JP2009069264A - Feature identifying device, feature identifying method, and feature identifying program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a feature identifying device capable of exactly identifying the types of features without the need for complex calculation. <P>SOLUTION: The feature identifying device comprises a feature detecting means, a passing time calculating means, a feature dimension calculating means, and an identifying means. The feature detecting means is mounted on a mobile object and detects a feature present above the mobile object. The passing-through time calculating means calculates, in accordance with a detection signal from the feature detecting means, the passing-through time of the mobile object passing-through below the feature. The feature dimension calculating means calculates, in accordance with the passing-through time calculated by the passing-through time calculating means and the moving speed of the mobile object at the time of passing-through below the feature, the dimension of the feature in the traveling direction of the mobile object. The identifying means identifies, in accordance with the dimension of the feature calculated by the feature dimension calculating means, the type of the feature. Thus, the type of the feature can be exactly identified without the need for complex calculation. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a feature identifying apparatus for identifying features provided on a road.

  In map data mounted on navigation devices, etc., location information of features on roads such as tunnels and pedestrian bridges is recorded, and the user can view the map displayed on the display screen of the navigation device, The position of the feature can be known in advance.

  Such position information of the feature is obtained by conducting a traveling survey in which the investigator actually photographs a landscape including the feature while traveling on a road with a moving body such as a vehicle. The position information obtained by the traveling survey is incorporated into the map data, and the user can know the position of the feature with the navigation device. As a specific method of the travel survey, for example, an investigator installs a camera inside the vehicle toward the front of the vehicle, and while the vehicle travels on the road, the camera is used to view the landscape in front of the vehicle. The still image is taken at regular time intervals.

  In Patent Document 1 below, it is determined whether or not an image of a building is included in a captured image obtained by imaging the upper side of the vehicle. A navigation device that detects which one of the vehicles is traveling is described.

JP 2002-148054 A

  However, in order to recognize a feature such as a pedestrian bridge using a camera directed to the front of the vehicle, complicated calculations such as pattern matching and construction of a three-dimensional space by stereo vision are required. In particular, when using stereo vision, two or more cameras are required. Moreover, even when advanced processing involving such calculation is performed, it is difficult to increase the detection accuracy of features such as footbridges that are not always in the same shape.

  The present invention has been made in view of the above points, and provides a feature identification device that can accurately identify the type of a feature without requiring a complicated calculation. Let it be an issue.

  The invention according to claim 1 is a feature identification device, and is a feature detection unit that detects a feature that is mounted on a mobile body and that is present above the mobile body, and the feature detection unit. Based on the detection signal from, the passage time calculation means for obtaining the passage time of the moving body passing under the feature, the passage time obtained by the passage time calculation means and the passage under the feature The feature size calculation means for obtaining the dimension of the feature in the traveling direction of the moving body based on the moving speed of the moving body at the time of the movement, and the dimension of the feature obtained by the feature dimension calculation means And an identification means for identifying the type of the feature.

  According to a fourth aspect of the present invention, there is provided a feature detection unit that detects a feature that is mounted on the moving object and that exists above the moving object. A feature identification method for identifying the type of an object, wherein a transit time calculating step for obtaining a transit time of the moving body that passes under the feature based on a detection signal from the feature detection means; The feature size for determining the size of the feature in the traveling direction of the moving body based on the passing time obtained in the passing time calculating step and the moving speed of the moving body when passing under the feature. It comprises a calculation step and an identification step for identifying the type of the feature based on the feature size obtained in the feature size calculation step.

  According to a fifth aspect of the present invention, there is provided a feature detection unit that is executed by a computer and is mounted on a movable body and detects a feature existing above the movable body. A feature identification program for identifying the type of an existing feature, and a transit time for obtaining a transit time of the moving object passing under the feature based on a detection signal from the feature detection means Based on the passing time obtained by the calculating means and the passing time calculating means and the moving speed of the moving body when passing under the feature, the dimension of the feature in the traveling direction of the moving body is determined. The computer is caused to function as a feature size calculation unit to be obtained, and an identification unit for identifying the type of the feature based on the feature size obtained by the feature size calculation unit.

  In one aspect of the present invention, a feature identifying device is mounted on a moving body and detects a feature existing above the moving body, and detection from the feature detecting means. Based on the signal, the passage time calculation means for obtaining the passage time of the moving body passing under the feature, and the passage time obtained by the passage time calculation means and when passing under the feature On the basis of the moving speed of the moving body, on the basis of the feature size calculating means for obtaining the size of the feature in the traveling direction of the moving body, and on the size of the feature obtained by the feature size calculating means. And an identification means for identifying the type of the feature.

  The feature identification device is a device for identifying the type of feature on the road, and includes a feature detection unit, a transit time calculation unit, a feature dimension calculation unit, and an identification unit. The feature detection means is, for example, a camera or an ultrasonic sensor, and detects a feature mounted on the moving body and existing above the moving body. The transit time calculating means obtains the transit time of the moving body passing under the feature based on a detection signal from the feature detecting means. The feature size calculation means is based on the passage time determined by the passage time calculation means and the moving speed of the moving body when passing under the feature, and the moving body moves in the traveling direction of the moving body. Find the dimensions of the feature. The identification means identifies the type of the feature based on the dimension of the feature obtained by the feature size calculation means. The passage time calculation means, the feature size calculation means, and the identification means are realized by, for example, a system controller.

  According to the feature identification device of the present invention, compared to the case of identifying a feature using a camera directed toward the front of the vehicle, the type of the feature can be accurately obtained without requiring a complicated calculation. Can be identified.

  According to another aspect of the feature identifying apparatus, a position detecting unit that detects a position of the moving body when the moving body passes below the feature, and the movement detected by the position detecting unit. Recording means for recording the position of the body in association with the type of the feature identified by the identification means. The recording means is, for example, a system controller. In this way, the type of the feature can be associated with the map data, and the user can specify the position and type of the feature on the map data.

  In a preferred embodiment of the above feature identifying apparatus, the feature detecting means is a photographing means for photographing the upper part of the moving body, and the passing time calculating means is a photographed image photographed by the photographing means. The passing time is obtained based on the luminance.

  In another aspect of the present invention, a feature that is mounted on a moving body and that detects a feature that exists above the moving body is used to detect a feature that exists above the moving body. The feature identifying method for identifying the type of the vehicle includes a transit time calculating step for obtaining a transit time of the moving body that passes under the feature based on a detection signal from the feature detection means, and the transit time calculation. A feature size calculating step for obtaining a size of the feature in the traveling direction of the moving body based on the transit time obtained in the step and a moving speed of the moving body when passing under the feature; And an identification step of identifying the type of the feature based on the dimension of the feature obtained in the feature size calculation step. According to this method, it is possible to accurately identify the type of the feature without requiring a complicated calculation.

  In still another aspect of the present invention, a feature detection unit that detects a feature that is executed by a computer and is mounted on a mobile body and that exists above the mobile body is provided above the mobile body. The feature identification program for identifying the type of the feature existing in the vehicle is a transit time calculation for obtaining a transit time of the moving body passing under the feature based on a detection signal from the feature detection means. Means for determining the size of the feature in the traveling direction of the moving body based on the passing time determined by the passing time calculating means and the moving speed of the moving body when passing below the feature. The computer is caused to function as an identification unit for identifying the type of the feature based on the feature size calculation unit and the feature size obtained by the feature size calculation unit. The above map identification device can be realized by causing a computer to execute this feature identification program.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

(Feature identification device)
FIG. 1 shows the configuration of the feature identification apparatus 100. As shown in FIG. 1, the feature identification device 100 includes a self-supporting positioning device 10, a GPS receiver 18, a system controller 20, a data storage unit 36, a display unit 40, a camera 50, and an input device 60.

  The autonomous positioning device 10 includes an acceleration sensor 11, an angular velocity sensor 12, and a distance sensor 13. The acceleration sensor 11 is made of, for example, a piezoelectric element, detects vehicle acceleration, and outputs acceleration data. The angular velocity sensor 12 is composed of, for example, a vibrating gyroscope, detects the angular velocity of the vehicle when the direction of the vehicle is changed, and outputs angular velocity data and relative azimuth data. The distance sensor 13 measures a vehicle speed pulse composed of a pulse signal generated with the rotation of the vehicle wheel.

  The GPS receiver 18 receives radio waves 19 carrying downlink data including positioning data from a plurality of GPS satellites. The positioning data is used to detect the absolute position of the vehicle from latitude and longitude information.

  The system controller 20 includes an interface 21, a CPU (Central Processing Unit) 22, a ROM (Read Only Memory) 23, and a RAM (Random Access Memory) 24, and controls the entire feature identifying apparatus 100.

  The interface 21 performs an interface operation with the acceleration sensor 11, the angular velocity sensor 12, the distance sensor 13, and the GPS receiver 18. From these, vehicle speed pulses, acceleration data, relative azimuth data, angular velocity data, GPS positioning data, absolute azimuth data, and the like are input to the system controller 20. The CPU 22 controls the entire system controller 20. The ROM 23 includes a nonvolatile memory (not shown) in which a control program for controlling the system controller 20 is stored. The RAM 24 stores various data such as route data preset by the user via the input device 60 so as to be readable, and provides a working area to the CPU 22. The feature identification apparatus of the present invention is realized by the CPU 22 executing a program recorded in advance in the ROM 23 or the like.

  The system controller 20, the data storage unit 36, the display unit 40, the camera 50, and the input device 60 are connected to each other via the bus line 30.

  The data storage unit 36 is configured by, for example, an HDD or the like and stores map data. In the map data, for example, road information is expressed in the form of vector data composed of a plurality of nodes and links connecting the nodes.

  As will be described in detail later, the camera 50 is attached to a vehicle and captures a scene outside the vehicle at a predetermined shooting interval while the vehicle is traveling. Specifically, the camera 50 is attached directly above the vehicle and photographs a landscape above the vehicle. The camera 50 supplies an image signal of a captured image including a luminance signal to the system controller 20 via the bus line 30. The shooting interval of the camera 50 is controlled by the system controller 20. Needless to say, the camera 50 is not limited to one that shoots still images at a predetermined shooting interval, but may instead shoot a moving image.

  The display unit 40 displays various display data on a display device such as a display under the control of the system controller 20. Specifically, the system controller 20 reads map data from the data storage unit 36. The display unit 40 displays the map data read from the data storage unit 36 by the system controller 20 on a display screen such as a display. The display unit 40 includes a graphic controller 41 that controls the entire display unit 40 based on control data sent from the CPU 22 via the bus line 30 and a memory such as a VRAM (Video RAM), and can display image information that can be displayed immediately. A buffer memory 42 that temporarily records, a display control unit 43 that controls display of a display 44 such as a liquid crystal display or a CRT (Cathode Ray Tube) based on image data output from the graphic controller 41, and a display 44 are provided. .

  The input device 60 includes keys, switches, buttons, a remote controller, and the like for inputting various commands and data. When the display 44 is a touch panel system, the touch panel provided on the display screen of the display 44 also functions as the input device 60.

(Feature identification method)
The feature identifying method according to the present embodiment will be specifically described. FIG. 2 is a schematic diagram when the vehicle 70 as a moving body passes below the feature 80. In FIG. 2, a vehicle 70 is equipped with a camera 50 in addition to a camera (not shown) that captures the front and / or rear. The shooting direction of the camera 50 is set directly above the vehicle 70. The camera 50 captures an external scenery above the vehicle 70 at a predetermined photographing interval while the vehicle 70 is traveling. Moreover, in FIG. 2, sectional drawing of the feature 80 is shown. Examples of the feature 80 include structures provided on roads such as footbridges and elevated roads. In FIG. 2, an entrance that enters below the feature 80 is a point A, and a point that has passed below the feature 80 is a point B.

  In FIG. 2, until the vehicle 70 reaches below the feature 80, that is, before the vehicle 70 enters the point A, the camera 50 captures an image of the sky above the vehicle 70. Become. When the vehicle 70 passes below the feature 80, that is, until the vehicle 70 travels from point A to point B, the camera 50 captures an image of the feature 80. After the vehicle 70 passes below the feature 80, that is, after the vehicle 70 passes the point B, the camera 50 again takes an image of the sky above the vehicle 70.

  The graph shown in FIG. 3 shows a change in luminance of a captured image captured by the camera 50 when the vehicle 70 passes below the feature 80. The vehicle 70 passes below the feature 80 until the vehicle 70 reaches the point A or compared with the brightness of the photographed image taken by the camera 50 after the vehicle 70 passes the point B. In the meantime, the brightness of the captured image captured by the camera 50 decreases. This is because the vehicle 70 passes under the feature 80 until the vehicle 70 reaches the point A or compared with the amount of sun light incident on the camera 50 after the vehicle 70 passes the point B. This is because the amount of the sun incident on the camera 50 while the vehicle is in the sun decreases due to the sunlight blocked by the feature 80.

  Therefore, in the feature identifying apparatus 100 according to the present embodiment, the system controller 20 obtains the passing time of the vehicle 70 passing under the feature 80 based on the luminance of the photographed image taken by the camera 50. To do. Specifically, the system controller 20 determines the average value of the brightness of the captured image (for example, the brightness of the captured image at regular intervals) based on the brightness signal of the captured image supplied by the camera 50 via the bus line 30. (Average value) is calculated, and when it is determined that the average value of the brightness of the captured image has decreased below a predetermined value, it is determined that the vehicle 70 has entered below the feature 80, and the time at that time is stored in the RAM 24. Record. If the system controller 20 subsequently determines that the average value of the brightness of the captured image has risen above a predetermined value based on the brightness signal of the captured image, the vehicle 70 passes below the feature 80. It is determined that the process has been completed, and the time at that time is recorded in the RAM 24. This predetermined value is a value determined in advance by experiments or the like, and is recorded in the RAM 24 or the like. The luminance signal corresponds to the detection signal in the present invention. The system controller 20 determines the feature 80 based on the time when it is determined that the vehicle 70 has entered below the feature 80 and the time when the vehicle 70 has finished passing below the feature 80. The passing time of the vehicle 70 passing below is obtained. Therefore, the system controller 20 functions as a passage time calculation unit in the present invention.

  Next, the system controller 20 determines the ground in the traveling direction of the vehicle 70 based on the transit time of the vehicle 70 passing below the feature 80 and the moving speed of the vehicle 70 when passing below the feature 80. The dimension L of the object 80 is obtained. Specifically, the dimension L of the feature 80 is obtained by multiplying the passing time of the vehicle 70 passing under the feature 80 by the moving speed of the vehicle 70 when passing under the feature 80. . Thus, for example, when the feature 80 is a tunnel, the dimension L is the length of the tunnel, and when the feature 80 is a pedestrian bridge, the dimension L is the width of the pedestrian bridge. Therefore, the system controller 20 functions as the feature size calculation means in the present invention.

  The system controller 20 identifies the type of the feature 80 based on the determined dimension L of the feature 80. Specifically, the system controller 20 records a map indicating the relationship between the dimension L of the feature 80 and the type of the feature 80 in the RAM 24 or the like, and uses the map to set the dimension L of the feature 80. The type of the corresponding feature 80 is identified. Therefore, the system controller 20 functions as identification means in the present invention.

  FIG. 4 is an example of a table showing the relationship between the dimension L of the feature 80 and the type of the feature 80. In the example shown in FIG. 4, when the dimension L of the feature 80 is within 1 m, the system controller 20 is one of the electric wire, the direction guide, the lane guide, the traffic light, the N system, and the Orbis. When the dimension L of the feature 80 is 1 m to 10 m, it is determined that the feature 80 is either a pedestrian bridge or an overpass, and when the dimension L of the feature 80 is 10 m or more, It is determined that the feature 80 is one of an elevated road, a tunnel, and a cave.

  As described above, in the feature identifying apparatus 100 according to the present embodiment, the camera 50 is mounted on the vehicle 70 and photographs the upper side of the vehicle 70, and the luminance of the photographed image photographed by the camera 50 is based. Thus, the passage time calculating means for obtaining the passage time of the vehicle 70 passing under the feature 80, and the movement of the vehicle 70 when passing under the feature 80 and the passage time obtained by the passage time calculating means. Based on the speed, the feature size calculating means for determining the dimension of the feature 80 in the traveling direction of the vehicle 70, and the size of the feature 80 determined by the feature size calculating means, Identification means for identifying the type.

  According to the feature identifying apparatus 100 according to the present embodiment, compared with a device that identifies a feature using a camera directed to the front of the vehicle, the ground is accurately identified without requiring complicated calculations. The type of the object 80 can be identified.

(Feature identification processing)
Next, the feature identifying process according to the present embodiment will be described with reference to the flowchart shown in FIG. FIG. 5 is a flowchart showing the feature identifying process according to the present embodiment. This process is realized by the system controller 20 executing a program prepared in advance.

  First, in step S <b> 101, the system controller 20 detects whether or not the feature 80 exists above the vehicle 70 based on the luminance of the captured image captured by the camera 50. Specifically, when the system controller 20 determines that the average value of the brightness of the captured image is lower than a predetermined value based on the brightness of the captured image captured by the camera 50, the vehicle 70 is the vehicle 70. It is determined that the feature 80 exists above (step S101: Yes), and the time at that time is recorded in the RAM 24 as the time when the vehicle 70 entered below the feature 80, and then the process proceeds to step S102. On the other hand, when the system controller 20 determines that the average value of the brightness of the captured image is not lower than the predetermined value based on the brightness of the captured image captured by the camera 50 (step S101: No), The operation in step S101 is repeated. The predetermined value is a value determined in advance by experiments or the like, and is recorded in the RAM 24 or the like. In this way, it is possible to detect whether or not the vehicle 70 has entered below the feature 80 by the processing of step 101.

  In step S102, if the system controller 20 determines that the average value of the brightness of the captured image has risen again above the predetermined value based on the brightness of the captured image captured by the camera 50, the system controller 20 sets the time at that time. The time when the vehicle 70 has passed below the feature 80 is assumed. Then, the system controller 20 determines the feature based on the time when the vehicle 70 has passed below the feature 80 and the time when the vehicle 70 determined below in step S101 entered the feature 80. The passing time of the vehicle 70 when passing below 80 is obtained. As described above, the passing time of the vehicle 70 is obtained by the processing of step 102.

  In step S103, the system controller 20 determines the feature 80 in the traveling direction of the vehicle 70 based on the passing time of the vehicle 70 obtained in step S102 and the moving speed of the vehicle 70 when passing below the feature 80. Determine the dimensions.

  In step S104, the system controller 20 displays a relationship between the size of the feature 80 and the type of the feature 80 based on the size of the feature 80 obtained in step S103 (for example, the map shown in FIG. 4). Is used to identify the type of the feature 80. The map is recorded in advance in the RAM 24 or the like. In this way, the system controller 20 can accurately identify the type of the feature 80 without requiring complicated calculation.

(Application example)
Here, the feature identification apparatus 100 according to the present embodiment may further associate the position information of the vehicle 70 with the type of the feature 80. Specifically, the system controller 20 obtains the position information of the vehicle 70, for example, the latitude and longitude of the vehicle 70, based on the signal from the GPS receiver 18 when passing below the feature 80. Then, the system controller 20 records the type of the feature 80 previously obtained in association with the position information of the vehicle 70 obtained when passing below the feature 80 in the data storage unit 36 or the like. . In this way, the type of the feature 80 can be associated with the map data, and the user can specify the position and type of the feature 80 on the map data. Therefore, the GPS receiver 18 functions as position detecting means in the present invention, and the system controller 20 functions as recording means in the present invention.

  Note that, in the feature identifying apparatus 100 according to the present embodiment described above, whether or not the vehicle 70 passes below the feature 80 based on the average value of the brightness of the captured image taken by the camera 50. However, the present invention is not limited to this. Instead of determining whether or not the vehicle 70 is passing below the feature 80 based on the average value of the brightness of the captured image, the vehicle 70 is based on the standard deviation of the brightness of the captured image. It may be determined whether or not the vehicle passes below. Furthermore, instead of using the brightness of the photographed image photographed by the camera 50, the vehicle 70 moves below the feature 80 based on the color of the photographed image or the two-dimensional Fourier transform of the photographed image. It may be determined whether or not it has passed. For example, when determining based on the color of the captured image, the system controller 20 determines that the vehicle 70 is passing below the feature 80 when it is determined that the number of black pixels has increased by a certain number or more in the captured image. Can be determined. This is because it is considered that the feature 80 photographed by the camera 50 is projected in black as a shadow when light from the sun is shielded by the feature 80.

  Further, in the feature identifying apparatus 100 according to the above-described embodiment, the camera 50 serving as a photographing unit for photographing the upper portion of the vehicle 70 is used as the feature detecting unit that detects the feature 80 existing above the vehicle 70. Although it is supposed to be used, it is not limited to this. Instead of using the camera 50, an ultrasonic sensor or a laser range finder may be used. In this case, the detection direction of the ultrasonic sensor or the laser range finder is directed upward of the vehicle 70. By doing in this way, system controller 20 can detect feature 80 which exists above vehicles 70 also based on a detection signal from an ultrasonic sensor or a laser range finder. The passing time of the vehicle 70 passing below can be obtained. That is, instead of using the camera 50, the same effect as in the present embodiment can be obtained by using an ultrasonic sensor or a laser range finder.

  Further, the feature identification apparatus 100 according to the present embodiment described above includes the camera 50 whose shooting direction is directly above the vehicle 70, but in addition to this, the shooting is performed obliquely behind the vehicle 70. A camera directed in a direction (hereinafter, referred to as “an oblique rear camera”) may be provided. For example, when the system controller 20 determines that the vehicle 70 has passed below the feature based on the brightness of the photographed image, the system controller 20 photographs the feature 80 with the oblique rear camera. By doing in this way, the user can pinpoint the feature 80 finely by seeing the picked-up image image | photographed with the diagonally backward camera. In the feature identification device 100 described above, for example, when the dimension L of the feature 80 is 10 m or more, it can be determined that it is either an elevated road, a tunnel, or a cave, It is not possible to specify which is actually. On the other hand, in this feature identifying apparatus, the user can identify in detail what the feature 80 is actually by confirming the captured image taken by the oblique rear camera.

  As described above, the feature identification device of the present invention includes a feature detection unit that detects a feature that is mounted on a movable body and that is present above the movable body, and the feature detection unit. Based on the detection signal, the passage time calculation means for obtaining the passage time of the moving body passing under the feature, the passage time obtained by the passage time calculation means, and the passage under the feature. The feature size calculation means for obtaining the dimension of the feature in the traveling direction of the moving body based on the moving speed of the moving body at the time, and the size of the feature obtained by the feature dimension calculation means And an identification means for identifying the type of the feature. According to the feature identification device of the present invention, compared with a device for identifying a feature using a camera directed to the front of the vehicle, the feature identification device can be accurately and without requiring a complicated calculation. The type can be identified.

It is a block diagram which shows schematic structure of the feature identification apparatus by a present Example. It is a schematic diagram when a vehicle passes under the feature. It is a graph which shows the change of the brightness | luminance of the picked-up image image | photographed with the camera. It is an example of the table | surface which shows the relationship between the dimension of a feature, and the kind of feature. It is a flowchart which shows the feature identification process by a present Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Stand-alone positioning device 20 ... System controller 36 ... Data storage unit 40 ... Display unit 50 ... Camera 100 ... Feature identification apparatus

Claims (5)

A feature detecting means for detecting a feature mounted on the movable body and existing above the movable body;
Based on a detection signal from the feature detection means, a transit time calculation means for obtaining a transit time of the moving body that passes under the feature;
The feature for obtaining the dimension of the feature in the traveling direction of the moving body based on the passing time obtained by the passing time calculating means and the moving speed of the moving body when passing under the feature. Dimension calculating means;
An identification unit for identifying a type of the feature based on the dimension of the feature obtained by the feature dimension calculation unit; Position detecting means for detecting the position of the moving body when the moving body passes below the feature;
The ground according to claim 1, further comprising: a recording unit that records the position of the moving body detected by the position detection unit in association with the type of the feature identified by the identification unit. Object identification device. The feature detecting means is a photographing means for photographing an upper part of the moving body,
3. The feature identifying apparatus according to claim 1, wherein the passage time calculation unit obtains the passage time based on a luminance of a photographed image photographed by the photographing unit. Feature identification for identifying the type of feature existing above the moving body using feature detection means mounted on the moving body and detecting the feature present above the moving body A method,
Based on a detection signal from the feature detection means, a transit time calculating step for obtaining a transit time of the moving body that passes below the feature;
The feature for obtaining the dimension of the feature in the traveling direction of the moving body based on the passage time obtained in the passing time calculating step and the moving speed of the moving body when passing under the feature. A dimension calculation step;
And a step of identifying the type of the feature based on the size of the feature obtained in the feature size calculating step. A feature detection unit that is executed by a computer and is mounted on a moving body and detects a feature that exists above the moving body, and the type of the feature that exists above the moving body is determined. A feature identification program for identifying
Based on a detection signal from the feature detection means, a transit time calculation means for obtaining a transit time of the moving body that passes under the feature,
The feature for obtaining the dimension of the feature in the traveling direction of the moving body based on the passing time obtained by the passing time calculating means and the moving speed of the moving body when passing under the feature. Dimension calculation means,
A feature identification program that causes the computer to function as identification means for identifying the type of a feature based on the dimension of the feature obtained by the feature dimension calculation means.

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