JP2010066221A - Range image data generating device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a range image data generating device for a vehicle for continuously grasping a forward state of an own vehicle. <P>SOLUTION: The range image data generating device for the vehicle includes: a projector 5; an image intensifier 7b and a high speed camera 8; a timing controller 9; and an image processing part 10 for generating range image data expressing a distance up to an object of each pixel. The projector 5 includes a plurality of near infrared ray LED 5a for modifying a lighting number. The timing controller 9 modifies the lighting number of the near infrared ray LED 5a of the projector 5 on the basis of a target distance. <P>COPYRIGHT: (C)2010,JPO&INPIT

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 is a plurality of light emission whose number of lighting can be changed The timing control means changes the number of lighting of the light projecting means based on the target distance.

  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.
The near-infrared LED 5a provided in the projector 5 is provided with a lens 51 having a predetermined light distribution angle, and a plurality of near-infrared LEDs 5a are arranged as shown in FIG. In the first embodiment, the number of lighting is 24, and the whole is in a staggered arrangement.

[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 that has been captured a plurality of times with a preset number of multiple exposures according to the distance range to be captured, and is previously based on the distance range to be captured and the multiple exposure. The image is captured by the set number of lightings. 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 step S11, the timing controller 9 acquires or determines the imaging target distance to be projected this time.

  In step S12, the timing controller 9 determines the number of multiple exposures based on the imaging target distance projected this time as the multiple exposure number determination process.

  In step S13, the timing controller 9 determines the lighting number based on the imaging target distance to be projected this time as the lighting number determination process.

  In step S14, the timing controller 9 controls the projector 5 using the number of times of multiple exposure determined in steps S12 and S13 as light projection control processing, and performs light projection.

In step S15, 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.
For the sake of explanation, the flow chart has been described, but since the actual control timing is performed at a very short time interval, the number of times of multiple exposure with respect to the imaging target distance described in FIG. It is desirable that the lighting number based on the number of times is converted into data in advance, and the timing controller 9 can output a control signal at a sufficient speed.

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).

[Controlling the number of lighting]
FIG. 12 is a graph illustrating the relationship between the imaging target distance and the luminance in the distance image data generation device according to the first embodiment. FIG. 13 is an explanatory diagram of an imaging target distance and luminance at the time of switching the number of times of multiple exposure in the distance image data generation device of the first embodiment. FIG. 14 is an explanatory diagram of a captured image and luminance in the imaging target distance direction in the distance image data generation device of the first embodiment.
In the first embodiment, sufficient luminance can be obtained even when the imaging target distance is long by the multiple exposure control as described above. As shown in FIG. 11, this control is performed so that the luminance of the image obtained by imaging as a result approaches the target luminance.

  Thereby, the luminance range width (difference between the minimum luminance value and the maximum luminance value) of each captured image having different imaging target distances is made uniform regardless of the imaging area. With respect to the number of times of multiple exposure controlled by this multiple exposure control, the number of area scan stages (units) to be imaged while changing the distance to be imaged is detected as shown in FIGS. 3 and 10. It is decided from. For this reason, the number of multiple exposures and the number (unit) of area scans do not match, and the number of area scans (unit) is larger. For this reason, imaging is performed with the same number of multiple exposures for a plurality of times of imaging at the imaging target distance.

FIG. 13 shows how the luminance value of the same pixel in the image changes due to the reflection of the object while the imaging distance is captured as A to F. In FIG. 13, at the switching point (imaging distance C) of the number of multiple exposures, for example, the luminance value 203 and one time before the number of multiple exposures is increased by 1 (for example, the number of exposures is 1 and indicated by reference numeral 201). After the increase (for example, the number of exposures is 2 and indicated by reference numeral 202), the obtained brightness value is different. This difference in luminance value becomes an error.
In addition, as shown in FIG. 12, since a sufficient luminance value is obtained in a relatively short distance range, switching between multiple exposures is reduced. Therefore, this error becomes large. Further, this is a section where the effect of the multiple exposure control is small.

  When the error due to switching of the number of multiple exposures affects the imaging target distance for determining the peak value as shown in FIGS. 3 and 10, ideally, as shown in FIG. What becomes the peak at the luminance value C1 at the peak of the luminance value D1 at the imaging distance D occurs.

In the first embodiment, the projector 5 includes 24 near-infrared LEDs 5a, and 1 to 24 vary the number of lighting. This control is performed based on the process of step S13 of the timing controller 9.
In this lighting number control, control for changing the lighting number is performed based on the imaging target distance and the number of multiple exposures.

For example, when the multiple exposure count is switched as shown in FIG. 13, if the multiple exposure count is set so as not to change with respect to the change of the imaging target distance, the number of lighting is controlled to change.
As shown in FIG. 12, the luminance of the pixel (image) desired to be obtained with respect to the imaging target distance is the target value 101 in FIG. 12, whereas only the control of the number of times of multiple exposure is shown by a line 102 in FIG. Thus, it has an error in switching the number of times. On the other hand, by combining the change in the number of multiple exposures and the change in the number of lighting, as shown by the line 103 in FIG. To improve and bring it closer to the target value line 101.
Therefore, the distance image generated by processing the captured image becomes more accurate.

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 The image processing unit 10 that generates distance image data representing the distance to the object for each pixel based on the luminance is provided. The projector 5 includes a plurality of near-infrared LEDs 5a whose lighting numbers can be freely changed. The timing controller 9 includes: Based on the target distance, in order to change the number of lights of the near-infrared LED 5a of the projector 5, The square status of can continuously grasp, it is possible to further improve the accuracy of the distance image.

  (2) In the above (1), the timing controller 9 determines that a captured image of one target distance is projected a plurality of times by the projector 5 and a plurality of times at the imaging timing by the image intensifier 7b and the high-speed camera 8. In order to perform multiple exposure control to increase the number of light projections and imaging as the target distance increases, the brightness range width of each captured image with different imaging target distances is made uniform regardless of the imaging area, It is possible to approach the target brightness set in advance so that good processing can be performed.

  (3) In the above (2), the timing controller 9 has a target distance that increases the number of switching stages with respect to the number of switching stages that increases the number of times of light projection and imaging as the target distance increases by multiple exposure control. Since the lighting number control for increasing the lighting number of the light projecting means is performed, the number of switching steps of the multiple exposure can be increased, the error at the time of switching the multiple exposure can be suppressed, and the accuracy of the distance image can be further improved. .

(4) In the above (2) or (3), the timing controller 9 determines the number of lighting of the light projector 5 at the target distance in which the multiple exposure control is not changed in the number of times of light projection and imaging because the target distance is close. In order to control the number of lighting to be changed, the brightness range width of each captured image is made uniform regardless of the imaging area in the entire target distance range of the distance image, including the near distance part, and is set in advance so that good processing can be performed. The target brightness can be approached.
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.
The number of near-infrared LEDs 5a in the projector 5 may be different from that in the first embodiment.
In the first embodiment, the switching number of the lighting number of the projector 5 is made larger than the switching number of the multiple exposure, but the switching number of the lighting number of the projector 5 may be smaller than the switching number of the multiple exposure. In that case, the effect of uniformization becomes smaller than that of the first embodiment, but the accuracy of the distance image can be improved as compared with the case of only the multiple exposure.

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 a graph which shows the relationship between the imaging target distance and the brightness | luminance in the distance image data generation apparatus of Example 1. FIG. It is explanatory drawing of the imaging target distance and the brightness | luminance at the time of switching of the multiple exposure frequency in the distance image data generation apparatus of Example 1. FIG. It is explanatory drawing of the captured image and brightness | luminance of the imaging target distance direction 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 Lens 6 Objective lens 7 Photomultiplier 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 (indicating target value of brightness with respect to target distance) line 102 (indicating brightness with respect to target distance when multiple exposure control is performed) line 103 (target when performing lighting number control in addition to multiple exposure control) Line 201 (indicating brightness with respect to distance) Explanation portion 202 (showing a state with one exposure) Description portion 202 (showing a state with two exposures)

Claims (4)

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 a plurality of light emitters whose lighting numbers can be freely changed,
The timing control means changes the number of lighting of the light projecting means 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 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. In the vehicular distance image data generating device according to claim 2,
The timing control means includes
By the multiple exposure control, as the target distance increases, the number of lightings for increasing the number of lighting of the light projecting means at the target distance for increasing the number of switching steps with respect to the number of switching steps for increasing the number of times of light projection and imaging. Do control,
A vehicular distance image data generating apparatus characterized by the above. In the vehicular distance image data generating device according to claim 2 or 3,
The timing control means includes
The multiple exposure control performs lighting number control for changing the number of lighting of the light projecting means at a target distance where there is no change in the number of times of light projection and imaging because the target distance is close.
A vehicular distance image data generating apparatus characterized by the above.