JP2008293280A - Traffic light detection device, traffic light detection method, and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traffic light detection device, a traffic light detection method and a program, capable of surely detecting the light emitting part of an LED traffic light ahead of an own-vehicle. <P>SOLUTION: When the photographic cycle of front a camera 53 for imaging is longer than 1/2 of the lighting cycle of the light emitting part of an LED traffic light ahead of its traveling direction, and the lighting cycle of the light emitting part of the LED traffic light ahead of the traveling direction is harmonic with the imaging cycle of the front camera 53 for imaging, a CPU 41 outputs a control signal to instruct the photographic timing of the front camera 53 for imaging to be shifted from the lighting-out timing of the LED element to a camera ECU 51 when the photographic image of the front camera 53 for imaging is turned to be a photographic image where the light emitting part of the LED traffic light disappears (S11 to S17; NO to 19: YES to S20). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a traffic signal detection device, a traffic signal detection method, and a program for detecting a traffic signal ahead of the host vehicle.

Conventionally, various techniques for detecting a traffic light in front of the host vehicle have been proposed.
For example, provided with a photographing means provided in the vehicle for photographing a traveling direction and outputting a photographed image, and a red signal detecting means for extracting a red light emitting portion from a photographed image by the photographing means and detecting a red signal of a traffic light, This red signal detection means includes a safe driving support device configured to detect a red signal based on the extracted luminance and / or height of the red light emitting unit (for example, a patent) Reference 1).
JP 2007-034693 A (paragraphs (0013) to (0037), FIGS. 1 to 12)

  However, in the safe driving support apparatus described in Patent Document 1 described above, when the traffic light in front of the host vehicle is an LED (light emitting diode) type traffic light (hereinafter referred to as “LED traffic light”), it is a light emitting unit. Due to the difference between the lighting cycle of the LED element and the photographing cycle of the photographing means, there is a problem that the light emitting part of the LED traffic light is photographed in the unlit state and the light emitting part of the traffic light may not be detected.

  Accordingly, the present invention has been made to solve the above-described problems, and provides a traffic signal detection device, a traffic signal detection method, and a program capable of reliably detecting the light emitting portion of an LED traffic light ahead of the host vehicle. The purpose is to do.

  In order to achieve the above object, the traffic signal detection apparatus according to claim 1 includes a host vehicle position detection means (11) for detecting the host vehicle position, and a map information storage means (25) for storing map information including traffic signal information relating to the traffic signal. And the traffic signal information acquisition means (13) for acquiring the traffic signal information ahead of the host vehicle based on the host vehicle position and the map information, and the host vehicle based on the traffic signal information acquired by the traffic signal information acquisition means. Type determination means (13) for determining whether or not the front traffic light is an LED traffic light, and when it is determined that the traffic light ahead of the host vehicle is an LED traffic light, the LED lighting related to the LED traffic light is based on the traffic signal information The lighting information acquisition means (13) for acquiring information, the imaging means (51, 53) for imaging the front of the host vehicle, the LED lighting information and the imaging cycle of the imaging means Shooting timing setting means (13, 51) for setting the shooting timing for shooting in front of the host vehicle, and traffic signal detection means (13) for detecting a traffic light based on the shot image shot at the shooting timing. It is characterized by that.

  The traffic light detection device according to claim 2 is the traffic light detection device (1) according to claim 1, wherein the LED lighting information includes an LED lighting cycle of the LED traffic light, and the photographing timing setting means (13, 51) is a photographing timing changing means (13, 51) for changing the photographing timing so as not to photograph when the LED of the LED traffic light is off when the photographing cycle is larger than ½ of the LED lighting cycle of the LED traffic light. ).

  According to a third aspect of the present invention, there is provided the traffic light detection device according to the second aspect, wherein the photographing timing setting means (13, 51) is configured such that the photographing period is an LED lighting period of the LED traffic light. In the case of 1/2 or less, the photographing timing is not changed, and the traffic light detection means (13) detects a traffic light based on a photographed image only when the LED of the LED traffic light is lit.

  According to a fourth aspect of the present invention, there is provided a traffic signal detection method for acquiring traffic signal information relating to a traffic signal ahead of the host vehicle based on the host vehicle position detecting step (S11) for detecting the host vehicle position and the host vehicle position and map information. A traffic light information acquisition step (S11), a type determination step (S12 to S13) for determining whether or not the traffic light ahead of the host vehicle is an LED traffic light based on the traffic signal information acquired in the traffic signal information acquisition step, and the type determination If it is determined in the step that the traffic light ahead of the host vehicle is an LED traffic light, a lighting information acquisition step (S15) for acquiring LED lighting information related to the LED traffic light based on the traffic signal information, and the lighting information acquisition step The shooting timing for setting the shooting timing for shooting the front of the host vehicle based on the LED lighting information acquired in step 1 and the shooting cycle of the shooting means for shooting the front of the host vehicle. A signal setting step (S16 to S21) and a traffic light detection step (S22) for detecting a traffic light based on the captured image captured at the imaging timing set in the imaging timing setting step. To do.

  Further, the program according to claim 5 obtains signal information on a traffic light ahead of the host vehicle based on the host vehicle position detecting step (S11) for detecting the host vehicle position and the host vehicle position and map information. A traffic signal information acquisition step (S11), a type determination step (S12 to S13) for determining whether the traffic signal ahead of the host vehicle is an LED traffic signal based on the traffic signal information acquired in the traffic signal information acquisition step, and the type When it is determined in the determination step that the traffic signal ahead of the host vehicle is an LED traffic signal, a lighting information acquisition step (S15) for acquiring LED lighting information related to the LED traffic signal based on the traffic signal information, and the lighting information acquisition Based on the LED lighting information acquired in the process and the photographing period of the photographing means for photographing the front of the host vehicle, the photographing timing for photographing the front of the host vehicle is set. A program for executing a photographing timing setting step (S16 to S21) and a traffic light detection step (S22) for detecting a traffic light based on a photographed image photographed at the photographing timing set in the photographing timing setting step. It is.

  In the traffic light detection device according to claim 1 having the above configuration, an LED traffic light is set in order to set a photographing timing for photographing the LED traffic light based on LED lighting information regarding the LED traffic light ahead of the host vehicle and a photographing period of the photographing means. Thus, it is possible to reliably shoot with the light emitting portion in the lit state. In addition, the LED traffic light can be reliably detected based on a captured image in a state where the light emitting unit of the LED traffic light is turned on.

  Further, in the traffic light detection device according to claim 2, when the shooting cycle of the shooting means is longer than ½ of the LED lighting cycle of the LED traffic light, the shooting timing is changed so as not to shoot when the LED of the LED traffic light is turned off. For this reason, it is possible to further reliably take a picture with the light emitting portion of the LED traffic light in the lighting state.

  Further, in the traffic light detection device according to claim 3, when the shooting cycle of the shooting means is ½ or less of the LED lighting cycle of the LED traffic light, only when the LED of the LED traffic light is lit without changing the shooting timing. Since the traffic light is detected based on the captured image, the LED traffic light can be reliably detected.

  Further, in the traffic light detection method according to claim 4, in order to set the photographing timing for photographing the LED traffic light based on the LED lighting information relating to the LED traffic light ahead of the host vehicle and the photographing period of the photographing means, the light emission of the LED traffic light is set. It is possible to reliably shoot with the part lit. In addition, the LED traffic light can be reliably detected based on a captured image in a state where the light emitting unit of the LED traffic light is turned on.

  Furthermore, in the program according to claim 5, when the computer reads the program, the computer photographs the LED traffic light based on the LED lighting information related to the LED traffic light ahead of the host vehicle and the photographing period of the photographing means. Since the photographing timing is set, it is possible to reliably photograph the light emitting part of the LED traffic light in the lighting state. In addition, the computer can reliably detect the LED traffic light based on a captured image in a state where the light emitting unit of the LED traffic light is turned on.

  Hereinafter, a traffic light detection device, a traffic light detection method and a program according to the present invention will be described in detail with reference to the drawings based on an embodiment in which a navigation device is embodied.

[Schematic configuration of navigation device]
First, a schematic configuration of the navigation device according to the present embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a navigation device 1 according to the present embodiment.
As shown in FIG. 1, the navigation apparatus 1 according to the present embodiment includes a current position detection unit 11 that detects a current position of the own vehicle (hereinafter referred to as “own vehicle position”), and data in which various data are recorded. A recording unit 12, a navigation control unit 13 that performs various arithmetic processes based on the input information, an operation unit 14 that receives operations from an operator, and a liquid crystal that displays information such as a map to the operator A display 15, a speaker 16 that outputs voice guidance regarding route guidance and the like, and a communication device 17 that communicates with a road traffic information center, a map information distribution center, and the like (not shown) via a mobile phone network or the like. Has been. The navigation control unit 13 is connected to a vehicle speed sensor 21 that detects the traveling speed of the vehicle.

  The navigation control unit 13 is electrically connected to a camera ECU (Electronic Control Unit) 51 that controls driving of a CCD camera or the like. The camera ECU 51 is electrically connected to a front imaging camera 53 that is configured by a CCD (stereo) camera or the like fixed in the vicinity of the rearview mirror and captures the front in the traveling direction.

  Hereinafter, each component constituting the navigation device 1 will be described. The current location detection unit 11 includes a GPS 31, an orientation sensor 32, a distance sensor 33, an altimeter (not shown), and the like. It is possible to detect a distance to a target (for example, an intersection).

  Specifically, the GPS 31 detects the current location and current time of the vehicle on the earth by receiving radio waves generated by artificial satellites. The azimuth sensor 32 includes a geomagnetic sensor, a gyro sensor, an optical rotation sensor attached to a rotating portion of a steering wheel (not shown), a rotation resistance sensor, an angle sensor attached to a wheel, or the like. Detect the direction of the vehicle. The distance sensor 33 measures, for example, the rotational speed of a wheel (not shown) of the host vehicle, detects the distance based on the measured rotational speed, measures the acceleration, and integrates the measured acceleration twice. Thus, it is composed of a sensor or the like for detecting the distance, and detects the moving distance of the own vehicle.

  The data recording unit 12 reads out an external storage device and a hard disk (not shown) as a recording medium, a map information database (map information DB) 25 stored in the hard disk, a predetermined program, etc. And a recording head (not shown) which is a driver for writing data.

  The map information DB 25 is composed of various information necessary for route guidance and map display. For example, new road information for specifying each new road, map display data for displaying a map, each intersection Intersection data on nodes, node data on node points, link data on roads (links) that are a type of facility, search data for searching for routes, store data on points of interest (POI) of stores that are a type of facility, points Search data for searching for traffic lights, traffic signal information relating to traffic lights at intersections, and the like.

This traffic signal information includes information such as the position coordinates and height data of the traffic signal at the intersection, the traffic signal to be paired in the case of a pair traffic signal, the type of the traffic signal (such as an LED traffic light or a light bulb-type normal traffic light). It is. Further, in the case of an LED traffic light, the traffic light information includes a lighting cycle for each region of the LED elements constituting the light emitting unit (for example, in a region where the commercial power source is AC100V and 60 Hz, the lighting cycle is 120 Hz). include.
Further, the contents of the map information DB 25 are updated by downloading update information distributed from an information distribution center (not shown) via the communication device 17.

  As shown in FIG. 1, the navigation control unit 13 constituting the navigation device 1 is a working device that controls the entire navigation device 1, the CPU 41 as the control device, and the CPU 41 performs various types of arithmetic processing. A RAM 42 for storing route data when a route is searched, a control program, and a shooting timing adjustment program for adjusting the shooting timing of a front imaging camera 53 (to be described later). 2) and the like, and an internal storage device such as a flash memory 44 for storing a program read from the ROM 43, a timer 45 for measuring time, and the like.

  Furthermore, the navigation control unit 13 is electrically connected to peripheral devices (actuators) of the operation unit 14, the liquid crystal display 15, the speaker 16, and the communication device 17.

The operation unit 14 is operated when correcting the current location at the start of travel, inputting a departure point as a guidance start point and a destination as a guidance end point, or searching for information about facilities, and the like. And a plurality of operation switches. The navigation control unit 13 performs control to execute various corresponding operations based on switch signals output by pressing the switches. Note that the operation unit 14 may be configured by a keyboard, a mouse, or the like, or a touch panel provided on the front surface of the liquid crystal display 15.
The liquid crystal display 15 also has operation guidance, operation menus, key guidance, guidance route from the current location to the destination, guidance information along the guidance route, traffic information, news, weather forecast, time, mail, TV program, etc. Is displayed.

Further, the speaker 16 outputs a travel guide along the guidance route based on an instruction from the navigation control unit 13. Here, the voice guidance to be guided is, for example, “200m ahead, right at XX intersection”.
The communication device 17 is a communication means such as a mobile phone network that communicates with the information distribution center and the road traffic information center, and transmits and receives the latest version of updated map information and the like with the information distribution center. In addition to the information distribution center and the like, the communication device 17 is configured to be capable of bidirectional communication with the navigation device 1 mounted on another vehicle.

  The camera ECU 51 includes a data receiving unit 51A that receives control information transmitted from the navigation control unit 13, and a camera control unit 51C that drives and controls the front imaging camera 53 based on the received control information. An image recognition unit 51B that performs image recognition of a captured image captured by the front imaging camera 53. Here, the image recognizing unit 51B performs image processing on the video signal of the front imaging camera 53, and extracts the position of the traffic light, the height of the traffic light, the shape and color information of the light emitting unit of the traffic light, and the like. Output.

[Shooting timing adjustment processing]
Next, an imaging timing adjustment process for adjusting the imaging timing of the front imaging camera 53, which is a process executed by the CPU 41 of the navigation device 1 configured as described above, will be described with reference to FIGS.

FIG. 2 is a flowchart illustrating a “shooting timing adjustment process” that is performed by the CPU 41 of the navigation device 1 according to the present embodiment and that adjusts the shooting timing of the front imaging camera 53. FIG. 3 is a diagram illustrating an example of extracting a captured image only when the light emitting unit of the LED traffic light is turned on. FIG. 4 is a diagram illustrating an example of extracting a captured image by shifting the imaging timing of the front imaging camera 53 by a half cycle of the imaging cycle.
2 is stored in the ROM 43 provided in the navigation control unit 13 of the navigation device 1, and is executed by the CPU 41.

  As shown in FIG. 2, first, in step (hereinafter abbreviated as “S”) 11, the CPU 41 detects the vehicle position and the vehicle direction indicating the direction of the vehicle by the current position detection unit 11, and the vehicle position is detected. The coordinate data (for example, latitude and longitude data) and the vehicle direction are stored in the RAM 42. Further, the CPU 41 acquires traffic signal information in front of the host vehicle (for example, from the host vehicle position to a predetermined distance (about 200 m to 300 m) ahead) from the map information stored in the map information DB 25 and stores it in the RAM 42. To do.

Subsequently, in S12, the CPU 41 executes a determination process for determining whether there is a traffic light ahead of the host vehicle (for example, from the vehicle position to a predetermined distance (about 200 m to 300 m) ahead).
And when there is no traffic light ahead of the own vehicle (S12: NO), CPU41 complete | finishes the said process.

On the other hand, when there is a traffic light ahead of the host vehicle (S12: YES), the CPU 41 proceeds to the process of S13. In S13, the CPU 41 re-reads the traffic signal information regarding the traffic signal ahead in the traveling direction from the map information stored in the map information DB 25, and executes a determination process for determining whether or not the traffic signal ahead in the traveling direction is an LED traffic signal. To do.
When the traffic light ahead in the traveling direction is not an LED traffic light, that is, when it is a light bulb type normal traffic light (S13: NO), the CPU 41 proceeds to the process of S14. In S14, the CPU 41 outputs a control signal instructing the camera ECU 51 to perform image recognition of the captured image of the front imaging camera 53, and then proceeds to the process of S22 described later. As a result, the image recognition unit 51B of the camera ECU 51 performs image processing on the video signal of the front imaging camera 53 to determine the position of the traffic light on the captured image, the height of the traffic light, the shape and color information of the light emitting part of the traffic light, and the like. Extract and output.

  On the other hand, when the traffic light ahead in the traveling direction is an LED traffic light (S13: YES), the CPU 41 proceeds to the process of S15. In S15, the CPU 41 reads again the traffic signal information regarding the traffic signal ahead in the traveling direction from the map information stored in the map information DB 25, acquires the lighting cycle of each LED element constituting the light emitting unit of the LED traffic signal, and acquires the RAM 42 To remember.

  In S <b> 16, the CPU 41 acquires the number of shot frames per second of the front imaging camera 53 via the camera control unit 51 </ b> C of the camera ECU 51, and stores it in the RAM 42. The camera control unit 51C of the camera ECU 51 is configured to be able to detect the number of frames taken per second of the front imaging camera 53 connected to the camera ECU 51.

  Subsequently, in S <b> 17, the CPU 41 again reads out the number of frames taken per second of the front imaging camera 53 from the RAM 42 and calculates a shooting cycle. Then, the CPU 41 again reads the lighting cycle of the light emitting unit of the LED traffic light from the RAM 42, and whether or not the calculated shooting cycle of the front imaging camera 53 is equal to or less than ½ of the lighting cycle of the light emitting unit of the LED traffic light. A determination process for determining

  And when the imaging cycle of the front imaging camera 53 is ½ or less of the lighting cycle of the light emitting part of the LED traffic light ahead in the traveling direction (S17: YES), the CPU 41 proceeds to the process of S18. In S <b> 18, the CPU 41 performs image recognition on the camera ECU 51 by setting a sampling cycle for extracting a captured image only when the light emitting unit of the LED traffic light is lit out of the captured image of the front imaging camera 53. After outputting the control signal instructing so, the process proceeds to S22 described later. As a result, the image recognition unit 51B of the camera ECU 51 performs image processing on the video signal of the front imaging camera 53, and the position of the LED traffic light, the height of the LED traffic light, the shape and color of the light emission part of the LED traffic light on the captured image. Information and the like can be extracted and output reliably.

  For example, as shown in FIG. 3, the light emission characteristic 61 indicating the light emission state of the LED elements constituting the light emitting unit of the LED traffic light has a lighting cycle twice as long as the power cycle of the commercial power supply. The imaging cycle of the front imaging camera 53 is about 1/4 times the lighting cycle of the light emitting part of the LED traffic light. Therefore, the CPU 41 samples the camera ECU 51 so as to extract a captured image only when the LED element of the light emitting unit of the LED traffic light is stably lit out of the captured images of the front imaging camera 53 every four frames. A cycle is set, and a control signal instructing to perform image recognition of the captured image is output.

  As a result, the image recognition unit 51B of the camera ECU 51 can extract a captured image of the front imaging camera 53 only when the light emitting unit of the LED traffic light is turned on, and performs image processing on the video signal of the front imaging camera 53. Thus, the position of the LED traffic light on the captured image, the height of the LED traffic light, the shape of the light emitting portion of the LED traffic light, color information, and the like can be extracted and output reliably.

  On the other hand, when the shooting period of the front imaging camera 53 is longer than ½ of the lighting period of the light emitting unit of the LED traffic light ahead in the traveling direction (S17: NO), the CPU 41 proceeds to the process of S19. To do. In S19, the CPU 41 determines whether or not the lighting cycle of the light emitting unit of the LED traffic light ahead of the traveling direction is synchronized with the shooting cycle of the front imaging camera 53, that is, the shooting cycle of the front imaging camera 53 is the LED traffic light. The determination process which determines whether it is substantially integral multiple of the lighting period of the light emission part is performed.

  When the lighting cycle of the light emitting unit of the LED traffic light ahead of the traveling direction and the shooting cycle of the front imaging camera 53 are synchronized, that is, the shooting cycle of the front imaging camera 53 is the lighting cycle of the light emitting unit of the LED traffic light. If it is approximately an integer multiple of (S19: YES), the CPU 41 proceeds to the process of S20. In S20, when the captured image of the front imaging camera 53 is a captured image in which the LED element of the LED traffic light is turned off and the light emission portion of the LED traffic light disappears, the CPU 41 performs forward imaging. After outputting a control signal for instructing to shift the photographing timing of the camera 53 from the turn-off timing of the LED element to the camera ECU 51, the process proceeds to S22 described later.

  Specifically, when the front imaging camera 53 captures the number of frames from 2 frames to 5 frames, the CPU 41 receives the light emitting unit of the LED traffic light on the captured image from the image recognition unit 51B of the camera ECU 51. When shape, color information, or the like is not input, a control signal that instructs the camera ECU 51 to shift the shooting period of the front imaging camera 53 by a half period is output. Alternatively, when the shape or color information of the light emitting unit of the LED traffic light on the captured image is no longer input from the image recognition unit 51B of the camera ECU 51, the CPU 41 causes the camera ECU 51 to capture the imaging cycle of the front imaging camera 53. A control signal for instructing to shift by half a cycle is output.

  For example, as shown in FIG. 4, the light emission characteristic 61 indicating the light emission state of the LED elements constituting the light emitting unit of the LED traffic light has a lighting cycle twice as long as the power cycle of the commercial power source. Moreover, the imaging cycle of the front imaging camera 53 is substantially the same as the lighting cycle of the light emitting part of the LED traffic light. Therefore, as shown in the upper side of FIG. 4, when the photographing timing of the front imaging camera 53 coincides with the turn-off timing of the LED element of the light emitting unit of the LED traffic light, the image recognition unit 51B of the camera ECU 51 sends the CPU 41 to the CPU 41. Thus, the shape and color information of the light emitting part of the LED traffic light on the photographed image are not input.

  For this reason, as shown in the lower side of FIG. 4, the CPU 41 outputs a control signal that instructs the camera ECU 51 to shift the imaging cycle of the front imaging camera 53 by a half cycle. As a result, the captured image of the front imaging camera 53 can be captured only when the LED element of the light emitting unit of the LED traffic light is stably lit, and the image recognition unit 51B of the camera ECU 51 can The video signal of the imaging camera 53 is image-processed, and the position of the LED traffic light, the height of the LED traffic light, the shape and color information of the light emitting part of the LED traffic light, etc. can be extracted and output reliably. It becomes.

  On the other hand, when the lighting cycle of the light emitting unit of the LED traffic light ahead in the traveling direction is not synchronized with the shooting cycle of the front imaging camera 53 in S19, that is, the shooting cycle of the front imaging camera 53 is the light emitting unit of the LED traffic light. If it is not substantially an integral multiple of the lighting cycle (S19: NO), the CPU 41 proceeds to the process of S21. In S <b> 21, the CPU 41 periodically sets the shooting timing of the front imaging camera 53 to the camera ECU 51 in accordance with the phase difference between the lighting cycle of the light emitting unit of the LED traffic light and the shooting cycle of the front imaging camera 53. After the control signal is output to the camera ECU 51 to instruct to shift from the LED element turn-off timing (for example, to instruct to shift by half of the shooting period), the process proceeds to S22.

  Specifically, the CPU 41 periodically determines how many times the shape, color information, and the like of the light emitting unit of the LED traffic light on the photographed image are received from the image recognition unit 51B of the camera ECU 51 (for example, 3 to 5 times periodically). If there is a time when no input is made, the shooting cycle of the front imaging camera 53 is shifted by a half cycle in a cycle in which the shape, color information, etc. of the light emitting portion of the LED traffic light is not input to the camera ECU 51. A control signal for instructing is output. Accordingly, the front imaging camera 53 can capture a captured image only when the LED element of the light emitting unit of the LED traffic light is turned on, and the image recognition unit 51B of the camera ECU 51 can detect the video signal of the front imaging camera 53. , The position of the LED traffic light on the captured image, the height of the LED traffic light, the shape and color information of the light emitting part of the LED traffic light, etc. can be extracted and output reliably.

  Subsequently, in S22, the CPU 41 determines the position of the LED traffic light or the normal traffic light on the captured image input from the image recognition unit 51B of the camera ECU 51, the height of the LED traffic light or the normal traffic light, the light emitting portion of the LED traffic light or the normal traffic light. Shape, color information, etc. are stored in the RAM 42. Further, the CPU 41 reads the traffic signal information regarding the traffic signal ahead in the course direction from the map information DB 25, calculates the distance and angle between the nearby traffic signal on the map data and the host vehicle, and stores them in the RAM 42. Then, the CPU 41 is the LED signal or the normal signal on the photographed image, the distance and the angle from the own vehicle of the light emitting unit coincide with the distance and the angle between the nearby signal on the map data and the own vehicle, Detect as a nearby traffic light on the route. Then, the CPU 41 stores the signal state of the LED traffic light or the normal traffic light in the RAM 42 based on the shape or color information of the light emitting unit of the LED traffic light or the normal traffic light on the detected photographed image, and then ends the processing. .

[Effect of the above embodiment]
As described above in detail, in the navigation device 1 according to the present embodiment, when the shooting period of the front imaging camera 53 is ½ or less of the lighting period of the light emitting unit of the LED traffic light ahead in the traveling direction, the CPU 41. Instructs the camera ECU 51 to perform image recognition of the captured image by setting a sampling period for extracting a captured image of the front imaging camera 53 only when the light emitting unit of the LED traffic light is lit. A control signal is output (S11 to S17: YES to S18).

  As a result, the image recognition unit 51B of the camera ECU 51 performs image processing on the video signal of the front imaging camera 53, and the position of the LED traffic light, the height of the LED traffic light, the shape and color of the light emission part of the LED traffic light on the captured image. Information and the like can be extracted and output reliably. Therefore, the CPU 41 detects the position of the LED traffic light on the captured image input from the image recognition unit 51B of the camera ECU 51, the height of the LED traffic light, the shape and color information of the light emitting part of the LED traffic light, and the traffic light ahead in the course direction. On the basis of the traffic light information regarding the LED traffic light, it is possible to detect the LED traffic light that is close in the course and to reliably detect the signal state of the LED traffic light (S22).

  Further, the imaging cycle of the front imaging camera 53 is longer than ½ of the lighting cycle of the light emitting part of the LED traffic light ahead in the traveling direction, and the lighting cycle of the light emitting part of the LED traffic light ahead of the traveling direction, and the front imaging When the shooting cycle of the camera 53 is synchronized, the CPU 41 sets the shooting timing of the front imaging camera 53 when the captured image of the front imaging camera 53 becomes a captured image in which the light emitting unit of the LED traffic light has disappeared. A control signal instructing to deviate from the timing of turning off the LED elements is output to the camera ECU 51 (S11 to S17: NO to S19: YES to S20).

  Accordingly, the front imaging camera 53 can capture a captured image only when the LED element of the light emitting unit of the LED traffic light emits light stably, and the image recognition unit 51B of the camera ECU 51 can capture the captured image. It is possible to perform image processing on the 53 video signals, extract the position of the LED traffic light on the captured image, the height of the LED traffic light, the shape and color information of the light emitting portion of the LED traffic light, and output them reliably. Therefore, the CPU 41 detects the position of the LED traffic light on the captured image input from the image recognition unit 51B of the camera ECU 51, the height of the LED traffic light, the shape and color information of the light emitting part of the LED traffic light, and the traffic light ahead in the course direction. On the basis of the traffic light information regarding the LED traffic light, it is possible to detect the LED traffic light that is close in the course and to reliably detect the signal state of the LED traffic light (S22).

  Further, the imaging cycle of the front imaging camera 53 is longer than ½ of the lighting cycle of the light emitting part of the LED traffic light ahead in the traveling direction, and the lighting cycle of the light emitting part of the LED traffic light ahead of the traveling direction, and the front imaging When the shooting cycle of the camera 53 is not synchronized, the CPU 41 periodically instructs the camera ECU 51 to match the phase difference between the lighting cycle of the light emitting unit of the LED traffic light and the shooting cycle of the front imaging camera 53. Is instructed to shift the shooting timing of the front imaging camera 53 from the turn-off timing of the LED element (eg, to shift the shooting timing by a half period of the shooting cycle), and outputs a control signal to the camera ECU 51 ((S11 -S17: NO-S19: NO-S21).

  Accordingly, the front imaging camera 53 can capture a captured image only when the LED element of the light emitting unit of the LED traffic light is turned on, and the image recognition unit 51B of the camera ECU 51 can detect the video signal of the front imaging camera 53. , The position of the LED traffic light on the captured image, the height of the LED traffic light, the shape and color information of the light emitting part of the LED traffic light, etc. can be extracted and output reliably. Therefore, the CPU 41 detects the position of the LED traffic light on the captured image input from the image recognition unit 51B of the camera ECU 51, the height of the LED traffic light, the shape and color information of the light emitting part of the LED traffic light, and the traffic light ahead in the course direction. On the basis of the traffic light information regarding the LED traffic light, it is possible to detect the LED traffic light that is close in the course and to reliably detect the signal state of the LED traffic light (S22).

  In addition, this invention is not limited to the said Example, Of course, various improvement and deformation | transformation are possible within the range which does not deviate from the summary of this invention.

It is the block diagram which showed the navigation apparatus which concerns on a present Example. FIG. 10 is a flowchart illustrating a “shooting timing adjustment process” that is a process executed by a CPU and that adjusts the shooting timing of a front imaging camera. It is a figure which shows an example which extracts the picked-up image only at the time of lighting of the light emission part of an LED traffic light. It is a figure which shows an example which shifts the imaging | photography timing of the camera for front imaging by the half period of an imaging | photography period, and extracts a picked-up image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Navigation apparatus 11 Present location detection part 12 Data recording part 13 Navigation control part 25 Map information DB
41 CPU
42 RAM
43 ROM
51 Camera ECU
53 Front camera 61 Light-emitting characteristics

Claims (5)

Own vehicle position detecting means for detecting the own vehicle position;
Map information storage means for storing map information including traffic signal information relating to traffic signals;
Traffic signal information acquisition means for acquiring the traffic signal information ahead of the host vehicle based on the host vehicle position and the map information;
Based on the traffic signal information acquired by the traffic signal information acquisition means, a type determination means for determining whether the traffic signal ahead of the host vehicle is an LED traffic signal,
When it is determined that the traffic light ahead of the host vehicle is an LED traffic light, lighting information acquisition means for acquiring LED lighting information related to the LED traffic light based on the traffic signal information;
Photographing means for photographing the front of the host vehicle;
Shooting timing setting means for setting shooting timing for shooting the front of the host vehicle based on the LED lighting information and the shooting cycle of the shooting means;
A traffic light detection means for detecting a traffic light based on a photographed image photographed at the photographing timing;
A traffic light detection apparatus comprising: The LED lighting information includes an LED lighting cycle of the LED traffic light,
The photographing timing setting means includes photographing timing changing means for changing the photographing timing so as not to photograph when the LED of the LED traffic light is turned off when the photographing period is larger than half of the LED lighting period of the LED traffic light. The traffic light detection device according to claim 1, further comprising: The shooting timing setting means does not change the shooting timing when the shooting cycle is ½ or less of the LED lighting cycle of the LED traffic light,
The traffic signal detection device according to claim 2, wherein the traffic signal detection means detects a traffic signal based on a captured image only when the LED of the LED traffic signal is lit. A vehicle position detection step for detecting the vehicle position;
A traffic signal information acquisition step of acquiring traffic signal information related to a traffic signal ahead of the host vehicle based on the host vehicle position and map information;
Based on the traffic signal information acquired in the traffic signal information acquisition step, a type determination step of determining whether the traffic signal ahead of the host vehicle is an LED traffic signal,
When it is determined that the traffic light ahead of the host vehicle is an LED traffic light in the type determination step, a lighting information acquisition step of acquiring LED lighting information related to the LED traffic light based on the traffic signal information;
A shooting timing setting step for setting a shooting timing for shooting the front of the host vehicle based on the LED lighting information acquired in the lighting information acquisition step and a shooting period of the shooting means for shooting the front of the host vehicle;
A traffic light detection step of detecting a traffic light based on a captured image captured at the capturing timing set in the capturing timing setting step;
A traffic light detection method comprising: On the computer,
A vehicle position detection step for detecting the vehicle position;
A traffic signal information acquisition step of acquiring traffic signal information relating to a traffic signal ahead of the host vehicle based on the host vehicle position and map information;
Based on the traffic signal information acquired in the traffic signal information acquisition step, a type determination step of determining whether the traffic signal ahead of the host vehicle is an LED traffic signal,
When it is determined in the type determination step that the traffic light ahead of the host vehicle is an LED traffic light, a lighting information acquisition step of acquiring LED lighting information related to the LED traffic signal based on the traffic signal information;
A shooting timing setting step for setting a shooting timing for shooting the front of the host vehicle based on the LED lighting information acquired in the lighting information acquisition step and a shooting period of the shooting means for shooting the front of the host vehicle;
A traffic light detection step of detecting a traffic light based on a captured image captured at the capturing timing set in the capturing timing setting step;
A program for running

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