Peripheral monitoring device

Abstract

The objective is to provide a surrounding monitoring device that, upon detecting a moving object, emits infrared light using an infrared illuminator, with the amount of light emitted corresponding to the measured ambient solar radiation intensity. [Solution] A surrounding monitoring device comprising an infrared illuminator that emits infrared light into the surrounding area and an infrared imaging device that images the surrounding area using infrared light, further comprising: a moving object detection means for detecting moving objects in the surrounding area; a solar radiation intensity measuring means for measuring the solar radiation intensity in the surrounding area; and an infrared illuminating means that, upon detection of a moving object by the moving object detection means, emits infrared light from the infrared illuminator with a light emission amount corresponding to the surrounding solar radiation intensity measured by the solar radiation intensity measuring means.

Description

Technical Field

[0001] The present invention relates to a surroundings monitoring apparatus using infrared light. Background Art

[0002] Various surroundings monitoring apparatuses that project infrared light via an infrared projector and capture images of the surroundings with the infrared light have been conventionally proposed.

[0003] Here, depending on the usage environment and usage conditions, there is a problem that the infrared projector is used frequently, resulting in high power consumption. As a means for solving this problem, as disclosed in, for example, Japanese Patent Laid-Open No. 2008-055941, it is conceivable to limit the light projection of the infrared projector and reduce the power consumption of the infrared projector by changing the projection amount of the infrared projector according to whether it is nighttime and the state of the own vehicle. Prior Art Documents Patent Documents

[0004] Patent Document 1 Japanese Patent Laid-Open No. 2008-055941 Summary of the Invention Problem to be Solved by the Invention

[0005] The above-mentioned Patent Document 1 discloses that when a user operates a switch, if it is nighttime, the projection amount of infrared light is changed to perform projection by the infrared projector. However, at night, the projection time of infrared light is not limited, for example, infrared projection is performed even when there are no obstacles in the surroundings. Therefore, even if the use of the infrared projector is restricted as shown in Patent Document 1, there is a problem that the reduction in power consumption of the infrared projector is limited.

[0006] The present invention was made to solve the aforementioned problems of the conventional invention, and aims to provide an ambient monitoring device that, upon detecting a moving object, emits infrared light with a light emission amount corresponding to the measured ambient solar radiation intensity using an infrared illuminator. [Means for solving the problem]

[0007] To achieve the above objective, the present invention provides a peripheral monitoring device comprising an infrared illuminator that emits infrared light into the surrounding area, and an infrared imaging device that captures images of the surrounding area using infrared light, the device further comprising: a moving object detection means for detecting moving objects in the surrounding area; a solar radiation intensity measuring means for measuring the solar radiation intensity in the surrounding area; and an infrared illuminating means that, upon detection of a moving object by the moving object detection means, emits infrared light from the infrared illuminator with a light emission amount corresponding to the solar radiation intensity in the surrounding area measured by the solar radiation intensity measuring means. [Effects of the Invention]

[0008] According to the surrounding monitoring device of the present invention having the above configuration, when a moving object is detected in the surroundings, infrared light corresponding to the surrounding solar radiation intensity is emitted, thereby limiting the frequency and amount of infrared light emitted and reducing the power consumption of the infrared illuminator. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic diagram of the vehicle according to this embodiment. [Figure 2] This is a block diagram showing the configuration of the peripheral monitoring device according to this embodiment. [Figure 3] This diagram shows the positional relationship between the imaging area captured by the imaging device and the illumination area captured by the infrared illuminator. [Figure 4] This is a flowchart of the peripheral monitoring program according to this embodiment. [Figure 5] This is an example illustrating the positional relationship between the imaging device and the moving object in the selection of the infrared illuminator. [Figure 6]This is an example illustrating the positional relationship between the imaging device and the moving object during the re-selection of the infrared illuminator. [Figure 7] This is an example that concretely illustrates the selection of an infrared illuminator and the setting of the infrared light intensity. [Figure 8] This is an example illustrating the relationship between the number of illuminated lights and the surrounding solar radiation intensity. [Modes for carrying out the invention]

[0010] Hereinafter, one embodiment of the passenger assistance system according to the present invention will be described in detail with reference to the drawings. First, the vehicle 2 equipped with the surrounding monitoring device according to this embodiment will be described below. Figure 1 is a schematic configuration diagram of the vehicle 2 according to this embodiment.

[0011] Here, Vehicle 2 may be, for example, an automobile powered by an internal combustion engine (internal combustion engine vehicle), an automobile powered by an electric motor (electric vehicle, fuel cell vehicle, etc.), or an automobile powered by both (hybrid vehicle). Furthermore, there is no restriction on the type of vehicle; it may be a regular passenger car, a large commercial truck, a bus, construction machinery, etc. Also, although the following explanation will refer to it as a four-wheeled vehicle, it may also be a two-wheeled or three-wheeled vehicle.

[0012] As shown in Figure 1, Vehicle 2 is equipped with a front camera 3 that captures images of the area in front of the vehicle, a right-side camera 4 that captures images of the area to the right of the vehicle, a left-side camera 5 that captures images of the area to the left of the vehicle, and a rear camera 6 that can capture images of the area behind the vehicle. In the following description, these cameras may be collectively referred to as cameras 3 to 6. Vehicle 2 is also equipped with front infrared illuminators 7A to 7B that emit infrared light in front of the vehicle, right-side infrared illuminators 8A to 8B that emit infrared light to the area to the right of the vehicle, left-side infrared illuminators 9A to 9B that emit infrared light to the area to the left of the vehicle, and rear infrared illuminators 10A to 10B that emit infrared light to the area behind the vehicle. In the following description, these infrared illuminators may be collectively referred to as infrared illuminators 7A to 10B. Furthermore, vehicle 2 is equipped with a forward millimeter-wave radar 11 for detecting moving objects in front of the vehicle, a right-side millimeter-wave radar 12 for detecting moving objects to the right of the vehicle, a left-side millimeter-wave radar 13 for detecting moving objects to the left of the vehicle, and a rear-side millimeter-wave radar 14 for detecting moving objects to the rear of the vehicle. In the following description, these may be collectively referred to as millimeter-wave radars 11 to 14.

[0013] Vehicle 2 includes the aforementioned cameras 3-6, infrared illuminators 7A-10B, and millimeter-wave radars 11-14, as well as a solar panel 15 for measuring solar radiation intensity and a peripheral monitoring ECU (Electronic Control Unit) 16 for performing various calculations. The peripheral monitoring device 1 includes the peripheral monitoring ECU 16 and other components.

[0014] The following describes each component of vehicle 2. First, the front camera 3 is an infrared imaging device equipped with a lens and an image sensor, and is capable of capturing infrared images using ambient infrared light such as reflected light from infrared light emitted by the front infrared illuminators 7A to 7B. It is installed, for example, on the front grille or behind the rearview mirror of vehicle 2, with its optical axis facing forward in the direction of vehicle travel.

[0015] The right side camera 4 and the left side camera 4 are both infrared imaging devices each including a lens and an image sensor, and are capable of capturing infrared images by using ambient infrared light such as the reflected light of infrared projected by the right side infrared projectors 8A to 8B and the left side infrared projectors 9A to 9B, respectively. Further, for example, the cameras are respectively installed on the left and right center pillars with their optical axes directed toward the side of the vehicle.

[0016] The rear camera 6 is also an infrared imaging device including a lens and an image sensor, and is capable of capturing an infrared image by using ambient infrared light such as the reflected light of infrared projected by the rear infrared projectors 10A to 10B. Further, for example, the camera is installed at the center of the rear spoiler of the vehicle 2 or near the upper center of the license plate with the optical axis directed toward the rear of the vehicle 2. There is no restriction on the number and arrangement of the cameras 3 to 6, and for example, the cameras may also serve as cameras used in other systems, such as a camera mounted on a drive recorder.

[0017] The front infrared projectors 7A to 7B are, for example, infrared light emitting diodes, and are capable of projecting infrared light to the surroundings. Further, the front infrared projectors 7A to 7B are disposed in the vicinity of the front camera 3, and the direction axes of the projected infrared light are disposed to be inclined left and right respectively from the optical axis of the front camera 3.

[0018] Like the front infrared projectors 7A to 7B, the right side infrared projectors 8A to 8B and the left side infrared projectors 9A to 9B are, for example, infrared light emitting diodes, and are capable of projecting infrared light to the surroundings. Further, the projectors are respectively disposed in the vicinity of the right side camera 4 and the left side camera 5, and the direction axes of the projected infrared light of the projectors are disposed to be inclined left and right respectively from the optical axes of the right side camera 4 and the left side camera 5.

[0019] The rear infrared projectors 10A to 10B are also, for example, infrared light emitting diodes, and are capable of projecting infrared light to the surroundings. Further, the rear infrared projectors 10A to 10B are disposed in the vicinity of the rear camera 6, and the direction axes of the projected infrared light are disposed to be inclined left and right respectively from the optical axis of the rear camera 6.

[0020] Each of the millimeter-wave radars 11 to 14 is installed on the front, rear, and side portions of the vehicle, respectively, and is capable of detecting surrounding objects outside the vehicle and the distance to the surrounding objects by emitting electromagnetic waves and detecting the reflected waves thereof. Further, the millimeter-wave radars can continuously perform detection and detect moving objects around the vehicle 2.

[0021] The solar panel 15 is a photovoltaic power generator installed on the roof of the vehicle 2, which generates a current corresponding to the solar radiation intensity in the surroundings outside the vehicle 2 by the photoelectric effect. Further, the solar radiation intensity outside the vehicle can be measured by the generated current.

[0022] The surroundings monitoring ECU 16 is an electronic control unit that performs various types of processing related to surroundings monitoring, and performs various types of control, calculation, and management in surroundings monitoring. Furthermore, the surroundings monitoring ECU 16 is connected to each of the above-described cameras 3 to 6, each of the infrared projectors 7A to 10B, each of the millimeter-wave radars 11 to 14, and the solar panel 15 via an in-vehicle network such as CAN. The surroundings monitoring ECU 16 is also connected to various sensors 17 mounted on the vehicle 2, such as a vehicle speed sensor, an acceleration sensor, and a steering angle sensor. The detailed configuration of the surroundings monitoring ECU 16 will be described later.

[0023] In addition, although the vehicle 2 includes basic components as the vehicle 2 in addition to the components shown in Fig. 1, only the configuration related to surroundings monitoring control and the control related to said configuration will be described.

[0024] Next, the details of, in particular, the surroundings monitoring ECU 16 among the surroundings monitoring device 1 included in the above-described vehicle 2 will be described. Fig. 2 is a block diagram showing the configuration of the surroundings monitoring device 1 according to the present embodiment.

[0025] The Peripheral Monitoring ECU 16 is an electronic control unit that comprehensively controls the entire vehicle 2, including the peripheral monitoring device 1. It includes a CPU 20 as a computing device and control device, RAM 21 used as working memory for the CPU 20 to perform various calculations, and ROM 22 which stores control programs as well as the peripheral monitoring program (see Figure 4) described later. The Peripheral Monitoring ECU 16 also has various functions as a processing algorithm. For example, it has a function to individually control the start and end of imaging for each camera 3 to 6, a function to individually control the amount of infrared light emitted for each infrared illuminator 7A to 10B, a function to control the start and end of detection for each millimeter-wave radar 11 to 14, and a function to control the light emission according to the solar radiation intensity.

[0026] ROM22 contains the vehicle information DB23, which stores various information about vehicle 2. For example, the installation positions (height from the ground, left-right position), detection axis X, overall length, and vehicle width of each camera 3-6 and each millimeter-wave radar 11-14 installed on vehicle 2 are recorded. This information is entered in advance by the occupants or personnel from the vehicle manufacturer.

[0027] Here, we will explain the positional relationship between the imaging area of ​​each camera 3-6 and the illumination area of ​​each infrared illuminator 7A-10B using Figure 3. Figure 3 shows the positional relationship on the right side of vehicle 2 as an example, but the positional relationship between the imaging area and the illumination area is the same on the front, rear, and left side.

[0028] Figure 3 schematically shows the positional relationship between the imaging area and the light projection area. The imaging area 30 enclosed by a solid line is the area imaged by the right-side camera 4. The first light projection area 31 enclosed by a dashed line is the area where infrared light is projected by the right-side infrared illuminator 8A, and the second light projection area 32 enclosed by a dotted line is the area where infrared light is projected by the right-side infrared illuminator 8B. As shown in the figure, the first light projection area 31 and the second light projection area 32 are configured to have different light projection areas. Furthermore, the right-side infrared illuminators 8A and 8B are configured so that their projection directions are tilted to the left and right from the optical axis of the right-side camera 4, respectively, in order to sufficiently illuminate the imaging area 30 by combining the first light projection area 31 and the second light projection area 32. As a result, the right-side camera 4 can sufficiently image the area within the imaging area 30 with the light projection from the right-side infrared illuminators 8A and 8B.

[0029] Furthermore, the surrounding monitoring device 1 can comprehensively image the area around the vehicle 2 by combining the imaging areas of each camera 3 to 6, and can also comprehensively project infrared light onto the area around the vehicle 2 by combining the illumination areas of each infrared illuminator 7A to 10B. Note that the millimeter-wave radars 11 to 14, which are not shown in Figure 3, can also comprehensively detect the area around the vehicle 2 by combining their respective detection areas, similar to the cameras 3 to 6.

[0030] Next, the peripheral monitoring program executed by the peripheral monitoring ECU 16 in the peripheral monitoring device 1 having the above configuration will be explained with reference to Figure 3. Figure 3 is a flowchart of the peripheral monitoring program according to this embodiment. The program shown in the flowchart in Figure 3 below is recorded in the ROM 22 provided in the peripheral monitoring ECU 16 and executed by the CPU 20. The peripheral monitoring device 1, for example, detects when the ACC power (accessory power supply) is turned off or when the engine is stopped using various sensors 17, and determines that the vehicle 2 has transitioned from a driving state to a parked state, and starts processing the peripheral monitoring program.

[0031] First, in step 1 (hereinafter abbreviated as S), the CPU 20 performs solar radiation intensity measurement. Specifically, the CPU 20 obtains the solar radiation intensity around the outside of the vehicle 2, as measured by the solar panel 15, from the solar panel 15 and records it in the RAM 21. In other words, the solar radiation intensity when the vehicle 2 transitions from a driving state to a parked state is recorded in the RAM 21.

[0032] In S2, the CPU 20 predicts the necessary parameters for automatic exposure for each camera 3-6, such as shutter speed and lens aperture value, based on the solar radiation intensity recorded in RAM 21 in S1, and records them in RAM 21. In other words, the CPU 20 predicts the brightness around vehicle 2 from the solar radiation intensity measured in S1, thereby predicting the automatic exposure in advance.

[0033] In S3, the CPU 20 controls each of the millimeter-wave radars 11-14 to begin detecting moving objects around the vehicle 2. As a result, each of the millimeter-wave radars 11-14 detects moving objects around the vehicle 2. If a moving object is detected, the process proceeds to S5; otherwise, it proceeds to S4. Note that the detection of moving objects by each of the millimeter-wave radars 11-14 continues from S2 onward. Furthermore, although moving object detection is indicated as S3 for the sake of explanation, it may also be started simultaneously with the solar radiation intensity measurement in S1. Moreover, the moving object can be a person or something other than a person.

[0034] In S4, the CPU 20 determines whether a predetermined time has elapsed since the measurement of solar radiation intensity in S1. If the predetermined time has elapsed, the system proceeds to S1; otherwise, it proceeds to S3. Until the predetermined time has elapsed, S3 and S4 are repeated to continue detecting moving objects. Furthermore, if no moving object is detected for an extended period, S1 to S4 are repeated, and after vehicle 2 transitions from a driving state to a parked state, solar radiation intensity measurements and automatic exposure predictions are performed at predetermined intervals.

[0035] In S5, the CPU 20 instructs each millimeter-wave radar 11-14 to detect the position of the moving object detected in S3. The CPU 20 records the position coordinates of the moving object obtained from each millimeter-wave radar 11-14 in the RAM 21.

[0036] In S6, the CPU 20 selects at least one camera capable of imaging the moving object from the front camera 3, right-side camera 4, left-side camera 5, and rear camera 6, based on the position coordinates of the moving object acquired in S5 and the information of each camera 3 to 6 stored in the vehicle information DB 23. Specifically, it selects a camera whose imaging area includes the moving object. Furthermore, similarly, based on the position coordinates of the moving object acquired in S5 and the information of each infrared illuminator 7A to 10B stored in the vehicle information DB 23, it selects at least one infrared illuminator capable of emitting infrared light onto the moving object from the front infrared illuminators 7A to 7B, right-side infrared illuminators 8A to 8B, left-side infrared illuminators 9A to 9B, and rear infrared illuminators 10A to 10B. Specifically, it selects an infrared illuminator whose illumination area includes the moving object. In this way, the CPU selects an infrared illuminator that emits infrared light from among the multiple infrared illuminators 7A to 10B depending on the position of the moving object.

[0037] For example, Figure 5 shows a case where a moving object 40 is approaching vehicle 2 from the front right side. In this case, since the moving object 40 is located within the imaging area 30, the CPU 20 selects the right-side camera 4 from among the cameras 3 to 6. In addition, since the moving object 40 is located within the first illumination area 31, the CPU 20 selects the right-side infrared illuminator 8A from among the infrared illuminators 7A to 10B. If multiple moving objects are detected in S3, the CPU 20 can select multiple cameras and infrared illuminators in S6 to enable infrared illumination and imaging of each moving object. If the moving object 40 is located near the boundary of the illumination area of ​​an infrared illuminator, multiple infrared illuminators may be used. For example, if the moving object 40 is located near the boundary between the first illumination area 31 and the second illumination area 32, the CPU 20 will simultaneously illuminate with both the right-side infrared illuminator 8A and the right-side infrared illuminator 8B. This makes it possible to project infrared light onto moving objects sufficiently and reliably.

[0038] In S7, the CPU 20 sets the amount of infrared light emitted according to the solar radiation intensity around the vehicle 2, which was measured in S1 and recorded in RAM 21. Specifically, the amount of infrared light emitted is set using a correspondence table between solar radiation intensity and emission amount recorded in ROM 22, or by a calculation formula that calculates the emission amount from the solar radiation intensity. Here, for example, the emission amount is set to be small when the solar radiation intensity is high, and large when the solar radiation intensity is low. Furthermore, the emission amount does not necessarily have to be constant; for example, it may be set to decrease over time. In addition, if the ambient solar radiation intensity measured in S1 and recorded in RAM 21 is high, it may be set not to emit infrared light.

[0039] In S8, the CPU20 instructs the camera selected in S6 to start imaging and also instructs the infrared illuminator selected in S6 to emit infrared light with the emission amount calculated in S7. As a result, the camera selected in S6 starts imaging, and the infrared illuminator selected in S6 starts emitting infrared light with an emission amount corresponding to the ambient solar radiation intensity measured in S1. When the camera selected in S6 starts imaging, it starts imaging based on the parameters necessary for automatic exposure predicted in S2, and corrects the automatic exposure parameters. This makes it possible to shorten the time required for automatic exposure, and to start imaging relatively quickly.

[0040] In S9, the CPU 20 determines whether the moving object has moved from the imaging area of ​​the camera selected in S6 and started imaging in S8 to the imaging area of ​​a camera not selected in S6. Specifically, this determination is made by detecting the position coordinates of the moving object using the millimeter-wave radars 11-14. If the moving object has moved from the imaging area of ​​the camera selected in S6 to the imaging area of ​​a camera not selected in S6, the process proceeds to S11. If the moving object has not moved from the imaging area of ​​the camera selected in S6 to the imaging area of ​​a camera not selected in S6, the process proceeds to S10.

[0041] In S10, the CPU 20 re-selects a new camera that includes the moving object after it has moved in its imaging area, and a new infrared illuminator that includes the moving object after it has moved in its illumination area. For example, Figure 6 shows a case where the moving object 40 approaches the vehicle 2 from the front right side, and then moves to the rear right side of the vehicle 2. In this case, since the moving object 40 after it has moved is located within the imaging area 30 and within the second illumination area 32, the CPU 20 does not change the camera that performs imaging, and re-selects the infrared illuminator from the right-side infrared illuminator 8A to the right-side infrared illuminator 8B. In this way, the CPU 20 can change the camera and infrared illuminator in accordance with the movement of the moving object by S9 and S10.

[0042] In S11, the CPU 20 determines whether the moving object has moved outside the imaging area of ​​each camera 3-6. Specifically, this can be determined by detecting the position coordinates of the moving object using each millimeter-wave radar 11-14, or by determining when the object can no longer be detected by each millimeter-wave radar 11-14. The moving object moving outside the imaging area of ​​each camera 3-6 means that the moving object has moved away from the vehicle 2, or has boarded the vehicle 2, etc.

[0043] In S12, the CPU20 instructs the camera that performs imaging and the infrared illuminator that emits infrared light to stop imaging and illuminating, respectively, and terminates the surrounding monitoring program.

[0044] As described in detail above, the surrounding monitoring device 1 according to this embodiment is an surrounding monitoring device 1 comprising infrared illuminators 7A to 10B that emit infrared light into the surroundings and infrared imaging devices 3 to 6 that image the surroundings with infrared light, and has a moving object detection means (S3) for detecting moving objects in the surroundings, a solar radiation intensity measuring means (S1) for measuring the solar radiation intensity in the surroundings, and an infrared illuminating means (S8) that, triggered by the detection of a moving object by the moving object detection means, emits infrared light (S7) with an emission amount corresponding to the surrounding solar radiation intensity measured by the solar radiation intensity measuring means (S1) using the infrared illuminators. Therefore, it is possible to reduce the emission of unnecessary infrared light from the infrared illuminators and suppress the amount of light emitted by excess infrared light from the infrared illuminators. As a result, the power consumption and heat generation of the infrared illuminators can be reduced. Furthermore, by deliberately not triggering the solar radiation intensity measuring means by the detection of a moving object by the moving object detection means, it is possible to predict the brightness from the solar radiation intensity as in S2, and it is possible to shorten the time required for automatic exposure adjustment when imaging by the infrared imaging means is started. This allows for relatively quick initiation of imaging, as well as rapid commencement of surrounding area monitoring. Furthermore, the system includes multiple infrared illuminators 7A to 10B (see Figure 3) with at least a portion of their illumination ranges differing. When illuminating with the infrared illuminators 7A to 10B, at least one of the multiple infrared illuminators 7A to 10B is used to emit infrared light. The moving object detection means detects the position of the moving object (S5), and the infrared illumination means selects an infrared illuminator from the multiple infrared illuminators 7A to 10B to emit infrared light according to the position of the moving object (S6). The infrared illumination means then emits infrared light using the selected infrared illuminator (S8). This makes it possible to reduce the emission of infrared light from unnecessary infrared illuminators even when there are multiple infrared illuminators, and to further reduce the power consumption and heat generation of the infrared illuminators. In addition, the surrounding monitoring device 1 is installed on the vehicle 2, the moving object detection means (S3) is performed on the surrounding area outside the vehicle 2, and the solar radiation intensity measurement means (S1) measures the solar radiation intensity outside the vehicle. This allows for monitoring of the area around the vehicle, and even when the vehicle is moving by driving, it is possible to reduce the power consumption and heat generation of the infrared illuminator according to the environment of the destination vehicle during the monitoring of the area around the vehicle. Furthermore, the solar radiation intensity measurement means (S1) is executed when the vehicle 2 transitions from a driving state to a parked state (S1), and thereafter it is executed at predetermined intervals (S4 and S4:Yes). This makes it possible to measure solar radiation intensity in response to changes in the surrounding environment due to the movement of the vehicle. Moreover, it is possible to reflect changes in the environment around the vehicle as time passes. As a result, it becomes possible to record a more appropriate solar radiation intensity.

[0045] It should be noted that the present invention is not limited to the embodiments described above, and various improvements and modifications are possible without departing from the spirit of the invention. In this embodiment, the mobile object detection means is described as using millimeter-wave radar, but other sensors such as motion sensors may also be used. Furthermore, the user's communication terminal may communicate with the surrounding monitoring ECU 16 to acquire the location information of the communication terminal, and the mobile object detection means may also detect the approach of the user who owns the communication terminal to the vehicle 2 by monitoring the location information. The techniques for acquiring and monitoring the location information of the communication terminal are known and conventional techniques, so details will not be explained, but for example, the location information may be acquired using triangulation based on the distance between the multiple wireless antennas provided by the surrounding monitoring device 1 and the communication terminal owned by the user. Furthermore, the surrounding monitoring device may acquire location information acquired by the satellite positioning system provided in the communication terminal from the communication terminal via wireless communication. This makes it possible to limit the mobile object detection means to a specific user, and makes it possible to reduce unnecessary surrounding monitoring and illumination by infrared illuminators.

[0046] In this embodiment, the infrared illumination means was described as emitting infrared light consisting of an emission amount corresponding to the solar radiation intensity measured by the solar panel 15, by calculating the emission amount according to the solar radiation intensity. However, it is not limited to this, and the emission amount from the infrared illumination device may be set in stages as multiple emission levels, and one of these emission levels may be selected for emission, thereby emitting infrared light consisting of an emission amount corresponding to the solar radiation intensity. For example, the emission level from the infrared illumination device may be divided into three levels: fully lit, half lit, and off. In this case, the emission level is determined by the flowchart shown in Figure 7. The flowchart shown in Figure 7 is a concrete example of the selection of the infrared illumination device and the setting of the emission amount of infrared light in S6 and S7 of Figure 4.

[0047] First, in S21, the CPU20 determines whether the solar radiation intensity measured in S1 is below the total illumination threshold. The total illumination threshold is the value at which the solar radiation intensity is judged to be low. If the solar radiation intensity is below the total illumination threshold, the process proceeds to S22; otherwise, the process proceeds to S27.

[0048] In S22, the CPU 20 determines whether the position of the moving object detected in S5 can be clearly identified. If the position of the moving object detected in S5 cannot be clearly identified, the process proceeds to S23; otherwise, the process proceeds to S24. The case in which the position of the moving object detected in S5 cannot be clearly identified is, for example, when the moving object moves to a position where it is obscured by a stationary object. In S23, the CPU 20 determines to turn on all infrared illuminators.

[0049] In S24, the CPU 20 determines whether the mobile object's position is near the boundary of the infrared illuminator's illumination area. If the mobile object's position is not near the boundary of the infrared illuminator's illumination area, the process proceeds to S25. If the mobile object's position is near the boundary of the illumination area, the process proceeds to S26. In S25, the CPU 20 selects one infrared illuminator corresponding to the mobile object's position and decides to illuminate all of the selected infrared illuminators. In S26, as previously explained, the CPU 20 selects two infrared illuminators corresponding to the boundaries of the illumination areas and decides to illuminate all of the two infrared illuminators.

[0050] In S27, the CPU20 determines whether the solar radiation intensity measured in S1 is below the half-light threshold. The half-light threshold is the value at which the solar radiation intensity is judged to be low. If the solar radiation intensity is below the half-light threshold, the process proceeds to S29; otherwise, it proceeds to S28. In S27, the CPU20 decides to turn off the lights. In other words, it decides not to emit infrared light because the solar radiation intensity is high. Furthermore, steps S29 to S33 are performed to select an infrared illuminator to be lit at half-light based on the same judgment as in S22 to S26, so the explanation is omitted. Based on the above, it is possible to easily determine the amount of light emitted by the infrared illuminator by selecting one of the progressively set illumination levels and emitting light, and it is possible to change the degree of reduction in the power consumption of the infrared illuminator by setting a threshold.

[0051] Furthermore, the infrared illuminator may be composed of multiple light-emitting units, and the number of light-emitting units that are illuminated from among the multiple light-emitting units may be changed to emit infrared light with an emission amount corresponding to the solar radiation intensity. Here, for example, if the infrared illuminator consists of two light-emitting units, the relationship between the number of illuminated light-emitting units and the surrounding solar radiation intensity may be as shown in Figure 8. More specifically, the infrared illuminator is equipped with two infrared light-emitting diodes as light-emitting units, and the CPU 20 illuminates both infrared light-emitting diodes when the solar radiation intensity is low, does not illuminate when the solar radiation intensity is high, and illuminates only one light-emitting unit in the intermediate range. This makes it possible to emit infrared light with an emission amount corresponding to the solar radiation intensity in a simple, rapid manner, while reducing the processing load on the CPU 20. Furthermore, each infrared illuminator may emit infrared light with an emission amount corresponding to the solar radiation intensity using a different method.

[0052] In this embodiment, an example in which the surrounding monitoring device 1 is installed on a vehicle has been described, but the surrounding monitoring device 1 according to the present invention is not limited to this, and can also be used in, for example, security cameras. Specifically, the moving object detection means for detecting moving objects in the surrounding area is implemented for the area monitored by the security camera, which is the area surrounding the surrounding monitoring device 1, the solar radiation intensity measuring means for measuring the solar radiation intensity around the surrounding monitoring device 1 measures the solar radiation intensity around the surrounding monitoring device 1, and the infrared illumination means for emitting infrared light with an illumination amount corresponding to the surrounding solar radiation intensity measured by the solar radiation intensity measuring means is implemented for the area monitored by the security camera.

[0053] [Note] The embodiments described above also disclose the following inventions. In the following description, the names and expressions of corresponding components in the embodiments, as well as the reference numerals used in the drawings, are indicated in parentheses for reference. However, the components of each invention are not limited to these indications.

[0054] (Invention A) The solar radiation intensity measuring means (S1) is This is performed when the detection of the moving object by the moving object detection means (S3) is initiated. The peripheral monitoring device according to claim 1 or 2, which is performed at predetermined intervals (S4) thereafter when the detection of the moving object by the moving object detection means begins.

[0055] According to this method, by measuring the solar radiation intensity in advance, it is possible to predict the brightness from the solar radiation intensity, and the time required for automatic exposure adjustment when imaging by infrared imaging means is started can be shortened.

[0056] (Invention B) The aforementioned moving object detection means (S3) The surrounding monitoring device according to claim 1, which detects the presence or absence of the mobile body in the vicinity by communicating with a portable communication terminal provided by the mobile body and acquiring location information of the communication terminal.

[0057] According to this, in addition to being able to limit the monitoring targets of the surrounding monitoring device, it becomes possible to reduce infrared radiation emitted to moving objects that are not being monitored.

[0058] (Invention C) The solar radiation intensity measuring means (S1) is The surrounding area monitoring device according to claim 4, which measures the amount of solar radiation intensity in the surrounding area based on the amount of power generated by the solar power generator (15) provided by the vehicle (2) (S1).

[0059] According to this, it is possible to create a peripheral monitoring device that is quiet and has a low environmental impact.

[0060] When the aforementioned moving object moves, The peripheral monitoring device according to claim 2, wherein the infrared illuminator that emits infrared light is re-selected from among a plurality of infrared illuminators according to the position of the moving body after movement, and the infrared light is emitted using the re-selected infrared illuminator.

[0061] According to this method, even if the moving object is in motion, it is possible to limit the number of infrared illuminators that emit light, thereby further reducing the power consumption and heat generation of the infrared illuminators.

[0062] The infrared imaging device comprises a plurality of infrared imaging devices, each having at least a portion of its imaging range different. When imaging is performed using the infrared imaging device, imaging is performed using at least one of the multiple infrared imaging devices. The moving object detection means detects the position of the moving object, The surrounding monitoring device according to claim 1, wherein the imaging by the infrared imaging device is performed by selecting an infrared imaging device from among a plurality of infrared imaging devices according to the position of the moving object, and then performing imaging using the selected infrared imaging device.

[0063] According to this, the power consumption and heat generation of the infrared imaging device, in addition to the infrared illuminator, can be reduced, making it possible to reduce power consumption as a peripheral monitoring device. [Explanation of symbols]

[0064] 1... Surroundings monitoring device, 2... Vehicle, 3... Front camera, 4... Right side camera, 5... Left side camera, 6... Rear camera, 7A~7B... Front infrared illuminator, 8A~8B... Right side infrared illuminator, 9A~9B... Left side infrared illuminator, 10A~10B... Rear infrared illuminator, 11... Front millimeter-wave radar, 12... Right side millimeter-wave radar, 13... Left side millimeter-wave radar, 14... Rear millimeter-wave radar, 15... Solar panel, 16... Surroundings monitoring ECU, 30... Imaging area, 31... First illumination area, 32... Second illumination area, 40... Moving object

Claims

1. A peripheral monitoring device comprising an infrared illuminator that projects infrared light into the surrounding area, and an infrared imaging device that captures images of the surrounding area using the infrared light, A means for detecting moving objects in the surrounding area, A solar radiation intensity measuring device for measuring the solar radiation intensity in the surrounding area, A peripheral monitoring device comprising: an infrared illuminating means that, upon detection of a moving object by the moving object detection means, emits infrared light from an infrared illuminator, the amount of infrared light emitted corresponding to the ambient solar radiation intensity measured by the solar radiation intensity measuring means.

2. The infrared illuminator comprises a plurality of infrared illuminators, each having at least a portion of its illumination area different. When emitting light from the infrared illuminator, at least one of the multiple infrared illuminators is used to emit the infrared light. The moving object detection means detects the position of the moving object, The surrounding monitoring device according to claim 1, wherein the infrared illuminating means selects an infrared illuminating device from among a plurality of infrared illuminating devices to emit the infrared light according to the position of the moving object, and then emits the infrared light using the selected infrared illuminating device.

3. The aforementioned surrounding monitoring device is installed in the vehicle, The aforementioned moving object detection means is performed on the surrounding area outside the vehicle, The surrounding monitoring device according to claim 1 or 2, wherein the solar radiation intensity measuring means measures the solar radiation intensity outside the vehicle.

4. The aforementioned solar radiation intensity measuring means is This is executed when the vehicle transitions from a driving state to a parked state. The surrounding monitoring device according to claim 3, which is executed at predetermined intervals after the vehicle transitions from a driving state to a parked state.

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