determining the traveling direction of the retroreflective material existing in the monitoring region.

An object detecting apparatus according to a fourth aspect of the present invention is the object detecting apparatus according to the third aspect, wherein the advancing direction determining means determines that the image of the retroreflective material is relative to the image of the monitoring area. It is detected that each of the lines crosses each of a plurality of preset lines, and the traveling direction of the retroreflective material is determined based on the temporal order of the detection by the plurality of lines.

An object detecting device according to a fifth aspect of the present invention is the object detecting device according to any one of the first to fourth aspects, wherein the light in the predetermined wavelength region is light in the near infrared wavelength region. Is.

An object detecting apparatus according to a sixth aspect of the present invention is the object detecting apparatus according to any one of the first to fifth aspects, wherein the object is a cane for the visually impaired.

In the object detecting method according to the seventh aspect of the present invention, a retroreflective material having a predetermined pattern that retroreflects light in a predetermined wavelength region is provided in advance on the object to be detected. A predetermined monitoring region is irradiated with light in the predetermined wavelength region. The monitoring region is imaged from a direction substantially the same as the irradiation direction of the light in the predetermined wavelength region by using an image capturing unit that captures an image of only the light in the predetermined wavelength region. Based on the image signal obtained from the image pickup means, it is determined whether or not the retroreflective material exists in the monitoring area.

In the object detecting method according to the eighth aspect of the present invention, in the object detecting method according to the seventh aspect, the pattern of the retroreflective material is changed according to the direction of the object, and the pattern is obtained from the image pickup means. The orientation of the retroreflective material present in the monitoring area is determined based on the image signal.

In the object detecting method according to the ninth aspect of the present invention, a retroreflective material having a predetermined pattern for retroreflecting light in a predetermined wavelength region is provided in advance on the object to be detected. A predetermined monitoring region is irradiated with light in the predetermined wavelength region. The monitoring region is imaged from a direction substantially the same as the irradiation direction of the light in the predetermined wavelength region by using an image capturing unit that captures an image of only the light in the predetermined wavelength region. The traveling direction of the retroreflective material existing in the monitoring area is determined based on the image signals obtained temporally before and after by the image pickup means.

According to the present invention, in use, a retroreflective material having a predetermined pattern that retroreflects light in a predetermined wavelength range irradiated by the irradiation means is provided in advance on the object to be detected.
The retroreflective material has the property of reflecting high-luminance light only in the same direction as the direction of the irradiation light (retroreflection).

Therefore, since the irradiation means irradiates the monitoring area with the light in the predetermined wavelength range, and the imaging means is arranged in the vicinity of the irradiation means, if the retroreflective material exists in the monitoring area, the imaging means is The brightness of the image of the retroreflective material to be captured is high, and the image is due to the light in the predetermined wavelength region.

On the other hand, the brightness of the image of the portion (background) other than the retroreflective material due to the light in the predetermined wavelength range irradiated by the irradiation means is much lower than the brightness of the image of the retroreflective material.
Although the background image is also generated by the light of the surrounding illumination and the sunlight, the predetermined wavelength region is defined so as not to include the light of the surrounding illumination and the sunlight (the predetermined wavelength region is defined as the fifth wavelength region). As in the embodiment, for example, the near infrared wavelength region is set)
As a result, even if the brightness of the background image due to the light of the surrounding illumination or the sunlight is increased, the background image due to the light is not due to the light in the predetermined wavelength region.

By the way, the image pickup means picks up an image of only the light in the predetermined wavelength region. Therefore, as described above, while the image of the retroreflective material in the monitoring area has high brightness and is due to the light in the predetermined wavelength range, the background image in the monitoring area has low brightness or Since it is not due to the light in the predetermined wavelength region, after all, only the image of the retroreflective material in the monitoring region can be easily extracted from the image signal obtained by the image pickup means by the brightness.

Therefore, the image of the object to be detected or the like is not extracted from the background by a sophisticated image processing circuit or a difficult image processing method, and based on the image signal from the image pickup means,
Whether or not the retroreflective material provided on the object to be detected is present in the monitoring area can be easily judged by the judgment means, and thus it is detected whether or not the object to be detected is present in the monitoring area. can do. Therefore, according to the present invention, there is no need for an advanced image processing circuit or the like, and the configuration is simple and the cost is low.

In the present invention, the object to be detected is
Only the retroreflective material is provided, and there is no need to provide a transmitter or the like as in the conventional case. Since the retroreflective material is much cheaper than a transmitter or the like, according to the present invention, the cost of the entire system can be significantly reduced. Also,
In the present invention, since only the retroreflective material is provided on the object, reliable operation of the object detection device can be ensured over a long period of time without the need for maintenance such as battery replacement and operation confirmation on the object side to be detected. Can be secured.

If the pattern of the retroreflective material is made different according to the direction of the object, the monitoring area is based on the image signal obtained from the image pickup means as in the second and eighth aspects. The direction of the retroreflective material present therein can be easily determined by the direction determining means. Therefore,
In this case, not only the presence or absence of the object to be detected but also the direction of the object to be detected can be known.

Further, as in the third, fourth and ninth modes, if the advancing direction of the retroreflective material is judged based on the image signals obtained temporally before and after from the image pickup means, it is detected. It is possible to detect the traveling direction of the moving object to be moved. When the traveling direction cannot be determined, the moving object does not exist, and as a result, it can be detected whether the moving object exists in the monitoring area.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an object detecting apparatus and method according to a first embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a schematic block diagram showing an object detecting device according to a first embodiment of the present invention. FIG. 2 is an explanatory diagram showing an arrangement example of the irradiation unit 1 and the CCD camera 2.

The object detecting apparatus according to the present embodiment is shown in FIG.
As shown in FIG. 1, the irradiation unit 1, the CCD camera 2, the binarization processing unit 3, the image memory 4, the determination unit 5, and the control unit 6 that controls each of these elements are provided.

In the present embodiment, the irradiation unit 1 is provided with an infrared LED, which is not shown in the drawing, for emitting light in the near infrared wavelength region, and a drive circuit for lighting and driving the infrared LED. . Then, as shown in FIG. 2, the irradiation unit 1 is installed above the monitoring area 7 so as to irradiate a predetermined monitoring area 7 with light having a near-infrared wavelength from above. In the present embodiment, the irradiation unit 1 constitutes an irradiation unit that irradiates the monitoring area 7 with light in a predetermined wavelength range. The light emitted by the irradiation unit 1 is not limited to the light in the near infrared wavelength range. Further, in the present embodiment, the irradiation unit 1 is
Although it is arranged so as to irradiate light from above the monitoring area 7 almost directly below it, it may be arranged so as to irradiate light from above the monitoring area 7 obliquely downward, or depending on the application, to the side of the monitoring area 7. It may be arranged so as to irradiate light laterally from.

As shown in FIG. 2, the CCD camera 2 is arranged in the vicinity of the irradiation unit 1, and is arranged so as to pick up an image of the monitoring area 7 from a direction substantially the same as the light irradiation direction of the irradiation unit 1. ing. Further, as shown in FIG. 1, the CCD camera 2 has an optical filter 8 which transmits only light in the near-infrared wavelength region on the light receiving side, and only the image of the monitoring region 7 by the light in the near-infrared wavelength region is displayed. It is designed to capture images. Further, the CCD camera 2 has a variable optical diaphragm 9 and an electronic shutter adjusting section 10, which are used to adjust the gain of an image signal amplifier (not shown) and the brightness threshold value of a binarization processing section 3 described later. The exposure of the CCD camera 2 is adjusted so that the image of high-intensity light can be discriminated by appropriately setting it in consideration of the above. In the present embodiment, the exposure adjustment is performed so that the brightness of the image signal from the CCD camera 2 other than the high brightness light portion becomes almost zero level and only the high brightness light image is extracted by the CCD camera 2 itself. Is being done. Of course, in the image signal from the CCD camera 2, the exposure adjustment may be performed so that the luminance of the portion other than the high-luminance light portion is not zero level but lower than the luminance level of the high-luminance light portion. Depending on 2 itself, only the image of high brightness light may not be extracted. Even in this case, for example, by appropriately setting the brightness threshold of the binarization processing unit 3 to be described later, only the image of high brightness light can be easily extracted. In the present embodiment, the CCD camera 2 is used as an image pickup unit that adjusts the exposure so that an image of high-intensity light can be discriminated and also picks up an image of the monitoring region 7 by only light in the near-infrared wavelength region. However, such an image pickup means is not limited to the CCD camera.

The maximum range of the monitoring area 7 is the overlapping area of the irradiation field of the irradiation unit 1 and the field of view of the CCD camera 2, but the monitoring area 7 is an area to be judged by the judgment unit 5 described later. By defining, it is possible to set the entire overlapping area or only an arbitrary partial area of the overlapping area.

The object detecting apparatus according to the present embodiment is shown in FIG.
As shown in FIG. 3, an object to be detected, for example, a walking blind 12 for the visually impaired person 11 is provided with a retroreflective material having a predetermined pattern for retroreflecting light in the near infrared wavelength region in advance. The premise is to put it.

FIG. 3 is a diagram showing examples of various patterns of the retroreflective material. In the example shown in FIGS. 2 and 3A, the retroreflective material 13 having a length L1 is provided over the entire circumference of the cane 12. In the example shown in FIG. 3B, two retroreflective members 14 a and 14 b having the same length L 2 are provided over the entire circumference of the cane 12 at intervals L 3 in the longitudinal direction of the cane 12.
In the example shown in FIG. 3C, the length L is set over the entire circumference of the cane 12.
The retroreflective material 15a of No. 4 is provided, and the length L6 (>
The retroreflective material 15b of L4) is provided over the entire circumference of the cane 12. In the example shown in FIG. 3D, three retroreflective members 16a, 16 having the same length L7 are provided over the entire circumference of the cane 12.
b and 16c are provided, and a distance L8 is provided between the retroreflective material 16a arranged on the tip side of the cane 12 and the central retroreflective material 16b.
A space L9 (<L8) is formed between the central retroreflective material 16b and the retroreflective material 16c on the gripping side of the cane 12.

The pattern of the retroreflective material shown in FIGS. 3 (a) and 3 (b) is the same regardless of the orientation of the cane 12 (that is, whether the tip side or the gripping side of the cane 12).
The pattern of the retroreflective material shown in (c) and FIG.
It differs depending on the direction of the cane 12. That is, FIG.
In the example shown in (c), the length L4 of the retroreflective material 15a on the tip side is different from the length L6 of the retroreflective material 15b on the grip side. In the example shown in FIG. 3D, the distance L between the retroreflective material 16a on the tip side and the retroreflective material 16b on the center side is L.
8 and the distance L9 between the central retroreflective material 16b and the grip side 16c are different.

In the following description, for the sake of convenience, it is assumed that the cane 12 is provided with a retroreflective material 13 as shown in FIGS. 2 and 3 (a).

Referring again to FIG. 1, the binarization processing unit 3
Performs binarization processing of the image signal obtained from the CCD camera 2 with a predetermined brightness threshold value to obtain binarized image data. The image memory 4 stores this binarized image data.

The retroreflective material 13 has the property of reflecting high-luminance light only in the direction substantially the same as the direction of the irradiation light (retroreflection). Therefore, since the irradiation unit 1 irradiates the monitoring region 7 with light in the near-infrared wavelength region, and the CCD camera 2 is arranged in the vicinity of the irradiation unit 1, if the retroreflective material 13 exists in the monitoring region 7, The brightness of the image of the retroreflective material 13 captured by the CCD camera 2 is high, and the image is due to light in the near infrared wavelength range. On the other hand, due to the light in the near-infrared wavelength range irradiated by the irradiation unit 1,
The brightness of the image of the portion (background) other than the retroreflective material 13 is much lower than the brightness of the image of the retroreflective material 13. The background image is also generated by the light of the surrounding illumination and the sunlight, but since the light of the ambient illumination and the sunlight hardly include light in the near-infrared wavelength region, even if the light of the ambient illumination and the background of the sunlight Even if the brightness of the image becomes high, the background image due to the light is not due to the light in the near infrared wavelength region. Therefore, in this embodiment, the CCD camera 2
Is subjected to the exposure adjustment so as to extract only the image of the high-intensity light and captures the image of only the light in the near-infrared wavelength region, so that the image of the retroreflective material 13 in the monitoring region 7 is finally obtained from the CCD camera 2. Only the image signal extracted as a high-intensity image is obtained. Therefore, by appropriately setting the brightness threshold of the binarization processing unit 3,
From this, image data obtained by extracting only the image of the retroreflective material 13 is obtained, and this image data is stored in the image memory 4.

If the visible image in the field of view of the CCD camera 2 is such an image as shown in FIG. 4A, the image represented by the image data stored in the image memory 4 is as shown in FIG. 4B. As shown in FIG. 7, only the image of the retroreflective material 13 is left and the background is erased. In FIG. 4, for convenience,
The images of the visually impaired person 11, the cane 12 and the retroreflective material 13 are also assigned the same reference numerals as those of the visually impaired person 11, the cane 12 and the retroreflective material 13. Further, the upward direction in FIG. 4 corresponds to the leftward direction in FIG. 2, and the downward direction in FIG. 4 corresponds to the rightward direction in FIG.

As described above, in this embodiment, only the image of the retroreflective material 13 can be easily extracted from the background without using an advanced image processing circuit or a difficult image processing method.

Further, in FIG. 1, the determination unit 5 determines whether or not the retroreflective material 13 is present in the monitoring area 7 based on the image data stored in the image memory 4, and when it is determined that it is present. , A detection signal indicating that the retroreflective material 13 is present in the monitoring area 7 is output.

For example, the determining unit 5 determines whether or not a high-intensity portion exists in the area corresponding to the monitoring area 7 in the image data, and if so, the pattern of the high-intensity portion is the pattern of the retroreflective material 13. Whether the retroreflective material 13 exists in the monitoring area 7 (that is, the pattern of the retroreflective material 13 is adapted to the area corresponding to the monitoring area 7 in the image data). It is determined whether or not there is an image of a predetermined pattern. Whether or not the pattern of the high-brightness portion matches the pattern of the retroreflective material 13 can be determined according to a normal image recognition method, for example, based on the shape, size, etc. of the retroreflective material 13. . Further, for example, in the example shown in FIGS. 3B to 3D, the determination can be made based on the distance between the retroreflective materials and the like.

The determination unit 5 simply determines whether or not there is a high-intensity portion in the area corresponding to the monitoring area 7 in the image data, so that the retroreflective material 13 is present in the monitoring area 7. It is also possible to determine whether or not it exists. However, there is a low possibility that the light of the surrounding illumination or the sunlight is strong even if the light in the near-infrared wavelength range includes the light in the near-infrared wavelength range. Therefore, in order to prevent erroneous detection, if there is a high-luminance portion in the area corresponding to the monitoring area 7 in the image data, it may be determined whether the pattern of the high-luminance portion matches the pattern of the retroreflective material 13. It is preferable to judge whether or not the retroreflective material 13 exists in the monitoring area 7 by judging.

In the present embodiment, the binarization processing unit 3, the image memory 4, and the determination unit 5 are provided on the cane 12 based on the image signal obtained from the CCD camera 2, and the retroreflective material 13 is provided. It constitutes a determination means for determining whether or not is present in the monitoring area 7.

Next, the operation of the object detecting device according to this embodiment will be described with reference to the flowchart shown in FIG.

When the operation is started, first, step S1
Then, the image data is loaded into the image memory 4. This fetching is performed as follows under the control of the control unit 6. First, the control unit 6 causes the irradiation unit 1 to emit light in the near-infrared wavelength region, and causes the CCD camera 2 to open its shutter to supply an image signal for one image to the binarization processing unit 3. The control unit 6 continues to turn on the irradiation unit 1 at least while the shutter of the CCD camera 2 is open. Also,
The control unit 6 causes the binarization processing unit 3 to binarize the image signal from the CCD camera 2, and stores the binarized image data obtained from the binarization processing unit 3 in the image memory 4.

Next, in step S2, under the control of the control unit 6, the determination unit 5 sets the retroreflective material 13 in the monitoring area 7 based on the image data stored in the image memory 4 as described above. Is present. When it is determined that the retroreflective material 13 exists in the monitoring area 7, the determination unit 5 outputs a detection signal (object identification signal) indicating that the retroreflective material 13 exists in the monitoring area 7, and returns to step S1. On the other hand, S
If it is determined in step 2 that there is not, the process directly returns to step S1.

In this embodiment, since the object to be detected is the cane 12 for the visually impaired person, the detection signal from the judging section 5 indicates that the visually impaired person 11 is within the predetermined area. Will be shown. This detection signal can be used, for example, to give the visually impaired person 11 a voice guidance of the current position or to warn the user of a dangerous place.

According to the object detecting apparatus of the present embodiment described above, the CCD camera 2 can be used without extracting the image of the visually impaired person 11 or the walking stick 12 from the background by using an advanced image processing circuit or a difficult image processing method. Based on the image signal from the
It is possible to easily determine whether or not the wand 12 is present in the inside of the monitoring area 7, and eventually it is detected whether or not the wand 12 to be detected is present within the monitoring area 7, and thus whether or not the visually impaired person 11 is within a predetermined area. can do. Therefore, according to the present embodiment, there is no need for an advanced image processing circuit or the like, and the configuration is simple and inexpensive.

Further, in this embodiment, the object to be detected is only provided with the retroreflective material 13, and it is not necessary to provide a transmitter or the like as in the conventional case. Since the retroreflective material 13 is much cheaper than the transmitter or the like, according to the present embodiment, the cost of the entire system can be significantly reduced. Further, in this embodiment, the retroreflective material 1 is used.
Since only 3 is provided on the cane 12, there is no need for maintenance work such as battery replacement and operation confirmation on the side of the visually impaired person 12,
It is possible to ensure a reliable operation of the object detection device for a long period of time.

Next, an object detecting device according to a second embodiment of the present invention will be described.

The object detecting device according to the present embodiment is basically the same as the object detecting device according to the first embodiment, but is partially modified. That is, the object detecting device according to the present embodiment is premised on that the retroreflective material having a different pattern depending on the direction of the cane 12 is provided on the cane 12 as shown in FIGS. 3C and 3D. And In the following description, for the sake of convenience, it is assumed that the cane 12 is provided with retroreflective materials 15a and 15b as shown in FIG. Further, in the object detection device according to the present embodiment, the determination unit 5 in FIG. 1 determines whether or not the retroreflective materials 15a and 15b are present in the monitoring area 7 based on the image data stored in the image memory 4. In addition, the orientations of the retroreflective materials 15a and 15b existing in the monitoring area 7 are determined based on the image data stored in the image memory 4.

The operation of the object detecting device according to this embodiment will be described with reference to FIGS. 6 and 7.

FIG. 6 is a diagram showing an example of an image represented by the image data stored in the image memory 4 in the present embodiment. In FIG. 6, for convenience, the retroreflective materials 15a, 15
The image of b is also given the same reference numerals as the retroreflective materials 15a and 15b, and the upward direction in FIG. 6 corresponds to the leftward direction in FIG.
The downward direction in the middle corresponds to the right direction in FIG. Further, FIG. 7 is a flowchart showing the operation of the object detection device according to the present embodiment. The same steps as those in the flowchart shown in FIG. 5 are designated by the same reference numerals, and detailed description thereof will be omitted.

In this embodiment, when the operation is started, the binary image data is loaded into the image memory 4 in step S1 described above. Now, as shown in FIG. 2, the visually handicapped person 11 advances (or is about to proceed) from the right side to the left side in FIG. 2 (however, the cane 12 is now provided with retroreflective materials 15a and 15b). 2) in the monitoring area 7, the tip side of the cane 12 is projected to the left side in FIG. The image of the data is shown in Figure 6.
As shown in (a), the background is erased with only the images of the retroreflective materials 15a and 15b, and the image of the retroreflective material 15a having a short length is located above the retroreflective material 15b having a long length. Appear in. On the other hand, when the visually impaired person 11 advances (or tries to proceed) from the left side to the right side in FIG.
Since the tip end side of 2 is projected rightward in FIG. 2 with respect to the gripping side, the image represented by the image data stored in the image memory 4 is the retroreflective material 15a, as shown in FIG. 6 (b). 1
The image of 5b is removed, the background is erased, and the image of the long-length retroreflective material 15b is the short-length of the retroreflective material 15.
Appears on the upper side with respect to a.

Next, in step S2, the determination section 5 determines whether or not the retroreflective materials 15a and 15b are present in the monitoring area 7 based on the image data stored in the image data image memory 4. If it is determined that there is not, the process returns to step S1. On the other hand, if it is determined in step S2 that the retroreflective materials 15a and 15b are present in the monitoring area 7, the determination unit 5 determines the orientation of the retroreflective materials 15a and 15b in step S10 based on the image data stored in the image memory 4. To do. The determination of this direction can be performed as follows, for example. That is, as shown in FIG. 6, the vertical projection length v1 of the upper retroreflective material 15a or 15b and the vertical projection length v2 of the lower retroreflective material 15b or 15a are obtained, and v1 < By determining whether or not v2 (the state of FIG. 6A), the retroreflective material 15
The direction of a, 15b (that is, the direction of the tip of the cane 12 and the traveling direction of the visually impaired person 11) is the forward direction (the upward direction in FIG. 6 and the leftward direction in FIG. 2) or the reverse direction. (Downward in FIG. 6 and rightward in FIG. 2) is determined.

When it is determined in step S10 that the direction is the forward direction, the determination section 5 outputs the forward direction determination signal in step 11, and the process returns to step S1. In the present embodiment, this forward direction discrimination signal indicates that the visually impaired person 11 is in the predetermined area and is or is about to proceed in the forward direction. On the other hand, when it is determined in step S10 that the direction is not the forward direction, the determination unit 5 outputs the reverse direction determination signal in step 12, and the process returns to step S1. In the present embodiment, this backward direction discrimination signal indicates that the visually impaired person 11 is in the predetermined area and is moving in the backward direction or is about to proceed. The forward direction determination signal and the backward direction determination signal can be used, for example, by voice to the visually impaired person 11 to guide not only the current position but also the destination in the traveling direction of the visually impaired person 11.
Further, these forward direction determination signal and reverse direction determination signal are
For example, it can be used not only for guidance when crossing a road but also for controlling a traffic signal.

As described above, according to the present embodiment, the direction of the object to be detected can be detected very easily.

In this embodiment, the retroreflective material 15 is used.
Although the directions of a and 15b (that is, the direction of the tip of the cane 12) are divided into two directions for determination, the directions may be determined by further subdividing them as necessary. For example, as described above, not only is it determined whether or not v1 <v2, but also the horizontal projection length h1 of the left retroreflector 15a or 15b and the right retroreflector 15a or 15b as shown in FIG. Reflector 15
The vertical projection length h2 of b or 15a is calculated, and h1 <
By also determining whether or not it is v2, it is determined which of the four directions (the upper left direction, the upper right direction, the lower left direction, and the lower right direction in FIG. 6) the orientation of the tip of the wand 12 is. You can also When it is necessary to strictly know the direction of the retroreflective materials 15a and 15b (that is, the direction of the tip of the cane 12), for example, the central coordinates of the images of the retroreflective materials 15a and 15b are obtained and the length is long. A vector from the center coordinates of the image of the retroreflective material 15b to the center coordinates of the image of the short-length retroreflective material 15a may be calculated.

Next, an object detecting device according to a third embodiment of the present invention will be described.

The object detecting apparatus according to this embodiment is obtained by modifying the object detecting apparatus according to the first embodiment as described below, and the other points are the object according to the first embodiment. It is configured similarly to the detection device. That is, in the object detection device according to the present embodiment, the image capturing in step S1 in FIG. 5 is sequentially performed at relatively short time intervals during the operation of the device, and the determination unit 5 in FIG.
Is a modification of the object detection device according to the first embodiment so as to perform the operation shown in FIG.

In the following description, it is assumed that the cane 12 is provided with a retroreflective material 13 as shown in FIGS. 2 and 3 (a) for the sake of convenience.

The operation of the determination unit 5 in this embodiment will be described with reference to FIGS. 9 and 10. FIG. 9 is a flowchart showing the operation of the determination unit 5 in this embodiment. FIG. 10 is a diagram showing an example of an image represented by the image data stored in the image memory 4 at a certain time. In FIG. 10, for convenience, the image of the retroreflective material 13 is also given the same reference numeral as the retroreflective material 13, and the upward direction in FIG. 10 corresponds to the leftward direction in FIG. 2 and the downward direction in FIG. Corresponds to the right direction in FIG.

In the present embodiment, as shown in FIG.
For the image indicated by the image data stored in the image memory 4 (that is, the image of the monitoring area 7), four lines C1 are previously set.
~ C4 is set. These lines C1 to C4
Does not appear in the image data itself, but indicates a linear position on the image and is virtual. In the present embodiment, the lines C1 to C4 are set so as to extend in the left-right direction in FIG. 10, are parallel to each other with a space therebetween, and are in order of the lines C1 to C4 from the bottom in FIG. ing. The intervals between the lines C1 to C4 and the positions in the monitoring area 7 are not limited to the example shown in FIG.

When the object detecting apparatus according to the present embodiment starts its operation, first in step S21, the determination unit 5 determines the image data based on the latest image data stored in the image memory 4 at that time. At a position crossing the line C1 in the image indicated by (in other words, on the line C1)
It is determined whether or not there is a high-luminance image (that is, an image of the retroreflective material 13 normally). Specifically, this determination can be performed by, for example, checking the value of each pixel on the line C1 and determining whether or not there is a pixel having a value indicating high brightness. If it is determined in step S21 that there is a high-luminance image at a position crossing the line C1, the process proceeds to step S23, and in step S21, the line C1 is detected.
If it is determined that there is no high-intensity image at a position that crosses, the process proceeds to step S22. Therefore, when the image of the retroreflective material 13 is located at a position crossing the line C1 as shown in FIG. 10A at the time point t during the process of step S21, the process proceeds to step S23.

In step S22, the determination section 5 determines, based on the latest image data stored in the image memory 4 at that time, that the image indicated by the image data crosses the line C4 (in other words, the line C4). On C4)
It is determined whether or not there is a high-luminance image (that is, an image of the retroreflective material 13 normally). If it is determined that there is a high-intensity image at the position that crosses the line C4, the process proceeds to step S33,
If it is determined that there is no high-intensity image at the position crossing the line C4, the process returns to step S21. Therefore, step S2
When the image of the retroreflective material 13 is located at a position that crosses the line C4 as shown in FIG. 10C at the time point t ′ during the processing of 2, the process proceeds to step S33.

In step S23, the determination section 5 waits for a predetermined time Δt1. This is detected by performing the determination in step S26, which will be described later, based on the image data obtained after a predetermined time Δt1 has elapsed since it was determined in step S21 that there is a high-luminance image at the position crossing the line C1. This is because the moving object moving at a higher speed than the moving speed of the cane 12 (in the present embodiment, the cane 12 is regarded as a moving object) that is an object to be ignored is ignored to improve the detection accuracy. However, it is not always necessary to perform the process of step S23, and if it is determined in step S21 that there is a high-luminance image at a position crossing the line C1, the process may immediately proceed to step S24.

Next, the determination section 5 starts time counting (step S24), and determines whether or not a predetermined time Δt2 has elapsed since the time counting started in step S24 (step S2).
5). If the predetermined time Δt2 has elapsed, step S21
Then, if the predetermined time Δt2 has not elapsed, the process proceeds to step S26. In step S26, the determination unit 5
On the basis of the latest image data stored in the image memory 4 at that time, at a position crossing the line C2 in the image indicated by the image data (in other words, the line C2
It is determined whether or not there is a high-luminance image (that is, an image of the retroreflective material 13 normally) on the upper side. If it is determined that there is no high-luminance image at the position that crosses the line C2, the process returns to step S25, and if it is determined that there is a high-luminance image at the position that crosses the line C2, the process proceeds to step S27. Therefore, at the time point t + Δt during the processing of step S26 (from the time point t, Δ
When the image of the retroreflective material 13 is located at a position that crosses the line C2 as shown in FIG. 10B after the time t has elapsed), the process proceeds to step S27.

It should be noted that the processing directly proceeds from step S23 or step S21 to step S26 without performing the processing of steps S24 and S25, and at the same time, proceeds to step S26.
If it is determined that there is no high-intensity image at the position crossing the line C2 at 26, the process may return to step S26 again. However, the image of the retroreflective material 13 advances diagonally upward in FIG. 10 and once crosses the line C1 and then the line C2.
Since it may happen that the image does not cross the image of the monitoring area 7 without crossing the path, as described above, step S2
It is preferable to perform the processing of S4 and S25.

In step S27, the determination section 5 determines whether or not the high-intensity image determined to cross the line C2 in step S26 matches the pattern of the retroreflective material 13. This determination is made, for example, in FIG.
It is possible to do this by obtaining the vertical projection length v10 of the image as shown in FIG. 3 and determining whether or not the projection length v10 is within a predetermined range. If it is determined that it does not match the pattern of the retroreflective material 13, the process returns to step S21, and if it is determined that it does not match the pattern of the retroreflective material 13, the process proceeds to step S28.

Note that the determination in step S27 is made in order to prevent erroneous detection and improve detection accuracy, since the high-luminance image may not be the image of the retroreflective material 13 although the possibility is low. Is. However, step S2
Instead of performing the process of step 7, if it is determined in step S26 that there is a high-luminance image at a position crossing the line C2, the process may immediately proceed to step S28.

In step S28, the determination section 5 outputs a forward direction determination signal, and the process returns to step S21. In the present embodiment, as shown in FIGS. 10A and 10B, this forward direction determination signal is first detected that the image of the retroreflective material 13 is located at the position where the image crosses the line C1 (step S21). If it is detected that the line C2 crosses the line C2 (YES in step S26), it is output. Therefore, the visually impaired person 11 is in a predetermined area and is in the forward direction (in FIG. 10). This means that the vehicle is traveling in the upward direction and to the left in FIG.

In step S22, line C4
If it is determined that there is a high-intensity image at a position that crosses, the steps S33 to S38 similar to the steps S23 to S28 described above are performed on the line C3.

That is, in step S33, the determination section 5 waits for a predetermined time Δt1. This is detected by performing the determination in step S36, which will be described later, based on the image data obtained after a predetermined time Δt1 has elapsed since it was determined in step S22 that there is a high-luminance image at the position crossing the line C4. This is because the moving object moving at a higher speed than the moving speed of the cane 12 (in the present embodiment, the cane 12 is regarded as a moving object) that is an object to be ignored is ignored to improve the detection accuracy. However, it is not always necessary to perform the process of step S33, and if it is determined in step S22 that there is a high-luminance image at a position crossing the line C4, the process may immediately proceed to step S34.

Next, the determination section 5 starts time counting (step S34), and determines whether or not a predetermined time Δt2 has elapsed since the time counting started in step S34 (step S3).
5). If the predetermined time Δt2 has elapsed, step S21
Then, if the predetermined time Δt2 has not elapsed, the process proceeds to step S36. In step S36, the determination unit 5
On the basis of the latest image data stored in the image memory 4 at that time, at a position crossing line C3 in the image indicated by the image data (in other words, line C3
It is determined whether or not there is a high-luminance image (that is, an image of the retroreflective material 13 normally) on the upper side. If it is determined that there is no high-luminance image at the position that crosses the line C3, the process returns to step S35, and if it is determined that there is a high-luminance image at the position that crosses the line C3, the process proceeds to step S37. Therefore, the time point t ′ + Δt ′ (the time point t ′ during the processing of step S36)
(At the time point when Δt ′ time has elapsed from the time), FIG.
When the image of the retroreflective material 13 is located at a position that crosses the line C3 as shown in (4), the process proceeds to step S37.

It should be noted that the processing directly proceeds from step S33 or step S22 to step S36 without performing the processing of steps S34 and S35.
If it is determined at 36 that there is no high-intensity image at the position crossing the line C3, the process may return to step S36. However, the image of the retroreflective material 13 advances diagonally downward in FIG. 10 and once crosses the line C4 and then the line C3.
It may happen that the image does not cross the image of the monitoring area 7 without crossing the line, so as described above, step S3.
It is preferable to perform the processing of S35.

In step S37, the determination section 5 determines whether or not the high-intensity image determined to cross the line C3 in step S36 matches the pattern of the retroreflective material 13. This determination is made, for example, in FIG.
It is possible to do this by obtaining the vertical projection length v20 of the image as shown in FIG. 2 and determining whether or not the projection length v20 is within a predetermined range. If it is determined that it does not match the pattern of the retroreflective material 13, the process returns to step S21, and if it is determined that it does not match the pattern of the retroreflective material 13, the process proceeds to step S38.

The determination in step S37 may be performed in order to prevent erroneous detection and improve the detection accuracy, since the high-luminance image may not be the image of the retroreflective material 13 although the possibility is low. Is. However, step S3
Instead of performing the process of 7, it may be possible to immediately shift to step S38 when it is determined in step S36 that a high-luminance image is present at a position crossing the line C3.

In step S38, the determination section 5 outputs a reverse direction determination signal, and the process returns to step S21. In the present embodiment, this forward direction determination signal is first detected that the image of the retroreflective material 13 crosses the line C4, as shown in FIGS. If YES in step S36 is detected (YES in step S36), it is output. Therefore, the visually handicapped person 11 is in the predetermined area in the opposite direction (in FIG. 10). It means that the vehicle is traveling downward and to the right in FIG.

Also in the present embodiment, the forward direction discrimination signal and the backward direction discrimination signal are, for example, voiced to the visually impaired person 11 and guide not only the current position but also the destination in the traveling direction of the visually impaired person 11. Can be used to Further, the forward direction determination signal and the reverse direction determination signal can be used not only for guidance when walking on a road but also for controlling a traffic signal.

As can be seen from the above description, in the present embodiment, the judging section 5 is provided in advance on the object to be detected and monitors based on the image signals obtained from the CCD camera 2 temporally before and after. A traveling direction determination unit that determines the traveling direction of the retroreflective material 13 existing in the area 7 is configured. Then, the determination unit 5 determines that the image of the retroreflective material 13 is the monitoring area 7
Of the retroreflective material 13 based on the temporal order of the detection by the plurality of lines C1 to C4, respectively. The direction of travel is being determined. However, the advancing direction determining means is not limited to one using such a plurality of lines.

In this embodiment, a pair of lines C
1, C2 determines the forward direction, and another pair of lines C
Although the reverse direction is determined by 3 and C4, both directions may be determined by a pair of lines. For example, a pair of lines C
If only 1 and C2 are set, step 2 in FIG.
2, based on the latest image data stored in the image memory 4 at that time, it is determined whether or not there is a high-intensity image at a position crossing the line C2 in the image indicated by the image data, and FIG. In step 36 in the middle, based on the latest image data stored in the image memory 4 at that time, it is judged whether or not there is a high-luminance image at a position crossing the line C1 in the image indicated by the image data. Good.

Although the respective embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, in each of the above embodiments, the object to be detected is a cane for the visually impaired, but the object to be detected is not limited to such a cane.

[0083]

According to the present invention, it is not necessary to provide an expensive transmitter or the like on an object to be detected, maintenance of the object to be detected is easy, and an advanced image processing circuit or the like is provided. There is no need, and the configuration is simple and inexpensive.

[Brief description of drawings]

FIG. 1 is a schematic block diagram showing an object detection device according to each embodiment of the present invention.

FIG. 2 is an explanatory diagram showing an arrangement example of an irradiation unit and a CCD camera.

FIG. 3 is a diagram showing examples of various patterns of a retroreflective material.

FIG. 4 is a diagram showing an example of a visible image in the field of view of a CCD camera and an image represented by image data stored in an image memory.

FIG. 5 is a flowchart showing the operation of the object detection device according to the first embodiment of the present invention.

FIG. 6 is a diagram showing another example of an image represented by image data stored in an image memory.

FIG. 7 is a flowchart showing an operation of the object detection device according to the second embodiment of the present invention.

FIG. 8 is a schematic configuration diagram showing a conventional detection device.

FIG. 9 is a flowchart showing an operation of a determination unit in the object detection device according to the third exemplary embodiment of the present invention.

FIG. 10 is a diagram showing still another example of the image represented by the image data stored in the image memory.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 irradiation part 2 CCD camera 3 binarization processing part 4 image memory 5 judgment part 6 control part 7 monitoring area 11 visually impaired person 12 cane 13, 14a, 14b, 15a, 15b retroreflective material 16a, 16b, 16c retroreflective material

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location H04N 7/18 G01V 9/04 S // G01J 1/02 G06F 15/70 350H

Claims (9)

[Claims] 1. An irradiation unit for irradiating a predetermined monitoring region with light in a predetermined wavelength region, and an image pickup unit arranged near the irradiation unit for capturing an image of the monitoring region only with light in the predetermined wavelength region. A retroreflective material having a predetermined pattern, which is provided in advance on an object to be detected based on an image signal obtained from the imaging means, and which retroreflects light in the predetermined wavelength region, An object detection apparatus comprising: a determination unit that determines whether or not the object is present. 2. The retroreflective material having the predetermined pattern has a different pattern depending on the orientation of the object, and the retroreflective material existing in the monitoring area is based on an image signal obtained from the imaging means. 2. The object detecting device according to claim 1, further comprising direction determining means for determining the orientation of the object. 3. An irradiation unit for irradiating a predetermined wavelength region with light in a predetermined wavelength region, and an image pickup unit arranged in the vicinity of the irradiation unit for capturing an image of the monitoring region only with light in the predetermined wavelength region. , A retroreflective material having a predetermined pattern provided in advance on an object to be detected based on image signals obtained temporally before and after from the image pickup means, and retroreflects light in the predetermined wavelength region to monitor the light. An object detection apparatus comprising: a traveling direction determination unit that determines a traveling direction of a retroreflective material existing in a region. 4. The traveling direction determination means respectively detects that the image of the retroreflective material is at a position that crosses each of a plurality of lines set in advance with respect to the image of the monitoring area, and detects the plurality of lines. The object detection apparatus according to claim 3, wherein the traveling direction of the retroreflective material is determined based on a temporal order of the detection by a line. 5. The object detection device according to claim 1, wherein the light in the predetermined wavelength region is light in the near infrared wavelength region. 6. The object detection device according to claim 1, wherein the object is a walking stick for a visually impaired person. 7. A retroreflective material having a predetermined pattern that retroreflects light in a predetermined wavelength region is provided in advance on an object to be detected, and a predetermined monitoring region is irradiated with light in the predetermined wavelength region, The monitoring area is imaged in a direction substantially the same as the irradiation direction of the light in the predetermined wavelength area by using an image capturing means that captures an image of only light, and the retroreflection is performed based on the image signal obtained from the image capturing means. An object detection method, comprising: determining whether or not a material exists within the monitoring area. 8. A pattern of the retroreflective material is changed according to the orientation of the object, and the orientation of the retroreflective material existing in the monitoring area is determined based on an image signal obtained from the image pickup means. The object detection method according to claim 7, wherein 9. A retroreflective material having a predetermined pattern that retroreflects light in a predetermined wavelength region is provided in advance on an object to be detected, and a predetermined monitoring region is irradiated with the light in the predetermined wavelength region, By using an image pickup means for picking up an image of only light, the monitoring area is imaged in a direction substantially the same as the irradiation direction of the light in the predetermined wavelength range, and an image signal obtained temporally before and after the image pickup means is obtained. On the basis of this, the traveling direction of the retroreflective material existing in the monitoring area is determined.