JP2018154979A - Information processing system, evaluation system, and information processing method and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a system and method and the like, with which it is possible to detect an evaluation section with high accuracy even when the state of an evaluation object is different or when temporal changes occur in an evaluation object.SOLUTION: An information processing system for estimating an evaluation section of an evaluation object includes: image acquisition means for acquiring an image including an evaluation object imaged by an imaging device installed in a vehicle traveling on the evaluation object; detection means for referring to the acquired image and detecting a reference object having designated characteristics; instruction means for instructing a distance measuring apparatus installed in the vehicle to measure the travel distance of the vehicle in response to the detection of the reference object; distance acquisition means for acquiring the travel distance measured by the distance measuring apparatus; and position estimating means for estimating the positions of one end and the other end of an evaluation section based on the positions at which each travel distance acquired by the distance acquisition means reaches the designated distances for the one end and the other end of the evaluation section.SELECTED DRAWING: Figure 5

Description

  The present invention relates to an information processing system for estimating an evaluation section to be evaluated, an evaluation system, an information processing method, and a program for causing a computer to execute processing for estimating the evaluation section.

  Roads, railways, tunnels, etc. are damaged by vehicle traffic, climate, external pressure, etc., and if the damage expands, it will lead to the occurrence of serious accidents. Is needed. For road surfaces, typical damage inspection items include cracks, rutting (unevenness in the width direction of the road), flatness (unevenness in the vehicle traveling direction), and the like.

  When inspecting these items, it is necessary to acquire a photographed image of the road surface for cracks, and to acquire three-dimensional shape measurement data for rubbing and flatness. From this, the camera equipment for shooting cracks, the light cutting measurement equipment that measures the three-dimensional shape by irradiating the subject with laser and taking the camera, and the road surface height sensor installed at two or more places in the front and back of the vehicle The equipped system is generally used.

  Road inspections are conducted once a year on specific routes, and a preliminary survey is conducted prior to photography and measurement using the above system. In the preliminary survey, the start position and end position of the evaluation section (inspection section) of the evaluation target (road surface), the boundaries of municipalities, the lane configuration, the position of road structures (bridges, tunnels, viaducts), and the route are confirmed. It is necessary to mark the road surface at the start position and the end position of the inspection section so that they can be confirmed from the captured image. This marking on the road surface increases the inspection cost and increases the number of inspection steps.

  Therefore, a technique has been proposed in which a road surface index indicating road surface properties is calculated based on the acquired position data and acceleration data, and the lane corresponding to the pre-measured road surface index similar to the road surface index is identified as the lane on which the vehicle has traveled. (See Patent Document 1).

  However, the above-described technique has a problem in that it may not be determined as a similar pre-measured road surface index due to a road surface condition, a change with time, or the like even though the corresponding section is a corresponding section.

  The present invention has been made in view of the above problems, and a system that can estimate an evaluation interval with high accuracy even when the state of an evaluation object is different or when a change with time occurs in the evaluation object, An object is to provide a method and a program.

In order to solve the above-described problem, an embodiment of the invention is an information processing system that estimates an evaluation section of an evaluation target,
Image acquisition means for acquiring an image including an evaluation object imaged by an imaging device mounted on a vehicle traveling on the evaluation object;
Detecting means for detecting a reference object having a specified feature with reference to the image acquired by the image acquiring means;
Instructing means for instructing the distance measuring device mounted on the vehicle to measure the travel distance of the vehicle in response to the detection of the reference object by the detecting means,
Distance acquisition means for acquiring a travel distance measured by the distance measuring device;
Position estimation means for estimating the positions of one end and the other end of the evaluation section based on the positions at which the respective travel distances acquired by the distance acquisition means reach the designated distance for one end and the other end of the evaluation section An information processing system is provided.

  According to the present invention, it is possible to estimate the evaluation interval with high accuracy even when the state of the evaluation target is different or when the evaluation target changes with time.

The figure which showed the example of a structure of the evaluation system. The figure which illustrated the place which is checking the road surface as evaluation object by the evaluation system. The figure which showed an example of the hardware constitutions of the road surface camera which images the road surface with which an evaluation system is provided. The figure which showed an example of the hardware constitutions of the information processing apparatus with which an evaluation system is provided. The block diagram which showed an example of the function structure of information processing apparatus. The flowchart which showed an example of the road surface inspection process performed by an evaluation system. The flowchart which showed an example of the process which sets the starting point of the inspection area performed by an evaluation system. The figure which illustrated the position of the vehicle on the road surface at the time of specifying the starting point of an inspection section, and the picture picturized with a peripheral camera. The flowchart which showed an example of the process which sets the end point of the inspection area performed by an evaluation system. The figure which illustrated the position of the vehicle on the road surface at the time of specifying the end point of an inspection section, and the picture picturized with a peripheral camera. The figure explaining summary information. The figure which showed an example of the reference | standard subject. The figure which showed another example of the reference | standard subject. The figure explaining the process which estimates the start point or end point away from the reference | standard subject. The flowchart which showed an example of the process which estimates area length. The flowchart which showed an example of the quality determination process of position estimation data and road surface property measurement data.

  FIG. 1 is a diagram illustrating a configuration example of an evaluation system. The evaluation system is a system that estimates an evaluation section to be evaluated and evaluates the surface properties of the estimated evaluation section. The evaluation object may be any structure as long as it is a structure that extends long in one of the road surface, the track, the inner surface of the tunnel, and the like. This evaluation system is used when a surface structure is evaluated by dividing a structure extending in one direction into a certain section. Hereinafter, the evaluation target is a road surface, the evaluation section is a road surface inspection section, and the evaluation system is described as a road surface inspection system that inspects the road surface and evaluates the presence or absence of damage.

  The road surface inspection system is mounted on the vehicle 10 and stores a road camera 12 as an imaging device that images the road surface 11, a peripheral camera 13 as an imaging device that images the periphery of the road surface 11 including the road surface 11, and various types of information. And an information processing device 14 that performs processing. The road surface inspection system further includes a GPS (Global Positioning System) sensor 15 that is mounted on the vehicle 10 and measures the position of the vehicle 10, and a distance measurement device 16 that measures the travel distance of the vehicle 10. I have.

  The road surface 11 is cracked or ruched due to the passage of a large number of vehicles, and the flatness is impaired. These are included in the damage inspection items as damage to the road surface 11. Rutting is an unevenness in the width direction of the road. That flatness is impaired means that the unevenness | corrugation of the advancing direction of the vehicle generate | occur | produced.

  The road surface camera 12 is installed on the rear side of the vehicle 10 as shown in FIGS. 1 and 2A, and as shown in FIG. 2B, the two or more cameras are arranged in a row so as to face the road surface 11 obliquely below. Stereo cameras arranged side by side. The road surface camera 12 images the predetermined range 17 of the road surface 11 to be evaluated with each camera as shown in FIGS. The stereo camera is a camera for obtaining depth information such as unevenness formed on the road surface 11 to be evaluated using, for example, parallax information of two cameras arranged side by side.

  Parallax means that the target point (target point) is different in the direction in which it can be seen. By using parallax, the distance to the target point can be obtained by the principle of triangulation. If this distance is constant at any target point, the road surface 11 has no unevenness, and if it is not constant, it can be detected that there is unevenness. In addition, it is possible to detect how high a mountain or a deep groove exists according to the distance.

  In this road surface inspection system, as shown in FIG. 2, while traveling on the road surface 11 with the vehicle 10, the road surface camera 12 images the predetermined range 17 of the road surface 11 so that a part thereof overlaps in the traveling direction. . Then, surface properties such as irregularities of the road surface 11 are measured from each captured image, and the presence or absence of the road surface 11 and the degree of damage are evaluated based on the measured surface properties. Note that the information processing apparatus 14 can perform the process of measuring the surface property from the captured image, detecting the presence or absence of damage based on the surface property, and evaluating the degree of damage.

  In the example shown in FIGS. 1 and 2, the road surface camera 12 is used to acquire information for measuring the surface property of the road surface 11. However, the present invention is not limited to this. For example, it may be a light cutting measuring instrument composed of a laser irradiation device and a camera, a monocular camera capable of distance recognition, or the like.

  The peripheral camera 13 is installed in the vehicle 10 and images a reference object having a predesignated characteristic on the road surface 11 in front of the vehicle 10 and its periphery. The reference object may be any object as long as it is a reference object for estimating one end and the other end of the inspection section. Examples of the reference object include a traffic light, a sign, a curb, a stop line, a pedestrian crossing line, a manhole, an intersection central set, and a post box.

  The information processing apparatus 14 is a tablet terminal, a notebook PC, or the like, and estimates one end and the other end of the inspection section of the road surface 11 based on the image captured by the peripheral camera 13 in addition to the measurement and evaluation of the surface properties. Execute the process.

  The GPS sensor 15 includes a GPS receiver, receives signals transmitted from a plurality of GPS satellites, and measures the position of the GPS receiver as latitude and longitude information from the time difference between arrival times of the signals. Accordingly, the GPS sensor 15 can also measure the current position of the vehicle 10. However, since the GPS sensor 15 measures the position of the GPS receiver with an accuracy of several meters, it means that the measurement error is about several meters, and the accuracy is low.

  The distance measuring device 16 is a travel distance meter or the like, for example, holds information on the circumferential length of the wheel of the vehicle 10 and calculates the travel distance by measuring the number of rotations. The travel distance can be calculated by the product of the circumference of the wheel and the measured rotational speed. Since this is an example, the distance may be measured by other methods.

  The road surface inspection system uses the peripheral camera 13, the information processing device 14, the GPS sensor 15, and the distance measurement device 16, so that one end and the other end of the inspection section of the road surface 11 are higher in accuracy than the position measurement accuracy of the GPS sensor 15. presume. One end is the start position (start point) of the inspection section, and the other end is the end position (end point) of the inspection section.

  The vehicle 10 can be of a two-box type consisting of two boxes (boxes) of a front engine part and a passenger compartment part following it, or a one-box type body type consisting of one box. The road surface camera 12 and the peripheral camera 13 can be mounted on the roof of the vehicle 10, and the road surface 11 behind the vehicle 10 and the periphery around the front of the vehicle 10 can be imaged. The peripheral camera 13 may be attached near the windshield inside the vehicle. The information processing device 14 is arranged in the room of the vehicle 10, and the GPS sensor 15 and the distance measurement device may be installed either in the room of the vehicle 10 or outdoors.

  In the example shown in FIG. 1, measurement of surface properties, evaluation, and estimation of an inspection section are performed by one device called the information processing device 14, but the present invention is not limited to this, and each process is performed by two or more devices. It may be configured to execute. In that case, each apparatus may be connected by wire, such as a cable, and may be connected by radio | wireless. The devices may be directly connected to each other, or may be connected via a network such as a LAN (Local Area Network) or a WAN (Wide Area Network).

  When connected via a network, the network may be a single network or a network composed of two or more connected by a relay device such as a router or a proxy server. For this reason, an information processing system including any of the information processing apparatus 14 configured by one device and a system configured by two or more devices can be employed as a system for executing the above-described processing. The information processing system is not limited to one constituted by one or more devices, and may be constituted by electronic components (modules) such as an integrated circuit.

  The road surface camera 12 is not limited to being installed on the rear side of the vehicle 10 in a direction opposite to the traveling direction, and may be installed on the front side of the vehicle 10 in the traveling direction. . Similarly to the road surface camera 12, the peripheral camera 13 is not limited to being installed on the front side of the vehicle 10 in the traveling direction, but is installed on the rear side of the vehicle 10 in the direction opposite to the traveling direction. It may be.

  A hardware configuration of the road surface camera 12 will be described with reference to FIG. The road surface camera 12 is composed of two or more imaging means. In the example illustrated in FIG. 3, the road surface camera 12 includes two left and right cameras 20 and 21. The camera 20 includes a lens 22, an image sensor 23, and a sensor controller 24, and the camera 21 also includes a lens 25 and an image sensor 26. The sensor controller 27 is provided. The lens 22 and the lens 25, the image sensor 23 and the image sensor 26, and the sensor controller 24 and the sensor controller 27 are the same.

  The two left and right cameras 20 and 21 are assembled in parallel, and the road surface 11 is simultaneously imaged by the two cameras 20 and 21. Since the object on the two images obtained by imaging has different positions on each image, the position and three-dimensional shape of the object can be obtained from the difference in position (parallax). The method is well known and will not be described in detail here.

  The image sensor 23 converts light incident through the lens 22 into an electrical signal and outputs it as image data. As the image sensor 23, for example, an image sensor constituted by a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor) can be used.

  The sensor controller 24 performs exposure control of the image sensor 23, image readout control, communication with an external device, image data transmission control, and the like. Exposure refers to exposing the image sensor 23 to incident light that has passed through the lens 22. The exposure control can be realized, for example, by controlling the exposure time by opening / closing a shutter. The sensor controller 24 communicates with the information processing apparatus 14 as an external device, and transmits image data of the captured image to the information processing apparatus 14.

  The peripheral camera 13 can employ the same configuration as that of one of the two left and right cameras 20 and 21 constituting the road surface camera 12. The peripheral camera 13 can also be a stereo camera composed of two left and right cameras, like the road surface camera 12. Note that the road surface camera 12 and the peripheral camera 13 are not limited to one each, and may be a plurality.

  The hardware configuration of the information processing apparatus 14 will be described with reference to FIG. The information processing apparatus 14 includes, as hardware, a CPU (Central Processing Unit) 30, a ROM (Read Only Memory) 31, a RAM (Random Access Memory) 32, an HDD (Hard Disk Drive) 33, a communication I / F 34, an input / output I / F 35, display device 36, and input device 37. These are connected to the bus 38 and exchange information with each other via the bus 38.

  The CPU 30 controls the entire information processing apparatus 14 and executes processing such as detection of the presence or absence of damage to the road surface 11 and evaluation of damage. Further, the CPU 30 executes processing for estimating one end and the other end of the inspection section of the road surface 11 based on the image captured by the peripheral camera 13. The ROM 31 stores a boot program for starting the information processing apparatus 14, firmware for controlling the HDD 33, the communication I / F 34, and the like. The RAM 32 provides a work area for the CPU 30.

  The HDD 33 stores an OS (Operating System), received images, a program for executing the above processing, and the like. The communication I / F 34 is connected to the road surface camera 12, the peripheral camera 13, the GPS sensor 15, and the distance measuring device 16 and communicates with these devices.

  The input / output I / F 35 connects the display device 36 and the input device 37 to the bus 38, displays the information processed by the CPU 30 on the display device 36, and provides the information input from the input device 37 to the CPU 30. Control input and output of information. The display device 36 is a device that displays information such as a liquid crystal display, and the input device 37 is a device that accepts input of information such as a mouse and a keyboard.

  In addition to these, the information processing device 14 is connected to an external storage device such as an external HDD, and an external storage I / F, a voice input device, and a voice output device for controlling storage and reading of information in the external storage device. An imaging device such as a camera can also be provided.

  The functional configuration of the information processing apparatus 14 will be described with reference to FIG. The information processing apparatus 14 can generate one or more functional units when the CPU 30 executes a program stored in the HDD 33, and can include these functional units.

  The information processing apparatus 14 stores, as function units, a road surface image acquisition unit 40 that acquires two images simultaneously captured by the road surface camera 12 and two images acquired by the road surface image acquisition unit 40 as image data. The unit 41 is provided. Further, the information processing device 14 calculates the distance from the road camera 12 to each position of the road surface 11 by using the two images stored by the storage unit 41, measures the surface property, and measures the data to measure the road surface property. A measurement unit 42 that outputs data is provided. Furthermore, the information processing apparatus 14 detects the presence or absence of damage to the road surface 11 based on the surface property measured by the measurement unit 42, that is, the road surface property measurement data output from the measurement unit 42, and evaluates the evaluation result of the degree of damage. And an evaluation unit 43 for outputting. In this example, the road surface property measurement data output from the measurement unit 42 is temporarily stored in the storage unit 41, and the evaluation unit 43 acquires the road surface property measurement data from the storage unit 41.

  The information processing apparatus 14 has a function of estimating an inspection section, and as functional units therefor, a peripheral image acquisition unit 44, an object detection unit 45, an instruction unit 46, a distance acquisition unit 47, and a position estimation unit 48. With. The peripheral image acquisition unit 44 acquires an image captured by the peripheral camera 13 from the peripheral camera 13.

  The object detection unit 45 refers to the image acquired by the peripheral image acquisition unit 44 and detects a reference object having a specified feature, that is, a reference subject serving as a reference when estimating the start point or end point of the inspection section. To do. The object detection unit 45 sequentially refers to the images acquired by the peripheral image acquisition unit 44, and confirms whether or not the reference subject exists in the images.

  In response to the detection of the reference subject by the object detection unit 45, the instruction unit 46 instructs the distance measurement device 16 mounted on the vehicle 10 to start measuring the travel distance of the vehicle 10. In response to this instruction, the distance measuring device 16 starts measuring the travel distance of the vehicle 10. The distance acquisition unit 47 receives a notification that the measurement of the travel distance has been started from the instruction unit 46 and acquires the travel distance measured from the distance measurement device 16. The distance acquisition unit 47 can acquire the travel distance at regular time intervals after receiving the above notification.

  The position estimation unit 48 confirms whether or not the travel distance acquired by the distance acquisition unit 47 has been measured in advance and has reached a specified distance. If the travel distance has been reached, the position estimation unit 48 checks based on the position that has reached the distance. Estimate the start point of the interval. The position estimation unit 48 similarly estimates the end point.

  Note that a position estimated by detecting the first reference subject by the object detection unit 45 and measuring the travel distance is a starting point. A position that passes through the start point, then detects the reference subject by the object detection unit 45, and measures and estimates the travel distance is the end point. For the estimation of the start point and the end point, the position that has reached the specified distance may be estimated as the start point and the end point, or a position that is separated from the position that has reached the specified distance by a predetermined distance. You may estimate as a start point and an end point. Further, either one of the start point and the end point may be a position that has reached a specified distance, and the other may be a position that is separated from a position that has reached a specified distance by a predetermined distance.

  The information processing apparatus 14 can include a position information acquisition unit 49 that acquires position information of the vehicle 10 from the GPS sensor 15. Further, the information processing apparatus 14 is based on the position information acquired by the position information acquisition unit 49, and is an intersection as a target object that exists in the traveling direction of the vehicle 10 before or at the back of the start point or end point of the inspection section. The intersection detection part 50 which detects can be provided. The target object may be any object as long as it is a target object for specifying the reference subject, and includes a T-junction as well as an intersection. Hereinafter, the target object will be described as an intersection.

  The intersection detection unit 50 detects an intersection when the distance between the GPS sensor 15 and the intersection is within a certain distance. When detecting the intersection, the intersection detection unit 50 uses the position information of the intersection. The position information of the intersection can be set in advance as GPS position information of the center position of the intersection, for example. The center position of the intersection is a position that is the intersection of the center line (center line) of the road surface extending in one direction and the center line of the road surface extending perpendicularly thereto.

  The instruction unit 46 can instruct the peripheral camera 13 to start imaging in response to the detection of the intersection by the intersection detection unit 50. Then, the instruction unit 46 can notify the peripheral image acquisition unit 44 that imaging by the peripheral camera 13 has started.

  The road surface inspection process executed by the road surface inspection system will be described with reference to FIG. The inspection process starts from step 600, and in step 605, outline information of the inspection section is set. The summary information is GPS position information regarding the start and end points of the inspection section. The GPS position information is information with low accuracy such as an accuracy of several meters to 10 meters. The GPS position information is position information of an intersection existing before the start point and end point of the inspection section.

  In step 610, the start point of the inspection section is set. The start point is estimated based on the position at which the distance measurement is started and the specified distance is reached when an intersection near the reference subject is detected and then the reference subject is detected. Details thereof will be described later.

  In step 615, traveling shooting is performed from the position where the start point of the inspection section is set, and recording of the captured road surface image is started. The road surface image is repeatedly captured at a timing at which a part of the image overlaps the traveling direction of the vehicle 10. Since a plurality of road surface cameras 12 are installed so that the entire width direction of the road surface 11 can be imaged, a plurality of road surface images are simultaneously imaged so that a part of the images overlap in the width direction. In this way, the road surface image is taken, and in step 620, the end point of the inspection section is set. The end point is estimated by the same method as the start point. Details of this will also be described later.

  In step 625, the travel distance measured from the start point to the end point of the inspection section is set as the section length. In step 630, the set section length is divided into sub-sections with a maximum length of 100 m, the cracking rate, rutting amount, flatness, and MCI (Maintenance Control Index) are obtained, and a form with these added is output as the section evaluation result. MCI is a pavement maintenance management index, which indicates the degree of pavement damage in terms of points by combining three factors: cracking rate, rutting, and flatness. When the section evaluation result is output for each subdivision section, the process ends at step 635.

  In addition to the above, the section evaluation result can include the number of cracks, the area of a partially repaired part (patch), and the amount of dents. In this way, the section position can be automatically set, and even in the reevaluation running after a certain period of time, evaluation at substantially the same position and monitoring with the passage of time of road surface properties are possible. In order to realize this monitoring, the information processing apparatus 14 can further include a display unit, and can display an evaluation result, an image captured by the road surface camera 12, or the like on the display unit.

  With reference to FIG. 7 and FIG. 8, the process which sets the starting point of the inspection area of step 610 shown in FIG. 6 is demonstrated. Starting from step 700 shown in FIG. 7, at this stage, the GPS sensor 15 has already started measuring the position of the vehicle 10, and the road surface camera 12, the peripheral camera 13, and the distance measuring device 16 are on standby (standby). State).

  In step 705, the position information acquisition unit 49 acquires the position information of the vehicle 10 from the GPS sensor 15, and in step 710, the intersection detection unit 50 confirms whether or not an intersection has been detected based on the acquired position information. The situation at this time is that the vehicle 10 is traveling around the intersection 60 toward the intersection 60 as shown in FIG. The intersection detection unit 50 confirms whether the center position of the intersection 60 is within 10 m, for example, with the GPS sensor 15 as the center.

  The detection range of the GPS sensor 15 is desirably set to be longer than the sum of the position detection accuracy of the GPS sensor 15 and the distance from the installation position of the GPS sensor 15 to the center position of the imaging range of the road surface camera 12. The center position of the imaging range of the road surface camera 12 will be described later.

  If an intersection is not detected, the process returns to step 705. If an intersection is detected, the process proceeds to step 715. In step 715, the instruction unit 46 instructs the peripheral camera 13 to start imaging, and the peripheral camera 13 that has started the operation starts capturing an image including the road surface 11 and the periphery of the road surface 11. . The image captured at this time is an image of the road surface 11 extending in one direction in the traveling direction of the vehicle 10 as shown in FIG.

  In step 720, the peripheral image acquisition unit 44 acquires an image from the peripheral camera 13, and in step 725, the object detection unit 45 refers to the image, and first confirms whether an intersection is included in the image. For this reason, the object detection part 45 can also detect the intersection which is a target object in an image as an object. If not included, the process returns to step 720. If included, the intersection 60 is detected and the process proceeds to step 730.

  The image when the intersection 60 is detected is an image as shown in FIG. In this image, the road surface 11 extending with substantially the same vehicle width on one side reaches the intersection 60, so that only the intersection 60 has a vehicle width that expands to the left and right. It extends. Note that roads that extend to the left and right are hidden by buildings, etc., and may not extend to the left and right edges of the image.Therefore, by detecting the part where the vehicle width extends to the left and right beyond a certain length, 60 can be detected. When the intersection 60 is detected, the instruction unit 46 instructs the road camera 12, and the road camera 12 that has started the operation starts imaging the road surface 11.

  In step 730, the object detection unit 45 refers to the image and confirms whether the reference subject is included in the image. If it is not included, the process returns to step 720. If it is included, it is determined that the reference subject is detected, and the process proceeds to step 735. The image when the reference subject is detected is an image as shown in FIG. The reference subject 61 can be detected when at least a part of the reference subject 61 is included in the image and can be recognized as the target reference subject 61. During this time, imaging by the road surface camera 12 is continued. However, the captured image is not recorded.

  In step 735, the instruction unit 46 instructs the distance measuring device 16, and the distance measuring device 16 starts measuring the travel distance of the vehicle 10. The situation at this time is as follows. The position of the road surface camera 12 mounted on the vehicle 10 as shown in FIG. 8E, specifically the center position of the imaging range of the road surface camera 12, and the reference subject 61 facing the vehicle 10. The distance from the closest end to be the distance [D_1]. Therefore, the measurement of the travel distance is started with the travel distance value [D_C1] = 0, and the travel distance is measured until the distance [D_1] is reached.

  In step 740, the distance acquisition unit 47 acquires the travel distance measured from the distance measurement device 16. In step 745, the position estimation unit 48 confirms whether a predetermined distance has been reached based on the acquired travel distance. That is, it is confirmed whether the distance [D_1] shown in FIG. If not, the process returns to step 740. If reached, the process proceeds to step 750. When the distance [D_1] is reached, the position of the road surface camera 12 mounted on the vehicle 10, as shown in FIG. 8 (f), specifically, the center position of the imaging range of the road surface camera 12, and the reference object 61 described above. The end portion is a position coincident with the traveling direction.

  In step 750, the starting point of the inspection section is estimated from the position that has reached the specified distance. Here, the position that has reached the specified distance is estimated as the start point of the inspection section. In step 755, the distance value and time of the travel distance measured up to the position where the designated distance is reached are recorded, and the start point of the inspection section is set. The captured image at that time is recorded as an imaging frame, and recording of an image captured by the road surface camera 12 is started.

  When the start point of the inspection section is set, the instruction unit 46 instructs the peripheral camera 13 to end the imaging, and the peripheral camera 13 returns to the standby state. When returning to the standby state, in step 760, the process of setting the start point is terminated. At this time, the instruction unit 46 can instruct the distance measurement device 16 to end the measurement of the travel distance.

  In the inspection section, the process of step 615 in FIG. 6 is performed, and the road surface camera 12 simultaneously captures the road surface 11 and records the simultaneously captured image. Also, distance measurement is performed. The distance can be measured by a distance measuring device provided separately. The distance measurement can be performed following the setting of the start point of the inspection section by the distance measuring device 16.

  With reference to FIG. 9 and FIG. 10, the process which sets the end point of the inspection area of step 620 shown in FIG. 6 is demonstrated. Starting from step 900, at this time, recording of an image captured by the road surface camera 12 is continued. In addition, distance measurement continues. In step 905, the position information acquisition unit 49 acquires the position information of the vehicle 10 from the GPS sensor 15, and in step 910, the intersection detection unit 50 confirms whether or not an intersection has been detected based on the acquired position information. This intersection is an intersection near the end point of the inspection section, and is an intersection 62 different from the intersection 60 near the start point.

  The situation at this time is that the vehicle 10 is traveling around the intersection 62 toward the intersection 62 as shown in FIG. The intersection detection unit 50 confirms whether the center position of the intersection 62 is within 10 m, for example, with the GPS sensor 15 as the center. The position information of the center position is also set in advance as GPS position information.

  If no intersection is detected in step 910, the process returns to step 905. If an intersection is detected, the process proceeds to step 915. In step 915, the instruction unit 46 instructs the peripheral camera 13 to start imaging, and the peripheral camera 13 that has started the operation captures an image including the road surface 11 and the periphery of the road surface 11. The image captured at this time is an image of the road surface 11 extending in one direction in the traveling direction of the vehicle 10 as shown in FIG.

  In step 920, the peripheral image acquisition unit 44 acquires an image from the peripheral camera 13, and in step 925, the object detection unit 45 refers to the image, and first confirms whether an intersection is included in the image. If not included, the process returns to step 920. If included, the intersection 62 is detected, and the process proceeds to step 930.

  The image when the intersection 62 is detected is an image as shown in FIG. In this image, the road surface 11 that extends with substantially the same vehicle width on one side reaches the intersection 62, so that only the intersection 62 has a vehicle width that expands to the left and right, and that reaches the left and right ends of the image. It extends. The road extending left and right is hidden by a building or the like and may not extend to the left and right ends of the image. Therefore, the intersection 62 is detected by detecting a portion where the vehicle width extends to the left and right by a certain length. Can be detected. When the intersection 62 is detected, the instruction unit 46 instructs the road camera 12, and the road camera 12 that has started the operation starts imaging the road surface 11.

  In step 930, the object detection unit 45 refers to the image and confirms whether the reference subject is included in the image. If it is not included, the process returns to step 920. If it is included, it is determined that the reference subject has been detected, and the process proceeds to step 935. The image when the reference subject is detected is an image as shown in FIG. The reference subject 63 can be detected when at least a part of the reference subject 63 is included in the image and can be recognized as the target reference subject 63. During this time, the imaging by the road surface camera 12 and the recording of the captured image are continued.

  In step 935, the instruction unit 46 instructs the distance measuring device 16, and the distance measuring device 16 starts measuring the travel distance of the vehicle 10. When the travel distance of the inspection section has already been measured, the distance measurement is continued and the position of the travel distance at which the measurement is started is recorded. In step 940, the distance acquisition unit 47 acquires the travel distance measured from the distance measurement device 16. The situation when the reference subject 63 is detected is as follows. The position of the road camera 12 installed in the vehicle 10 as shown in FIG. 10E, specifically, the center position of the imaging range of the road camera 12 and the reference subject 63 The distance from the nearest end facing the vehicle 10 is the distance [D_2]. Therefore, the current travel distance value [D_C2] is set to 0, and the travel distance until reaching the distance [D_2] is measured.

  In step 945, the position estimation unit 48 confirms whether or not a predetermined distance has been reached based on the acquired travel distance. That is, it is confirmed whether the distance [D_2] shown in FIG. If not, the process returns to step 940. If reached, the process proceeds to step 950. When the distance [D_2] is reached, as shown in FIG. 10 (f), the position of the road camera 12 installed on the vehicle 10, more specifically, the center position of the imaging range of the road camera 12 and the reference object 63 described above. The end portion is a position coincident with the traveling direction.

  In step 950, the end point of the inspection section is estimated from the position that has reached the specified distance. Here, the position that has reached the specified distance is estimated as the end point of the inspection section. In step 955, the distance value and time of the travel distance measured up to the position where the designated distance is reached are recorded, and the end point of the inspection section is set. Also, the captured image at that time is recorded as the last captured frame of this inspection section.

  When the end point of the inspection section is detected, the instruction unit 46 instructs the peripheral camera 13 to end the imaging, and the peripheral camera 13 returns to the standby state. Further, the instruction unit 46 instructs the distance measuring device 16 to end the measurement of the travel distance, and the distance measuring device 16 returns to the standby state. Further, the instruction unit 46 instructs the road surface camera 12 to end the imaging, and the road surface camera 12 returns to the standby state. When these return to the standby state, in step 960, the process of estimating the end point ends.

  Here, summary information to be measured and set in advance will be described. The summary information includes GPS position information of the intersections 60 and 62 as target objects. The GPS position information is position information with low latitude and longitude detection accuracy as low as several m to 10 m and low accuracy. The summary information includes information on the distance between the start point and the end point. Since this information is also GPS position information, it is distance information with low accuracy.

  The summary information includes the distance [D_CS] between the reference subject 61 shown in FIG. The distance [D_CS] is the above distance [D_1]. The same applies to the reference subject 63. In this case, the distance [D_CS] is the distance [D_2] described above. The distance [D_CS] is between the position of the peripheral camera 13, specifically the image sensor of the peripheral camera 13, and the position of the reference subject 61 when even a part of the reference subject 61 falls within the imaging range of the peripheral camera 13. It can be determined as a distance. The distance is not limited to this, and may be determined as a distance when the entire reference subject 61 enters.

The summary information includes a distance [D_CC] as a distance between the position of the image sensor of the peripheral camera 13 and the center position of the imaging range of the road surface camera 12. The center position of the imaging range is a position on the road surface 11 that is the center position of the captured image. From these distance measurements, the distance between the position of the reference subject 61 and the center position of the imaging range of the road surface camera 12 can be added to obtain the distance as the distance [D_ ^* ]. In the case of the reference subject 63, the distance [D_ ^* ] can be obtained in the same manner.

  By setting these summary information in advance and executing the processing shown in FIGS. 7 and 9, the position accuracy of the start point and end point of the inspection section can be changed from several m to 10 m of GPS information to 0.05 m. It can be improved to ˜0.1 m.

  The reference subjects 61 and 63 will be described with reference to FIG. Reference subjects 61 and 63 include a traffic light and a sign pole 70 in FIG. 12A, a curb 71 in FIG. 12B, a white line stop line 72 in FIG. 12C, a pedestrian crossing line 73 in FIG. The manhole 74 in FIG. 12E, the intersection central point 75 in FIG. 12F, and the like can be employed. In addition, since road surface signs such as the intersection Chuose 75 in FIG. 12 (f) may disappear, the possibility of breakage, movement, or disappearance over time is low, as shown in FIGS. 12 (a) to 12 (e). Is desirable. In FIGS. 12A to 12E, the priority order preferably used as the reference subjects 61 and 63 is the traffic light, the sign pole 70, the manhole 74, and the curb in descending order of the possibility of breakage, movement and disappearance. 71, white line stop line 72, and pedestrian crossing line 73.

  In adopting these reference subjects 61 and 63 and measuring the travel distance, it is desirable to pay attention to the following points. That is, in order to ensure the measurement accuracy of the travel distance, at the traffic light or the sign pole 70, the end of the curved surface facing the vehicle 10 closest to the vehicle 10 or the end of the curved surface farthest from the vehicle 10 in the traveling direction. It is desirable to use the part as a reference. Regarding the curbstone 71, the white line stop line 72, the pedestrian crossing line 73, and the manhole 74, it is desirable to use the end of the traveling direction closest to the vehicle 10 or the end farthest from the vehicle 10 as a reference.

  Further, the distance measurement device 16 starts measurement and estimates the position that has reached the specified distance as the start point or end point of the inspection section, but the measurement is sufficiently close to the reference subjects 61 and 63. It is desirable to start from the state. That is, it is desirable that the specified distance is shorter. This is because the longer the distance, the greater the measurement error by the distance measuring device 16. The distance [D_CS] shown in FIG. 12 is preferably less than 3 m, for example.

  Depending on the inspection section, there may be two or more subjects. In that case, the subject can be selected in accordance with the above priority order. The reference subjects 61 and 63 may be on the near side of the intersections 60 and 62, may be on the back side, or may be in the intersections 60 and 62. In the example shown in FIG. 12, the white line stop line 72 in FIG. 12 (c) is on the near side, the intersection central point 75 in FIG. 12 (f) is in the intersections 60 and 62, and the others are on the back side. .

  When the subject as shown in FIG. 12 does not exist, or even when the subject is present, the subject is hidden by another vehicle and the subject detection accuracy is not sufficient, the intersections shown in FIGS. 13 (a) and 13 (b) 60 road surface edges 76 may be adopted as the reference subject 61. The road surface end 76 is not the road surface 11a extending in the traveling direction, but is a road surface end portion on either the front side or the back side of the road surface 11b extending in a direction substantially perpendicular to the road surface 11a. 13 (a) and 13 (b), a rear road surface end 76 is employed. Incidentally, FIG. 13A is a captured image, and FIG. 13B is a diagram when the road surface 11 is viewed from above. Similarly, the road surface end 76 can be adopted for the reference subject 63.

  Until now, the start and end points of the inspection section are the positions of the reference subjects 61 and 63, specifically the end portions of the reference subjects 61 and 63 closer to the vehicle 10, and the same positions as the end portions, The position is estimated. However, the start point and the end point may be different from the positions of the reference subjects 61 and 63. For example, a position separated from the position of the reference subjects 61 and 63 by a predetermined distance is set as the start point and the end point. It is also possible.

  This is because the distance from the road surface end 76 on the back side of the intersection 60 as shown in FIG. 14A to the end of the reference subject 61 closest to the vehicle 10 exceeds 3 m, or the detection accuracy is high. It is effective when it is not sufficiently obtained (when accuracy is greater than 0.1 m).

  In this case, for example, when the intersection detection unit 50 detects the intersection 60, the instruction unit 46 instructs the distance measurement device 16 to start distance measurement, and instructs the road surface camera 12 to image the road surface 11. To start. Thereafter, when the object detection unit 45 detects the reference subject 61, as shown in FIG. 14B, the distance [D_SS] set as the summary information is used, and an arbitrary distance less than 3 m from the road surface end 76 of the intersection 60 Can be estimated as a virtual starting point, and that position can be set as the starting point. Similarly, the end point can be estimated using the distance [D_SE] set as the summary information, and the position can be set as the end point. In addition, as long as it is less than 3 m from the road surface end 76, any distance such as 1 m or 2 m from the road surface end 76 may be used.

  As described above, the start point and end point of the inspection section can be estimated, and the distance from the start point to the end point can be set as the section length. The section length is calculated by the distance acquisition unit 47 from the distance from the start point to the end point measured by a separately provided distance measurement device or from the measurement start position to the start point and end point measured by the distance measurement device 16. It can be obtained by calculating using information on travel distance.

  The section length of the inspection section varies depending on the width and shape of the road and the position where the vehicle 10 travels. For this reason, it is desirable to set the section length in consideration of these conditions.

  FIG. 15 is a flowchart illustrating an example of a process for estimating the section length in consideration of the above conditions. After the start point of the inspection section is estimated and recorded by the above method and set, the process starts from step 1500. In step 1505, the peripheral image acquisition unit 44 acquires images captured from the peripheral camera 13 so as to include from one end to the other end in the width direction of the roadway. Here, the peripheral camera 13 is used as a width measuring device that measures the width of the road surface 11, and the peripheral image acquisition unit 44 is used as a width information acquisition unit that acquires the width information of the road surface 11. However, the present invention is not limited to this. Alternatively, a width measuring device and a width information acquiring unit may be provided separately.

  In step 1510, the separately provided interval estimation unit estimates the road width including the opposite lane and the position of the center line (the center position of the road width) based on the acquired image. The interval estimation unit estimates the interval between the travel position and the center line based on the acquired image. For example, the roadway width, the position of the center line, and the interval can be calculated from the number of pixels constituting the image. Note that the position estimation unit 48 may be used to execute these estimation processes.

  The road surface inspection system further includes a curvature radius measurement device that measures the curvature radius of the travel route in the vehicle 10. In step 1515, the instruction unit 46 instructs the curvature radius measurement device, and the curvature radius measurement device measures the curvature radius of the travel route. As the curvature radius measuring device, a measuring instrument such as the GPS sensor 15 can be used. And the curvature radius acquisition part provided separately acquires the measured curvature radius information (value of a curvature radius).

  Here, although it has been described that the radius of curvature of the travel route is measured by the curvature radius measurement device, the present invention is not limited to this, and is based on road surface property measurement data obtained based on an image captured by the road surface camera 12. You may ask for it. Specifically, it can be estimated from the curvature of three-dimensional data synthesized and connected in the traveling direction of the road surface 11 using road surface property measurement data.

  In step 1520, the interval length between the travel position estimated in step 1510 and the center line and the radius of curvature measured in step 1515 are used to estimate the section length of the center line. This section length estimation can be performed by a section length estimation unit provided separately. When this calculation is finished, the process proceeds to step 1525, and the process of estimating the section length is finished. By such processing, it becomes possible to set the section length with high accuracy even for the road width and the curve situation.

  After setting the section length, the crack rate etc. can be obtained and a report with these added can be output, but if the section length cannot be calculated correctly or the image of the road surface 11 cannot be acquired correctly, the correct section The evaluation result cannot be output. Therefore, it is desirable to perform pass / fail judgments such as the estimation result of the start point and end point used for calculating the section length after setting the section length and before outputting the section evaluation result. This quality determination process will be described with reference to FIG.

  After setting the section length, the pass / fail judgment process is started from step 1600. In step 1605, it is determined whether or not the object detection unit 45 can detect the intersection in the image captured by the peripheral camera 13. This determination process can be performed by a determination unit provided separately. If the intersection can be detected, the process proceeds to step 1610. If the intersection cannot be detected, the process proceeds to step 1630.

  As an example where the intersection is not detected, there is an obstacle such as another vehicle on the road edge and it is necessary to meander around the obstacle, and the image of the road surface of the intersection spreading to the left or right with respect to the traveling direction This may be the case where the image has not been captured. In other words, this is a case where there is a defect in an image portion necessary to determine an intersection.

  From this, whether or not an intersection can be detected can be determined by whether or not the loss ratio is equal to or less than a threshold value. The loss ratio is obtained by measuring in advance the area of the road surface portion that spreads to the left and right of the intersection when no obstacle is present, and hiding the obstacle with the obstacle in the road surface portion in the image captured by the peripheral camera 13 for that area. It can be calculated as a ratio of the areas of the obtained portions.

  In step 1610, it is determined whether or not the object detection unit 45 can detect the reference subject in the image captured by the peripheral camera 13. The reference subject is a traffic light, a manhole, a curb, a pedestrian crossing line, a white line stop line, or the like. If the reference subject has been detected, the process proceeds to step 1615. If the reference subject has not been detected, the process proceeds to step 1630.

  Examples of cases where the reference subject has not been detected include cases where other vehicles are parked on the road edge, as in the case of an intersection, or when there is a foreign object on the road and covers a part of the reference subject. Can be mentioned. Whether or not the reference subject can be detected as well as the intersection can be determined based on whether or not the deficiency ratio is equal to or less than a threshold value.

  In addition to detecting intersections and reference subjects, the object detection unit 45 can detect obstacles such as other vehicles parked on the roadside, foreign objects on the road, water pools, snow accumulation, and the like. Examples of the foreign matter on the road include fallen leaves, earth and sand, and fallen objects.

  In step 1615, it is determined whether or not the object detection unit 45 has detected a foreign object or an obstacle on the road in the image captured by the road surface camera 12. If detected, in step 1620, the ratio of the area of a foreign object or obstacle covering the road surface 11 to the area of the set section length of the road surface 11 (area of an area where the evaluation is invalid (invalid area)) is a threshold value. It is determined whether or not: If it is determined that the threshold value is equal to or less than the threshold value, the process proceeds to step 1625, where it is determined to be good. Similarly, if no foreign matter or the like is detected in step 1615, the process proceeds to step 1625, where it is determined to be good. In addition, when it determines with it being favorable, a crack rate etc. can be calculated | required with the set area length, and an area evaluation result can be output.

  On the other hand, if it is determined in steps 1605 and 1610 that detection is not possible, if it is determined in step 1620 that the threshold value is exceeded, it is determined NO in step 1630, and this pass / fail determination process is terminated in step 1635. In addition, when it determines with no, area evaluation is not performed.

  Each of the above threshold values may be a different value or the same value. Each threshold may be the same value as an allowable threshold, for example, and may be 3/100 (3%). As a result, automatic determination without human intervention is possible.

  By having such a function to perform pass / fail determination processing, it is possible to minimize rework in evaluation work, such as performing determination immediately after imaging, or immediately after several seconds or minutes, and rerunning. .

  The present invention has been described with the embodiments described above as an information processing system, an evaluation system, an information processing method, and a program. However, the present invention is not limited to the above-described embodiments, and other embodiments, additions, modifications, deletions, and the like can be modified within a range that can be conceived by those skilled in the art. . In addition, any aspect is included in the scope of the present invention as long as the operations and effects of the present invention are exhibited.

  Therefore, a recording medium on which the program is recorded, an external device that provides the program, and the like can also be provided.

DESCRIPTION OF SYMBOLS 10 ... Vehicle, 11, 11a, 11b ... Road surface, 12 ... Road surface camera, 13 ... Peripheral camera, 14 ... Information processing apparatus, 15 ... GPS sensor, 16 ... Distance measuring device, 20, 21 ... Camera, 22, 25 ... Lens , 23, 26 ... Image sensor, 24, 27 ... Sensor controller, 30 ... CPU, 31 ... ROM, 32 ... RAM, 33 ... HDD, 34 ... Communication I / F, 35 ... Input / output I / F, 36 ... Display device 37 ... Input device, 38 ... Bus, 40 ... Road surface image acquisition unit, 41 ... Storage unit, 42 ... Measurement unit, 43 ... Evaluation unit, 44 ... Ambient image acquisition unit, 45 ... Object detection unit, 46 ... Instruction unit, 47 ... Distance acquisition unit, 48 ... Position estimation unit, 49 ... Position information acquisition unit, 50 ... Intersection detection unit, 60, 62 ... Intersection, 61, 63 ... Reference subject, 70 ... Traffic light or sign pole, 71 ... Curbstone, 72 ... white line stop line, 73 ... pedestrian crossing line, 74 ... man Lumpur, 75 ... crossing the central Seto, 76 ... the road ends

JP, 2006-045063, A

Claims (10)

An information processing system for estimating an evaluation section to be evaluated,
Image acquisition means for acquiring an image including the evaluation object imaged by an imaging device mounted on a vehicle traveling on the evaluation object;
Detecting means for detecting a reference object having a specified characteristic with reference to the image acquired by the image acquiring means;
Instructing means for instructing the distance measuring device mounted on the vehicle to measure the travel distance of the vehicle in response to detection of the reference object by the detecting means;
Distance acquisition means for acquiring the travel distance measured by the distance measuring device;
Position estimation means for estimating the positions of one end and the other end of the evaluation section based on the positions at which the travel distances acquired by the distance acquisition means reach the specified distance for one end and the other end of the evaluation section, respectively. And an information processing system. Position information acquisition means for acquiring position information of the vehicle measured by a position measurement device mounted on the vehicle;
Second detection means for detecting a designated target object based on the position information acquired by the position information acquisition means,
2. The information processing system according to claim 1, wherein the instruction unit instructs the imaging apparatus to start imaging in response to detection of the target object by the second detection unit.   The position estimation means uses the position that has reached each travel distance acquired by the distance acquisition means as the position of one end and the other end of the evaluation section, or the one travel distance acquired by the distance acquisition means. The reached position is set as one of the positions of the one end and the other end of the evaluation section, and the position separated by a certain distance from the position where the other travel distance is reached is the position of one end and the other end of the evaluation section. The information processing system according to claim 2, wherein a position separated by a certain distance from the position that has reached each travel distance acquired by the distance acquisition unit is estimated as the position of one end and the position of the other end as the other position. Width information acquisition means for acquiring width information measured by a width measuring device that measures the width of the evaluation target;
A radius-of-curvature acquisition means for acquiring a radius of curvature measured by a radius-of-curvature measuring device that measures the radius of curvature of the evaluation target;
Using the width information measured by the width information acquisition means and the curvature radius measured by the curvature radius acquisition means, the position of the one end and the position of the other end of the evaluation section estimated by the position estimation means The information processing system according to any one of claims 1 to 3, further comprising: a section length estimation unit that estimates a section length determined by. The vehicle is equipped with a second imaging device that images the evaluation object,
The information processing system includes:
Second image acquisition means for acquiring an image captured by the second imaging device;
Measuring means for measuring the surface property of the evaluation object in the evaluation section using the image acquired by the second image acquisition means;
The information processing system according to claim 1, further comprising: an evaluation unit that evaluates the evaluation object in the evaluation section based on the surface property measured by the measurement unit.   The determination unit according to claim 1, further comprising: a determination unit that determines whether the detection unit can detect the reference object based on the image acquired by the image acquisition unit. Information processing system.   The information processing system according to claim 2, further comprising a determination unit that determines whether the detection unit can detect the reference object and the target object based on the image acquired by the image acquisition unit. . A first imaging device mounted on a vehicle traveling on an evaluation target, a distance measuring device mounted on the vehicle and measuring a travel distance of the vehicle, and an information processing system for estimating an evaluation section of the evaluation target; An evaluation system including a second imaging device that images the evaluation object,
The information processing system is
First image acquisition means for acquiring an image including the evaluation object imaged by the first imaging device;
Detection means for detecting a reference object having a specified characteristic with reference to the image acquired by the first image acquisition means;
Instructing means for instructing the distance measuring device to measure the travel distance of the vehicle in response to detection of the reference object by the detecting means;
Distance acquisition means for acquiring the travel distance measured by the distance measuring device;
Position estimation means for estimating the positions of one end and the other end of the evaluation section based on the positions at which the travel distances acquired by the distance acquisition means reach the specified distance for one end and the other end of the evaluation section, respectively. When,
Second image acquisition means for acquiring an image captured by the second imaging device;
Measuring means for measuring the surface property of the evaluation object in the evaluation section using the image acquired by the second image acquisition means;
An evaluation system including evaluation means for evaluating the evaluation object in the evaluation section based on the surface property measured by the measurement means. An information processing method for estimating an evaluation section to be evaluated,
Obtaining an image of the evaluation object imaged by an imaging device mounted on a vehicle traveling on the evaluation object;
Referring to the acquired image and detecting a reference object having a specified feature;
Instructing the distance measuring device mounted on the vehicle to measure the travel distance of the vehicle in response to the detection of the reference object;
Obtaining the travel distance measured by the distance measuring device;
An information processing method including a step of estimating positions of one end and the other end of the evaluation section based on positions at which the travel distances acquired for one end and the other end of the evaluation section reach a specified distance, respectively. . A program for causing a computer to execute a process for estimating an evaluation interval to be evaluated,
Obtaining an image including the evaluation object imaged by an imaging device mounted on a vehicle traveling on the evaluation object;
Referring to the acquired image and detecting a reference object having a specified feature;
Instructing the distance measuring device mounted on the vehicle to measure the travel distance of the vehicle in response to the detection of the reference object;
Obtaining the travel distance measured by the distance measuring device;
The program which performs the step which estimates the position of the one end and the other end of the said evaluation area based on the position where each traveling distance acquired about the one end and the other end of the said evaluation area respectively reached the designated distance.