JP2011145143A - Distance measuring device and distance measuring method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a distance measuring device at a low cost that can efficiently conduct distance measurement meeting the required accuracy by preventing an increase in the number of cameras to be installed, suppressing calculation load for searching for corresponding points after comparing two images and shortening the moving time of cameras when extending the base line length. <P>SOLUTION: The distance measuring device includes a plurality of imaging means (10a and 10b) for photographing an object, a distance calculation means (13) for computing a distance to the object by using the images from two or more imaging means among the imaging means, a position control means (18) for controlling the position of the imaging means, a base line length calculation means (15) for computing the base line length necessary for attaining the required accuracy by using the distance computed by the distance calculation means, and a base line length storage means (16) for storing the base line length computed by the base line length calculation means. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a distance measuring apparatus and a distance measuring method for measuring a distance to an object and a position of the object using a stereo camera.

A distance measurement device using a stereo camera takes advantage of the fact that when the same object is photographed from different viewpoint positions, the imaging point on the sensor image changes depending on the distance to the object. It is a device that measures.
In recent years, there has been an increasing need for environmental recognition. For example, a system that supports driving by providing a vehicle with a stereo camera and providing information such as the presence or absence of a pedestrian to the driver is being put into practical use. .

FIG. 1 shows the principle of a stereo camera. In a stereo camera (camera a and camera b), the base line length B (distance between cameras), focal length f, parallax d (difference in the position of the image point of the object from the viewpoint), and the distance Z to the object are: , Z / B = f / d. The distance Z to the object can be calculated using this relationship.
In the stereo camera, the disparity d becomes smaller as the object is farther away, so that the measurement error becomes large. When measuring the distance of a distant object, increasing the baseline length B can increase the parallax d and increase the measurement accuracy. However, as shown in FIG. It takes. In addition, since the appearance of the object changes, there is a problem that it is difficult to search for corresponding points. 2A and 2B show the difference in the appearance of the object depending on the camera position of the stereo camera. FIG. 2A shows a case where the base line length is short, and FIG. 2B shows a case where the base line length is long.
For this reason, a method that combines a stereo camera with a long baseline length and a stereo camera with a short baseline length, or searches for corresponding points when the baseline length is short, and tracks the corresponding points while moving the imaging device individually, and the range in which the object appears A method for extending the base line length to the maximum is proposed.

However, the method of combining a long base length stereo camera and a short base length stereo camera has a problem that the number of cameras has to be increased, resulting in an increase in cost.
Further, in the method of extending the base line length, it is necessary to continue searching for corresponding points while moving the camera, so that the calculation load increases. Furthermore, since the baseline length is extended to the limit where an object can be seen in both cameras, the baseline length may be extended more than necessary, which increases the camera movement time and unnecessarily takes measurement time. There is a problem.

Japanese Unexamined Patent Application Publication No. 2004-93457 (“Image Processing Device and Image Processing Method”, Patent Document 1) discloses a baseline length of an imaging unit (imaging device) for the purpose of measuring the distance to an object with high accuracy. A distance measuring device having a camera control unit (position control means) for extending the distance is disclosed.
As shown in FIG. 6, the conventional distance measuring apparatus includes an imaging unit 31 having two stereo cameras 31a and 31b, a corresponding point searching unit 32 for searching for corresponding points from a pair of images, and 2 A camera control unit 33 that moves the stereo cameras 31a and 31b, a corresponding point tracking unit 34 that tracks each corresponding point when the two stereo cameras 31a and 31b move, and a distance calculation that calculates the distance to the object A portion 35 is provided.

  In the conventional distance measuring apparatus, as shown in FIG. 7, first, the base length between the stereo cameras 31a and 31b is set short by the camera control unit 33 (step S21). Next, an object is photographed by the imaging unit 31 (step S22), and a corresponding point is searched from the pair of images photographed in step S22 by the corresponding point searching unit 32 (step S23). Subsequently, while tracking the corresponding points mapped in the imaging surface by the corresponding point tracking unit 34, the camera control unit 33 moves the two stereo cameras 31a and 31b by the same distance in the reverse direction at a constant speed (step S24). ). As a result of the movement of the stereo cameras 31a and 31b, it is determined whether or not each corresponding point has reached the end of the imaging surface (step S25). When each corresponding point reaches the end of the imaging surface, the extended base line length is maintained, and the corresponding point tracked from the pair of images photographed in step S22 is detected by the corresponding point search unit 32. Search again (step S26). Finally, the distance calculation unit 35 calculates the distance to the object using the corresponding points tracked and re-searched and the pair of images photographed in step S22 (step S27).

As described above, the conventional distance measuring device described in Patent Document 1 recognizes an object with high accuracy at a short baseline length first, and then tracks the corresponding points so that two stereo cameras can detect the object. Is used to measure the distance to the object by extending the baseline length within the range that can be photographed simultaneously.
However, this distance measuring device has the problem that the calculation load is high and the measurement time is long, as in the conventional example described above, and the conventional problems are not solved.

  Therefore, in order to solve the above-described problems, the object of the present invention is not to increase the number of cameras, so that the calculation load for searching corresponding points by comparing two images is not increased, and It is to provide a distance measuring apparatus that can efficiently perform distance measurement that satisfies the required accuracy in a short time by making the movement time of the camera not long when extending the base line length.

Below, the technical means taken in order to solve the said subject are demonstrated with an effect | action.
(1) A distance measuring device according to the present invention (corresponding to claim 1) includes a plurality of imaging means for imaging an object,
Distance calculating means for calculating a distance to an object from images from two or more imaging means of the imaging means;
Position control means for controlling the position of the imaging means;
Baseline length calculation means for calculating a baseline length necessary to achieve the required accuracy by the distance calculated by the distance calculation means;
Baseline length storage means for storing the baseline length calculated by the baseline length calculation means.

By configuring in this way, an object is photographed by a plurality of imaging means, the distance to the object is calculated from the photographed image by the distance calculating means, and the baseline length necessary to satisfy the required accuracy is calculated by the calculated distance. It is calculated by the baseline length calculation means. Then, the base line length for measuring the distance is extended to the calculated base line length by the position control means, and an object is photographed by the plurality of image pick-up means in the state of the extended base line length, and the object is obtained from the photographed image by the distance calculation means. The distance to is calculated.
In this way, first, the base line length necessary to satisfy the required accuracy in distance measurement is calculated, and then distance measurement is performed in the state of the calculated base line length, so that distances can be obtained at many camera positions. Since there is no need to perform measurement, calculation load and measurement time can be reduced.

(2) The distance measuring device according to (1) may further include a movement amount storage unit that stores a movement amount of each imaging unit. (Corresponding to claim 2)
With such a configuration, the movement amount of the imaging unit can be stored by the movement amount storage unit, so that the position of the imaging unit in the baseline length direction and the baseline length can be accurately detected.

(3) Further, the distance measuring device according to the above (1) or (2) may have a position detecting means capable of detecting the position of each imaging means. (Corresponding to claim 3)
With such a configuration, since the baseline length can be detected by detecting the position of each imaging means by the position detection means, feedback control is possible for the position of the imaging means, and more accurate distance measurement is performed. be able to.

(4) In the distance measuring device according to any one of (1) to (3), at least one of the plurality of imaging units may not include the position control unit. (Corresponding to claim 4)
With such a configuration, it is possible to reduce the number of distance measuring devices and position detecting means that are required, so that the configuration is simplified and the manufacturing cost can be reduced.

(5) Further, in the distance measuring device according to any one of the above (1) to (3), when the base line length is changed, even if the two imaging means for creating the parallax image are driven so as to have the same movement amount. Good. (Corresponding to claim 5)
When the movement amounts of the two image pickup means are made equal by such a configuration, the center of the measurable range (the range in which the measurement target is reflected in both cameras) becomes the center of the baseline length. When the distance measuring device is mounted in the center, the distance can be measured in a range centered on the automobile. In this way, if the movement amounts of the two image pickup means are equal, the movement amounts of the corresponding points of the two images are also equal, so that the corresponding points can be easily searched.

(6) Further, in the distance measuring device according to any one of the above (1) to (3), when the baseline length is changed, the object to be measured is reflected in both of the two imaging units that create the parallax image. It may be driven. (Corresponding to claim 6)
With such a configuration, distance measurement can be performed from a short distance to a long distance by taking an appropriate baseline length with respect to the distance to be measured.

(7) In the distance measuring device according to any one of (1) to (6), a warning message may be output when the base line length calculated by the base line length calculating unit cannot be set by the position control unit. . (Corresponding to claim 7)
With such a configuration, if the baseline length calculated by the baseline length calculation means cannot be set by the position control means, the measured distance to the object does not satisfy the required accuracy, so this is indicated by a warning message. Can be notified.

(8) A distance measuring method according to the present invention (corresponding to claim 8) is a distance measuring method of photographing an object from a plurality of viewpoint positions using a plurality of imaging means and calculating a distance from the photographed image to the object. Because
Perform distance measurement at the first baseline length,
Based on this measured distance, the second baseline length required to achieve the required accuracy is calculated,
When the first baseline length is shorter than the second baseline length, the distance measurement is performed by extending the distance between the imaging means to the second baseline length.

With this configuration, when the first baseline length is shorter than the second baseline length, the distance measured in the first baseline length state does not satisfy the required accuracy, so the distance between the imaging means The distance is measured in a state in which is extended to the second baseline length, and is set as the distance to the object.
When the first baseline length is equal to or longer than the second baseline length, the distance measured in the first baseline length state is the distance to the object that satisfies the required accuracy. .
In this way, first, the base line length necessary to satisfy the required accuracy in distance measurement is calculated, and then distance measurement is performed in the state of the calculated base line length, so that distances can be obtained at many camera positions. Since there is no need to perform measurement, calculation load and measurement time can be reduced.

The effects of the present invention are summarized as follows.
First, a baseline length necessary to satisfy the required accuracy in distance measurement is calculated according to the measured distance to the object, and then distance measurement is performed with the baseline length extended to the calculated baseline length. This eliminates the need to measure distances at many camera positions, thereby reducing calculation load and measurement time.
Further, since the base line length is extended to the calculated base line length, the base line length is not unnecessarily extended, and distance measurement that satisfies the required accuracy can be efficiently performed in a short time.

FIG. 1 is an explanatory diagram showing the principle of a stereo camera. 2A and 2B are explanatory diagrams showing the difference in the appearance of the object depending on the camera position of the stereo camera. FIG. 2A shows a case where the base line length is short, and FIG. 2B shows a case where the base line length is long. FIG. 3 is a block diagram illustrating a functional configuration of the distance measuring apparatus according to the first embodiment of the present invention. FIG. 4 is a flowchart for explaining the procedure of the distance measurement process performed by the distance measurement apparatus according to the first embodiment. FIG. 5 is a block diagram illustrating a functional configuration of the distance measuring apparatus according to the second embodiment of the present invention. FIG. 6 is a block diagram illustrating a functional configuration of a conventional distance measuring device. FIG. 7 is a flowchart for explaining the procedure of the distance measurement process performed by the conventional distance measurement apparatus.

The purpose of the present invention is to calculate the baseline length necessary to satisfy the required accuracy in distance measurement based on the distance to the object first measured for the purpose of efficiently performing distance measurement that satisfies the required accuracy in a short time. Then, the distance is measured by extending the base line length to the calculated base line length, so that the calculation load and manufacturing cost are not increased.
Below, Example 1 and Example 2 by this invention are demonstrated using FIGS.

A distance measuring apparatus according to Embodiment 1 of the present invention will be described with reference to FIGS. FIG. 3 is a block diagram illustrating the functional configuration of the distance measuring apparatus, and FIG. 4 is a flowchart illustrating the procedure of the distance measuring process.
The distance measuring apparatus according to the first embodiment includes a first camera 10a and a second camera 10b, and measures a distance to an object using images from the two cameras 10a and 10b.
The second camera 10b is provided with a position control unit 18 for changing the position and a movement amount storage unit 19, and the position control unit 18 moves the position of the second camera 10b only in the baseline length direction. be able to. The movement amount storage unit 19 stores the movement amount from the initial position when the apparatus is assembled, that is, the absolute movement amount ub of the second camera 10b.
Thus, since the means for changing the base line length of the first and second cameras 10a and 10b has a simple configuration, cost reduction can be achieved.

  In addition, the distance measuring device includes an image processing unit 11 that corrects images from the first and second cameras 10a and 10b, a parallax calculation unit 12 that calculates parallax between corresponding points of the two images, and an object. A distance calculation unit 13 that calculates a distance, a distance storage unit 14 that stores the calculated distance, a baseline length calculation unit 15 that calculates a baseline length necessary to achieve the required accuracy, and a calculated baseline A baseline length storage unit 16 that stores the length, a movement amount calculation unit 17 that calculates the movement amount of the second camera 10b, and an output unit 20 that outputs the distance to the object calculated by the distance calculation unit 13 are provided. Yes.

Next, distance measurement processing by the distance measuring apparatus according to the first embodiment will be described with reference to FIG.
First, in a state where the base line length is B1 (step S1), images are captured from the first camera 10a and the second camera 10b (step S2). The images from the respective cameras 10a and 10b are corrected by the image processing unit 11 in order to convert them into images obtained by an ideal pinhole model (step S3). In the image processing unit 11, for example, magnification correction, image center correction, or distortion correction is performed.

The parallax calculation unit 12 compares the corrected images output from the image processing unit 11 to detect corresponding points of the two images, and calculates the parallax d1 (step S4). The distance calculation unit 13 calculates the distance Z1 to the object using the parallax d1, the absolute movement amount ub of the second camera 10b, the initial baseline length B0, and the focal length f of the ideal pinhole model. Calculate (step S5).
Since the distance (base line length) B1 between the first and second cameras 10a and 10b is B1 = B0 + ub, the distance Z1 to the object is calculated by the following equation.
Z1 / B1 = f / d1
The distance Z1 to the object calculated by the distance calculation unit 13 is stored in the distance storage unit 14.

を満たさなければならない。 Next, a description will be given of how the baseline length calculation unit 15 calculates the baseline length B2 necessary for the accuracy of distance measurement to satisfy the required accuracy.
An error Δd is added to the parallax d due to various factors. If the accuracy that must be satisfied in the distance measurement is Z ± ΔZ, the allowable value Δdmax of the parallax error is

Must be met.

を満たさなければ、距離測定の精度は要求精度を満たすことができない。視差誤差Δｄの最大値としては、センサやレンズの組み付けや経年変化などを考慮した各種の誤差を積み上げたものを用いてもよい。
Ｚ＝Ｚ１（基線長Ｂ１で測定した距離）を使って、式(２)より距離測定の精度が要求精度を満たす基線長Ｂ２を算出する（ステップＳ６）。また、基線長Ｂ１における距離測定の誤差ΔＺ１を見積もり、Ｚ＝Ｚ１＋△Ｚ１として基線長Ｂ２を算出してもよい。基線長計算部１５で算出された基線長Ｂ２は、基線長記憶部１６に記憶される。 When the parallax error Δd is generated only by the detection resolution, the parallax error Δd is 2a at the maximum if the detection resolution of the corresponding point in the parallax calculation unit 12 is a. Here, the resolution of an image refers to the resolution including image processing. For example, if it is possible to detect an image captured by a sensor having a pixel size of 10 μm up to 1/5 pixel by image processing, the detection resolution a is 2 μm.
At this time, the baseline length B is

Otherwise, the accuracy of distance measurement cannot meet the required accuracy. As the maximum value of the parallax error Δd, a value obtained by accumulating various errors in consideration of sensor and lens assembly and secular change may be used.
Using Z = Z1 (distance measured with the baseline length B1), a baseline length B2 that satisfies the required accuracy of distance measurement is calculated from the equation (2) (step S6). Alternatively, the distance measurement error ΔZ1 in the baseline length B1 may be estimated, and the baseline length B2 may be calculated as Z = Z1 + ΔZ1. The baseline length B2 calculated by the baseline length calculation unit 15 is stored in the baseline length storage unit 16.

When the baseline length B2> baseline length B1, the distance Z1 measured in the state of the baseline length B1 does not satisfy the required accuracy (step S7).
In order to perform distance measurement with the required accuracy or more, it is necessary to extend the baseline length to B2.
The movement amount calculation unit 17 calculates the movement amount of the second camera 10b necessary for extending the baseline length to B2. The amount of movement of the second camera 10b is B2-B1. When the second camera 10b is moved by B2-B1, if the movable range or the position where the measurement target can be photographed is exceeded, the distance measuring device may include a means for issuing a warning. Further, in order to set the baseline length to B2, the relative movement amount is compared by comparing the necessary movement amount, the movable range of the second camera 10b, and the range of the position of the second camera 10b where the measurement object can be photographed. It may be calculated.

The position control unit 18 includes a stepping motor and a motor control unit. The motor control unit outputs drive pulses having the number of pulses corresponding to the movement amount calculated by the movement amount calculation unit 17 to drive the stepping motor. The base line length is extended to B2 (step S8). At this time, the movement amount storage unit 19 updates the movement amount of the second camera 10b.
In a state where the base line length is extended to B2 by the position control unit 18, the first and second cameras 10a and 10b capture an image and capture an image (step S9), and the image processing unit 11 performs image processing. The parallax calculation unit 12 detects corresponding points of the two images and calculates the parallax d2. When calculating the parallax d2, the image of the first camera 10a has not changed, but the image of the second camera 10b has changed, so it is necessary to search for corresponding points. In the search for corresponding points, the position of the corresponding point can be predicted from the distance Z1 already calculated by the distance calculation unit 13 and the movement amount of the second camera 10b. Can reduce the calculation load.

The distance calculation unit 13 calculates the distance Z2 to the object using the calculated parallax d2, the baseline length B2, and the focal length f of the ideal pinhole model, as in the case of calculating the distance Z1 described above. (Step S10). The distance Z2 calculated when the base line length is extended to B2 satisfies the required accuracy.
In this way, by calculating the baseline length B2 necessary for the distance measurement accuracy to meet the required accuracy, it is not necessary to measure distances at many camera positions, so the calculation load and measurement time can be reduced. .

The output unit 20 outputs the calculated distance Z to the object as a numerical value, or generates a distance image in which the distance to be measured is characterized by a color or the like, and outputs it (step S11). If the baseline length cannot be extended to B2, a warning lamp may be provided to indicate that the required accuracy cannot be guaranteed. In addition, a marker may be displayed on an object for which the required accuracy cannot be guaranteed on the distance image.
In this way, the distance Z to the object calculated by the distance calculation unit 13 is output to the output unit 20, but if the baseline length B2> baseline length B1 in step S7, the baseline length B1 is satisfied. Since the distance Z1 measured in the state does not satisfy the required accuracy, the distance Z2 calculated in step 10 is output as the distance Z to the object. On the other hand, if the base line length B2> the base line length B1 is not satisfied (base line length B2 ≦ base line length B1), the distance Z1 measured in the state of the base line length B1 satisfies the required accuracy. The distance Z1 calculated in is output as the distance Z to the object.

  The position control unit 18 may shorten the baseline length to the shortest baseline length (initial baseline length) B0 when the distance measurement for one measurement object is completed, or when the distance measurement device is activated or terminated. Thereby, since the baseline length at the first distance calculation is the shortest baseline length B0, the recognition accuracy of the corresponding points of the two images is increased. Further, a stopper may be attached at the position of the second camera 10b that becomes the base line length B0. Accordingly, the second camera position can be initialized by moving to the position where it hits the stopper, so that the repeatability of the position control unit 18 can be improved.

A distance measuring apparatus according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 5 is a block diagram illustrating a functional configuration of the distance measuring apparatus.
The distance measuring apparatus according to the second embodiment includes a first camera 10a and a second camera 10b, and measures a distance to an object using images from the two cameras 10a and 10b.
The first and second cameras 10a and 10b include position control units 18a and 18b that change the respective positions, and position detection units 18c and 18d that detect the respective positions. The position control units 18a and 18b can move the cameras 10a and 10b in the baseline length direction. Further, since the position detectors 18c and 18d can detect the positions of the respective cameras 10a and 10b, the base line length can be accurately known.
The distance measurement apparatus according to the second embodiment is similar to that of the first embodiment, in that the image processing unit 11, the parallax calculation unit 12, the distance calculation unit 13, the distance storage unit 14, the baseline length calculation unit 15, the baseline length. A storage unit 16, a movement amount calculation unit 17, and an output unit 20 are provided.

Next, distance measurement processing by the distance measuring apparatus according to the second embodiment will be described with reference to FIG. Also in the second embodiment, the distance to the object is measured by the same measurement procedure as in the first embodiment.
First, in a state where the base line length is B1 (step S1), images are captured from the first and second cameras 10a and 10b (step S2). The images from the respective cameras 10a and 10b are corrected by the image processing unit 11 in order to convert them into images obtained by an ideal pinhole model (step S3). In the image processing unit 11, for example, magnification correction, image center correction, or distortion correction is performed.

The parallax calculation unit 12 compares the corrected images output from the image correction unit 11 to detect corresponding points between the two images, and calculates the parallax d1 (step S4). Further, in the distance calculation unit 13, the parallax d1 calculated by the parallax calculation unit 12 and the distance xa in the baseline length direction from the same reference point detected by the respective position detection units 18c and 18d to the cameras 10a and 10b, A distance Z1 to the object is calculated using xb and the focal length f of the ideal pinhole model (step S5).
Since the distance (baseline length) B1 between the first and second cameras 10a and 10b is B1 = xa−xb, the distance Z1 to the object is calculated by the following equation.
Z1 / B1 = f / d1
The distance Z1 to the object calculated by the distance calculation unit 13 is stored in the distance storage unit 14.

Next, as in the case of the first embodiment, the base line length calculation unit 15 calculates the base line length B2 necessary for the measurement distance accuracy to satisfy the required accuracy (step S6). The baseline length B2 calculated by the baseline length calculation unit 15 is stored in the baseline length storage unit 16.
When the baseline length B2> baseline length B1, the distance Z1 measured in the baseline length B1 state does not satisfy the required accuracy (step S7), and it is necessary to perform the distance measurement by extending the baseline length to B2. Therefore, the movement amount calculation unit 17 calculates the movement amounts of the first and second cameras 10a and 10b. The relative movement amount of the first and second cameras 10a and 10b is B2-B1. When moving each camera 10a, 10b, as in the first embodiment, if the movable range of each camera 10a, 10b or the position where the measurement object can be photographed is exceeded, a means for the distance measuring device to give a warning is provided. You may have. Further, in order to set the base line length to B2, the required moving amount, the movable range of each camera 10a, 10b, and the range of the position of each camera 10a, 10b capable of photographing the measurement object are compared, and each camera 10a, The movement amount of 10b may be calculated.

When the movement amounts of the first and second cameras 10a and 10b are calculated, if the movement amounts of the respective cameras 10a and 10b are made equal, a measurable range (a range in which the measurement target is reflected in both cameras). Therefore, when the distance measuring device is mounted at the center of the automobile, for example, the distance can be measured in a range centered on the automobile. Thus, if the movement amounts of the cameras 10a and 10b are equal, the movement amounts of the corresponding points of the two images are also equal, so that the corresponding points can be easily searched.
Further, when calculating the movement amounts of the first and second cameras 10a and 10b, the movement amounts of the respective cameras 10a and 10b may be different so that the measurement target is within the measurable range. Even if the measurement object is away from the center of the movable range of each camera 10a, 10b, the baseline length can be extended.

And each position control part 18a, 18b provided in the 1st and 2nd camera 10a, 10b respond | corresponds to the movement amount computed by the movement amount calculation part 17, like the case of the said Example 1. FIG. The cameras 10a and 10b are moved to extend the base line length to B2 (step S8). At this time, the position detection units 18c and 18d output the positions of the cameras 10a and 10b to the respective camera control units 18a and 18b, and the camera control units 18a and 18b perform the feedback control, thereby making the baseline more accurate. The length can be extended.
As described above, in the state where the base line length is extended to B2 by the position control units 18a and 18b, the first and second cameras 10a and 10b are used to photograph the object and capture the image in the same manner as in the first embodiment. (Step S9), the parallax d2 is calculated. Further, the distance calculation unit 13 calculates the distance Z2 to the object (step S10) and outputs it to the output unit 20 (step S11).

10a ... 1st camera (imaging means) 10b ... 2nd camera (imaging means)
DESCRIPTION OF SYMBOLS 11 ... Image processing part 12 ... Parallax calculation part 13 ... Distance calculation part 14 ... Distance memory | storage part 15 ... Baseline length calculation part 16 ... Baseline length memory | storage part 17 ... Movement amount calculation part 18, 18a, 18b ... Position control part 18c, 18d ... Position detection unit 19 ... Movement amount storage unit 20 ... Output unit B, B0, B1, B2 ... Base line length Z, Z1, Z2 ... Distance to the object d, d1, d2 ... Parallax

JP 2004-93457 A

Claims (8)

A plurality of imaging means for photographing an object;
Distance calculating means for calculating a distance to an object from images from two or more imaging means of the imaging means;
Position control means for controlling the position of the imaging means;
Baseline length calculation means for calculating a baseline length necessary to achieve the required accuracy by the distance calculated by the distance calculation means;
Baseline length storage means for storing the baseline length calculated by the baseline length calculation means;
A distance measuring device comprising:   The distance measuring apparatus according to claim 1, further comprising a movement amount storage unit that stores a movement amount of each of the imaging units.   The distance measuring device according to claim 1, further comprising a position detecting unit capable of detecting a position of each of the imaging units.   The distance measuring device according to claim 1, wherein at least one of the plurality of imaging units does not include the position control unit.   The distance measuring device according to any one of claims 1 to 3, wherein when changing the base line length, the two imaging means for creating a parallax image are driven so as to have the same movement amount.   The distance according to any one of claims 1 to 3, wherein when changing the base line length, the object to be measured is driven so as to appear in both of the two imaging means for creating a parallax image. measuring device.   The distance measuring device according to claim 1, wherein a warning message is output when the base line length calculated by the base line length calculating unit cannot be set by the position control unit. A distance measurement method for photographing an object from a plurality of viewpoint positions using a plurality of imaging means and calculating a distance from the photographed image to the object,
Perform distance measurement at the first baseline length,
Based on this measured distance, the second baseline length required to achieve the required accuracy is calculated,
When the first baseline length is shorter than the second baseline length, the distance measurement is performed by extending the distance between the imaging units to the second baseline length.

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