JPH09270013A - Device for detecting position of moving body - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive moving body position detector capable of precisely detecting the current position of a moving body by processing a picture obtained by an image pickup means fixed to the moving body. SOLUTION: An input picture obtained by photographing the periphery of a traveling route by a camera fixed on a traveling train 1 and quantizing the photographed picture by an A/D converter and comparing processing data obtained by extracting a characteristic environmental picture part from a comparing picture obtained by previously photographing the periphery of the traveling route are compared with each other by a position arithmetic part 4 and the current position of the train 1 is operated based upon the compared result. The comparing processing data to be used for the position arithmetic part 4 are stored to a comparing processing data base 5 as a data base and accessed from a comparing processing data accessing pointer 6 in accordance with the current position of the train 1. The operated current position of the train 1 is stored in a current position register 7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving body position detecting device for processing an image picked up on a moving body to detect the current position.

[0002]

2. Description of the Related Art Generally, as a device for detecting the current position of a moving body, for example, G using a radio wave from a communication satellite is used.
A PS (Global Positioning System) and a device using a gyro are known. In addition, for example, Japanese Patent Laid-Open No.
-44300 and Japanese Patent Laid-Open No. 59-167716 disclose devices such as fixed signs on the road that are taken by a camera installed on a moving body and move based on the obtained images. What detects the present position of the body is disclosed.

[0003]

However, in the above-mentioned conventional device, it is difficult for the GPS to detect the current position in a place where radio waves do not reach or are difficult to reach, such as in a tunnel. And the like, and is susceptible to noise.
Further, in an apparatus using a gyro, drift errors are accumulated, so that it becomes necessary to perform calibration for each certain point or each distance. A device for installing a fixed sign or the like on a traveling path is effective for such a problem of the device using the GPS or the gyro, but the device is expensive because the installation cost of the fixed sign or the like is required. Become.

The present invention has been made in view of the above problems, and is an inexpensive moving body position detection capable of accurately detecting the current position of a moving body by processing an image obtained by an image pickup means provided on the moving body. The purpose is to provide a device. Japanese Patent Laid-Open No. 1-133183 discloses a device that detects the position of a moving body by extracting and converting edge information at one end of the passage from an image obtained by capturing a path through which the moving body passes. However, this device is for detecting the direction and distance of the moving body with respect to the end of the passage and is not a device for detecting the current position (absolute position) of the moving body, and therefore has a different purpose from the present invention. Further, in Japanese Patent Laid-Open No. 2-3582, etc., the observed feature pattern extracted from the imaged image of the periphery of the leg walking type moving body and the prediction pattern based on the position information of the moving body are compared to determine the setting. An apparatus is disclosed that corrects a shift and guides and controls a moving body. However, in this device, the position information of the moving body is only detected by a gyro or the like, and the predicted pattern is determined by the position information. Therefore, the above-mentioned problems regarding the position detection of the moving body cannot be solved.

[0005]

For this reason, in the invention according to claim 1 of the present invention, an image pickup means provided on a moving body for picking up an image of the periphery of a traveling road to generate an input image, and the periphery of the traveling road. A comparative image storage unit that extracts a characteristic environmental image portion and stores the environmental image portion and the imaging position of the comparative image with respect to each of the plurality of comparative images generated by previously capturing images at a fixed distance interval; The environment image portion stored in the comparison image storage means is compared with the corresponding image portion in the input image, and based on the comparison result, the current position of the moving body from the image pickup position of the comparison image stored in the comparison image storage means. And a position detecting means for detecting a position.

According to this structure, when detecting the current position of the moving body, a characteristic environmental image of an existing structure or the like which is not affected by environmental changes such as seasons or day and night is detected from a plurality of comparison images obtained in advance. The portion is extracted and stored in the comparison image storage means together with the image pickup position of the comparison image. Then, when the moving body travels and the input image is obtained by the image pickup means, the position detection means compares the obtained input image with the environmental image portion stored in the comparison image storage means, and based on the comparison result. The current position of the moving body is detected.

According to a second aspect of the present invention, in the first aspect of the present invention, the position detection means stores the size of the environmental image portion stored in the comparative image storage means and the environmental image portion in the input image. To detect the current position of the moving body by calculating the size difference from the size of the image portion corresponding to the above, and calculating the distance from the imaging position stored in the comparison image storage means based on the size difference. Characterize.

According to this structure, the position detecting means moves the moving body in accordance with the size difference between the size of the environment image portion stored in the comparison image storage means and the size of the image portion corresponding to the environment image portion in the input image. The current position of will be detected. In the invention described in claim 3, claim 1 or 2
In the invention described in (3), the comparative image information calling for calling the information obtained from the comparative image captured at the position closest to the current position detected by the position detecting means from the comparative image storing means and outputting to the position detecting means. The position detecting means is configured to detect the current position of the moving body in the next measurement cycle based on the comparison image information from the comparison image information calling means.

According to this structure, the information of the comparative image storage means used by the position detecting means is called by the comparative image calling means according to the current position of the moving body, and the position detecting means determines the next measurement cycle. The information to be compared with the input image is limited to the information obtained from the comparison image captured at the position closest to the current position.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of the present embodiment. In FIG. 1, the present apparatus includes a camera 2 as an imaging means attached to the tip of a train 1 as a moving body, and an A / D for quantizing an input image obtained by the camera 2.
The D converter 3 and the position calculation unit 4 as position detection means for calculating the current position of the train 1 based on the quantized input image.
According to the current position of the train 1 calculated by the position calculation unit 4, and a comparison processing database 5 as a comparison image storage unit that makes a database of comparison process data obtained from a comparison image used later by the position calculation unit 4. The comparison processing data call pointer 6 as a comparison image information calling means for calling the comparison processing data from the comparison processing database 5 to the position calculation unit 4, the current position register 7 for storing the current position obtained by the position calculation unit 4, and the train 1. An axle rotation detection unit 8 for detecting the number of rotations of the axle and a departure command unit 9 for initializing the comparison processing data call pointer 6 and the current position register 7 at the time of departure.

As the camera 2, for example, a video camera having a CCD as an image pickup device is used, and when the train is in operation, the periphery of the track in the traveling direction is imaged at regular time intervals to generate an analog input image. Here, a fixed time interval is n
It is set to the second interval. Therefore, one measurement cycle is n seconds.
The A / D converter 3 quantizes the input image captured by the camera 2 and converts it into a digital input image.

The position calculation unit 4 inputs the input image from the A / D converter 3 and the comparison processing data from the comparison processing database 5, compares the input image and the comparison processing data as will be described later, and train 1 Calculate the current position of. The calculation result is output to the comparison processing data call pointer 6 and the current position register 7. The comparison processing database 5 is
Information on the comparative image obtained by running the train 1 and imaging the periphery of the route in the traveling direction with the camera 2 at regular intervals of about 100 m, for example, is stored in a database. In this database creation, for each comparison image, an area including an environment image part, which will be described later, is extracted, and information about the position at which the comparison image is captured and the extraction area (shape of image in area, brightness, position of area, etc.) ) Is stored as comparison processing data.

In the comparison processing data call pointer 6, the call pointer p is updated based on the current position of the train 1 calculated by the position calculation unit 4. This call pointer p is
This is a variable for calling from the comparison processing database 5 the comparison processing data obtained from the comparison image taken at the position closest to the current position of the train 1, and initialized at the departure of the train 1 (p =
0) and updated according to the movement of the train 1.

The current position register 7 receives the outputs of the position calculation unit 4, the axle rotation detection unit 8 and the departure command unit 9 and temporarily stores the current position of the train 1 according to the respective outputs, and Outputs the current position to other devices. The value of the register that stores the current position is initialized by the output of the departure command unit 9, updated according to the output of the axle rotation detection unit 8 described later, and further corrected according to the calculation result of the position calculation unit 4. It

The axle rotation detector 8 detects the number of rotations of the axle of the train 1 and obtains the current position of the train 1 based on the detected number of rotations. The current position obtained here may include an error due to, for example, wheel slip. Therefore, the axle rotation detection unit 8 outputs the current position of the train 1 having a certain error range. This output updates the current position register 7 as described above.

When the train 1 departs, the departure command unit 9 outputs a signal for signaling departure to the comparison processing data call pointer 6 and the current position register 7. Here, for example, the departure station of the train 1 is set at the departure place, and the output of the departure command unit 9 is generated when the departure station is departed. Next, the operation of this embodiment will be described.

First, in order to create the comparison processing database 5, the train 1 is run on the operating route in advance, and the periphery of the route is imaged by the camera 2 about every 100 m from the starting station to obtain a comparative image. From the obtained plurality of comparison images, an area including an environment image portion Gref in each image, for example, an existing structure that is not affected by environmental changes such as season and day and night is extracted. The image of the extracted area is converted into a data format that can be compared with the input image by the position calculation unit 4, and information about the position (distance from the starting station) where the comparative image is acquired and the extracted area is used as comparison processing data. Database is created.

The operation of detecting the current position of the train 1 using the comparison processing database 5 thus created will be described with reference to the flowchart of FIG. In FIG. 2, when train 1 departs from the starting station, step 1 (S in the figure)
1 and so on. ), A signal is issued from the departure command section 9 to signal the departure. In step 2, the comparison processing data call pointer 6 and the current position register 7 are initialized by the output from the departure command unit 9.

In step 3, when the train 1 starts running, the train 1 detected by the axle rotation detector 8 in response to the movement.
Is output to the current position register 7, and the current position register 7 is updated. In step 4, camera 2
The input image is acquired every n seconds. In step 5, the input image obtained in step 4 is quantized by the A / D converter 3 and then input to the position calculation unit 4.

In step 6, the comparison process data call pointer 6 compares the comparison process data corresponding to the call pointer p (the comparison process data based on the comparison image taken at the position closest to the current position of the train 1) with the comparison process database. It is called from 5 and input to the position calculation unit 4. In step 7, the position calculation unit 4 extracts an area that matches the extraction area of the input comparison processing data from the input image.

In step 8, the input image of the area extracted in step 7 is compared with the extracted area image of the comparison processing data to specify the environmental image portion Gin in the input image. In step 9, the environmental image portion Gin of the input image and the environmental image portion Gref of the comparison processing data are compared to determine the magnitude relationship. If the environmental image portion Gin is smaller than the environmental image portion Gref, the process proceeds to step 10. If the environmental image portion Gin and the environmental image portion Gref are equal, the process proceeds to step 12. If the environmental image portion Gin is larger than the environmental image portion Gref, the process proceeds to step 14.

In step 10, a ratio f (size difference) of the size of the environmental image portion Gin to the environmental image portion Gref is obtained, and based on this ratio f, the shift amount of the image pickup position of the input image with respect to the image pickup position of the comparative image. D is calculated. Then, the position information of the comparison processing data (imaging position of the comparison image)
The current position of the train 1 is obtained by subtracting the deviation amount D from the difference.

In step 11, the current position of the train 1 obtained in step 10 is output from the position calculation unit 4 to the current position register 7 and stored in the current position register 7.
Is corrected and the current position is output to another device or the like. Then, returning to step 3, the above operation is repeated. In step 12, the position information of the comparison process data is set as the current position of the train 1.

In step 13, the current position of the train 1 determined in step 12 is output from the position calculation unit 4 to the current position register 7 and the comparison processing data call pointer 6, and the current position of the train 1 stored in the current position register 7 is output. The position is corrected and output, and the value of the call pointer p is updated. Then, the process returns to step 3. In step 14, similarly to step 10, the shift amount D of the image pickup position of the input image with respect to the image pickup position of the comparative image is calculated. Then, the current position of the train 1 is obtained by adding the deviation amount D to the position information of the comparison processing data.

In step 15, the current position of the train 1 obtained in step 14 is output from the position calculation section 4 to the current position register 7 and the comparison processing data call pointer 6, and the current position of the train 1 stored in the current position register 7 is output. The position is corrected and output, and the value of the call pointer p is updated. Then, the process returns to step 3. As described above, the current position of the train 1 is accurately detected and the storage position of the current position register 7 is updated by the operations of steps 1 to 15. The operation of updating the current position register 7 by the output of the axle rotation detection unit 8 in step 3 enables the current position of the train 1 to be detected within a certain margin of error if the image processing system should fail. Have a role to play. Therefore, the current position detection by the axle rotation detection unit 8 may be any one that assists the detection by the image processing. Instead of the axle rotation detection unit 8, a conventional position detection device (GPS, gyro, etc.) is used to detect the current position. It may be configured to detect.

As described above, according to the present embodiment, the position calculating unit 4 compares the environmental image portion Gref of the comparison processing data corresponding to the input image with the environmental image portion Gin in the input image to determine the train 1 By obtaining the current position, the current position of the train 1 can be specified by the environmental image captured in the input image without providing a fixed sign or the like on the traveling path, and thus an inexpensive device that can detect the current position with high accuracy. Can be provided. Further, when the current position of the train 1 is obtained based on the size difference between the size of the environment image portion Gref of the comparison processing data and the size of the environment image portion Gin in the input image, the respective environment image portions are substantially matched. That is, not only when the image pickup position of the comparison image and the image pickup position of the input image substantially match, but also when the input image is picked up between the image pickup positions of the adjacent comparison images, the current position of the train 1 is obtained. Therefore, it is possible to detect the current position more accurately. Further, by using the comparison processing data called by the comparison processing data calling pointer 6 according to the current position of the train 1 in the next measurement cycle in the position calculation unit 4, the comparison taken at the position closest to the current position is compared. Since the calculation of the position calculation unit 4 is performed only on the comparison processing data obtained from the image, the calculation amount of the position calculation unit 4 is reduced, and the position detection operation can be speeded up.

[0027]

As described above, according to the invention described in claim 1 of the present invention, the environment image portion stored in the comparison image storage means is compared with the corresponding image portion in the input image. By determining the current position of the moving body, unlike the conventional device, it is not necessary to provide a fixed sign or the like on the traveling path, and the current position of the moving body can be specified by the environmental image captured in the input image. It is possible to provide an inexpensive device that can detect the current position with accuracy.

According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, the size of the environment image portion stored in the comparison image storage means and the input image corresponding to the environment image portion By obtaining the current position of the moving body based on the size difference from the size of the image portion, the current position of the moving body can be obtained even when the input image is captured between the image capturing positions of the adjacent comparison images. , It is possible to detect the current position more accurately.

According to a third aspect of the present invention, in addition to the effect of the first or second aspect of the present invention, by using the comparative image information called by the comparative image information calling means in the position detecting means, the moving object is moved. Since only the information obtained from the comparative image taken at the position closest to the present position is calculated by the position detection means in the next measurement cycle, the amount of calculation is reduced and the position detection operation can be speeded up. it can.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of the present invention.

FIG. 2 is a flowchart for explaining the operation of the above embodiment.

[Explanation of symbols]

 1 Train 2 Camera 3 A / D Converter 4 Position Calculation Section 5 Comparison Processing Database 6 Comparison Processing Data Call Pointer 7 Current Position Register 8 Axle Rotation Detection Section 9 Departure Command Section

Claims (3)

[Claims] 1. An image pickup means provided on a moving body for picking up an image of a periphery of a traveling road to generate an input image, and a plurality of comparative images generated by imaging the periphery of the traveling road in advance at predetermined distance intervals. Comparative image storage means for extracting a characteristic environmental image portion and storing the imaged positions of the environmental image portion and the comparative image, and the corresponding image in the environmental image portion and the input image stored in the comparative image storage means And a position detection unit that detects the current position of the moving body from the image pickup position of the comparison image stored in the comparison image storage unit based on the comparison result. Body position detection device. 2. The position detecting means obtains a size difference between the size of the environment image portion stored in the comparison image storage means and the size of an image portion corresponding to the environment image portion in the input image, and the size difference is obtained. 2. The moving body position detecting device according to claim 1, wherein the current position of the moving body is detected by calculating a distance from the image pickup position stored in the comparative image storage means based on the difference. 3. A comparative image information calling means for calling information obtained from the comparative image taken at the position closest to the current position detected by the position detecting means from the comparative image storing means and outputting the information to the position detecting means. 3. The position detecting means is configured to detect the current position of the moving body in the next measurement cycle based on the comparison image information from the comparison image information calling means. The moving body position detection device described.