Control device, control system, and control method

Abstract

The invention provides a control device, a control system and a control method, which can automatically perform control related to anti-dazzle without arranging a light quantity sensor on a reflecting mirror and further realize proper anti-dazzle. A control device (10) is provided with a control unit (13) that acquires a captured image on the basis of the imaging result of a camera (11) that images the rear of a vehicle, determines the reflectance of a mirror, which is the reflectance of the mirror, on the basis of the brightness of the captured image, and determines the reflectance of the mirror without using the detection result of a light quantity sensor provided to the mirror. The reflectance of the mirror is determined on the basis of the brightness of the captured image based on the imaging result of the camera (11).

Description

Technical Field

[0001] The present invention relates to a control device, a control system and a control method, and is particularly suitable for a control device that is installed in a vehicle and performs processing related to a reflector configured to change reflectivity, a control system including the control device and the reflector, and a control method based on the control device. Background Art

[0002] In the past, regarding the reflector (so-called interior rearview mirror) provided in the vehicle cabin, there is a reflector equipped with an anti-glare function. In Patent Document 1, regarding this reflector, the following technology is disclosed. That is, the reflector 2 in Patent Document 1 is provided with an ambient light sensor 31 for detecting the amount of light incident from the front of the vehicle and a rear light sensor 32 for detecting the amount of light incident from the rear of the vehicle. Furthermore, when the amount of light detected by the rear light sensor 32 is greater than the amount of light detected by the ambient light sensor 31, the reflector 2 is controlled to automatically put the reflector 2 into an anti-glare state. Patent Document 1 discloses the above technology. According to this structure, when the light of the headlight of the following vehicle is incident on the reflector 2 at night, the reflector 2 can be automatically put into an anti-glare state, thereby improving the convenience of the driver. As in Patent Document 1, two sensors for detecting the amount of light incident from the front and rear of the vehicle are provided on the reflector, and the technology of automatically performing anti-glare-related control according to the difference in the amount of light detected by these sensors is widely implemented.

[0003] Patent document 2 describes a technique in which, based on the shooting result of the rear camera 4 shooting the rear of the vehicle, a period during which anti-glare is expected to be required, i.e., an anti-glare period for the following vehicle, is set, and the brightness of the image shot by the rear camera 4 is reduced during this period.

[0004] [Prior art literature]

[0005] [Patent Document]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2010-173460

[0007] [Patent Document 2] Japanese Patent Application Publication No. 2021-172243 Summary of the invention

[0008] The reflector that performs anti-glare related controls by two light sensors provided on the reflector, as in the reflector of Patent Document 1, has the following situation. That is, it is necessary to design the reflector in consideration of the presence of the two light sensors, and the presence of the two light sensors that should be provided in the reflector becomes a restriction of the design. In addition, there is usually indoor lighting near the reflector, so it is necessary to design the reflector in consideration of the influence of the light from the indoor lighting when the indoor lighting is turned on, and the design difficulty is high. Based on the above situation, it is required to be able to automatically perform anti-glare related controls without providing a light sensor on the reflector. However, if the light sensor is not provided on the reflector, the appropriateness of anti-glare will be lost, so it is put the cart before the horse and it is required to achieve appropriate anti-glare in which the driver is suppressed from feeling excessive glare.

[0009] The present invention has been made to solve such a problem, and an object of the present invention is to automatically perform control related to anti-glare without providing a light amount sensor on a reflector, thereby realizing appropriate anti-glare.

[0010] In order to solve the above technical problems, the present invention obtains a captured image based on a result of a camera capturing images of the rear of a vehicle, and determines the reflectivity of the reflector, that is, the reflectivity of the reflector, based on the brightness of the captured image.

[0011] [Effects of the Invention]

[0012] In order to achieve proper anti-glare, the degree of reflectivity applied to the reflector should be determined according to the light and dark conditions of the actual environment behind the vehicle. In addition, according to the light and dark conditions of the actual environment behind the vehicle, the brightness of the captured image based on the shooting result of the camera that shoots the rear of the vehicle changes. Therefore, according to the brightness of the captured image, it is possible to understand to what extent the reflectivity of the reflector can achieve proper anti-glare. Based on the above, according to the present invention constructed as described above, the reflectivity of the reflector is determined based on the brightness of the image captured by the camera that shoots the rear of the vehicle instead of the light sensor provided on the reflector. Therefore, without providing a light sensor on the reflector, it is possible to automatically perform control related to anti-glare, and it is possible to achieve proper anti-glare. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is an external view of a reflecting mirror according to one embodiment.

[0014] Figure 2 This is a block diagram showing a functional configuration example of a control device according to an embodiment.

[0015] Figure 3 This is a flowchart showing an operation example of a control device according to one embodiment.

[0016] Figure 4 This is a flowchart showing an operation example of a control device according to one embodiment.

[0017] Figure 5 A diagram showing a captured image.

[0018] Figure 6 The histogram of the brightness of each pixel of the captured image and the focus line Figure 1 The diagram represented.

[0019] Figure 7 This is a flowchart showing an operation example of a control device according to one embodiment.

[0020] Figure 8 It is a graph that represents relationship definition information.

[0021] Fig. 9 It is a diagram showing a modified example of the focus line.

[0022] Fig.10 This is a flowchart showing an operation example of the control device according to the first modification.

[0023] Fig.11 A diagram showing a captured image.

[0024] Fig.12 This is a diagram used in the description of the maximum average luminance difference derivation process.

[0025] Fig.13 2 is a diagram showing a modified example of the focus line group.

[0026] Fig.14 It is a diagram showing a modified example of the block form. DETAILED DESCRIPTION

[0027] Hereinafter, one embodiment of the present invention will be described based on the drawings. Figure 1 : is an appearance diagram of the reflector 1 of the present embodiment. The reflector 1 is a so-called interior rearview mirror provided in the vehicle compartment 3 of the vehicle 2. The reflector 1 is provided at a position close to the front windshield 4 on the ceiling of the vehicle compartment 3. The reflector 1 is used at least for rear confirmation by the driver. Here, when driving at night, driving in a tunnel, or when the outside of other vehicles 2 is dark, the headlights of the following vehicles sometimes shine into the reflector 1. In addition, sometimes, for some reason, light shines into the reflector 1 from the rear of the vehicle 2. If no measures are taken to deal with this, the driver may feel excessive dazzle. On this basis, the reflector 1 of the present embodiment is configured to be able to change its reflectivity and has an automatic anti-dazzle function. The automatic anti-dazzle function is a function that automatically changes the reflectivity of the reflector 1 to suppress the dazzle felt by the driver. The automatic anti-dazzle function will be described in detail later.

[0028] Figure 2 1 is a block diagram showing an example of the functional configuration of the control device 10 of the present embodiment. Figure 2 As shown, the reflector 1 and the camera 11 are connected to the control device 10. The control device 10, the reflector 1 and the camera 11 constitute a control system 12 of the present embodiment.

[0029] like Figure 2 As shown, as a functional structure, the control device 10 includes a control unit 13 and a storage unit 14. The control unit 13 includes a processing device and a primary storage device. The processing device is a device having an information processing function, and includes a CPU. The CPU includes a central control device, an operation device, a register, and a cache memory. The primary storage device includes a DRAM and other volatile memories. The control unit 13 performs processing by having the processing device read the program stored in the storage unit 14 to the primary storage device and execute it. That is, the control unit 13 performs processing through the collaboration of hardware and software. The storage unit 14 includes a hard disk drive (it may also be other magnetic storage devices), ROM, flash memory, and other non-volatile memories. The storage unit 14 stores data in a non-volatile memory.

[0030] The camera 11 is a photographing device for photographing the rear of the vehicle 2. The camera 11 is set at a position where it can photograph the rear of the vehicle 2. For example, the camera 11 is set at the rear bumper, the top of the roof, or the license plate outside the vehicle, or the upper part of the inner side of the rear windshield inside the vehicle. The camera 11 continuously performs photographing at least while the driver is driving (regardless of whether the vehicle 2 is stopped), and outputs the photographed image F based on the photographing result to the control unit 13 at a predetermined frame rate (for example, 60fps).

[0031] The reflector 1 includes an optical device 15 including a liquid crystal panel. The control unit 13 can change the reflectivity of the reflector 1 by changing the transmittance of the liquid crystal panel of the optical device 15 via a drive circuit (not shown). Hereinafter, the reflectivity of the reflector 1 is particularly referred to as "reflector reflectivity". In the present embodiment, the control unit 13 can change the reflectivity of the reflector between 0 and 100%.

[0032] Next, the operation of the control device 10 related to the automatic anti-glare function will be described. Figure 3 This is a flowchart showing an operation example of the control device 10 , showing a process executed by the control device 10 regarding the automatic anti-glare function while the vehicle 2 is traveling (regardless of whether the vehicle 2 is stopped). Figure 3 Flowchart FA shows a control method of the control device 10. As described above, the camera 11 outputs the captured image F based on the captured image result to the control unit 13 at a predetermined frame rate. The control unit 13 executes the processing shown in flowchart FA every time the captured image F is acquired at a predetermined frame rate.

[0033] like Figure 3 As shown, the control unit 13 inputs and obtains the captured image F from the camera 11 (step SA1). In this embodiment, the captured image F is a pixel G ( Figure 5 ) is arranged in a matrix form. In step SA1, the captured image F is expanded in an image buffer that the control unit 13 can refer to.

[0034] Next, the control unit 13 performs a local degree derivation process (step SA2). The local degree derivation process refers to a process in which the control unit 13 derives a "local degree" based on the brightness of the captured image F, and the "local degree" is a degree that satisfies the condition that the rear of the vehicle is locally bright. In the present embodiment, the control unit 13 derives the difference in brightness between the pixel with the highest brightness and the pixel with the lowest brightness among the pixels on the line of interest extending in a predetermined direction on the captured image F, i.e., the "maximum brightness difference", as the local degree. The local degree derivation process is described in detail below.

[0035] Figure 4 The flowchart FB is a flowchart showing the details of the local degree derivation process. Figure 4 As shown, in the local degree derivation process, first, the control unit 13 executes a focus line determination process (step SB1). The focus line determination process is a process for determining a focus line (described later). The focus line determination process will be described in detail below.

[0036] Figure 5 The figure shows the captured image F in a manner suitable for explanation. The captured image F is composed of pixels G arranged in a matrix in the x-axis direction (the direction corresponding to the horizontal direction of the captured scenery) and the y-axis direction (the direction corresponding to the vertical direction of the captured scenery). Figure 5 In the above diagram, the upper left corner of the captured image F is taken as the origin, the direction to the right in the x-axis direction is the + side of the x-axis, the direction to the left is the - side of the x-axis, the direction to the down in the y-axis direction is the + side of the y-axis, and the direction to the up in the y-axis direction is the - side of the y-axis. Figure 6 , Fig. 9 , Figures 11 to 14 In this embodiment, Figure 5 As shown, in the captured image F, a line of pixels G extending from one end to another in the x-axis direction is defined as an "x-axis line". The captured image F is composed of a predetermined number of x-axis lines.

[0037] In the processing of step SB1, the control unit 13 determines the pixel with the highest brightness among the pixels constituting the captured image F (hereinafter referred to as the "highest brightness pixel"). The control unit 13 uses a predetermined calculation formula to derive the brightness of a certain pixel from the pixel value of the pixel. In the present embodiment, the brightness is set to take values ​​within the range of 0 to 255 pt (pt is a unit added for convenience). In addition, when there is only one highest brightness pixel or all the highest brightness pixels belong to one x-axis line, the control unit 13 determines the x-axis line containing the highest brightness pixel as the focus line.

[0038] On the other hand, when there are multiple highest brightness pixels and they exist on different x-axis lines, the control unit 13 determines the focus line by the following method. That is, when the x-axis line containing the largest number of highest brightness pixels (hereinafter referred to as the "largest x-axis line") can be reduced to one, the control unit 13 determines the largest x-axis line as the focus line. For example, referring to Figure 5 , assuming that pixels G-1, G-2, and G-3 are the highest brightness pixels. Pixels G-2 and G-3 belong to the same x-axis line. In this case, the control unit 13 determines the x-axis line including pixels G-2 and G-3 as the focus line.

[0039] On the other hand, when the maximum x-axis line cannot be reduced to one, in other words, when there are two or more maximum x-axis lines, the control unit 13 determines the maximum x-axis line including the highest brightness pixel closest to the specific position among the maximum x-axis lines as the focus line. In the present embodiment, the specific position is the center position of the captured image F. For example, referring to Figure 5 , let pixels G-1, G-4, and G-5 be the highest brightness pixels. In this case, the control unit 13 determines the x-axis line including pixel G-1 as the focus line. This is because pixel G-1 among pixels G-1, G-4, and G-5 is closest to the specific position (= the position of the center of the captured image F). In addition, setting the specific position to "the position of the center of the captured image F" is to assume the position of the headlights of the following vehicle. Based on this, the specific position can also be set to a position corresponding to the "position of the headlights of the following vehicle" and a position different from the "position of the center of the captured image F".

[0040] In some cases, there are multiple most x-axis lines including the highest brightness pixel closest to the specific position. In this case, the control unit 13 determines an arbitrary most x-axis line among the multiple most x-axis lines including the highest brightness pixel closest to the specific position as the focus line.

[0041] As described above, in the focus line determination process of step SB1 , the control unit 13 determines the focus line.

[0042] After the process of step SB1, the control unit 13 executes the maximum brightness difference derivation process (step SB2). In the maximum brightness difference derivation process, the control unit 13 derives the brightness difference between the pixel G with the highest brightness and the pixel G with the lowest brightness on the focus line determined in step SB1 as the maximum brightness difference. Figure 6 (A) is a diagram showing an example of a captured image F. Figure 6 In (A) of FIG. 1 , reference numeral L1 denotes a focus line. Figure 6 (B) is Figure 6 1 and 2. A histogram of the brightness of each pixel G on the focus line L1 of the captured image F of (A).

[0043] about Figure 6 In the image shown in (A), the brightness of the pixel G with the highest brightness is 255 pt, and the brightness of the pixel G with the lowest brightness is 3 pt. The captured image F obtained in step SA1 is Figure 6 In the case of the image shown in (A), in the maximum brightness difference derivation process, the control unit 13 derives 252 pt (255 pt-3 pt) as the maximum brightness difference.

[0044] Here, it can be said that the larger the maximum brightness difference is, the higher the possibility that the rear of the vehicle 2 is partially bright. In other words, there is a correlation between the size of the maximum brightness difference and the degree (local degree) of satisfying the condition that the rear of the vehicle 2 is partially bright, such that the larger the maximum brightness difference is, the larger the local degree is. Therefore, the maximum brightness difference can be used as an index value representing the local degree in the range of 0 to 255 pt. Based on the above, in step SB2, the control unit 13 derives the maximum brightness difference as the local degree.

[0045] As described above, in the local degree derivation process of step SA2, the control unit 13 derives the maximum luminance difference. Hereinafter, the maximum luminance difference derived in the local degree derivation process is referred to as "derived maximum luminance difference".

[0046] In addition, return to Figure 3 FA, after executing the local degree derivation process of step SA2, the control unit 13 executes the darkness degree derivation process (step SA3). The darkness degree derivation process refers to the process in which the control unit 13 derives the overall darkness degree of the scenery recorded in the captured image F, i.e., the "darkness degree", based on the brightness of the captured image F. In this embodiment, the control unit 13 derives the average value of the brightness of the pixels G constituting the focus line (hereinafter referred to as the "line average value") as the darkness degree. For example, the captured image F obtained in step SA1 is Figure 6 In the case of the captured image F shown in (A) of FIG. Figure 6The average value of the brightness of all pixels G in the attention line L1 of (A), that is, the line average value is taken as the darkness level. Hereinafter, the line average value derived in the darkness level derivation process is referred to as the “derived line average value”.

[0047] Here, the line average value and the degree (darkness) of "the overall darkness of the scenery recorded in the captured image F (= the darkness of the actual environment behind the vehicle 2)" have a correlation relationship that the smaller the line average value, the greater the darkness. Therefore, the line average value can be used as an index value representing the darkness within the range of 0 to 255 pt. Based on the above, in step SA3, the control unit 13 derives the line average value as the darkness based on the brightness of the captured image F.

[0048] After executing the darkness degree derivation process of step SA3, the control unit 13 executes the reflector reflectivity determination process (step SA4). The reflector reflectivity determination process is a process for determining the reflector reflectivity that is actually applicable. Hereinafter, the "actually applicable reflector reflectivity" determined in step SA4 is referred to as the "applicable reflector reflectivity", which is generally distinguished from the reflector reflectivity. Hereinafter, the reflector reflectivity determination process is described in detail.

[0049] Figure 7 Flowchart FC is a detailed flowchart showing the process of determining the reflectance of the reflector. Figure 7 As shown, in the reflector reflectivity determination process, first, the control unit 13 determines the level of the derived line average value (hereinafter referred to as "darkness level") (step SC1). In the present embodiment, the control unit 13 determines the darkness level to be level LV1 when the derived line average value is 0-85 pt, determines it to be level LV2 when it is 86-170 pt, and determines it to be level LV3 when it is 171 pt-255 pt. Level LV1 is the smallest level, indicating that the darkness outside the vehicle is the darkest. On the other hand, level LV3 is the largest level, indicating that the darkness outside the vehicle is the brightest. In addition, the relationship between the range of the line average value and the darkness level illustrated in the present embodiment is only a simplified example. This relationship is a matter that should be appropriately determined in advance based on testing or simulation from the perspective of achieving appropriate anti-glare.

[0050] Next, the control unit 13 determines the relationship definition information to be used based on the darkness level (step SC2). Here, in the present embodiment, relationship definition information is prepared for each darkness level (level of darkness degree). Specifically, first relationship definition information corresponding to the darkness level: level LV1, second relationship definition information corresponding to the darkness level: level LV2, and third relationship definition information corresponding to the darkness level: level LV3 are prepared. Then, the control unit 13 determines to use the relationship definition information of the first relationship definition information when the darkness level is level LV1, determines to use the relationship definition information of the second relationship definition information when the darkness level is level LV2, and determines to use the relationship definition information of the third relationship definition information when the darkness level is level LV3. Hereinafter, the relationship definition information determined here will be referred to as "used relationship definition information".

[0051] The following is an explanation of the relationship definition information. The relationship definition information is information that defines the relationship between the maximum brightness difference and the reflector reflectivity. The reflector reflectivity corresponding to the maximum brightness difference of a certain value refers to the reflector reflectivity that achieves appropriate anti-glare when the maximum brightness difference is the value. In the relationship definition information, the reflector reflectivity is associated with each of the possible values ​​of the maximum brightness difference. Therefore, any maximum brightness difference can be converted into the reflector reflectivity using the relationship definition information.

[0052] exist Figure 8 In FIG. 1 , the first to third relationship definition information are represented by a curve on the coordinates where the horizontal axis is the reflectance of the reflector and the vertical axis is the maximum brightness difference. Figure 8 The curve CV1 represents the first relationship definition information, the curve CV2 represents the second relationship definition information, and the curve CV3 represents the third relationship definition information. Figure 8 In the curve CV1 of FIG. 1 , in the first relationship definition information, the maximum brightness difference: 200 pt is associated with the reflector reflectivity: 40%. This means that when the first relationship definition information is used to determine the reflector reflectivity, the maximum brightness difference: 200 pt is converted into the reflector reflectivity: 40%. Furthermore, as shown in the curve CV1, in the first relationship definition information, the greater the maximum brightness difference, the smaller the reflector reflectivity. This relationship also holds true for the second and third relationship definition information.

[0053] In addition, according to Figure 8It can be seen from the curves CV1 to CV3 that when the maximum brightness difference is the same, it becomes "mirror reflectivity of the first relationship definition information < mirror reflectivity of the second relationship definition information < mirror reflectivity of the third relationship definition information". For example, regarding the maximum brightness difference: 200pt, the corresponding mirror reflectivity in the first relationship definition information is 40%, the corresponding mirror reflectivity in the second relationship definition information is 70%, and the corresponding mirror reflectivity in the third relationship definition information is 80%, "mirror reflectivity of the first relationship definition information (40%) < mirror reflectivity of the second relationship information (70%) < mirror reflectivity of the third relationship definition information (80%)". In addition, in the present embodiment, for any one of the first to third relationship definition information, when the maximum brightness difference is less than 125pt, the reflectivity is 100%.

[0054] After the processing of step SC2, the control unit 13 determines the applicable reflector reflectivity based on the utilization relationship definition information (step SC3). Specifically, the control unit 13 converts the derived maximum brightness difference into the reflector reflectivity using the utilization relationship definition information and determines it as the applicable reflector reflectivity. Figure 8 , when the utilization relationship definition information is the first relationship definition information and the maximum brightness difference is 200 pt, the control unit 13 determines the applicable reflector reflectivity to be 40%. In addition, for example, when the utilization relationship definition information is the third relationship definition information and the maximum brightness difference is 200 pt, the control unit 13 determines the applicable reflector reflectivity to be 80%. The above is the content of the reflector reflectivity determination process.

[0055] Here, as described above, when focusing on one kind of relationship definition information, in the relationship definition information, the relationship that the greater the maximum brightness difference, the smaller the reflectance of the reflector is established. That is, if the darkness levels are the same, the control unit 13 determines the reflectance of the reflector in such a way that the greater the maximum brightness difference (local degree), the smaller the reflectance. This is based on the following reasons. That is, the greater the maximum brightness difference, the higher the possibility of a situation where the rear of the vehicle 2 is locally bright (for example, when it is dark outside the vehicle, the light of the headlights of the following vehicle is projected toward the vehicle 2). Therefore, in order to achieve appropriate anti-glare, the greater the maximum brightness difference, the lower the reflectance of the reflector is basically required. Based on the above reasons, the control unit 13 determines the reflectance of the reflector in such a way that the greater the maximum brightness difference (local degree), the smaller the reflectance.

[0056] In addition, as described above, the control unit 13 determines the first relationship definition information as the utilization relationship definition information when the darkness level is level LV1, determines the second relationship definition information as the utilization relationship definition information when it is level LV2, and determines the third relationship definition information as the utilization relationship definition information when it is level LV3. And, when the maximum brightness difference is the same, it becomes "mirror reflectivity of the first relationship definition information < mirror reflectivity of the second relationship information < mirror reflectivity of the third relationship definition information". That is, the smaller the average value (level) of the derived line is (= the larger the darkness level (level) is), even if the maximum brightness difference is the same, the control unit 13 determines the mirror reflectivity in a manner that the reflectivity becomes smaller. This is based on the following reasons.

[0057] That is, the smaller the derived line average value is, the darker the actual environment behind the vehicle 2 (hereinafter referred to as the "external environment") is. Furthermore, if the conditions of the light irradiated from the rear of the vehicle 2 toward the vehicle 2 are the same, the darker the external environment is, the greater the degree to which the driver will be dazzled by the light reflected by the reflector 1 when the reflectivity is 100%. Therefore, in order to reliably suppress the dazzle felt by the driver, even if the maximum brightness difference is the same, the smaller the derived line average value is (= the greater the degree of darkness), the smaller the reflectivity needs to be. Based on the above reasons, the smaller the derived line average value is (= the greater the degree of darkness), the control unit 13 determines the reflectivity of the reflector in a manner that reduces the reflectivity even if the maximum brightness difference is the same.

[0058] The above is the mirror reflectivity determination process. As described above, the control unit 10 determines the applicable mirror reflectivity based on the brightness of the captured image F in the mirror reflectivity determination process of step SA4.

[0059] After the process of step SA4 , the control unit 13 controls the optical device 15 of the reflector 1 so that the reflector reflectivity of the optical device 15 becomes the applicable reflector reflectivity determined in step SA4 (step SA5 ).

[0060] Since the above-described processing is executed in a cycle corresponding to the frame rate, the mirror reflectivity of the reflecting mirror 1 is automatically and dynamically adjusted to an appropriate value determined based on the brightness of the captured image F in the cycle.

[0061] As described above, the control device 10 includes the control unit 13, which obtains the captured image F based on the shooting result of the camera 11 that shoots the rear of the vehicle 2, and determines the reflector reflectivity that is the reflectivity of the mirror 1 based on the brightness of the captured image F. According to this structure, the reflector reflectivity is determined based on the brightness of the captured image F of the camera 11 that shoots the rear of the vehicle 2 instead of the light amount sensor provided on the reflector, so that the control related to anti-glare can be automatically performed without providing the light amount sensor on the reflector 1, and appropriate anti-glare can be achieved.

[0062] <Variation of Local Degree Derivation Processing>

[0063] Next, a modified example of the local degree derivation process (step SA2 of flowchart FA, flowchart FB) of the above embodiment is described. In the above embodiment, a specific example of the method by which the control unit 13 determines the focus line is described through the description of the focus line determination process (step SB1) included in the local degree derivation process. However, the method by which the control unit 13 determines the focus line is not limited to the method exemplified in the above embodiment. For example, the focus line may also be as follows: Fig. 9 A line of pixels G extending in the y-axis direction like the line L2 of FIG. Fig. 9 In this case, the focus line is appropriately determined based on the results of a prior test or simulation, from the viewpoint of ensuring the appropriateness of the local degree (in the above embodiment, the maximum brightness difference) and the darkness degree (in the above embodiment, the line average) derived using the focus line.

[0064] In addition, regarding the derivation of the local degree, the control unit 13 may also execute Fig.10 The flowchart of FD processing is replaced by Figure 4 The structure of the processing of flowchart FB. Hereinafter, the modified example of executing the processing of flowchart FD will be referred to as the "first modified example". In detail, first, the control unit 13 executes the focus line group determination processing (step SD1). The focus line group determination processing is the processing of determining the focus line group. The focus line group is a line group composed of multiple (5 in the first modified example) x-axis lines extending along the x-axis direction on the captured image F. In step SD1, the control unit 13 determines the focus line group by the following method. That is, the control unit 13 determines the focus line by the same method as the method described in the focus line determination processing (step SB1) of the above-mentioned embodiment. Next, the control unit 13 determines a group of 5 x-axis lines including the focus line and 2 x-axis lines in the y-axis + direction and 2 x-axis lines in the y-axis - direction centered on the focus line as the focus line group.

[0065] Fig.11 1 is a diagram showing the captured image F in a manner suitable for explanation. For example, when the focus line is the focus line LH1, the control unit 13 determines a group of five x-axis lines belonging to the range A1 as the focus line group. Fig.11 , when the focus line is from the x-axis line Lx1 located at the end of the captured image F in the y-axis - direction or the x-axis line Lx2 located one line away from the x-axis line Lx1 in the y-axis + direction, the control unit 13 will move from the x-axis line Lx1 toward the 5 x-axis lines in the y-axis + direction (belonging to Fig.11 Similarly, when the focus line is the x-axis line Lx3 located at the end of the captured image F in the y-axis + direction or the x-axis line Lx4 located one line away from the x-axis line Lx3 in the y-axis - direction, the control unit 13 moves the five x-axis lines (belonging to the x-axis line Lx4) from the x-axis line Lx3 toward the y-axis - direction. Fig.11 The group of 5 x-axis lines in the range A3 is determined as the focus line group.

[0066] After the process of step SD1, the control unit 13 executes the maximum average brightness difference derivation process (step SD2). The process of step SD2 will be described in detail below. Fig.12 SD2 is a diagram for explaining the processing of step SD2. Fig.12 As shown in FIG. 1 , the control unit 13 divides the focus line group into blocks B arranged without gaps in the x-axis direction. One block B is configured to include 25 pixels G, 5 in the x-axis direction and 5 in the y-axis direction. In addition, when the number of pixels G in the x-axis direction of the focus line group is not a multiple of 5, the structure of any block B is deformed.

[0067] Next, the control unit 13 derives the average value of the brightness of each pixel G of the block B. Next, the control unit 13 derives the difference between the average values ​​of the block B with the largest average value and the block B with the smallest average value, i.e., the "maximum average brightness difference", as the local degree. Here, there is a correlation between the size of the maximum average brightness difference and the degree (local degree) of satisfying the condition that the rear of the vehicle 2 is locally bright, in that the larger the maximum average brightness difference, the larger the local degree. Therefore, the maximum average brightness difference, like the maximum brightness difference in the above-mentioned embodiment, can be used as an index value representing the local degree in the range of 0 to 255 pt. Regarding the first variant, the control unit 13 performs various processing using the maximum average brightness difference as the local degree instead of the maximum brightness difference. In addition, the relationship definition information is information that defines the relationship between the maximum average brightness difference and the reflectivity of the reflector.

[0068] The first modification example has been described above. However, the first modification example can be further modified as follows. That is, the method of determining the focus line group is not limited to the method illustrated. For example, the focus line group can also be as follows: Fig.13 A group of lines of pixels G extending in the y-axis direction, such as the line group LG1 of FIG. Fig.13 The line group LG2 and the line group LG3 of the block B are groups of lines of pixels G extending obliquely with respect to the x-axis. In addition, it is also possible to predetermine which line group the focus line group is set to. In addition, the number of pixels G included in the block B does not necessarily have to be "5 in the x-axis direction and 5 in the y-axis direction, a total of 25" (hereinafter, for the same example, it is expressed as 25 of 5×5), as an example, it may also be 9 of 3×3 or 24 of 4×6. In addition, the blocks B do not have to be arranged without gaps on the focus line group, for example, they may also be as follows. Fig.14 The structure in which the blocks B are arranged at intervals as in (A) of FIG. Fig.14 As shown in (B), there is a portion overlapping with the adjacent block B.

[0069] In addition, the content of the local degree is not limited to the content exemplified above. That is, the local degree can be a degree that can be derived based on the brightness of the captured image F and satisfies the condition that the rear of the vehicle 2 is locally bright. In addition, the control unit 13 may also be configured to use a model learned by a predetermined machine learning method when deriving the local degree.

[0070] <Modification of Darkness Degree Derivation Processing>

[0071] Next, a modification of the darkness degree derivation process (step SA3) of the above-mentioned embodiment is described. In the above-mentioned embodiment, the control unit 13 derives the line average value of the focus line as the darkness degree. In addition, the point that the focus line can be determined by various methods is as described above. However, the darkness degree is not limited to the line average value of the focus line. For example, the control unit 13 may also be a structure that derives the average value of the brightness of the pixels constituting the focus line group as the darkness degree after determining the focus line group. This structure is particularly effective when the control unit 13 derives the local degree by the method described in the first modification. In addition, for example, the control unit 13 may also be a structure that derives the average value of the brightness of all pixels G constituting the captured image F as the darkness degree. In addition, for example, the control unit 13 may also be a structure that determines a part of the captured image F by image processing and derives the average value of the brightness of the pixels G belonging to the part of the area as the darkness degree.

[0072] <Modification of Mirror Reflectivity Determination Process>

[0073] Next, a modified example of the reflector reflectivity determination process of the above-mentioned embodiment is described. In the above-mentioned embodiment, the control unit 13 determines the reflector reflectivity (applicable reflector reflectivity) by using three kinds of relationship definition information prepared in advance. However, the method by which the control unit 13 determines the reflector reflectivity is not limited to the method illustrated in the above-mentioned embodiment. For example, it can also be a structure in which the control unit 13 uses "input darkness degree and local degree as parameters, and outputs a calculation formula of the reflector reflectivity" to determine the reflector reflectivity (applicable reflector reflectivity). In this calculation formula, the reflector reflectivity is derived by a calculation method in which if the darkness degree is the same, the greater the local degree, the smaller the reflectivity, and the greater the darkness degree, the smaller the reflectivity even if the local degree is the same.

[0074] In addition, in the first to third relationship definition information, the relationship between the maximum brightness difference and the reflector reflectivity is a proportional relationship. However, the relationship between the maximum brightness difference and the reflector reflectivity is not limited to a proportional relationship. The relationship between the maximum brightness difference and the reflector reflectivity is a matter that should be appropriately determined from the perspective of achieving appropriate anti-glare. For example Figure 8 The curves CV1 to C3 may not be straight lines but may be curved or bent.

[0075] In addition, the control unit 13 may also be a structure that does not use the degree of darkness when determining the applicable reflector reflectivity. In the case of this structure, the control unit 13 does not perform the process of deriving the degree of darkness. In this structure, the control unit 13 performs the following process, for example. For example, a relationship definition information is prepared as the relationship definition information. Then, the control unit 13 does not derive the degree of darkness, but uses the prepared relationship definition information to determine the local degree (the maximum brightness difference in the above embodiment) as the applicable reflector reflectivity. In addition, for example, the control unit 13 determines the reflector reflectivity (applicable reflector reflectivity) by "inputting the local degree as a parameter and outputting the calculation formula of the reflector reflectivity". The calculation formula derives the reflector reflectivity by a calculation method in which the larger the local degree, the smaller the reflectivity.

[0076] In addition, the method by which the control unit 13 determines the reflectance of the reflector based on the brightness of the captured image F is not limited to the method exemplified above. That is, the reflectance of the reflector can be derived by the control unit 13 as long as the method reflects the brightness of the captured image F. In addition, the control unit 13 may also be configured to use a model learned by a predetermined machine learning method when deriving the reflectance of the reflector.

[0077] The above describes an embodiment of the present invention (including variations), but the above embodiment is only an example of a specific implementation of the present invention, and the technical scope of the present invention cannot be interpreted restrictively. That is, the present invention can be implemented in various forms without departing from its main purpose or its main features.

[0078] For example, in the above-described embodiment, the function of displaying an image is not installed in the reflecting mirror 1 , but the reflecting mirror 1 may be installed with this function.

[0079] In the above-mentioned embodiment, for example, the reflectance of the reflector 1 is changed by the optical device 15. In this regard, an electrochromic layer may be provided instead of the optical device 15 to change the reflectance of the reflector.

[0080] In addition, for example, in the above embodiment, the reflector 1 is not provided with a light sensor, but a light sensor may be provided. That is, in order to realize functions other than the automatic anti-glare function, it is of course permissible to provide more than one light sensor on the reflector 1.

[0081] In addition, the function blocks shown in the above embodiments can be implemented by any hardware, or by the cooperation of any hardware and any software. That is, these function blocks are not limited to specific hardware. For example, in the case where a certain function block is composed of hardware and software, it can be set to the following structure. That is, the function block is composed of a CPU, RAM and ROM of a computer. And, the function block performs processing by the CPU reading the program stored in ROM or other recording media into RAM and executing it.

[0082] In addition, for example, the control unit 13 may execute various processes in cooperation with an external device. For example, the control unit 13 may execute processes in cooperation with an external device (eg, a cloud server) that can communicate via a network.

[0083] In addition, in order to facilitate the understanding of the processing, the processing units of the flowchart of the above embodiment are divided according to the main processing content. The present invention is not limited by the division method and name of the processing unit. The processing of each device can also be divided into more processing units according to the processing content. In addition, it is also possible to divide it in a way that one processing unit contains more processing. In addition, as long as the same processing can be performed, the processing order of the above flowchart is not limited to the example shown in the figure.

[0084] In addition, for example, the provision of a program executed by a computer of the control device 10 can be included in the embodiment. In addition, the provision of a recording medium on which the program is recorded in a computer-readable manner can be included in the embodiment. As the above-mentioned recording medium, a magnetic, optical recording medium or a semiconductor memory device can be used. Specifically, a removable or fixed recording medium such as a floppy disk, HDD (Hard Disk Drive), CD-ROM (Compact Disk Read Only Memory), DVD (Digital Versatile Disk), Blu-ray (registered trademark) Disk, optical magnetic disk, flash memory, card-type recording medium, etc. can be cited.

[0085] [Explanation of Reference Numerals]

[0086] 1 Reflector

[0087] 2 Vehicles

[0088] 10 Control Device

[0089] 11. Camera

[0090] 12 Control System

[0091] 13. Control unit.

Claims

1. A control device, installed in a vehicle cabin, for executing processing related to a rearview mirror configured to change reflectivity, characterized in that: A control unit is provided for acquiring a captured image based on a result of capturing an image of the rear of the vehicle by a camera and determining a reflectivity of the rearview mirror, that is, a rearview mirror reflectivity, based on a brightness condition of the captured image.

2. The control device according to claim 1, characterized in that: The control unit, Based on the brightness condition of the captured image, a local degree is derived to satisfy the condition that the rear of the vehicle is locally bright, The reflectivity of the rearview mirror is determined such that the greater the local degree, the smaller the reflectivity.

3. The control device according to claim 2, characterized in that: The control unit, The difference in brightness between a pixel with the highest brightness and a pixel with the lowest brightness among pixels on a line of interest that extends in a predetermined direction on the captured image is derived as the local degree.

4. The control device according to claim 2, characterized in that: The control unit, deriving an average value of the brightness of each of the pixels of a plurality of blocks arranged along the predetermined direction on a focus line group consisting of a plurality of lines extending along the predetermined direction in the captured image, The difference between the average values ​​of the block with the largest average value and the block with the smallest average value is derived as the local degree.

5. The control device according to claim 2, characterized in that: The control unit, deriving the overall darkness of the scenery recorded in the captured image, that is, the darkness level, based on the brightness of the captured image, The reflectance of the mirror is determined so that the reflectance becomes smaller as the darkness degree increases even if the local degree remains the same.

6. The control device according to claim 5, characterized in that: For each level of the darkness degree, relationship definition information is prepared, the relationship definition information defining the relationship between the local degree and the reflectivity of the reflector, The control unit derives a level of the darkness degree, and determines the reflectance of the mirror using the relationship definition information corresponding to the derived level.

7. The control device according to claim 5, characterized in that: The control unit, The reflector reflectivity is determined by inputting the darkness degree and the local degree as parameters and outputting a calculation formula for the reflector reflectivity.

8. The control device according to any one of claims 5 to 7, characterized in that: The control unit, An average value of the brightness of pixels constituting a focus line extending in a predetermined direction on the captured image is derived as the darkness level.

9. The control device according to any one of claims 5 to 7, characterized in that: The control unit, An average value of the brightness of pixels constituting a focus line group consisting of a plurality of lines extending in a predetermined direction in the captured image is derived as the darkness degree.

10. A control system comprising: a reflector provided in a vehicle cabin and configured to be capable of changing reflectivity; and a control device for executing processing related to the reflector. It is characterized in that The control device acquires a captured image based on a result of capturing an image of the rear of the vehicle by a camera, and determines the reflectivity of the reflector, ie, the reflectivity of the reflector, based on a brightness condition of the captured image.

11. A control method, comprising: a control method for a control device, the control device being provided in a vehicle cabin, and executing a process related to a reflective mirror configured to be capable of changing reflectivity; The control method is characterized by comprising: The control unit of the control device acquires a captured image based on a result of capturing an image of the rear of the vehicle by a camera; as well as The control unit of the control device determines the reflectivity of the reflector, that is, the reflectivity of the reflector, based on the brightness status of the captured image.

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