JPH0954893A - Vehicle recognizing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely recognize the vehicle number of a number plate at a low cost with one image pickup camera without being affected by the approaching direction of the vehicle approaching from an entrance port and the mounting location of the number plate in the vehicle even when the image pickup range of the image pickup camera is narrower than the vehicle approaching range of the entrance port. SOLUTION: This device is provided with a PAN driving part 7 performing the rotation driving of an image pickup camera 2. When the number plate of a vehicle does not exist in the image data picked up by the image pickup camera 2, the vehicle is tracked by performing the PAN driving of the image pickup camera 2 in a PAN driving range by the PAN driving part 7 till the existence of the number plate is confirmed in image data via a number plate check part 9.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention picks up an image of a vehicle entering from an entrance such as a gas station through an image pickup camera, and based on the picked-up image data, displays the vehicle number on a license plate attached to the vehicle. The present invention relates to a vehicle recognition device that recognizes a vehicle by performing reading recognition, and particularly, even when the imaging range of an imaging camera is narrower than the vehicle entrance range of an entrance, The present invention relates to a vehicle recognition device capable of reliably recognizing a vehicle number of a license plate at a low cost with a single image pickup camera without being affected by a license plate mounting position in a vehicle.

[0002]

2. Description of the Related Art Conventionally, various types of devices have been proposed for recognizing a vehicle by reading and recognizing a license plate attached to the vehicle. For example, Japanese Patent Laid-Open No. 5-32
Japanese Patent No. 5091 has a vehicle head detection camera that photographs a predetermined area on the road to detect the vehicle head of the vehicle, and a vehicle number reading camera that photographs the vehicle number on the license plate of the vehicle when illuminated by a strobe device, Automatic vehicle number reading configured to switch the video signal of the vehicle head detecting camera to the video signal of the vehicle number reading camera via the image signal processing means when the vehicle head of the vehicle enters the field of view of the vehicle number reading camera The device is described.

Further, Japanese Patent Laid-Open No. 6-68376 discloses that
An image of a vehicle traveling on the road was taken through a TV camera, and the license plate was extracted by performing image processing of the captured image through a license plate reading device to recognize the number characters and measure the speed of the vehicle. After that, there is described a speeding warning device which displays a warning of speeding and a number of a violating vehicle on a display plate when the measured speed of the vehicle exceeds a threshold value. Each of the vehicle number automatic reading device and the speed warning device performs the specific recognition of the vehicle by reading and recognizing the license plate of the vehicle (automobile) traveling straight on the road.

By the way, in recent years, there is an increasing demand for recognizing a vehicle entering from an entrance at a gas station or the like and providing various services to the user of the vehicle. In order to achieve this request, the license plate attached to the vehicle entering from the entrance is read and recognized as quickly as possible, and the user name and various maintenance information are grasped based on the read license plate car number. It is then necessary to provide various services.

On the other hand, when a vehicle enters through an entrance such as a gas station, it enters while making a left turn (when entering from the right of the entrance) and when making a right turn (at the entrance). On the other hand, when entering from the left)
There is. In this way, in order to read and recognize the license plate of the vehicle entering from the entrance, the vehicle is photographed through a fixedly installed imaging camera, and the license plate is cut out from the photographed image data. It is common to recognize the vehicle number, but in order to accurately read and recognize the license plate of the vehicle in each of the above two cases, whether the vehicle enters from the right direction to the entrance, Alternatively, the front image data of the vehicle cannot be accurately acquired unless the timing of capturing the image data of the vehicle captured by the imaging camera is changed depending on whether the vehicle enters from the left direction. It is necessary to detect whether it is coming in or coming in from the left.

However, each of the above-mentioned JP-A-5-32
The devices described in Japanese Patent No. 5091 and Japanese Patent Application Laid-Open No. 6-68376 both perform reading recognition of a license plate of a vehicle traveling straight on a road, and the vehicle enters while bending in any direction. There is no means for detecting that. Therefore, since each of these devices cannot detect the bending direction of the vehicle, it is not possible to accurately and accurately acquire the front image of the vehicle entering from the entrance such as a gas station taken through the imaging camera, As a result, there is a problem that the reading and recognition of the license plate cannot be performed quickly.

In order to solve the above problems, the applicant of the present application has proposed a new vehicle recognition device in Japanese Patent Application No. 6-257665. In such a vehicle recognition device, the two sensors are used to detect the approach direction of the vehicle entering from the entrance, and the image is taken through one imaging camera corresponding to the detected approach direction of the vehicle. By adjusting the timing of capturing the front image of the vehicle, the front image of the vehicle can always be captured accurately regardless of the approaching direction of the vehicle, and the license plate attached to the vehicle can be read and recognized accurately. It is possible to provide a vehicle recognizing device that can achieve low cost.

[0008]

However, vehicles having various sizes such as trucks, passenger cars, and wagons come to the gas stations and the like, and vehicles of any size can safely enter the gas stations. Therefore, the entrance area of the vehicle is generally designed to be wide enough. On the other hand, the imaging range (area) of the imaging camera for recognizing the license plate of the vehicle entering from the entrance is narrower than the vehicle entrance range of the entrance. here,
Regarding the relationship between the vehicle entry range of the entrance and the image pickup area of the image pickup camera in the conventional gas station, FIG.
It will be described based on.

FIG. 8 is an explanatory view schematically showing the relationship between the vehicle entrance range of the entrance of a conventional gas station and the image pickup area of the image pickup camera. There are two gas station G (left side in FIG. 8). An entrance gate 51, which is regulated between two gate pillars 50, is provided.
The vehicle entry range of 1 is the distance A between the gate columns 50.
Further, at a predetermined position in the gas station G, an image of the vehicle entering through the entrance gate 51 is taken, and the image data obtained by the image is taken to recognize the vehicle number of the license plate attached to the vehicle. The camera 52 is fixedly installed. The image pickup area B of the image pickup camera 52, as shown in FIG. 8, can pick up only a part of the vehicle entry range A.

Therefore, in the case as shown in FIG.
When the vehicle enters the gas station G from the entrance gate 51 and enters the imaging area B of the imaging camera 52, the vehicle is properly imaged through the imaging camera 52 and the vehicle number of the license plate is displayed. Although recognizable, on the other hand, when the vehicle enters from a position outside the imaging area B of the imaging camera 52, the imaging camera 52 cannot properly image the vehicle. In such a case, naturally, the vehicle number of the license plate in the vehicle cannot be surely recognized, and as a result, various customer services cannot be provided to the user of the vehicle.

Further, if a plurality of image pickup cameras 52 are installed in the gas station G so that the vehicle can be imaged over the entire entry area of the entrance gate 51, the vehicle can be seen from any position of the entrance gate 51. It is possible to recognize the license plate even when entering,
In this case, a plurality of image pickup cameras 52 are required, resulting in high cost.

The present invention has been made in order to solve the above-mentioned conventional problems. Even when the image pickup range of the image pickup camera is narrower than the vehicle entry range of the entrance, the entrance enters from the entrance. An object of the present invention is to provide a vehicle recognition device capable of reliably recognizing the vehicle number of a license plate at a low cost with a single imaging camera without being influenced by the approaching direction of the vehicle or the mounting position of the license plate in the vehicle. And

[0013]

In order to achieve the above object, a vehicle recognition device according to a first aspect of the present invention captures an image of a vehicle entering from an entrance having a predetermined vehicle entry range, and
An image pickup camera having an image pickup range narrower than a vehicle approach range, a first judgment means for judging whether or not a vehicle license plate is present in image data picked up by the image pickup camera, and the first judgment means. When it is determined that the license plate does not exist in the image data by the rotational driving means, the imaging camera is driven to rotate in the horizontal direction until the existence of the license plate in the image data is confirmed by the first determining means. When the first judging means judges that a license plate is present in the image data, the second judging means judges whether the vehicle number of the license plate can be recognized, and the second judging means determines whether the license plate is included in the license plate. When it is determined that the vehicle number can be recognized, the vehicle number recognition means for recognizing the vehicle number is provided.

In the vehicle recognition device of the first aspect, the vehicle entering through the entrance is imaged by the imaging camera. Also,
The first determining means determines whether or not the vehicle license plate is present in the image data captured by the image capturing camera. If the license plate does not exist in the image data based on the judgment result of the first judging means, the imaging camera confirms the existence of the license plate in the image data through the rotation driving means. Is driven to rotate horizontally. Then, when the presence of the license plate in the image data is confirmed by the first judging means, it is further judged by the second judging means whether the vehicle number of the license plate can be recognized. When it is determined by the second determining means that the license plate can be recognized, the vehicle number of the license plate is recognized through the vehicle number recognizing means.

As described above, in the vehicle recognition device according to the first aspect, when the license plate is not present in the image data of the vehicle, until the presence of the license plate in the image data is confirmed by the first judging means, Since the vehicle can be tracked by rotationally driving the image pickup camera in the horizontal direction via the rotational driving means, it is affected by the approaching direction of the vehicle entering from the entrance and the mounting position of the license plate in the vehicle. Instead, it is possible to reliably recognize the vehicle number of the license plate at a low cost with one imaging camera.

A vehicle recognition device according to a second aspect of the present invention is
The vehicle recognition apparatus according to claim 1, wherein when the second determination unit determines that the vehicle number of the license plate cannot be recognized, the rotational drive is performed until the vehicle number of the license plate is recognized through the second determination unit. A tilting means for driving the image pickup camera in an oblique direction in cooperation with the means is provided.

According to another aspect of the vehicle recognition device of the present invention, when the second judging means judges that the vehicle number of the license plate cannot be recognized, the vehicle number of the license plate is recognized through the second judging means. Up to, the tilting means cooperates with the rotation driving means to drive the image pickup camera in an oblique direction, whereby the image pickup camera is tilted in an oblique direction while being rotationally driven in the horizontal direction. It becomes possible to efficiently track the vehicle and reliably recognize the vehicle number of the license plate.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a vehicle recognition device according to the present invention will be described in detail with reference to the drawings based on an embodiment embodying the present invention. First, a vehicle recognition device according to the first embodiment will be described with reference to FIG. FIG. 1 is a control block diagram of the vehicle recognition device in the first embodiment.

In FIG. 1, the vehicle recognition device 1 is basically composed of an image pickup camera 2, a camera drive unit 3, and a control unit 4 for controlling the camera drive unit 3. The imaging camera 2 captures image data of the vehicle captured through the lens unit 5 and the lens unit 5 that performs zoom-up and zoom-down, and sends the image data to the A / D conversion unit 8 of the control unit 4. It has a part 6. The image pickup camera 2 is fixedly installed inside the gas station G (see FIG. 3 and the like) and always takes an image of the vehicle 16 (see FIG. 4).

The camera drive unit 3 rotates the image pickup camera 2 in the horizontal direction (hereinafter referred to as PAN drive) P.
The PAN driver 7 includes an AN driver 7.
Generally, it is composed of a gear mechanism connected to a camera base to which the image pickup camera 2 is fixed and a pulse motor for driving the gear mechanism. By rotating the pulse motor by a predetermined amount, the camera base is moved by a predetermined amount via the gear mechanism. It works by rotating each. The PAN drive unit 7 always sets the camera base at a predetermined reference position, and the imaging camera 2 takes an image of the center position of the entrance gate 15 provided at the gas station G at this reference position. (See Figure 3).

The control unit 4 converts the image data sent from the camera unit 6 into digital image data by A / D conversion, and the edge detection of the digital image data from the A / D conversion unit 8. License plate check unit 9, license plate check unit 9 for checking whether or not an image of the license plate 17 (see FIG. 4) is present in the image data by performing image processing such as processing, binarization processing, etc.
When it is determined that the license plate 17 is present in the image data, it is determined whether the vehicle number (number) on the license plate 17 can be recognized. If the vehicle number can be recognized, the vehicle number is recognized. If there is no image of the license plate 17 in the image data in the character recognition unit 10 that performs the above, the recognition result output unit 11 that outputs the recognition result in the character recognition unit 10 to the outside (for example, a monitor, etc.), and the license plate check unit 9. When it is determined, the input control unit 12 that controls the drive control signal input to the PAN drive unit 7 to perform the PAN drive of the imaging camera 2 and the character recognition unit 10 each time the vehicle number is determined to be unrecognizable. In addition, the counter unit 13 is composed of a counter unit 13 in which the counter value n is incremented by one.

It is to be noted that the image processing performed by the license plate check unit 9, the determination process as to whether the license plate 17 is present in the image data, and whether the vehicle number recognition performed by the character recognition unit 10 are possible. Since the determination process and the vehicle number recognition process are known, the description thereof is omitted here.

Next, the operation of the vehicle recognizing device 1 of the first embodiment constructed as described above will be described with reference to FIG. FIG. 2 is a flowchart showing the operation of the vehicle recognition device. Before the recognition operation of the vehicle 16 is started, the PAN drive unit 7 is set at the reference position, and accordingly, the imaging camera 2 is set at the center position of the entrance gate 15 provided at the gas station G. Imaging is being performed (see FIG. 3).

When the vehicle recognition operation starts, first in step (hereinafter abbreviated as S) 1, the counter unit 1
The counter value n of 3 is cleared to 0. Here, the counter value n indicates the number of times a series of search operations from the acquisition of image data to the recognition of the vehicle number, which will be described later, are performed, and 6 is set as the maximum value (maximum search number) of the counter value n. ing. Further, in the vehicle recognition device 1 of the present embodiment, it takes about 500 msec per search operation on average, although it varies depending on the imaged image, and the maximum value of the counter value n is 6, so a series of The search operation is performed for about 3 seconds (sec).

At S2, the image data picked up through the lens unit 5 and the camera unit 6 of the image pickup camera 2 is A / D.
The image data is sent to the conversion unit 8 and the image data is taken in. At the same time, the A / D conversion unit 8 converts the image data into digital image data. In S3,
A / D converter 8 via license plate checker 9
Image processing such as edge detection processing and binarization processing of the digital image data is performed to check whether the image of the license plate 17 exists in the image data.

When it is determined in S3 that the image of the license plate 17 does not exist in the image data (S3: N
O), the PAN drive of the imaging camera 2 is performed via the PAN drive unit 7 (S4). Here, the PAN drive of the imaging camera 2 performed in S4 will be described with reference to FIGS. 3 and 4. FIG. 3 is an explanatory diagram schematically showing a state in which the image pickup camera 2 is PAN-driven, and FIG. 4 is an explanatory diagram schematically showing a state in which the vehicle 16 is imaged by the image pickup camera 2.

In FIG. 3, a gas station G (see FIG.
On the left side of the center, there is an entrance gate 15 that is regulated between two gate pillars 14.
The vehicle approaching range is the distance A between the gate pillars 14. Further, at a predetermined position in the gas station G, an image pickup camera 2 for picking up an image of the vehicle 16 entering from the entrance gate 15 is installed. An image pickup area where the image pickup camera 2 can pick up an image is indicated by B. As is clear from FIG. 3, the image pickup area B of the image pickup camera 2 is about 1/3 of the vehicle entry range A.
The degree is constantly imaged. The imaging camera 2 is a PAN.
When the drive unit 7 is set at the reference position, the entrance gate 15 is substantially at the center position (the center part of the vehicle entry range A).
Is imaged (indicated by a dotted line in FIG. 3).

Then, during the PAN driving of the image pickup camera 2 performed in S4, the image pickup camera 2 is rotationally driven by a predetermined amount in the left or right direction from its reference position via the PAN drive section 7. The PAN driving in S2 to S4 is performed until the determination in S3 becomes YES, that is, until the license plate check unit 9 confirms that the image of the license plate 17 is present in the image data. During this period, the image pickup camera 2 is rotationally driven by a predetermined amount each time the operation of S4 is performed, whereby the image pickup camera 2 is rotationally driven within the PAN drive range C shown in FIG. As a result, the imaging camera 2 can image the vehicle 16 over the entire vehicle approach range A.

By performing the PAN drive of the image pickup camera 2 as described above, as shown in FIG.
When the presence of the license plate 17 is confirmed in the image data obtained by imaging the vehicle 16 via the (S
If the answer is 3: YES, the process proceeds to S5.

Next, returning to FIG. 2, the processing after S5 will be described. In S5, in the character recognition unit 10,
License plate 17 whose existence was confirmed in S3
It is determined whether the vehicle number (number) is recognizable, and if the vehicle number is recognizable, the vehicle number is recognized. If the vehicle number in the license plate 17 is recognizable (S6: YES), the recognition result regarding the recognized vehicle number is output to the external monitor or the like via the recognition result output unit 11 (S7). Furthermore, the PAN driving unit 7 is returned to the reference position and the imaging camera 2 is moved to the reference position (see FIG.
Set to the position of the imaging area B indicated by the dotted line in the middle) (S
8) After that, it returns to S1.

On the other hand, when the vehicle number in the license plate 17 cannot be recognized (S6: NO), the count value n set in the counter section 13 in S9 is the maximum number of vehicle number (number) searches. (Set to 6 in the case of the present embodiment). When the count value n is smaller than the maximum number of vehicle number searches (S9: NO),
After incrementing the count value n of the counter unit 13 by 1 in S10, the process returns to S2 and the processes in S2 and thereafter are performed again. The processes of S2, S3, S5, S6 and S9 are repeated until the determination of S9 becomes YES, that is, the count value n of the counter unit 13 reaches 6, which is the maximum number of vehicle number searches. When YES is determined in S9, the PAN driving unit 7 is returned to the reference position and the imaging camera 2 is set to the reference position in S8 as described above, and then the process returns to S1.

As described above, the vehicle recognition apparatus 1 of the first embodiment is provided with the PAN driving section 7 for rotationally driving the image pickup camera 2, and the license plate of the vehicle 16 is added to the image data picked up by the image pickup camera 2. If the license plate 17 is not present, the license plate check unit 9 confirms the presence of the license plate 17 in the image data.
PAN drive of the imaging camera 2 by the PAN drive unit 7
Since the vehicle 16 is configured to be tracked by performing the operation over the N drive range C, even when the imaging camera 2 having a narrow imaging area B is used, the entire vehicle entry range A of the entrance 15 of the gas station G is used. The image of the vehicle 16 can be taken over the range. Thereby, without being influenced by the approach direction of the vehicle 16 entering from the entrance 15 or the mounting position of the license plate 17 in the vehicle 16,
The vehicle number of the license plate 17 can be reliably recognized by one imaging camera 2 at a low cost.

Next, a vehicle recognition apparatus according to the second embodiment will be described with reference to FIG. The vehicle recognition device of the second embodiment basically has the same configuration as the vehicle recognition device 1 of the first embodiment, and the vehicle recognition device 1 of the first embodiment is the same.
The camera drive section 3 of FIG. 3 is different from the vehicle recognition apparatus 1 of the first embodiment in that a TILT drive section 18 for driving the imaging camera 2 in an oblique direction is provided in addition to the PAN drive section 7. Therefore, in the following description, the same members and the like in the vehicle recognition device 1 of the first embodiment will be denoted by the same reference numerals, and only the configuration different from the vehicle recognition device 1 of the first embodiment will be described. And

FIG. 5 is a control block diagram of the vehicle recognizing device according to the second embodiment. The vehicle recognizing device 20 is similar to the vehicle recognizing device 1 of the first embodiment in that the image pickup camera 2, the camera drive unit 3, and , And the control unit 4. The camera driving unit 3 is provided with a PAN driving unit 7 for driving the imaging camera 2 in a PAN, and a TILT driving unit 18 as a tilting unit for driving the imaging camera 2 in an oblique direction. Like the PAN drive unit 7, the TILT drive unit 18 is composed of a gear mechanism connected to a camera base to which the imaging camera 2 is fixed and a pulse motor for driving the gear mechanism, and rotates the pulse motor by a predetermined amount. By doing so, the camera base is actuated obliquely by a predetermined amount via the gear mechanism, and, as will be described later, it is determined that the license plate 17 is present in the imaging data via the license plate check unit 9. If it is determined that the vehicle number in the license plate 17 cannot be recognized through the character recognition unit 10, the imaging camera is used until the vehicle number of the license plate 17 can be recognized by the character recognition unit 10. 2 has a function of performing TILT driving. Further, the PAN driving unit 7 and the TILT driving unit 18 cooperate with each other to drive the imaging camera. Therefore, the image pickup camera 2 is driven along the right diagonal direction or the left diagonal direction since the horizontal rotation drive and the vertical rotation drive are simultaneously performed.

Since the configurations of the image pickup camera 2 and the control unit 4 are the same as those in the first embodiment, the description thereof will be omitted.

Next, the operation of the vehicle recognition device 20 of the second embodiment will be described with reference to FIG. FIG. 6 is a flowchart showing the operation of the vehicle recognition device 20. The vehicle 16
Before the recognition operation is performed, the PAN driving unit 7
In the same manner as in the first embodiment, the image pickup camera 2 is set at the reference position to image the center position of the entrance gate 15 provided in the gas station G (see FIG. 3), and the TILT drive unit. 18 is set at its reference position (the position of the imaging camera 2 shown by the solid line in FIG. 7) and images the outside of the gate post 14 of the gas station G.

When the vehicle recognition operation starts, first, at step 11, the counter value n of the counter section 13 becomes 0.
Will be cleared. Here, regarding the counter value n, the first
It is set in the same manner as in the embodiment. In subsequent S12, the image data picked up via the lens unit 5 and the camera unit 6 of the image pickup camera 2 is sent to the A / D conversion unit 8, and the image data is captured and the A / D conversion unit 8 At, the image data is converted into digital image data by A / D conversion. In S13, image processing such as edge detection processing and binarization processing of the digital image data from the A / D conversion unit 8 is performed via the license plate check unit 9, and the image of the license plate 17 is included in the image data. Checks for existence.

When it is determined in S13 that the image of the license plate 17 does not exist in the image data (S13:
NO), the PAN of the imaging camera 2 via the PAN drive unit 7
Driving is performed (S14). The PAN of the imaging camera 2
The driving is performed in the same manner as in the case of the first embodiment described with reference to FIGS. 3 and 4, and therefore the description thereof is omitted here.

When the presence of the license plate 17 is confirmed in the image data obtained by imaging the vehicle 16 through the imaging camera 2 by the PAN driving of the imaging camera 2 (S13: YES). ), The process proceeds to S15. In S15, in the character recognition unit 10, the S1
It is determined whether the vehicle number (number) of the license plate 17 whose existence is confirmed in 3 is recognizable,
If the vehicle number can be recognized, the vehicle number is recognized. If the vehicle number in the license plate 17 is recognizable (S16: YES), the recognition result regarding the recognized vehicle number is output to the external monitor or the like via the recognition result output unit 11 (S17). , And PAN driver 7
Back to the reference position to move the imaging camera 2 to the reference position (in FIG. 3,
It is set to the position of the imaging area B shown by the dotted line) (S1
8) After that, it returns to S11.

On the other hand, when the vehicle number in the license plate 17 cannot be recognized (S16: NO), the count value n set in the counter section 13 in S19 is the maximum number of vehicle number (number) searches. (Set to 6 in the case of the present embodiment). Count value n
Is smaller than the maximum number of vehicle number searches (S19: NO), the PAN drive unit 7 and the TILT drive unit 18 perform the PAN drive and the TILT drive of the imaging camera 2 in S20.

The TILT driving of the image pickup camera 2 will be described with reference to FIG. The PAN of the imaging camera 2
The driving is the same as the operation performed in S14. FIG. 7 is an explanatory view schematically showing a state in which the image pickup camera 2 is driven by TILT. Before the TILT drive is started, the image pickup camera 2 is at the reference position (upper position) shown by the solid line in FIG. It is set.

Then, the image pickup camera 2 carried out in S20
When the TILT is driven, the imaging camera 2
The driving unit 18 tilts a predetermined amount downward from the reference position. At the same time as this TILT driving, the imaging camera 2 is PAN driven via the PAN driving unit 7,
A predetermined amount of rotation is driven from the reference position to the left or right. As a result, the imaging camera 2 is driven in the diagonal right direction or the diagonal left direction. The PAN / TILT driving of the imaging camera 2 performed in S20 is S16.
Until the determination in step 1 is YES, that is, the character recognition unit 1
0 until the car number of the license plate 17 is recognized,
Or until the determination in S19 becomes YES, that is,
The process is repeated until the count value n set in the counter unit 13 becomes larger than the maximum number 6 of vehicle number (number) searches. During this time, the imaging camera 2 is driven in the right diagonal direction or the left diagonal direction by a predetermined amount each time the operation of S20 is performed, whereby the imaging camera 2 is moved to the P direction shown in FIG.
P in the AN drive range C and the TILT drive range D shown in FIG.
AN drive and TILT drive are performed. As a result, the imaging camera 2 can image the vehicle 16 over the entire vehicle approach range A through the PAN drive, and also through the TILT drive after the presence of the license plate 17 is confirmed. The vehicle number of the license plate 17 attached to the vehicle 16 entering the gas station G from the entrance gate 15 of the gas station G can be surely recognized.

As described above, after the PAN / TILT drive of the image pickup camera 2 is performed in S20, the count value n of the counter section 13 is incremented by 1 in S21, and the process returns to S12 to perform the processes of S12 and thereafter again. Be seen.
The processing of S12, S13, S15, S16, and S19 is repeated until the determination of S19 becomes YES, that is, the count value n of the counter unit 13 reaches the maximum number of vehicle number search, which is 6. If YES is determined in S19, the PAN driving unit 7 and the TIL are processed in S18.
After returning the T drive part 18 to each reference position and setting the imaging camera 2 in a reference position, it returns to S11.

As described above, in the vehicle recognition device 20 of the second embodiment, the PAN for rotationally driving the image pickup camera 2 is used.
If the license plate 17 of the vehicle 16 is not present in the image data captured by the imaging camera 2, the drive unit 7 and the TILT drive unit 18 for performing TILT drive are provided, and the license plate check unit 9 stores the license plate in the image data. Until the presence of the license plate 17 is confirmed, the PAN drive unit 7 drives the PAN of the imaging camera 2 over the PAN drive range C so that the vehicle 16 is tracked. After the confirmation, the TILT driving unit 18 drives the TILT of the imaging camera 2 over the TILT driving range D until the vehicle number is recognized, so that the license plate 17 is tracked. Even when the imaging camera 2 with a narrow space is used, the entrance 15 of the gas station G Over the entire range of both ingress range A, and can perform imaging of the vehicle 16 over the outside of the entrance gate 15 to the interior of the gas station G.

As a result, one image pickup camera 2 can be manufactured at a lower cost and further without being influenced by the approach direction of the vehicle 16 entering from the entrance 15 or the mounting position of the license plate 17 on the vehicle 16. The vehicle number of the license plate 17 can be reliably recognized in a short time and efficiently. The present invention is not limited to the first and second embodiments described above, and it goes without saying that various improvements and modifications can be made without departing from the spirit of the present invention.

[0046]

As described above, according to the present invention, even when the image pickup range of the image pickup camera is narrower than the vehicle entrance range of the entrance, the entrance direction of the vehicle entering through the entrance or the license plate of the vehicle. It is possible to provide a vehicle recognition device capable of reliably recognizing the vehicle number of a license plate by a single imaging camera at low cost without being affected by the mounting position of the vehicle.

[Brief description of drawings]

FIG. 1 is a control block diagram of a vehicle recognition device according to a first embodiment.

FIG. 2 is a flowchart showing the operation of the vehicle recognition device.

FIG. 3 is an explanatory diagram schematically showing a state in which the imaging camera is being PAN-driven.

FIG. 4 is an explanatory diagram schematically showing a state in which a vehicle is being imaged by an imaging camera.

FIG. 5 is a control block diagram of a vehicle recognition device according to a second embodiment.

FIG. 6 is a flowchart showing the operation of the vehicle recognition device.

FIG. 7 is an explanatory diagram schematically showing a state in which the imaging camera is driven by TILT.

FIG. 8 is an explanatory diagram schematically showing a relationship between a vehicle entrance range of an entrance of a conventional gas station and an imaging area of an imaging camera.

[Explanation of symbols]

1, 20 Vehicle recognition device 2 Imaging camera 3 Camera drive unit 4 Control unit 5 Lens unit 6 Camera unit 7 PAN drive unit 9 License plate check unit 10 Character recognition unit 11 Recognition result output unit 15 Entrance gate 16 Vehicle 17 License plate 18 TILT Drive unit A Vehicle approach range B Imaging area C PAN drive range D TILE drive range G Gas station

Claims (2)

[Claims] 1. An imaging camera that images a vehicle entering from an entrance having a predetermined vehicle entry range and has an imaging range narrower than the vehicle entry range, and image data taken through the imaging camera. First to determine if there is a vehicle license plate in
When the determination means and the first determination means determine that the license plate does not exist in the image data, the imaging camera is kept horizontal until the presence of the license plate in the image data is confirmed via the first determination means. Rotation driving means for rotationally driving in the direction, and second judging means for judging whether or not the vehicle number of the license plate can be recognized when the first judging means judges that the license plate exists in the image data. A vehicle recognizing device comprising: a vehicle number recognizing means for recognizing the vehicle number when the second determining means determines that the vehicle number on the license plate can be recognized. 2. When the second judging means judges that the vehicle number of the license plate is not recognizable, the second driving means cooperates with the rotation driving means until the vehicle number of the license plate is recognized. 2. The vehicle recognition device according to claim 1, further comprising tilting means for driving the image pickup camera in an oblique direction.