Correction system

Abstract

This correction system includes a first imaging device, a second imaging device, and a server. The first imaging device comprises: a first imaging unit that images, by each of a pair of imaging elements, an object image of the same object for which an image was formed by each of a pair of imaging optical systems; and a first calculation device that acquires, from the imaging result from the first imaging unit, first information including the size of the object, the position thereof, the time at which the object was imaged, and the position of the first imaging unit when the object was imaged, and transmits the first information to the server. The second imaging device comprises: a second imaging unit that images, by each of a pair of imaging elements, a subject image of the same subject for which an image was formed by each of the pair of imaging optical systems; and a second computation device that acquires second information from the imaging result from the second imaging unit, receives the first information stored in a storage unit from the server, compares the first information with the second information, and performs optical axis correction control of the second imaging unit on the basis of the comparison results.

Description

Compensation System

[0001] The present invention relates to a correction system.

[0002] Stereo cameras are known that measure the distance to a subject using two cameras. For the accuracy of distance measurement using a stereo camera, it is important that the positions of the optical axes of the two cameras have a known relationship. Patent Document 1 describes an in-vehicle camera calibration device that calculates camera parameters indicating the positional relationship between the optical axes of the two cameras from feature quantities of road markings such as white lines, and controls the correction of the optical axes of the two cameras.

[0003] JP 2008-11174 A

[0004] In an environment where a parallax peak is unlikely to occur or where there are no white lines, the technique described in Patent Document 1 has the problem that it is not possible to perform sufficient optical axis correction control.

[0005] The present invention aims to perform appropriate optical axis correction control even in an environment where a parallax peak is unlikely to occur or in a situation where there are no white lines.

[0006] A correction system according to one aspect of the present invention is a correction system having a first imaging device, a second imaging device, and a server, wherein the first imaging device comprises a first imaging unit that captures object images of the same object formed by a pair of imaging optical systems using a pair of imaging elements, and a first arithmetic unit that acquires first information from the imaging results by the first imaging unit, the first information including the size of the object, the position of the object, the time when the object was imaged, and the position of the first imaging unit when the object was imaged, and transmits the first information to the server, the server comprises a memory unit that stores the first information transmitted by the first arithmetic unit, and the second imaging device comprises a second imaging unit that captures object images of the same object formed by the pair of imaging optical systems using a pair of imaging elements, and a second arithmetic unit that acquires second information from the imaging results by the second imaging unit, receives the first information stored in the memory unit from the server, compares the first information with the second information, and performs optical axis correction control of the second imaging unit based on the comparison result.

[0007] According to the present invention, appropriate optical axis correction control can be performed even in an environment where a parallax peak is unlikely to occur or in a situation where there are no white lines.

[0008] FIG. 1 is a schematic diagram showing the overall configuration of a correction system according to a first embodiment. FIG. 2 is a schematic diagram showing the hardware configuration of a master camera. FIG. 3 is a schematic diagram showing the hardware configuration of a server. FIG. 4 is a schematic diagram showing the hardware configuration of a camera. FIG. 5 is a schematic diagram showing the functional configuration of the correction system according to the first embodiment. FIG. 6 is a flowchart showing an example of optical axis correction processing executed by the correction system according to the first embodiment. FIG. 7 is a flowchart showing an example of optical axis correction processing executed by the correction system according to a second embodiment.

[0009] First Embodiment A correction system according to an embodiment of the present invention will be described with reference to FIGS.

[0010] Fig. 1 is a schematic diagram showing the overall configuration of a correction system according to a first embodiment. The correction system 1 of this embodiment includes a server 2, a master vehicle 3, and a subordinate vehicle 4. Note that Fig. 1 shows only one subordinate vehicle 4, but in reality, the correction system 1 may include multiple subordinate vehicles 4. Similarly, the correction system 1 may include multiple master vehicles 3.

[0011] The master vehicle 3 is equipped with a master camera 6, a communication device 7, and a position detection device 10. The subordinate vehicle 4 is equipped with a camera 8, a communication device 9, and a position detection device 11. The server 2, the master camera 6, and the camera 8 are configured to be able to communicate data via a wireless communication network 5. The wireless communication network 5 is, for example, a network such as a mobile phone network.

[0012] 2 is a schematic diagram showing the hardware configuration of the master camera 6. The master camera 6 is a so-called stereo camera. The master camera 6 is composed of an imaging unit 25, a computing device 21, a non-volatile memory 22, a volatile memory 23, an input / output interface 24, and a computer equipped with other peripheral circuits. These hardware components work together to run software and realize multiple functions. The master camera 6 may be composed of one computer or multiple computers.

[0013] The imaging unit 25 has a pair of imaging optical systems 26 and a pair of imaging elements 27. One imaging element 27 captures the subject image formed on the imaging surface by one imaging optical system 26 and outputs an imaging signal. Similarly, the other imaging element 27 captures the subject image formed on the imaging surface by the other imaging optical system 26 and outputs an imaging signal. The pair of imaging optical systems 26 are aligned during manufacture of the master camera 6, when mounted on the master vehicle 3, when the master vehicle 3 starts traveling, etc., so that the optical axis positions of the two optical systems 26 are strictly aligned in the vertical direction and are spaced a specific distance apart in the horizontal direction. Generally, this distance between the optical axis positions in the horizontal direction is called the baseline length.

[0014] The arithmetic device 21 is, for example, a device such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or a DSP (Digital Signal Processor). Note that the arithmetic device 21 may also be an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or the like. The non-volatile memory 22 is a storage device such as a ROM (Read Only Memory), a flash memory, or a hard disk drive. The volatile memory 23 is a storage device known as a RAM (Random Access Memory).

[0015] The nonvolatile memory 22 stores programs capable of executing various calculations. In other words, the nonvolatile memory 22 is a storage medium (storage device) from which programs realizing the functions of this embodiment can be read. The nonvolatile memory 22 also stores camera parameters of the imaging unit 25. The camera parameters include, for example, numerical values ​​representing the positional relationship between the optical axes of a pair of imaging optical systems 26. The volatile memory 23 is a storage medium (storage device) that temporarily stores the results of calculations performed by the calculation device 21 and signals input from the input / output interface 24. The calculation device 21 loads the programs stored in the nonvolatile memory 22 into the volatile memory 23 and executes calculations, and performs predetermined calculations on data taken in from the input / output interface 24, the nonvolatile memory 22, and the volatile memory 23 in accordance with the programs.

[0016] The master camera 6 is connected to the communication device 7 and the position detection device 10. The input section of the input / output interface 24 converts signals input from various devices (such as the communication device 7 and the position detection device 10) into data that can be calculated by the calculation device 21. The output section of the input / output interface 24 generates an output signal corresponding to the calculation result of the calculation device 21 and outputs the signal to various devices (such as the communication device 7). The communication device 7 performs wireless communication using an antenna (not shown) to perform data communication with other devices connected to the wireless communication network 5. The position detection device 10 detects the current position of the master camera 6 using a so-called Global Navigation Satellite System (GNSS). For example, the position detection device 10 receives positioning signals transmitted from multiple artificial satellites and calculates absolute coordinates (hereinafter simply referred to as coordinates) in a specific geodetic system.

[0017] 3 is a schematic diagram showing the hardware configuration of the server 2. The server 2 is composed of a computer equipped with a calculation device 31, a non-volatile memory 32, a volatile memory 33, an input / output interface 34, a master database 35, a communication device 36, and other peripheral circuits. These hardware components work together to run software and realize multiple functions. The server 2 may be composed of one computer or multiple computers. The calculation device 31, the non-volatile memory 32, the volatile memory 33, and the communication device 36 are the same as those described in the master camera 6, so their description will be omitted.

[0018] The master database 35 is a storage device such as a flash memory, a hard disk drive, etc. The master database 35 stores a large amount of object information (described later) transmitted from the master camera 6.

[0019] FIG. 4 is a schematic diagram showing the hardware configuration of the camera 8. The camera 8 is a so-called stereo camera. The camera 8 is composed of an imaging unit 45, a computing device 41, a non-volatile memory 42, a volatile memory 43, an input / output interface 44, and a computer equipped with other peripheral circuits. These hardware components work together to run software and realize multiple functions. The camera 8 may be composed of one computer or multiple computers. The camera 8 is connected to a communication device 9 and a position detection device 11. The components of the computing device 41, the non-volatile memory 42, the volatile memory 43, the communication device 9, and the position detection device 11 are the same as those described in the master camera 6, so their description will be omitted.

[0020] The imaging unit 45 has a pair of imaging optical systems 46 and a pair of imaging elements 47. One imaging element 47 captures the subject image formed on the imaging surface by one imaging optical system 46 and outputs an imaging signal. Similarly, the other imaging element 47 captures the subject image formed on the imaging surface by the other imaging optical system 46 and outputs an imaging signal. The pair of imaging optical systems 46 are aligned during the manufacture of the camera 8 or when mounted on the vehicle 4 so that their optical axis positions are aligned vertically and separated by a specific distance horizontally. The nonvolatile memory 42 of the camera 8 also stores camera parameters of the imaging unit 45, similar to the nonvolatile memory 22 of the master camera 6. The camera parameters include, for example, numerical values ​​representing the positional relationship between the optical axes of the pair of imaging optical systems 46. The camera parameters stored in the nonvolatile memory 42 of the camera 8 are updated by optical axis correction control, which will be described later.

[0021] 5 is a schematic diagram showing the functional configuration of the correction system according to the first embodiment. The master camera 6 includes an information acquisition unit 51 and a transmission unit 52. The information acquisition unit 51 acquires object information relating to a specific object included in the image capture result from the image capture result obtained by the image capture unit 25. The transmission unit 52 transmits the object information acquired by the information acquisition unit 51 to the server 2.

[0022] The server 2 includes a receiving unit 53 and a transmitting unit 54. The receiving unit 53 receives object information transmitted by the transmitting unit 52 of the master camera 6 and stores it in the master database 35. The receiving unit 53 also receives subject information transmitted from the camera 8 and searches the master database 35 for object information related to the same object as the subject corresponding to the subject information. The transmitting unit 54 transmits the search results from the master database 35 to the camera 8. For example, the transmitting unit 54 transmits object information found in the master database 35 to the camera 8. Alternatively, the transmitting unit 54 transmits information indicating that object information was not found in the master database 35 to the camera 8.

[0023] The camera 8 includes an information acquisition unit 55, a transmission unit 56, a reception unit 57, a comparison unit 58, and a correction unit 59. The information acquisition unit 55 acquires, from the image capture results obtained by the imaging unit 45, subject information related to a specific subject included in the image capture results. The transmission unit 56 transmits the subject information acquired by the information acquisition unit 55 to the server 2. The reception unit 57 receives information transmitted from the transmission unit 54 of the server 2. As described above, when the transmission unit 56 of the camera 8 transmits the subject information to the server 2, the transmission unit 54 of the server 2 responsively transmits to the camera 8 either object information corresponding to the subject information or information indicating that the object information was not found. The reception unit 57 of the camera 8 receives this information transmitted from the server 2. The comparison unit 58 compares the subject information acquired by the information acquisition unit 55 with the subject information transmitted from the server 2. The correction unit 59 performs optical axis correction control of the imaging unit 45 based on the comparison result by the comparison unit 58. In this embodiment, the optical axis correction control of the imaging unit 45 refers to control that suppresses distance measurement errors caused by misalignment of the optical axis of the imaging unit 45 by updating the camera parameters stored in the non-volatile memory 42.

[0024] Information collection by the master vehicle 3 will be described. The master vehicle 3 is operated by a company or the like that operates the correction system 1. The operator of the correction system 1 drives the master vehicle 3 around various locations. During the patrol, the master camera 6 appropriately photographs the surroundings of the master vehicle 3. As a result, objects visible from the driving route of the master vehicle 3 are appropriately photographed by the master camera 6. For example, objects installed on or on the road surface, such as traffic lights, road signs, and road markings, are photographed. Structures (so-called landmarks), such as buildings, houses, and steel towers, are also photographed in the same way.

[0025] The information acquisition unit 51 of the master camera 6 performs distance measurement using the image capture results from the image capture unit 25, and measures the distance from the image capture unit 25 to each subject included in the image capture results. The distance to each subject can be expressed by a so-called depth map, which arranges the distance from the image capture unit 25 for each pixel of the image, for example.

[0026] The information acquisition unit 51 of the master camera 6 detects these objects from the image capture results obtained by the image capture unit 25 using well-known techniques. For example, techniques such as template matching and object recognition using machine learning can be used. The information acquisition unit 51 acquires object information related to the object from the image capture results. The object information includes, for example, a partial image including the object cut out from the captured image, the size of the object, the position (coordinates) of the object, the date and time the object was captured, and the position (coordinates) of the image capture unit 25 when the object was captured. The size of the object can be calculated from the camera parameters of the image capture unit 25 and the distance measurement results. The position of the object can be calculated from the position of the master vehicle 3 detected by the position detection device 10, the installation position of the image capture unit 25 on the master vehicle 3, the orientation (azimuth) of the image capture unit 25 detected by a sensor (not shown), and the distance measurement results.

[0027] The transmitter 52 of the master camera 6 transmits the object information acquired by the information acquisition unit 51 to the server 2. When the receiver 53 of the server 2 receives the object information transmitted by the transmitter 52 of the master vehicle 3, the receiver 53 stores the object information in the master database 35.

[0028] As described above, by the master vehicle 3 traveling around the area, object information corresponding to objects in various locations is accumulated in the master database 35 of the server 2.

[0029] The information acquisition unit 55 of the camera 8 detects, as a subject, an object similar to that of the information acquisition unit 51 of the master camera 6 from the image capture results by the image capture unit 45 using well-known technology. The information acquisition unit 55 acquires subject information related to the subject from the image capture results. The subject information includes, for example, a partial image including the subject cut out from the captured image, the size of the subject, the position (coordinates) of the subject, the position (coordinates) of the image capture unit 45 when the subject was captured, and the like.

[0030] The master camera 6 mounted on the master vehicle 3 has higher performance than the cameras 8 mounted on the subordinate vehicles 4 and is configured to perform accurate distance measurement. For example, the baseline length of the pair of imaging optical systems 26 of the master camera 6 is set longer than the baseline length of the pair of imaging optical systems 46 of the camera 8. Generally, increasing the baseline length increases the size of the device, but improves distance measurement accuracy. Furthermore, the imaging unit 25 of the master camera 6 is made of a material with a smaller linear expansion coefficient than the imaging unit 45 of the camera 8. For example, the housing of the imaging unit 25 of the master camera 6 uses a material with a smaller linear expansion coefficient than the housing of the imaging unit 45 of the camera 8. A material with a small linear expansion coefficient experiences relatively less dimensional change due to temperature changes, thereby reducing the effect of temperature changes on the optical axis position and improving distance measurement accuracy. However, this reduces the options for materials that make up the imaging unit 25. Furthermore, the imaging element 27 of the master camera 6 uses a material with a larger number of pixels than the imaging element 47 of the camera 8. The greater the number of pixels, the more precise (i.e., higher resolution) distance measurement can be performed, but the size, price, power consumption, etc. of the image sensor will increase.

[0031] Furthermore, the optical axis of the master camera 6 mounted on the master vehicle 3 is aligned more precisely than that of the camera 8 mounted on the subordinate vehicle 4. To enable more accurate distance measurement, the optical axis may be aligned each time the vehicle travels, or the optical axis position may be calibrated and the camera parameters may be updated each time the vehicle travels. In this way, it is possible to eliminate (or make so small that it can be ignored) any misalignment of the optical axis of the master camera 6.

[0032] As described above, the distance measurement accuracy of the master camera 6 is extremely high, and therefore the object information acquired by the information acquisition unit 51 of the master camera 6 is extremely accurate. In other words, the object information stored in the master database 35 of the server 2 is extremely accurate.

[0033] FIG. 6 is a flowchart showing an example of an optical axis correction process executed by the correction system according to the first embodiment. The optical axis correction process is repeatedly executed by the arithmetic unit 41 of the camera 8 when the camera 8 is powered on. In step S100, the arithmetic unit 41 causes the position detection unit 11 to detect the position (coordinates) of the camera 8. In step S110, the arithmetic unit 41 determines whether the position of the camera 8 detected in step S110 is within a pre-designated facility under the management of the operator of the correction system 1, such as a factory or a car dealership, and whether the subordinate vehicle 4 is parked. If the camera 8 is located within the designated facility and the subordinate vehicle 4 is parked, the process proceeds to step S120. On the other hand, if the camera 8 is not located within the designated facility or the subordinate vehicle 4 is not parked, the process proceeds to step S150.

[0034] In step S120, the arithmetic device 41 causes the imaging unit 45 to capture an image of a subject. The imaging in step S130 is assumed to be of a calibration chart or the like. In step S130, the arithmetic device 41 acquires subject information from the imaging results of step S120 and receives object information corresponding to the subject information from the server 2. The master database 35 of the server 2 stores object information obtained in advance as a result of imaging a calibration chart or the like within a predetermined facility. In step S140, the arithmetic device 41 performs optical axis correction control using the subject information acquired in step S130 and the received object information. Specifically, the arithmetic device 41 compares the image of the object included in the object information with the image of the object included in the subject information, and calculates the size difference between the images of the object in each image. Then, the camera parameters stored in the non-volatile memory 42 are updated based on the size difference.

[0035] In step S150, the calculation device 41 determines whether the position of the camera 8 detected in step S110 is within a facility of a type designated in advance by the operator of the correction system 1, such as a gas station or a multi-story parking lot, and whether the subordinate vehicle 4 is parked. If the camera 8 is located within such a facility and the subordinate vehicle 4 is parked, the process proceeds to step S160. On the other hand, if the camera 8 is not located within such a facility or the subordinate vehicle 4 is not parked, the process proceeds to step S200.

[0036] In step S160, the arithmetic device 41 causes the imaging unit 45 to capture a subject image. In step S170, the arithmetic device 41 acquires subject information from the imaging result of step S160 and receives object information corresponding to the subject information from the server 2. Note that if object information corresponding to the subject information is not stored in the master database 35 of the server 2, i.e., if there is no object information related to the same object as the subject that is the subject of the subject information, the object information cannot be received from the server 2 in step S170 (reception fails). In step S180, the arithmetic device 41 determines whether or not the object information was received from the server 2 in step S170. If the object information was received, i.e., if there was object information corresponding to the subject information, the process proceeds to step S190. On the other hand, if the object information was not received, i.e., if there was no object information corresponding to the subject information, the process proceeds to step S200.

[0037] In step S190, the arithmetic unit 41 performs optical axis correction control using the subject information acquired in step S170 and the received object information. Specifically, the arithmetic unit 41 compares the image of the object included in the object information with the image of the object included in the subject information, and calculates the size difference between the images of the object. Then, the camera parameters stored in the non-volatile memory 42 are updated based on the size difference.

[0038] In step S200, the arithmetic device 41 causes the imaging unit 45 to capture an image of a subject. In step S210, the arithmetic device 41 acquires subject information from the imaging result of step S200 and receives object information corresponding to the subject information from the server 2. Note that if object information corresponding to the subject information is not stored in the master database 35 of the server 2, i.e., if there is no object information related to the same object as the subject that is the subject of the subject information, the object information cannot be received from the server 2 in step S210 (reception fails). In step S220, the arithmetic device 41 determines whether or not the object information was received from the server 2 in step S210. If the object information was received, i.e., if there was object information corresponding to the subject information, the process proceeds to step S230. On the other hand, if the object information was not received, i.e., if there was no object information corresponding to the subject information, the process shown in FIG. 6 ends.

[0039] In step S230, the arithmetic unit 41 performs optical axis correction control using the subject information acquired in step S210 and the received object information. Specifically, the distance to the object is calculated using the position of the object included in the object information and the position of the camera 8 detected by the position detection unit 11. The calculated distance is then compared with the distance to the subject included in the subject information. If there is no positional deviation in the optical axis position, these distances should match very well. Conversely, if there is a positional deviation in the optical axis position, the deviation in these distances will be large due to the positional deviation. The arithmetic unit 41 updates the camera parameters stored in the non-volatile memory 42 based on the difference between these distances, and then ends the processing shown in FIG. 6.

[0040] According to the above-described first embodiment, the following advantageous effects are achieved.

[0041] (1) The imaging unit 25 (first imaging unit) of the master camera 6 (first imaging device) captures object images of the same object formed by a pair of imaging optical systems 26, respectively, using a pair of imaging elements 27. The arithmetic unit 21 (first arithmetic unit) of the master camera 6 (first imaging device) acquires object information (first information) including the size of the object, the position of the object, the time the object was imaged, and the position of the imaging unit 25 (first imaging unit) when the object was imaged, from the imaging results of the imaging unit 25 (first imaging unit), and transmits the object information (first information) to the server 2. The server 2 includes a master database 35 (storage unit) that stores the object information (first information) transmitted by the master camera 6 (first imaging device). The imaging unit 45 (second imaging unit) of the camera 8 (second imaging device) captures object images of the same object formed by a pair of imaging optical systems 46, respectively, using a pair of imaging elements 47. The arithmetic unit 41 (second arithmetic unit) of the camera 8 (second imaging device) acquires subject information (second information) from the imaging results of the imaging unit 45 (second imaging unit), receives object information (first information) stored in the master database 35 (storage unit) from the server 2, compares the object information (first information) with the subject information (second information), and performs optical axis correction control of the imaging unit 45 (second imaging unit) based on the comparison results. This configuration allows for appropriate optical axis correction control even in environments where white lines are difficult to see due to weather or other factors, situations where white lines are difficult to see because they are faded or thin, or situations where there are no white lines. Furthermore, appropriate optical axis correction improves distance measurement accuracy, allowing for appropriate operation of devices that use distance measurement results, such as collision prevention brakes.

[0042] (2) The base line length of the imaging unit 25 (first imaging unit) is longer than the base line length of the imaging unit 45 (second imaging unit), the material constituting the housing of the imaging unit 25 (first imaging unit) has a smaller linear expansion coefficient than the material constituting the housing of the imaging unit 45 (second imaging unit), and the number of pixels of the pair of imaging elements 27 used by the imaging unit 25 (first imaging unit) is greater than the number of pixels of the pair of imaging elements 47 used by the imaging unit 45 (second imaging unit). As a result, the object information output by the master camera 6 is based on accurate distance measurement results, enabling highly accurate optical axis correction control.

[0043] (3) The subject information (second information) includes the size of the subject, the position of the subject, and the position of the imaging unit 45 (second imaging unit) when the subject was imaged. In this way, by using the subject information for objects that frequently appear on the driving route, such as traffic lights, road signs, and road markings, it becomes possible to correct the optical axis while driving.

[0044] (4) When the position of the imaging unit 45 (second imaging unit) when capturing the subject image is a predetermined position, the arithmetic unit 41 (second arithmetic unit) receives from the server object information (first information) including the predetermined position as the position of the imaging unit 25 (first imaging unit), compares the image of the object included in the object information (first information) with the image of the subject included in the subject information (second information), calculates the size difference between the images of the object in each image, and performs optical axis correction control of the imaging unit 45 (second imaging unit) based on the size difference. In this way, by performing optical axis correction control at a pre-specified point, it is possible to ensure that object information corresponding to the subject information is included in the master database 35, and it is possible to perform optical axis correction control with high accuracy.

[0045] (5) The subject information (second information) includes the distance from the imaging unit 45 (second imaging unit) to the subject. The camera 8 (second imaging device) includes a position detection device 11 (positioning device) that measures the position of the camera 8 (second imaging device). When the subject imaged by the imaging unit 45 (second imaging unit) is the same as the object imaged by the imaging unit 25 (first imaging unit), the arithmetic unit 41 (second arithmetic unit) calculates the distance to the subject using the position of the object included in the object information (first information) and the measured position, and performs optical axis correction control of the imaging unit 45 (second imaging unit) based on the calculated distance and the distance included in the subject information (second information). This allows for appropriate optical axis correction control.

[0046] Second Embodiment A correction system according to a second embodiment of the present invention will be described with reference to Fig. 7. Note that components that are the same as or equivalent to those described in the first embodiment will be given the same reference symbols, and differences will be mainly described.

[0047] Fig. 7 is a flowchart similar to Fig. 6, showing an example of the optical axis correction process executed by the correction system according to the second embodiment. In the flowchart of Fig. 7, the process of step S330 is executed instead of the process of step S230 in the flowchart of Fig. 6.

[0048] In step S330, the arithmetic device 41 performs coordinate correction control using the subject information acquired in step S210 and the received object information. The coordinate correction control is control for correcting the position (coordinates) of the camera 8 detected by the position detection device 11. Specifically, the current position of the camera 8 (position at the time of image capture) is calculated using the position of the object included in the object information and the distance from the camera 8 to the object included in the subject information. The calculated position is then used to correct the position of the camera 8 detected by the position detection device 11. In other words, here, the position deviation detected by the position detection device 11 is corrected on the assumption that no position deviation occurs in the optical axis position.

[0049] According to the second embodiment described above, the following advantageous effects are achieved.

[0050] (1) The subject information (second information) includes the distance from the imaging unit 45 (second imaging unit) to the subject. The camera 8 (second imaging device) includes a position detection device 11 (positioning device) that measures the position of the camera 8 (second imaging device). If the subject imaged by the imaging unit 45 (second imaging unit) is the same as the object imaged by the imaging unit 25 (first imaging unit), the calculation device 41 (second calculation device) calculates the position of the camera 8 (second imaging device) using the position of the object included in the object information (first information) and the distance to the subject included in the subject information (second information), and corrects the measured position using the calculated position. This allows not only optical axis correction but also measured position correction to be performed simultaneously.

[0051] The following modified examples are also within the scope of the present invention, and it is possible to combine the configuration shown in the modified example with the configuration described in the above embodiment, to combine the configurations described in the different embodiments above, or to combine the configurations described in the different modified examples below.

[0052] <Modification 1> High-precision map information may be stored in advance in the camera 8 or in a device mounted on the subordinate vehicle 4. In this case, the position of an object searched for from the high-precision map information can be used instead of the position of an object included in the object information.

[0053] <Modification 2> While traveling, the series of processes for correcting the coordinates described in the second embodiment (steps S200 to S330 in FIG. 7) and the series of processes for correcting the optical axis described in the first embodiment (steps S200 to S230 in FIG. 6) may be alternately executed repeatedly, thereby maintaining the accuracy of the optical axis appropriately.

[0054] Although the embodiments of the present invention have been described above, the above embodiments merely illustrate some of the application examples of the present invention, and it is not intended that the technical scope of the present invention be limited to the specific configurations of the above embodiments.

[0055] 1...Correction system, 2...Server, 3...Master vehicle, 4...Subordinate vehicle, 5...Wireless communication network, 6...Master camera (first imaging device), 7, 9, 36...Communication device, 8...Camera (second imaging device), 10, 11...Position detection device (positioning device), 21, 31, 41...Calculation device (first imaging device, second computing device), 22, 32, 42...Non-volatile memory, 23, 33, 43...Volatile memory, 24, 34, 44...Input / output interface, 25, 45...Imaging unit (first imaging unit, second imaging unit), 26, 46...Imaging optical system, 27, 47...Imaging element, 35...Master database (storage unit), 51, 55...Information acquisition unit, 52, 54, 56...Transmission unit, 53, 57...Reception unit, 58...Comparator, 59...Correction unit

Claims

1. A correction system having a first imaging device, a second imaging device, and a server, wherein the first imaging device comprises a first imaging section that captures object images of an identical object formed by a pair of imaging optical systems using a pair of imaging elements, and a first arithmetic unit that obtains first information from the imaging results by the first imaging section, the first information including a size of the object, a position of the object, a time when the object was imaged, and a position of the first imaging section when the object was imaged, and transmits the first information to the server, the server comprises a memory unit that stores the first information transmitted by the first arithmetic unit, and the second imaging device comprises a second imaging section that captures subject images of the same subject formed by the pair of imaging optical systems using a pair of imaging elements, and a second arithmetic unit that obtains second information from the imaging results by the second imaging section, receives the first information stored in the memory unit from the server, compares the first information with the second information, and performs optical axis correction control of the second imaging section based on the comparison result.

2. A correction system as described in claim 1, wherein the baseline length of the first imaging unit is longer than the baseline length of the second imaging unit, the material constituting the housing of the first imaging unit has a smaller linear expansion coefficient than the material constituting the housing of the second imaging unit, and the number of pixels of the pair of imaging elements used by the first imaging unit is greater than the number of pixels of the pair of imaging elements used by the second imaging unit.

3. A correction system according to claim 1, wherein the second information includes the size of the subject, the position of the subject, and the position of the second imaging unit when the subject was imaged.

4. A correction system as described in claim 1, wherein the second calculation device, when the position of the second imaging unit when the subject image is captured is a predetermined position, receives from the server the first information including the predetermined position as the position of the first imaging unit, compares the image of the object included in the first information with the image of the subject included in the second information to calculate a size difference between the images of the object in each image, and performs optical axis correction control of the second imaging unit based on the size difference.

5. A correction system as described in claim 1, wherein the second information includes a distance from the second imaging unit to the subject, the second imaging device further includes a positioning device that measures the position of the second imaging device, and when the subject is the object, the second computing device calculates the position of the second imaging device using the position of the object included in the first information and the distance to the subject included in the second information, and corrects the measured position using the calculated position.

6. A correction system as described in claim 1, wherein the second information includes a distance from the second imaging unit to the subject, the second imaging device further includes a positioning device that measures the position of the second imaging device, and when the subject is the object, the second computing device calculates the distance to the subject using the position of the object included in the first information and the measured position, and performs optical axis correction control of the second imaging unit based on the calculated distance and the distance included in the second information.