JP2019145888A - On-vehicle camera system - Google Patents

Abstract

To provide an on-vehicle camera system capable of surely preventing overexposure of the on-vehicle camera and capable of sufficiently securing an amount of exposure for an on-vehicle camera.SOLUTION: An on-vehicle camera system includes: a road side device 20 for transmitting control signals for giving operation instructions at different timing to vehicles C1 to C4 traveling in different directions; a NIR projector 4 for projecting near infrared rays ahead in the traveling directions of the vehicles C1 to C4; an imaging unit 2 capable of imaging at predetermined intervals near infrared rays from ahead in the traveling directions of the vehicles C1 to C4; and a system control unit 5 that when receiving the control signal from the road side device 20, makes the NIR projector 4 project near infrared rays on the basis of timing at which an operation instruction is given by the control signal, and makes the imaging unit 2 perform imaging.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an in-vehicle camera system suitable for traveling on a road that can travel along a first direction and a second direction opposite to the first direction.

  Various on-vehicle camera systems for various purposes have been proposed and realized depending on the use of the on-vehicle camera such as front, rear, and surrounding. In particular, the purpose of using the in-vehicle camera system at night is to improve the visibility when imaging the front of the vehicle, the rear of the vehicle, and the surroundings of the vehicle, the safety of preventing collision accidents, the comfort of posture control, the vehicle control, etc. The recognition performance is improved for the purpose.

  On the other hand, for the purpose of improving nighttime visibility and safety, for example, a high beam headlight provided in a vehicle is conventionally turned on at night to improve distance visibility. However, if a high beam headlight is turned on when there is an oncoming vehicle or a preceding vehicle in front of the vehicle, the driver may be dazzled by irradiating the driver of the oncoming vehicle with this high beam. For this reason, conventionally, every time a driver of a vehicle finds an oncoming vehicle or a preceding vehicle ahead of it, the vehicle is manually switched to a low beam.

  Therefore, in an in-vehicle camera system that can image the front of the vehicle for the purpose of realizing far visibility and high safety, when the high beam headlight is turned on and traveling, the on-vehicle camera uses the on-vehicle camera in front of the oncoming vehicle and the preceding vehicle. Once the vehicle is recognized, a light distribution control of the high beam headlight is implemented, and a vehicle camera system that can prevent the oncoming vehicle from being dazzled by preventing the oncoming vehicle from being illuminated is proposed and implemented. Has been.

  However, such an in-vehicle camera system preferably distributes light without irradiating the oncoming vehicle without irradiating the high beam, and irradiates the high beam on the area other than the oncoming car, but an area other than the oncoming car does not receive the high beam occurs. In this case, there is a possibility that sufficient visibility in front of the vehicle cannot be secured.

  Therefore, for the purpose of further improving the night vision and safety, a NIR-compatible in-vehicle camera that can receive near-infrared light (hereinafter also referred to as NIR: Near-InfraRed) and that images the front of the vehicle, An in-vehicle camera system having an NIR projector that projects near infrared rays in front of the vehicle has been proposed. Since humans cannot see the NIR, the driver of the oncoming vehicle is not dazzled by the NIR even when the NIR projector is irradiated in front of the vehicle. Therefore, there is no need to perform high beam light distribution control unlike the conventional in-vehicle camera system, and visibility is not deteriorated. As a result, it is possible to always capture subjects such as far away with the NIR-compatible in-vehicle camera, and it is expected to improve the visibility and safety of far away.

  However, when vehicles equipped with such an in-vehicle camera system face each other, there is a possibility that the image of the NIR-compatible in-vehicle camera may be overexposed by the NIR of each NIR projector.

  In response to such a problem, a technique has been proposed in which when the NIR pulse from the oncoming vehicle is received by the optical sensor, the NIR pulse emitted from the NIR light source of the own vehicle is shifted so as not to overlap with the NIR pulse from the oncoming vehicle. (See Patent Document 1).

JP 2005-222549 A

  In the technique disclosed in Patent Document 1 described above, blinding is prevented by gradually shifting the NIR pulse so that the oncoming vehicles do not overlap the irradiation timings of the NIR projectors. Therefore, there is a possibility that it takes time to complete the prevention of blinding, and as a result, the oncoming vehicles may pass before the prevention of blinding is executed.

  Further, since the blinding is prevented by shifting the pulse of the NIR projector, the duty cycle of the NIR projector may be reduced, and as a result, the exposure amount of the NIR-compatible in-vehicle camera may be reduced.

  Therefore, an object of the present invention is to provide an in-vehicle camera system that can surely prevent over-shooting of the in-vehicle camera and can sufficiently secure an exposure amount of the in-vehicle camera.

  In order to achieve the above object, an in-vehicle camera system of the present invention is disposed on a road where a vehicle can travel along a first direction and a second direction opposite to the first direction, and the first direction and the second direction. A roadside device that transmits control signals for instructing operations at different timings to a vehicle traveling in the direction of the vehicle, a near-infrared light source that is mounted on the vehicle and projects near-infrared light toward the front in the traveling direction, and the vehicle Mounted on the vehicle and capable of capturing near infrared rays from the front in the traveling direction at a predetermined imaging interval, and mounted on the vehicle and receiving a control signal from the roadside device, based on the timing instructed to operate by the control signal And a control unit that causes the near-infrared light source to project near-infrared light and causes the imaging unit to capture an image.

  Here, the roadside device can be configured to transmit the control signal in a state where the control unit can identify the traveling direction of the vehicle.

  Alternatively, the in-vehicle camera system of the present invention determines a traveling direction of a vehicle based on a GPS unit that outputs a vehicle position detection signal based on a signal from a GPS satellite and a position detection signal output from the GPS unit. The control unit can select a control signal to be used based on the determination result of the determination unit.

  In addition, the control unit may be configured to cause the near-infrared light source to project near-infrared light and to cause the imaging unit to capture an image after a predetermined time has elapsed since receiving the control signal.

  Further, the in-vehicle camera system of the present invention has a recognition processing unit that performs image recognition processing based on the imaging result of the imaging unit, and when the control unit receives a control signal from the roadside device, an operation instruction is given by the control signal. It can be set as the structure which performs the image recognition process by a recognition process part based on timing.

  Further, the roadside device transmits a travel information signal regarding the presence or absence of a vehicle traveling on a road within a predetermined distance range from the roadside device, and the control unit determines whether the near infrared light source and the imaging unit are controlled based on the travel information signal. It can be set as the structure to judge.

  The in-vehicle camera system of the present invention is mounted on a vehicle and projects a near-infrared light source that projects near-infrared light toward the front in the traveling direction, and the near-infrared light and visible light that are mounted on the vehicle and forward from the traveling direction. An imaging unit capable of imaging at a predetermined imaging interval, a detection unit that is mounted on the vehicle and detects near-infrared and visible light irradiation from the front of the traveling direction of the vehicle based on an imaging result of the imaging unit, and mounted on the vehicle And a control unit that does not cause the near-infrared light source to project near-infrared light and causes the image-capturing unit not to capture an image when the detection unit detects near-infrared irradiation.

  In the in-vehicle camera system of the present invention configured as described above, when receiving a control signal from the roadside device, the control unit performs near-infrared light projection on the near-infrared light source based on the timing instructed by the control signal. And the image pickup unit picks up an image.

  In this way, the near-infrared light source mounted on the vehicle traveling on the road projects near-infrared light at a different timing for each traveling direction, and the imaging unit captures near-infrared light in synchronization with this timing. can do. Therefore, it is possible to surely prevent the in-vehicle camera from being blown out. In addition, by appropriately selecting the transmission timing of the roadside device, the duty cycle of the light projection by the near infrared light source can be made sufficiently large, and as a result, the exposure amount of the in-vehicle camera can be sufficiently secured. It becomes possible.

  Here, since the roadside device transmits the control signal in a state where the control unit can identify the traveling direction of the vehicle, the control unit controls the near-infrared light source and the imaging unit without distinguishing the traveling direction of the vehicle by itself. This can be performed, and the control procedure can be simplified.

  Alternatively, the control unit includes a GPS unit that outputs a vehicle position detection signal based on a signal from a GPS satellite, and a determination unit that determines a traveling direction of the vehicle based on a position detection signal output from the GPS unit. However, since the control signal to be used is selected based on the determination result of the determination unit, the control unit can appropriately determine the traveling direction of the vehicle by itself, and as a result, controls the near-infrared light source and the imaging unit. Can be done appropriately.

  In addition, since the control unit causes the near-infrared light source to project near-infrared light after a predetermined time has elapsed after receiving the control signal and causes the imaging unit to capture an image, the near-infrared light source mounted on each vehicle and the imaging As a result, the near-infrared light source and the imaging unit can be controlled more appropriately.

  Further, the in-vehicle camera system of the present invention has a recognition processing unit that performs image recognition processing based on the imaging result of the imaging unit, and when the control unit receives a control signal from the roadside device, an operation instruction is given by the control signal. Since the image recognition processing by the recognition processing unit is performed based on the timing, the image recognition processing by the recognition processing unit is surely performed without being greatly affected by the projection timing of the near infrared light source or the imaging timing by the imaging unit. Can do.

  Further, the roadside device transmits a travel information signal regarding the presence or absence of a vehicle traveling on a road within a predetermined distance range from the roadside device, and the control unit determines whether the near infrared light source and the imaging unit are controlled based on the travel information signal. Therefore, when it is necessary to control the near-infrared light source and the imaging unit based on the driving information signal, in other words, when it is determined that near-infrared light may be projected from the oncoming vehicle, the near-infrared light source and the imaging Part can be controlled.

  Further, in the in-vehicle camera system of the present invention, when the detection unit detects near-infrared and visible light irradiation from the front in the traveling direction of the vehicle based on the imaging result of the imaging unit, and the detection unit detects near-infrared irradiation. Since the control unit does not cause the near-infrared light source to project near-infrared light and does not cause the image-capturing unit to capture images, it is possible to reliably prevent white-out due to near-infrared light projection from an oncoming vehicle and Similarly, the oncoming vehicle equipped with an image pickup unit capable of taking an image can be surely prevented from being overexposed.

It is a block diagram which shows schematic structure of the vehicle-mounted camera system which is 1st embodiment. It is a figure explaining the outline | summary of the light projection control by the vehicle-mounted camera system which is 1st embodiment. It is a figure which shows an example of the control signal transmitted to the lane of the advancing direction A from the roadside apparatus of the vehicle-mounted camera system which is 1st embodiment. It is a figure which shows an example of the control signal transmitted to the lane of the advancing direction B from the roadside apparatus of the vehicle-mounted camera system which is 1st embodiment. It is a figure which shows the other example of the control signal transmitted to the lane of the advancing direction A from the roadside apparatus of the vehicle-mounted camera system which is 1st embodiment. It is a figure which shows the other example of the control signal transmitted to the lane of the advancing direction B from the roadside apparatus of the vehicle-mounted camera system which is 1st embodiment. It is a flowchart for demonstrating operation | movement of the vehicle-mounted camera system which is 1st embodiment. It is a figure explaining an example of the advancing direction discrimination method in the vehicle-mounted camera system which is 1st embodiment. It is a figure explaining the other example of the advancing direction discrimination method in the vehicle-mounted camera system which is 1st embodiment. It is a figure explaining the other example of the advancing direction discrimination method in the vehicle-mounted camera system which is 1st embodiment. It is a block diagram which shows schematic structure of the vehicle-mounted camera system which is 2nd embodiment. It is a flowchart for demonstrating operation | movement of the vehicle-mounted camera system which is 2nd embodiment. It is a figure explaining the outline | summary of the light projection control by the vehicle-mounted camera system which is 3rd embodiment. It is a figure explaining the outline | summary of the light projection control by the vehicle-mounted camera system which is 3rd embodiment. It is a block diagram which shows schematic structure of the vehicle-mounted camera system which is 4th embodiment. It is a flowchart for demonstrating operation | movement of the vehicle-mounted camera system which is 4th embodiment.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of an in-vehicle camera system according to the first embodiment of the present invention.

  The in-vehicle camera system S according to the present embodiment includes an NIR projector (near-infrared light source) 4 that projects near-infrared rays (NIR) toward the front in the traveling direction of a vehicle (not shown) on which the in-vehicle camera system S is mounted. And a control signal for a vehicle equipped with an imaging unit 2 for imaging the NIR from the front in the traveling direction of the vehicle, the NIR projector 4 and the imaging unit 2, and a system control unit (control unit) 5 for controlling them. 2 (see FIG. 2).

  NIR incident on the lens 1 from the front in the traveling direction of the vehicle is collected by the lens 1 and guided to the imaging unit 2. The imaging unit 2 photoelectrically converts the NIR collected by the lens 1 at a predetermined imaging interval to generate a video signal, and sends this video signal to the signal detection unit / processing unit 3 at the subsequent stage.

  The imaging unit 2 includes an imaging element such as a CMOS or CCD having sensitivity to at least light in the near infrared region, and in the present embodiment, a predetermined frame rate (for example, 1/30 seconds, 1/60 seconds). Then, the NIR from the front of the vehicle is imaged and the video signal is sent to the signal detector / processor 3. Note that if the image pickup device included in the image pickup unit 2 is a CMOS, an A / D-converted video signal is output from the image pickup unit 2 after photoelectric conversion. A / D conversion blocks are provided, and video signals are output from the A / D conversion blocks. In FIG.

  As shown in FIG. 1, the signal detector / processor 3 includes a gain processor 8, a gamma processor 9, various camera signal processors 10, and a detector 11. The detection unit 11 detects the luminance level of the video signal input from the imaging unit 2, the gain processing unit 8 adjusts the gain (gain) of the video signal based on the detection information, and the gamma processing unit 9 is defined. The camera signal processing unit 10 performs white balance processing, interpolation processing corresponding to the RGB Bayer array filter, color signal processing, and the like. Since the processing performed by the signal detection unit / processing unit 3 is well known, further detailed description is omitted here.

  The video signal subjected to various signal processing by the signal detector / processor 3 is sent to a display installed on a dashboard portion of the vehicle via the sensing external interface (I / F). A video based on the video signal is displayed.

  The NIR projector 4 has a near-infrared light source that emits near-infrared light, such as a single or a plurality of light emitting diodes (LEDs), and projects NIR with a predetermined irradiation angle forward in the traveling direction of the vehicle.

  The system control unit 5 performs overall control of the components mounted on the vehicle in the in-vehicle camera system S according to the present embodiment. Specifically, the system control unit 5 controls the shutter speed and the like of the imaging unit 2 based on detection information by the detection unit 11 of the signal detection unit / processing unit 3. In addition, the system control unit 5 controls the imaging timing by the imaging unit 2 based on the control signal from the roadside device 20 received by the road-to-vehicle communication unit 6 described later, and the NIR light projection by the NIR projector 4 Control timing. Details of the control of the system control unit 5 based on the control signal from the roadside device 20 will be described later.

  The road-to-vehicle communication unit 6 receives a control signal transmitted by the roadside device 20 and sends this control signal to the system control unit 5.

  The details of the roadside device 20 of the in-vehicle camera system S according to the present embodiment and the outline of the operation of the system S will be described with reference to FIGS.

  As shown in FIG. 2, the roadside device 20 in the present embodiment has a predetermined road R that can pass in two directions (that is, both sides) facing each other in the traveling direction A (first direction) and the traveling direction B. A plurality are installed at intervals of. In the illustrated example, the roadside device 20 is installed on the road R having two lanes on one side, but the number of lanes, the lane width, and the like are not limited to the illustrated example.

  The roadside device 20 is, for example, VICS (registered trademark) (Vehicle Information & Communication System) or ETC (Electronic Toll) introduced as part of ITS (Intelligent Transport Systems) in Japan. A roadside base station used in the Collection System: automatic toll collection system is preferably used, and road traffic information, information necessary for fee settlement, etc. are communicated with the road-to-vehicle communication unit 6 of the vehicles C1 to C4 (see FIG. 2). Communicated between. Since road traffic information transmitted from the roadside apparatus 20 and information necessary for fee settlement are well known, further detailed description is omitted here. Or the roadside apparatus 20 which communicates only the control signal mentioned later to vehicles C1-C4 one-way may be sufficient.

  The roadside device 20 in the present embodiment further transmits a control signal that differs according to the traveling direction (that is, the traveling direction A and the traveling direction B) to the vehicles C1 to C4 traveling on the road R, whereby the vehicle C1. Control of the irradiation timing of the NIR projector 4 mounted on .about.C4 is performed.

  More specifically, for example, the roadside device 20 alternately turns the NIR projector 4 on the vehicles C3 and C4 traveling in the traveling direction A in units of the frame rate of the imaging unit 2, for example, in units of 1/30 seconds or 1/6 seconds. A control signal that synchronizes the operation of turning on (NIR irradiation by the NIR projector 4) and turning off (NIR irradiation interruption by the NIR projector 4) is transmitted to the vehicles C1 and C2 traveling in the traveling direction B. A control signal that synchronizes the operation of turning on and off the NIR projector 4 alternately at a timing different from that of the vehicles C3 and C4 traveling in the traveling direction A is transmitted.

  As an example, as shown in FIG. 3, the roadside device 20 turns on the NIR projector 4 at the timing of n (n is a natural number) + even number frames for vehicles C3 and C4 traveling in the traveling direction A, and n + A control signal for turning off the NIR projector 4 is transmitted at an odd frame timing.

  On the other hand, as shown in FIG. 4, the roadside device 20 turns on the NIR projector 4 at the timing of n + odd frames for the vehicles C1, C2 traveling in the traveling direction B, and NIR at the timing of n + even frames. A control signal for turning off the projector 4 is transmitted.

  When the control signal from the roadside device 20 is received by the road-to-vehicle communication unit 6, the system control unit 5 is, for example, Xmsec, error Y% (for example) after a predetermined time from the timing instructed to turn on the NIR projector 4 by the control signal. The NIR projector 4 is turned on after both X and Y are real numbers, and the image pickup unit 2 performs image pickup and exposure operations. The time for which the NIR projector 4 is turned on is preferably substantially equal to the frame rate of the imaging unit 2 from the viewpoint of ensuring a sufficient exposure level of NIR imaging by the imaging unit 2.

  On the other hand, the system control unit 5 similarly turns off the NIR projector 4 after a predetermined time from the timing instructed to turn off the NIR projector 4 by the control signal, and does not perform the imaging and exposure operations by the imaging unit 2.

  As a result, the video signal output from the sensing external interface 7 is composed of only odd or even frames, in other words, a video signal having a frame rate that is half the frame rate of the imaging unit 2. Alternatively, a blank signal may be output for a frame in which the imaging unit 2 does not perform imaging and exposure.

  3 and 4 show examples in which the NIR projector 4 is turned on at the timing of n + odd frame or n + even frame, respectively. That is, the example in which the NIR projector 4 is alternately turned on in units of one frame for each traveling direction is shown, but the timing for turning on the NIR projector 4 does not have to be in units of one frame, and the NIR projector 4 is turned on in units of multiple frames. You may let them.

  As an example of such a method, in FIGS. 5 and 6, the NIR projectors 4 are alternately turned on in units of three frames. That is, in the lane in the traveling direction A, as shown in FIG. 5, the NIR projector 4 is continuously turned on for n, n + 1, and n + 2 for 3 frames, and then n + 6, n + 7, and n + 8 are placed between 3 frames. The NIR projector 4 is turned on at the timing.

  On the other hand, in the lane in the traveling direction B, as shown in FIG. 6, the NIR projector 4 is turned on continuously for 3 frames of n + 3, n + 4, and n + 5, and then placed between 3 frames (not shown). ) The NIR projector 4 is turned on at the timing of n + 9 to n + 11.

  Next, details of the operation of the in-vehicle camera system S according to the present embodiment including the system control unit 5 will be described with reference to the flowchart of FIG.

  In step S <b> 1, the system control unit 5 determines whether the road-vehicle communication unit 6 has received a control signal from the roadside device 20. If the determination is affirmative (YES in step S1), the program proceeds to step S2, and the system control unit 5 turns on the NIR projector 4 at a timing based on the control signal from the roadside device 20. Next, in step S <b> 3, the system control unit 5 causes the imaging unit 2 to perform imaging and exposure operations at a timing based on a control signal from the roadside device 20.

  On the other hand, if the determination in step S1 is negative (NO in step S1), the program proceeds to step S4, and the system control unit 5 performs normal control, that is, control that always turns on the NIR projector 4. Next, in step S5, the system control unit 5 performs normal control, that is, performs imaging and exposure operations by the imaging unit 2 without synchronizing the frame rate.

  In this way, the NIR projector 4 is not turned on at the same time in the vehicles C1 to C4 traveling in different traveling directions, and the ON lane of the NIR projector 4 and the imaging timing by the imaging unit 2 are synchronized, so that the opposite lane is The NIR irradiated by the NIR projector 4 of the traveling vehicles C1 to C4 is no longer imaged by the imaging unit 2, and it is possible to suppress the occurrence of whiteout in the video imaged by the imaging unit 2.

  By the way, in order to implement | achieve this operation | movement, it is preferable that the vehicle-mounted camera system S mounted in each vehicle C1-C4, especially the system control part 5 is the state which can identify the advancing direction of the own vehicle.

  For this reason, it is preferable that the roadside apparatus 20 transmits a different control signal that allows the system control unit 5 to identify the traveling direction to each of the lanes corresponding to the traveling directions A and B. For example, such an operation can be realized by the roadside device 20 transmitting a control signal having a frequency of, for example, a GHz band that reaches only the lanes corresponding to the traveling directions A and B, respectively. Since the technology itself for selecting such a frequency band is well known (for example, DSRC (Dedicated Short Range Communications)), further explanation is omitted here.

  Alternatively, it is possible to adopt a configuration in which the system control unit 5 itself determines and identifies the traveling direction of the vehicles C1 to C4. As an example of such a configuration, an in-vehicle camera system S according to the present embodiment includes a GPS unit (not shown) and uses a signal output from the GPS unit.

  Specifically, the system control unit 5 receives the position detection signals of the vehicles C1 to C4 output from the GPS unit based on the signals from the GPS satellites, and continuously receives the position detection signals for a predetermined time, thereby controlling the system. The unit (determination unit) 5 acquires the absolute traveling direction of the vehicles C1 to C4, specifically, the direction of the traveling direction, and determines the traveling direction of the vehicles C1 to C4 based on the acquired direction.

  As an example, as shown in FIG. 8, when the road R extends in the north-south direction and the direction of the traveling direction A is north, the system control unit 5 moves the traveling direction of the vehicles C1 to C4 as indicated by an arrow AR. If the direction of the vehicle is within the range from northwest to north to northeast, it is determined that the vehicles C1 to C4 are traveling in the traveling direction A, and the direction of the traveling direction of the vehicles C1 to C4 is from southwest to south to southeast. If it is inside, it will discriminate | determine that vehicles C1-C4 are advancing in the advancing direction B.

  Here, the reason why the system control unit 5 sets a certain range (arrow AR) for azimuth determination is from the relationship between the error of the position detection signal from the GPS unit and the meandering of the vehicles C1 to C4 itself, etc. This is because a predetermined error is expected to occur in the direction of the traveling direction acquired by the system control unit 5.

  Further, the roadside apparatus 20 determines in which traveling direction (that is, the traveling direction A or the traveling direction B) the on / off signal is in addition to the above-described signal for instructing on / off of the NIR projector 4. A control signal to which a header signal or the like is added is transmitted.

  Therefore, the system control unit 5 is an appropriate control signal among the control signals transmitted from the roadside device 20 based on the traveling direction A or the traveling direction B determined by itself, that is, a control signal that matches the traveling direction of the vehicles C1 to C4. And the NIR projector 4 and the imaging unit 2 can be appropriately controlled.

  However, when the system control unit 5 uses a method in which the traveling direction of the vehicles C1 to C4 is determined based on the position detection signal from the GPS unit, for example, as shown in FIG. 9, the road R extends in the north-south or east-west direction. If not, the system control unit 5 may not be able to appropriately set the area (arrow AR) for determining the traveling direction. As an example, the direction of the traveling direction A of the road R shown in FIG. 9 is substantially east-northeast, but when the same range (arrow AR) as in FIG. 8 is set, the traveling direction of the vehicles C1 to C4 is slightly east. There is a possibility that an appropriate traveling direction cannot be determined.

  Therefore, a configuration in which the in-vehicle camera system S according to the present embodiment includes a navigation unit and uses road information (information on the traveling direction of the road R, etc.) output by the navigation unit is preferably exemplified.

  Specifically, as shown in FIG. 10, the system control unit 5 appropriately corrects the region (arrow AR) for determining the traveling direction based on the road information output from the navigation unit. In the example shown in FIG. 10, the system control unit 5 acquires the direction in which the road R extends based on the road information, and resets the range from northeast to east to southeast as an area for determining the traveling direction. Thereby, the advancing direction of vehicles C1-C4 can be discriminated appropriately.

  Or if the roadside apparatus 20 is transmitting road information, the system control part 5 may reset an area | region using this road information.

  In the above-described embodiment, the frame rate of the imaging unit 2 has been described as a general one of 1/30 seconds or 1/60 seconds. However, the video signal output from the sensing external interface 7 is smoother. For this purpose, the imaging unit 2 may be driven at a frame rate higher than a general frame rate such as 1/120 second or 1/240 second.

(Second embodiment)
Next, with reference to FIG.11 and FIG.12, the vehicle-mounted camera system S which is 2nd embodiment of this invention is demonstrated. In addition, in the following description, the same code | symbol is attached | subjected about the component same as the vehicle-mounted camera system S which is 1st embodiment mentioned above, and the description is simplified.

  The in-vehicle camera system S according to the present embodiment includes a recognition processing unit 12 that performs an image recognition process based on a video signal at the subsequent stage of the sensing external interface 7. Since the image recognition process performed by the recognition processing unit 12 is a well-known image recognition process such as oncoming vehicle recognition or lane recognition, further description thereof is omitted here.

  From the sensing external interface 7, as described above, odd-numbered or even-numbered video signals and blank signals may be output alternately. Therefore, if the recognition processing unit 12 can perform the image recognition processing with a single frame, the recognition processing result is not greatly affected. However, when the image recognition processing is performed with a plurality of frames, the video signal slightly lacking in continuity. There is a possibility.

  Therefore, in order to make the image recognition processing by the recognition processing unit 12 more reliable, when performing the image recognition processing with a plurality of frames, the recognition processing unit 12 temporarily stores the video signals of the past odd-numbered or even-numbered frames. The image recognition process is performed using a plurality of odd-numbered or even-numbered video signals. Thereby, the image recognition process can be performed while ensuring the continuity of the video signal.

  Alternatively, the system control unit 5 performs a predetermined time after the timing when the NIR projector 4 is instructed to be turned on by the control signal transmitted from the roadside device 20, in other words, the NIR projector 4 is turned on and the imaging and exposure operations by the imaging unit 2 are performed. At the same time, image recognition processing by the recognition processing unit 12 is performed. Thereby, the recognition process part 12 can perform an image recognition process reliably, without receiving to the influence of the blank signal output from the external interface 7 for sensing.

  Next, details of the operation of the in-vehicle camera system S according to the present embodiment including the system control unit 5 will be described with reference to the flowchart of FIG.

  Since Steps S10 to S12 are the same as Steps S1 to S3 in the in-vehicle camera system S according to the first embodiment described above, description thereof is omitted. In step S <b> 13, the system control unit 5 causes the recognition processing unit 12 to perform image recognition processing at a timing based on a control signal from the roadside device 20.

  Since Steps S14 to S15 are the same as Steps S4 to S5 in the vehicle-mounted camera system S according to the first embodiment described above, description thereof will be omitted. In step S16, the system control unit 5 performs normal control, that is, image recognition processing by the recognition processing unit 12 for all frames.

(Third embodiment)
Next, with reference to FIG.13 and FIG.14, the vehicle-mounted camera system S which is 3rd embodiment of this invention is demonstrated.

  In the in-vehicle camera system S according to the present embodiment, the roadside device 20 is a vehicle that travels on a road R within a predetermined distance from the place where the roadside device 20 is installed (vehicles C1 and C4 in the example shown in FIG. 13). Is detected by road-to-vehicle communication with the road-to-vehicle communication unit 6 mounted on the vehicles C1 and C4, and the presence of an oncoming vehicle (vehicle C4 for the vehicle C1, vehicle C1 for the vehicle C4) is notified. Send information signals. As an example, in the above-described DSRC, a procedure for transmitting own vehicle presence information from the road-to-vehicle communication unit 6 to the roadside device 20 is defined, and the road-to-vehicle communication unit 6 transmits the own vehicle presence information to the roadside device 20. Based on this, the roadside device 20 transmits a travel information signal together with the control signal described above.

  Here, the predetermined distance range described above is roughly determined by the frequency band of the radio wave transmitted from the roadside device 20, and as an example, if the radio wave from the roadside device 20 is in the GHz band, the line-of-sight distance is about several tens of meters. is there.

  As shown in FIG. 13, when the system control unit 5 receives a travel information signal in addition to the control signal from the roadside device 20, the system control unit 5 determines that there is an oncoming vehicle ahead of the traveling direction of the vehicles C <b> 1 and C <b> 4. Based on the control signal, the NIR projector 4 is turned on / off, the imaging by the imaging unit 2 and the exposure timing are controlled.

  On the other hand, as shown in FIG. 14, when the system control unit 5 does not receive a travel information signal from the roadside device 20, the system control unit 5 determines that there is no oncoming vehicle (in this case, C4) ahead of the traveling direction of the vehicle C1. Even if a control signal is received, control based on this control signal is not performed, the NIR projector 4 is always turned on, and imaging and exposure by the imaging unit 2 are performed at a normal frame rate.

  As a result, the system control unit 5 controls the ON / OFF of the NIR projector 4 and the imaging and exposure timing by the imaging unit 2 only when an oncoming vehicle exists. Further improvement of safety can be ensured.

(Fourth embodiment)
Next, an in-vehicle camera system S that is a fourth embodiment of the present invention will be described with reference to FIGS. 15 and 16. FIG. 15: is a block diagram which shows schematic structure of the vehicle-mounted camera system S which is 4th embodiment of this invention.

  In the in-vehicle camera system S according to the present embodiment, the imaging unit 2 can capture visible light in addition to near infrared rays. Such an imaging unit 2 has an optical characteristic in which an optical filter provided in the light receiving unit of the imaging unit 2 that receives visible light + near infrared light from the lens 1 transmits near infrared light in addition to visible light. It is realizable by having.

  The various camera signal processing units 10 apply the matrix calculation in the well-known color matrix signal processing to the visible light + near-infrared imaged by the imaging unit 2, in addition to the visible light video signal. Signal processing for extracting a video signal of only infrared light is performed.

  And the recognition process part 12 provided in the back | latter stage of the external interface 7 for sensing performs the image recognition process which detects the visible light and the near infrared ray in this video signal. Since such image recognition processing is also known, further explanation is omitted here.

  The in-vehicle camera system S according to the present embodiment is a system for preventing whiteout due to NIR from an oncoming vehicle even when road-to-vehicle communication between the roadside device 20 and the road-to-vehicle communication unit 6 is not performed. .

  Some vehicle-mounted camera systems currently installed in vehicles have an imaging unit having sensitivity to near infrared light in addition to visible light for the purpose of increasing nighttime sensitivity. Such an in-vehicle camera system is intended to increase sensitivity at night, and therefore does not have the NIR projector 4 as in the in-vehicle camera system S according to the present embodiment.

  Accordingly, when the imaging unit 2 having sensitivity to near-infrared light is used as in the on-vehicle camera system S according to the above-described embodiment, an imaging unit having sensitivity to near-infrared light in addition to visible light is used. It is difficult to detect the oncoming vehicle. In addition, even if the control using the control signal from the roadside device 20 is performed, the overexposure of the imaging unit having sensitivity to near infrared light in addition to visible light due to NIR emitted from the NIR projector 4 of the own vehicle It is difficult to suppress this.

  Therefore, in the in-vehicle camera system S according to the present embodiment, the imaging unit 2 captures and exposes visible light + near infrared light, and the various camera signal processing units 10 perform visible light + near infrared light based on the video signal from the imaging unit 2. Infrared video signals are respectively generated, and the recognition processing unit 12 performs image recognition processing for determining the presence or absence of the NIR projector 4 and the headlight from the visible light + near infrared video signal.

  Thereby, like the vehicle-mounted camera system S which is embodiment mentioned above, the system control part (detection part) 5 detects appropriately the presence of the oncoming vehicle which has the NIR projector 4 or a headlight, and the NIR projector of the own vehicle 4 on / off and image pickup by the image pickup unit 2 and exposure timing can be appropriately controlled to suppress whiteout in the in-vehicle camera systems of the host vehicle and the oncoming vehicle.

  Next, details of the operation of the in-vehicle camera system S according to the present embodiment including the system control unit 5 will be described with reference to the flowchart of FIG.

  First, in step S20, as a result of the image recognition processing by the recognition processing unit 12, it is determined whether or not the headlight of the oncoming vehicle is present in the video signal output by the imaging unit 2. If the determination is affirmative (YES in step S20), the program proceeds to step S21. As a result of the image recognition processing by the recognition processing unit 12, the imaging unit 2 includes NIR from the NIR projector 4 in the video signal. It is determined whether or not. If the determination is affirmative (YES in step S21), the program proceeds to step S22.

  On the other hand, if the determination is negative in step S20 (NO in step S20) and the determination is negative in step S21 (NO in step S21), the program proceeds to step S25.

  Steps S22 to S27 are the same as steps S10 to S16 in the in-vehicle camera system S according to the second embodiment described above, and thus the description thereof is omitted.

  In the in-vehicle camera system of the present invention configured as described above, when receiving a control signal from the roadside device, the control unit performs near-infrared light projection on the near-infrared light source based on the timing instructed by the control signal. And the image pickup unit picks up an image.

(Effect of in-vehicle camera system)
In the in-vehicle camera system S which is each embodiment configured as described above, the NIR projector 4 mounted on the vehicles C1 to C4 traveling on the road R projects near infrared rays at different timings for each traveling direction. In addition, the imaging unit 2 can capture near infrared rays in synchronization with this timing. Therefore, it is possible to reliably prevent whiteout in the imaging result by the imaging unit 2. In addition, by appropriately selecting the transmission timing of the roadside device 20, the duty cycle of light projection by the NIR projector 4 can be made sufficiently large, and as a result, the exposure amount of the imaging unit 2 is sufficiently ensured. It becomes possible.

  Here, since the roadside device 20 transmits the control signal in a state where the system control unit 5 can identify the traveling direction of the vehicles C1 to C4, the system control unit 5 determines the traveling direction of the vehicles C1 to C4 by itself. The NIR projector 4 and the imaging unit 2 can be controlled without any problems, and the control procedure can be simplified.

  Alternatively, the system control unit 5 determines the traveling direction of the vehicle based on the position detection signal output from the GPS unit, and selects the control signal to be used based on the determination result. Thus, the traveling direction of the vehicle can be appropriately determined, and as a result, the NIR projector 4 and the imaging unit 2 can be appropriately controlled.

  Further, since the system control unit 5 causes the NIR projector 4 to project near-infrared light after the control signal is received and causes the imaging unit 2 to perform imaging, the NIR projector mounted on each vehicle 4 and the imaging unit 2 can be synchronized more precisely. As a result, the NIR projector 4 and the imaging unit 2 can be controlled more appropriately.

  Further, when the system control unit 5 receives the control signal from the roadside device 20, the system control unit 5 causes the recognition processing unit 12 to perform the image recognition processing based on the timing instructed to operate by the control signal. The image recognition processing by the recognition processing unit 12 can be reliably performed without being greatly affected by the light timing or the imaging timing by the imaging unit 2.

  Further, the roadside device 20 transmits a travel information signal regarding the presence / absence of the vehicles C1 to C4 traveling on a road within a predetermined distance range from the roadside device 20, and the system control unit 5 includes the NIR projector 4 and the NIR projector 4 based on the travel information signal. Since it is determined whether or not the imaging unit 2 is controlled, it is determined that there is a possibility that near-infrared light may be projected from the oncoming vehicle when the NIR projector 4 and the imaging unit 2 need to be controlled based on the travel information signal. When this is done, the NIR projector 4 and the imaging unit 2 can be controlled.

  Moreover, in the vehicle-mounted camera system S which is embodiment, the system control part 5 detects irradiation of the near infrared rays and visible light from the advancing direction front of a vehicle based on the imaging result of the imaging part 2, and the system control part 5 If near-infrared irradiation is detected, the NIR projector 4 does not perform near-infrared light projection and does not cause the imaging unit 2 to image, so that it is possible to reliably prevent whiteout due to near-infrared light projection from an oncoming vehicle. In addition, for an oncoming vehicle equipped with an imaging unit capable of imaging near-infrared rays, it is also possible to reliably prevent whiteout.

  The embodiment of the present invention has been described in detail above with reference to the drawings. However, the specific configuration is not limited to the embodiment and the example, and the design change is within a range not departing from the gist of the present invention. Are included in the present invention.

S In-vehicle camera system 1 Lens 2 Imaging unit 3 Signal detection unit / processing unit 4 NIR projector (near infrared light source)
5 System control unit (control unit, determination unit, detection unit)
6 Road-to-vehicle communication unit 7 External interface for sensing 8 Gain processing unit 9 Gamma processing unit 10 Various camera signal processing units 11 Detection unit 12 Recognition processing unit 20 Roadside devices C1 to C4 Vehicle R Road

Claims (7)

The vehicle is arranged on a road where the vehicle can travel along the first direction and the second direction opposite to the first direction, and operation instructions are given at different timings to the vehicle traveling in the first direction and the second direction. A roadside device for transmitting a control signal for
A near-infrared light source that is mounted on the vehicle and projects near-infrared light toward the front of the traveling direction;
An imaging unit mounted on the vehicle and capable of imaging the near infrared rays from the front in the traveling direction at a predetermined imaging interval;
When the control signal is received from the roadside device mounted on the vehicle, the near-infrared light source is caused to project the near-infrared light based on the timing instructed by the control signal, and the imaging unit An in-vehicle camera system comprising: a control unit that performs imaging.   The vehicle-mounted camera system according to claim 1, wherein the roadside device transmits the control signal in a state where the control unit can identify a traveling direction of the vehicle. A GPS unit that outputs a position detection signal of the vehicle based on a signal from a GPS satellite;
A determination unit that determines a traveling direction of the vehicle based on the position detection signal output from the GPS unit;
The in-vehicle camera system according to claim 1, wherein the control unit selects the control signal to be used based on a determination result of the determination unit.   The control unit causes the near-infrared light source to project the near-infrared light after a predetermined time has elapsed since receiving the control signal, and causes the imaging unit to capture an image. The on-vehicle camera system according to Crab An image recognition processing unit that performs image recognition processing based on an imaging result of the imaging unit;
The control unit, when receiving the control signal from the roadside device, causes the image recognition processing unit to perform image recognition processing based on the timing instructed to operate by the control signal. The vehicle-mounted camera system in any one of -4. The roadside device transmits a travel information signal regarding the presence or absence of the vehicle traveling on the road within a predetermined distance range from the roadside device;
The in-vehicle camera system according to claim 1, wherein the control unit determines whether or not the near-infrared light source and the imaging unit are controlled based on the travel information signal. A near-infrared light source that is mounted on a vehicle and projects near-infrared light toward the front of the traveling direction;
An imaging unit mounted on the vehicle and capable of imaging the near-infrared light and visible light from the front in the traveling direction at predetermined imaging intervals;
A detector that is mounted on the vehicle and detects irradiation of the near-infrared ray and visible light from the front in the traveling direction of the vehicle based on an imaging result of the imaging unit;
And a control unit that is mounted on the vehicle and does not cause the near-infrared light source to project the near-infrared light when the detection unit detects irradiation of the near-infrared light and does not cause the imaging unit to capture an image. In-vehicle camera system.