JP2010061304A - Vehicular distance image data generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular distance image data generation device capable of continuously grasping a situation in front of a host vehicle.
A projector 5 includes a plurality of near-infrared LEDs 5a including lenses 51 to 53 having different light distribution angles so as to be turned on and off according to the light distribution angle. Based on the lighting and extinguishing of the plurality of near-infrared LEDs 5a including the lenses 51 to 53 having different light distribution angles of the light projector 5, the light distribution angle was changed in the processing of steps S11 to S16.
[Selection] Figure 1

Description

  The present invention belongs to the technical field of a vehicle distance image data generation device.

In Patent Literature 1, whether or not an object such as an obstacle exists at the target distance is based on an image that is projected in accordance with the timing of reflected light that is projected in front of the host vehicle and returned from the target distance. Techniques for detection are disclosed.
US Pat. No. 6,732,123

  However, in the above prior art, objects other than the target distance cannot be detected. That is, there is a problem that the situation is intermittently grasped and the situation ahead of the host vehicle cannot be grasped continuously.

  An object of the present invention is to provide a vehicular distance image data generation apparatus that can continuously grasp the situation ahead of the host vehicle.

  In order to achieve the above object, in the vehicle distance image data generation device of the present invention, a light projecting unit that projects pulsed light in front of the host vehicle at a predetermined cycle, and an imaging timing set according to the target distance. Imaging means for imaging reflected light returning from the distance, timing control means for controlling the imaging timing so that the target distance changes continuously, and a plurality of imagings with different target distances obtained by the imaging means Distance image data generating means for generating distance image data representing the distance to the object for each pixel based on the luminance of the same pixel in the image, and the light projecting means switches to a different light distribution angle and projects light The timing control means changes the light distribution angle to the switching means of the light projecting means based on the target distance. To, characterized in that.

  Therefore, in this invention, the situation ahead of the own vehicle can be grasped | ascertained continuously.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for realizing a vehicular distance image data generating apparatus according to the present invention will be described below with reference to the drawings.

First, the configuration will be described.
FIG. 1 is a block diagram illustrating a configuration of an obstacle detection apparatus 1 according to a first embodiment to which the vehicle distance image data generation apparatus according to the present invention is applied. A device 2, an object recognition processing unit 3, and a determination unit 4 are provided.

The distance image data generation device 2 includes a projector (projecting unit) 5, an objective lens 6, a light doubling unit 7, a high-speed camera (imaging unit) 8, a timing controller (timing control unit) 9, and image processing. Unit (distance image data generating means) 10.
The projector 5 is a near-infrared LED 5a (which constitutes a lens and a light emitting unit) disposed at the front end of the vehicle, and according to a pulse signal output from the timing controller 9, a predetermined projection time tL (for example, 5 ns). During this period, pulse light is output. The cycle of the pulse signal is the projection cycle tP of the projector 5, and the projection cycle tP is, for example, an interval of 1/100 s or less. Details of the projector 5 will be described later.
The objective lens 6 is for receiving reflected light from an object, and is disposed adjacent to the projector 5. For example, the optical system is set to have an angle of view capable of capturing a predetermined range in front of the host vehicle.

The light multiplication unit 7 includes a gate 7a and an image intensifier 7b.
The gate 7a opens and closes in response to an opening / closing command signal from the timing controller 9. Here, in Example 1, the opening time (gate time) tG of the gate 7a is set to 5 ns, which is the same as the light projection time tL. Here, the gate time tG corresponds to the imaging target width of the imaging area (target distance). The longer the gate time tG, the longer the imaging target width of the imaging area. In the first embodiment, since the gate time tG = 5 ns, the imaging target width is 1.5 m from the speed of light (about 3 × 10 ⁸ m / s) × gate time (5 ns).

The image intensifier 7b temporarily converts extremely weak light (reflected light from an object, etc.) into electrons and then electrically amplifies it, and returns it to a fluorescent image again to double the amount of light and to produce an image with contrast. It is a viewing device. Photoelectrons launched from the photocathode of the image intensifier 7b by a photoelectric phenomenon are accelerated at a high voltage of the order of kV, and are emitted into the phosphor screen on the anode side, thereby emitting fluorescence having a photon number of 100 times or more. The fluorescence generated on the phosphor screen is guided to the image sensor of the high-speed camera 8 by the fiber optic plate without being scattered while maintaining the same positional relationship.
The high-speed camera 8 captures an image emitted from the light doubling unit 7 in response to a command signal from the timing controller 9 and outputs a captured image (color image) to the image processing unit 10. In the first embodiment, a camera having a resolution of 640 × 480 (horizontal: vertical), a luminance value of 1 to 255 (256 levels), and 100 fps or more is used.

The timing controller 9 is the time from the light projection start time of the projector 5 until the gate 7a is opened so that the captured image captured by the high-speed camera 8 is the timing of the reflected light returning from the target imaging area. The imaging timing is controlled by setting a certain delay time tD and outputting an open / close command signal corresponding to the delay time. That is, the delay time tD is a value that determines the distance from the host vehicle to the imaging area (imaging target distance), and the relationship between the delay time tD and the imaging target distance is as follows.
Imaging distance = speed of light (approx. 3 x 10 ⁸ m / s) x delay time tD / 2
FIG. 2 shows a temporal relationship between the operation of the projector 5 (light projection operation) and the operation of the gate 7a (camera gate operation) when imaging one imaging area.

  The timing controller 9 increases the imaging range of the high-speed camera 8 by increasing the delay time tD by a predetermined interval (for example, 10 ns) so that the imaging area continuously moves from the front side of the vehicle to the front side. Change to the side. The timing controller 9 starts the imaging operation of the high-speed camera 8 immediately before the gate 7a is opened, and ends the imaging operation after the gate 7a is completely closed. However, in the first embodiment, the timing controller 9 sets the number of multiple exposures in advance according to the imaging target distance (target distance), reads this data, and performs imaging at a certain imaging target distance a predetermined number of times. And the opening / closing operation of the gate 7a. Therefore, when the predetermined number of times set is a plurality of times, the imaging operation is terminated after a plurality of light projection operations and the opening / closing operation of the gate 7a.

  Further, in the first embodiment, as illustrated in FIG. 3, when the imaging target distance is continuously changed from B1 → B2 → B3 →..., The imaging target distance is increased more than the imaging target width A of the imaging area. By increasing the amount (B2-B1), the increase amount of the imaging target distance is set so that a part of the imaging area changes while overlapping.

  FIG. 4 is a schematic diagram showing temporal luminance changes when the amount of increase in the imaging target distance is reduced to the limit, in other words, when imaging is performed with an infinite increase in the imaging area. By overlapping each other, the luminance value of the same pixel in a plurality of consecutive captured images gradually increases, and after the peak, the luminance value gradually decreases. In practice, the number of imaging areas is limited (1 to n), but by overlapping a part of continuous imaging areas, the temporal luminance change becomes close to the characteristics of FIG.

  The timing controller 9 outputs an image processing command signal to the image processing unit 10 when all the captured images for one frame, that is, the set predetermined range (area 1, area 2,..., Area n) are captured. To do.

  The image processing unit 10 generates distance image data representing distance information by color, luminance, and the like from one frame of captured images (imaging pixels) captured by the high-speed camera 8, and object recognition is performed on the generated distance image data. Output to the processing unit 3.

The object recognition processing unit 3 identifies an object included in the distance image data by performing image processing, for example, labeling, pattern matching, or the like on the object included in the distance image data.
Based on the relationship (distance, relative speed, etc.) between the object (person, car, sign, etc.) identified by the object recognition processing unit 3 and the host vehicle, the determination unit 4 presents information to the driver by an alarm, Determine whether vehicle control such as automatic braking is necessary.

FIG. 5 is an explanatory diagram of a projector of the distance image data generation device according to the first embodiment.
As shown in FIG. 5B, the near-infrared LED 5a provided in the projector 5 has an arrangement in which lenses 51 to 53 are attached to the output portion thereof.
The lens 51 is a lens with a light distribution angle of 30 degrees, the lens 52 is a lens with a light distribution angle of 15 degrees, and the lens 53 is a lens with a light distribution angle of 10 degrees.
The lenses 51 to 53 are disposed on the front surface of the projector 5 as shown in FIG. In the arrangement, 14 lenses 53 are arranged in the center, 4 lenses 52 are arranged on both the left and right sides, and one lens 51 is arranged on both the left and right sides. The entire lenses 51 to 53 are arranged in a staggered manner.
Further, the number of lenses 51 to 53 and the lens light distribution angle are preferably optimized based on actual light distribution characteristics.

In the first embodiment, as an example, the lens 51 with a light distribution angle of 30 degrees is assumed to be 15 m forward from the center where the left and right light distribution width of the near-infrared LED 5a is 4 m from one side. The near infrared LED 5a to which the lens 51 is attached is referred to as a near infrared LED 5a for short distance.
Further, as an example, in the lens 52 with a light distribution angle of 15 degrees, the distance at which the left and right light distribution width of the near-infrared LED 5a is 4 m from one side is 30 m forward. The near-infrared LED 5a to which the lens 52 is attached is referred to as a mid-range near-infrared LED 5a.
Further, as an example, in the lens 53 with a light distribution angle of 10 degrees, the distance at which the left and right light distribution widths of the forbidden infrared LEDs 5a are 4 m from the center is 45 m forward. The near-infrared LED 5a to which the lens 52 is attached is a long-distance near-infrared LED 5a.

[Distance image data generation control processing]
FIG. 6 is a flowchart illustrating the flow of the distance image data generation control process executed by the image processing unit 10 according to the first embodiment. Each step will be described below. This process is repeatedly executed at a predetermined calculation cycle.

  In step S1, the image processing unit 10 stores the luminance value data having the lowest luminance of the captured image obtained by imaging the front of the host vehicle without performing the light projection by the projector 5 for later luminance determination, and proceeds to step S2. To do. This data is used when generating the distance image data.

  In step S2, the image processing unit 10 inputs a captured image, and proceeds to step S3. In the first embodiment, the input captured image is an image captured a plurality of times with the number of multiple exposures set in advance according to the distance range to be captured. Details will be described later.

  In step S3, the image processing unit 10 determines whether image input for one frame (area 1, area 2,..., Area n) has been completed. If YES, the process proceeds to step S4. If NO, the process proceeds to step S2.

  In step S4, distance image data is generated as an image with distance information by color and brightness, and the process proceeds to return.

[Projection distance control processing]
FIG. 7 is a flowchart showing the flow of the projection distance control process of the projector 5 executed by the timing controller 9 of the first embodiment, and each step will be described below.
In the following processing, the imaging target distance of the imaging area scan is divided into three ranges of short distance, medium distance, and long distance, and the boundary distances are X1 and X2.

  In step S11, the timing controller 9 determines whether or not the imaging target distance X at the time of imaging is the distance X1 or less. If the distance is less than the distance X1, the process proceeds to step S12, and if it exceeds the distance X1, the process proceeds to step S13.

  In step S12, the timing controller 9 uses the near-infrared LED 5a for short distance to which the lens 51 having a light distribution angle of 30 degrees is attached for light projection, and the process proceeds to step S17.

  In step S13, the timing controller 9 determines whether or not the imaging target distance X at the time of imaging is within the range of the distance X1 and the distance X2 or less. If it is within this range, the process proceeds to step S14. If so, the process proceeds to step S15.

  In step S14, the timing controller 9 detects the near-infrared LED 5a for short distance to which the lens 51 having a light distribution angle of 30 degrees is attached and the near-infrared LED 5a for middle distance to which the lens 52 having a light distribution angle of 15 degrees is attached. Is used for floodlighting, and the process proceeds to step S17.

  In step S15, the timing controller 9 determines whether or not the imaging target distance X at the time of imaging exceeds the distance X2, and if so, proceeds to step S16, and if not, processes as an error. Exit.

  In step S16, the near-infrared LED 5a for short distance to which the lens 51 having a light distribution angle of 30 degrees is attached, the near-infrared LED 5a to which the lens 52 having a light distribution angle of 15 degrees is attached, and the light distribution angle to The long-distance near-infrared LED 5a to which the lens 53 of 10 degrees is attached is used for light projection, and the process proceeds to step S17.

  In step S17, a light projecting (imaging) process at the imaging target distance (imaging area) is performed.

  In step S18, processing for adding the inter-area distance L to the imaging target distance X is performed in order to shift to imaging at the next imaging target distance.

  In step S19, it is determined whether or not imaging for one frame has been completed. If completed, the process ends. If not completed, the process returns to step S11.

Next, the operation will be described.
[Distance image data generation function]
The timing controller 9 controls the imaging timing of the high-speed camera 8 by setting the delay time tD so that the captured image captured by the high-speed camera 8 becomes the timing of the reflected light returning from the target imaging area. To do. When an object is present in the target imaging area, the time for the light emitted from the projector 5 to return from the imaging area is the time for the light to reciprocate the distance between the host vehicle and the imaging area (imaging target distance). Therefore, the delay time tD can be obtained from the imaging target distance and the speed of light.

  In the captured image of the high-speed camera 8 obtained by the above method, when an object exists in the imaging area, the luminance value data of the pixel corresponding to the position of the object is affected by the reflected light, and the luminance of other pixels Indicates a value higher than the value data. Thereby, based on the luminance value data of each pixel, the distance from the object existing in the targeted imaging area can be obtained.

  Furthermore, in the first embodiment, captured images of the imaging areas 1 to n are acquired while changing the delay time tD. Subsequently, the brightness value data of the distance before and after the same pixel position is compared, the highest brightness value data is set as the distance of the object detected by the pixel, and the data (distance with distance information of the imaging range (640 × 480)) Image data).

  Conventional distance detection methods using laser radars and stereo cameras are susceptible to rain, fog, snow, etc., and the noise level with respect to the signal level is large (the SN ratio is small), so the reliability in bad weather is low. . When using a millimeter wave radar that is not easily affected by bad weather, the reliability of distance detection is high, but it is difficult to perform object recognition (object identification) from the millimeter wave radar signal. Is required. Further, since the camera image becomes unclear during bad weather, it is difficult to perform accurate object recognition.

On the other hand, in the first embodiment, only reflected waves returning from the target imaging area are reflected in the captured image, so that the light bent due to the influence of rain, fog, snow, or the like, that is, the noise mixing level is kept low. High signal-to-noise ratio can be obtained. That is, high distance detection accuracy can be obtained regardless of bad weather or night.
And since the distance of the object detected from an image is known from the produced | generated distance image data, when performing object recognition using methods, such as pattern matching after that, the distance with an object can be grasped | ascertained instantaneously.

  Furthermore, in the first embodiment, the captured area is continuously changed to acquire a plurality of captured images, and the captured images are compared to detect the distance of each pixel. In addition, it can be grasped over a wide range. For example, even in a situation where a pedestrian has jumped between the host vehicle and the preceding vehicle, the distance between the preceding vehicle and the pedestrian can be grasped at the same time. Control can be performed.

FIG. 8 shows a situation where four pedestrians A to D exist at different positions in front of the host vehicle, and the relationship between the distance between the host vehicle and each pedestrian is A <B <C <D. .
At this time, in the first embodiment, a part of the imaging area is overlapped so that the reflected light from one object is reflected on the pixels constituting the object of the captured image in the plurality of imaging areas in which the reflected light is continuous. For this reason, the temporal luminance change of the pixels constituting the object corresponding to each pedestrian shows a triangular characteristic that takes a peak at the position of the pedestrian, as shown in FIG.

  Since the distance image data is data used for alarms and vehicle control, it is impossible to set an imaging area infinitely finely as long as a certain calculation speed is required. By making the reflected light from the plurality of captured images included, as shown in FIG. 10, the temporal luminance change of the pixel is approximated to the above characteristics, and the imaging area corresponding to the peak of the triangular portion is The detection accuracy can be increased by setting the distance of the object in the pixel.

[Brightness correction by multiple exposure]
In the distance image data generation device 2 according to the first embodiment, a plurality of captured images are acquired while gradually increasing the imaging target distance. Therefore, reflected light from an object existing in a far imaging area is reflected in a nearby imaging area. It becomes weaker than the reflected light of the object existing in the. For this reason, when the imaging time (gate time tG) is constant in each imaging area, the captured image becomes darker as the imaging area is farther.

  On the other hand, the image processing unit 10 generates the distance image data representing the distance to the object for each pixel based on the luminance of the same pixel in the plurality of captured images. If a luminance difference due to a difference occurs, an accurate comparison cannot be performed when comparing the luminance of the same pixel.

  On the other hand, in the first embodiment, the number of multiple exposures is set and stored for the imaging target distance so that the luminance peak value (maximum luminance value) of the captured image in the imaging area where the object exists becomes the target luminance. . Then, the timing controller 9 performs a plurality of sets of a light projecting operation and an opening / closing operation of the gate 7a on one image according to the set number of multiple exposures. In other words, the number of multiple exposures in the first embodiment refers to the light projecting operation of the light projector 5 performed by the control of the timing controller 9 for one image captured by the high-speed camera 8, and the light projection as described above. This means the number of repetitions of the opening / closing operation of the gate 7a (by the delay time tD) paired with the operation.

  For this reason, the luminance range width (difference between the minimum luminance value and the maximum luminance value) of each captured image with different imaging target distances is made uniform regardless of the imaging area, and the target luminance is set in advance so that good processing can be performed. It can approach (refer FIG. 11).

[Change of light distribution angle depending on the distance to be imaged]
FIG. 12 is an explanatory diagram of changing the light distribution angle of light projection at the time of imaging in the distance image data generation device according to the first embodiment.
When the projector 5 has a relatively long distance as the light projection range, the light is condensed by a lens in order to efficiently project light to a far distance. Then, the light distribution angle of the lens is set so as to be in a sufficiently projected range at the long distance position.
In this case, the nearby light distribution range is narrowed. In the case where the light is projected onto the object by the projector 5 and the reflected light is imaged only within the open time of the gate as in the first embodiment, this influence becomes significant.

In addition, in the above-described luminance correction by multiple exposure, correction is performed so that the luminance is increased at a far imaging target distance, and thus the influence of the narrow light distribution width is not corrected. For this reason, when the luminance is corrected by the distance to be imaged and approached uniformly, the influence on the short distance portion outside the light distribution range where light projection is small increases.
In the distance image data generation device 2 according to the first embodiment, a short distance, for example, about 21 m is set as the distance X1 determined in step S11. When the distance X1 is closer than the distance X1, a lens 51 having a light distribution angle of 30 degrees is attached. Imaging is performed by light projection by the near-infrared LED 5a (steps S11 and S12).

Then, for example, in the case where the own vehicle C is running on the left side of the road center line 203 between the road ends 201 and 202 in FIG. 12, the light distribution width of the projector 5 is 101 in FIG. As shown in FIG. 2, the image pickup area is widened, and the range to be imaged is well received with uniform light.
Therefore, the distance image of the imaging range becomes more accurate.
Thereby, a person who is waiting for a pedestrian crossing or a signal on the sidewalk, a pedestrian near the traveling line, and the like are reliably detected, which is very preferable for detecting a front obstacle in the vehicle.
In addition, as the light distribution angle is increased, the luminance obtained by imaging is reduced. However, it is easy to obtain high brightness by imaging at short distance compared to long distance, and it is enough to correct by multiple exposure as described above, so there is no problem, rather the amount of correction is reduced and more uniform target brightness Make it easier to obtain.

Next, when the imaging area is scanned as shown in FIG. 2 and the like, the imaging target distance is gradually increased, and a medium distance, for example, about 37 m is set as the distance X2 determined in skip S13, and the distance X2 exceeds the distance X1. The distance between: In this case, imaging is performed by light projection by the near-infrared LED 5a to which the lens 51 having a light distribution angle of 15 degrees and the near-infrared LED 5a to which the lens 52 having a light distribution angle of 15 degrees is attached (steps S13 and S14). .
Then, for example, in FIG. 12, the light distribution width of the projector 5 is indicated by reference numeral 102 in addition to that indicated by reference numeral 101 in FIG. 12, and is widened in the middle distance range, and the imaging range is satisfactorily uniform. Receives light.

Further, when the imaging area is scanned, the imaging target distance becomes far, and the distance exceeds a long distance, that is, a distance X2 (for example, about 37 m) determined in skip S15. In this case, in addition to the near-infrared LED 5a to which the lens 51 having a light distribution angle of 30 degrees and the lens 52 having a light distribution angle of 15 degrees are attached, the near-infrared LED 5a to which the lens 53 having a light distribution angle of 10 degrees is attached. Imaging is performed by light projection (steps S15 and S16).
Then, for example, in FIG. 12, the light distribution width of the projector 5 is indicated by reference numeral 103 in addition to those indicated by reference numerals 101 and 102 in FIG. 12, and becomes wider at a long distance, and the imaging range is uniformly uniform. Receives light.

As described above, in the distance image data generation device 2 according to the first embodiment, the imaging range is favorably and uniformly projected in any of the short distance, medium distance, and long distance ranges.
Therefore, the distance image of the imaging range becomes more accurate. And people who are waiting for pedestrian crossings and signals on the sidewalk, pedestrians near the driving line, etc. will be detected reliably in the range of short distance, medium distance, and long distance. This is very favorable for detection.

  In the first embodiment, in the case of the intermediate distance (step S13), in addition to the intermediate distance, light is projected by the near infrared LED 5a to which the short distance lens 52 is attached (step S14), and the long distance (step S13). In the case of S15), near-infrared LEDs 5a for medium distance and short distance are projected in addition to those for long distance. This is because some of the light projecting portions for the short distance and the medium distance increase the amount of light projected at a longer distance. This further enhances the effect of uniforming the luminance at the multiple exposure distance.

  In the first embodiment, the distance range in which the effect of changing the light distribution angle at the short distance, medium distance, and long distance is about 80 m. This is because, for example, a distance image with improved accuracy in detecting a pedestrian crossing or a person waiting for a signal on a sidewalk or a pedestrian at a position close to a travel line is generated. Therefore, the speed of the own vehicle is premised on a speed that is suppressed corresponding to such a situation. In that case, it is because what reliably detects up to about 80 m from nearby will support good driving.

Next, the effect will be described.
The distance image data generation device 2 according to the first embodiment has the following effects.

  (1) A projector 5 that projects pulsed light in front of the host vehicle at a predetermined period, an image intensifier 7b that captures reflected light returning from the target distance at an imaging timing set according to the target distance, and a high speed The same pixel in a plurality of captured images with different target distances obtained by the camera 8, the timing controller 9 that controls the imaging timing so that the target distance changes continuously, the image intensifier 7b, and the high-speed camera 8 An image processing unit 10 that generates distance image data representing a distance to an object for each pixel based on luminance is provided. The projector 5 includes a plurality of near-infrared LEDs 5a including lenses 51 to 53 having different light distribution angles. The timing controller 9 is turned on and off according to the light distribution angle, and the timing controller 9 is based on the target distance. In order to change the light distribution angle in the processing of steps S11 to S16 by turning on / off the plurality of near-infrared LEDs 5a including the lenses 51 to 53 having different light distribution angles of the projector 5, the situation in front of the host vehicle is changed. It can be grasped continuously. Furthermore, the accuracy of the distance image can be improved by switching the light distribution angle.

  (2) In the above (1), the timing controller 9 is provided with a near-infrared LED 5a in which lenses 51 to 53 having a plurality of light distribution angles are attached to the light projector 5 so as to suppress a change in the light distribution width of the light projector 5 with respect to the target distance. In order to change the near-infrared LED 5a to be lit and change the light distribution angle, the near-infrared LED 5a to be lit is switched according to the target distance, so that the light distribution angle can be switched, and the projector 5 at the target distance. Thus, the distance image is generated with respect to more uniform luminance conditions so that the light distribution width of the light source does not change, and a distance image with improved accuracy can be obtained.

  (3) In (1) or (2) above, the timing controller 9 sets the range of the short distance (X ≦ X1), medium distance (X1 <X ≦ X2), and long distance (X2 ≦ X) as the target distance. However, as the target distance increases as the range is switched, the near-infrared LED 5a having a plurality of light distribution angle lenses 51 to 53 attached to the projector 5 is changed to change the near-infrared LED 5a to be lit. In order to change the light angle, the light distribution angle can be switched by switching the near infrared LED 5a to be lit according to the target distance in three stages so that the light distribution width of the projector 5 does not change at the target distance. Thus, the distance image is generated with respect to more uniform luminance conditions, and the distance image with improved accuracy can be obtained.

  (4) In the above (1) to (3), the timing controller 9 includes a pedestrian existing on the side of the roadway ahead of the own vehicle in the light distribution angle range at a position where the target distance is close to the own vehicle. Even if the distance increases, the near-infrared LED 5a having a plurality of light-distribution-angle lenses 51 to 53 attached to the projector 5 is changed so that the light-projection angle range is maintained. Since the light angle is changed so as to be narrowed, a person who is waiting for a pedestrian crossing or a signal on a sidewalk or a pedestrian close to the traveling line can be reliably detected in a short distance, medium distance, and long distance range.

(5) In the above (1) to (4), the timing controller 9 determines that the captured image of one target distance is projected multiple times by the projector 5 and the imaging timing by the image intensifier 7b and the high-speed camera 8. Because multiple exposure control is performed to increase the number of light projections and imaging as the target distance increases as the target distance increases, uniform brightness can be obtained with respect to the target distance, improving accuracy The distance image can be made.
The best mode for carrying out the present invention has been described above based on the embodiment. However, the specific configuration of the present invention is not limited to the configuration of the embodiment, and it relates to each claim of the claims. Design changes and additions are allowed without departing from the spirit of the invention.

For example, the light projection period, the light projection time, the gate time, the imaging target width, the amount of change in the imaging target distance, and the number of imaging areas in one frame are appropriately set according to the performance of the imaging means and the performance of the distance image data generation means can do.
Further, for example, in Example 1, the range from the own vehicle to about 80 m is divided into a short distance, a medium distance, and a long distance so that each has a sufficient light distribution width. When detection is emphasized and the vehicle speed in the situation is high, the range of sufficient light distribution width may be set to move forward, and a near-infrared LED 5a that projects light at a long distance is provided. You may do it.

It is a block diagram which shows the structure of the obstruction detection apparatus 1 of Example 1. FIG. It is a figure which shows the temporal relationship between the operation | movement (light projection operation | movement) of the light projector 5, and the operation | movement (camera gate operation | movement) of the gate 7a at the time of imaging one imaging area. It is a figure which shows the state which a part of imaging area overlaps. It is a schematic diagram which shows a temporal luminance change at the time of imaging by increasing an imaging area infinitely. It is explanatory drawing of the light projector of the distance image data generation apparatus of Example 1. FIG. 3 is a flowchart illustrating a flow of distance image data generation control processing executed by the image processing unit 10 according to the first embodiment. 6 is a flowchart illustrating a flow of a light projection distance control process of the light projector 5 executed by the timing controller 9 according to the first embodiment. It is a figure which shows the condition where four pedestrians AD exist in the different position ahead of the own vehicle. It is a schematic diagram which shows the temporal luminance change of the pixel corresponding to each pedestrian A-B. It is a figure which shows the distance image data generation effect | action of Example 1. FIG. It is a figure which shows the distance image data production | generation effect | action by the multiple exposure of Example 1. FIG. It is explanatory drawing of the light distribution angle change of the light projection in the case of the imaging in the distance image data generation apparatus of Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Obstacle detection apparatus 2 Distance image data generation apparatus 3 Object recognition process part 4 Judgment part 5 Light projector (light projection means)
5a Near-infrared LED
51 to 53 Lens 6 Objective Lens 7 Light Multiplier 7a Gate 7b Image Intensifier 8 High Speed Camera (Imaging Means)
9 Timing controller (timing control means)
10 Image processing unit (distance image data generating means)
101 Light distribution range 102 (of near-infrared LED 5a attached with lens 51) Light distribution range 103 (of near-infrared LED 5a attached with lens 52) Light distribution range 104 (of near-infrared LED 5a attached with lens 53) Lines 201 and 202 (indicating the extension of the center) Line 203 (indicating the end of the roadway) Line 203 (of the roadway) C

Claims (5)

Light projecting means for projecting pulsed light in front of the host vehicle at a predetermined period;
Imaging means for imaging reflected light returning from the target distance at an imaging timing set according to the target distance;
Timing control means for controlling the imaging timing so that the target distance changes continuously;
Distance image data generation means for generating distance image data representing a distance to an object for each pixel based on the luminance of the same pixel in a plurality of captured images with different target distances obtained by the imaging means;
With
The light projecting means includes switching means for performing light projection by switching to different light distribution angles,
The timing control unit causes the switching unit of the light projecting unit to change a light distribution angle based on the target distance.
A vehicular distance image data generating apparatus characterized by the above. The vehicle distance image data generation device according to claim 1,
The timing control unit causes the switching unit of the light projecting unit to change a light distribution angle so as to suppress a change in a light distribution width of the light projecting unit with respect to a target distance;
A vehicular distance image data generating apparatus characterized by the above. In the vehicular distance image data generating device according to claim 1 or 2,
The timing control means includes
Set a range of short distance, medium distance, long distance to the target distance, and change the light distribution angle to narrow the light distribution angle to the switching means of the light projecting means according to the target distance becomes longer by switching the range,
A vehicular distance image data generating apparatus characterized by the above. In the vehicular distance image data generation device according to any one of claims 1 to 3,
The timing control means includes
In a position where the target distance is close to the own vehicle, a pedestrian existing on the side of the roadway ahead of the own vehicle is included in the light distribution angle range so that the light distribution angle range is maintained even when the target distance is long. The switching means of the light projecting means is changed so as to narrow the light distribution angle.
A vehicular distance image data generating apparatus characterized by the above. In the vehicular distance image data generation device according to any one of claims 1 to 4,
The timing control means includes
A captured image of one target distance is generated by a plurality of times of light projection by the light projecting unit and a plurality of times of image capturing at the image capturing timing by the image capturing unit, and as the target distance becomes longer, light projection and image capturing are performed. Multiple exposure control to increase the number of times,
A vehicular distance image data generating apparatus characterized by the above.