JP2001317915A - Three-dimensional measurement apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional measurement apparatus which can define the relative position relationship and relative angular relationship of a camera at photographic points, without the user of any reference scale. SOLUTION: The three-dimensional measuring apparatus is provided with a photographing part 3 for photographing an object to be measured, a first feature point designating part (operating part 10) for designating feature points on an image of the object photographed by the photographing part 3, a distance- measuring part 4 for measuring the distance to the feature points on the object as designated by the operating part 10, a second feature point designating means for designating points on the object corresponding to the feature points on the image of the object, photographed at the first photographing position as feature points on the image of the object taken by the photographing part 3 at the second photographing point, and an arithmetic unit 2 for binding the relative position and angle between the first and second photographing positions from the feature points on the image of the object photographed at the first and second photographing positions and distances to the feature points measured at the respective photographing positions by the distance-measuring part 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION It is an object of the present invention to provide a three-dimensional measuring apparatus using a stereo method, in which coordinates of each photographing position can be easily obtained.

[0002]

2. Description of the Related Art When a traffic accident occurs, a record of the accident site is taken together with a hearing survey to identify the situation of the accident. A floor plan is an important element of this record,
The location where the accident occurred, the width of the road, buildings near the site, traffic lights and guardrails and other structures, the location, orientation, slip marks and the relative positional relationship of the accident vehicle are described in detail.

[0003] In preparing the site sketch, the dimensions of the accident vehicle, related structures and the like and the distance to each other are measured by a tape measure and the like, and the measurement results are written in the sketch, but these measurements are performed manually. Police officers are involved in secondary traffic accidents during measurement, and in many cases, this measurement is performed with partial or entire traffic blocked, and it takes a relatively long time to cause traffic jams. Was.

[0004] In order to cope with such a problem, a technique for surveying a site in a short time by a stereo method using a digital camera has been developed.

[0005] In the stereo method, two images are obtained by moving two cameras placed at different positions, or moving one camera to two different positions and photographing them at each position, thereby obtaining two images by human eyes. The distance information of the target object is obtained from a subtle difference between the images based on the parallax.

In this stereo method, the relative positional relationship and relative angle (orientation) relationship between two cameras, or 1
Since the position of each point of the object is calculated based on the relative positional relationship and the relative angular relationship when the camera is moved and photographed, it is assumed that the relative positions and the relative angles are known. .

In order to grasp the relative position and the relative angle, various methods are used, for example, placing an equilateral triangular scale having a known dimension on the site and analyzing an image of the scale taken together with the target site. A method for obtaining the relative position and the relative angle of two cameras is known.

In such a method of placing the scale at the target site, there is a restriction that there is no room for placing the scale or it cannot be placed in an appropriate direction depending on the situation, or the scale is required to obtain appropriate accuracy. However, there is a problem that handling of a standard scale and transportation to a site are troublesome due to the considerably large size.

[0009]

SUMMARY OF THE INVENTION The present invention provides a three-dimensional measuring apparatus which can determine a relative positional relationship and a relative angular relationship of a camera at each photographing point without using the reference scale as described above. The task is to provide.

[0010]

According to a first aspect of the present invention, there is provided a three-dimensional measuring apparatus comprising: an image pickup device for photographing an object to be measured; First feature point designating means for designating feature points;
A distance measuring unit for measuring a distance to a feature point on the object specified by the feature point designating unit; and a distance measuring unit on the image of the object measured at the first image capturing position. A second feature point designating unit for designating a corresponding point on the measured object as a feature point on an image of the measured object photographed at a second photographing position by the imaging means; From the characteristic points on the image of the object to be measured at the second photographing position and the distances to the characteristic points measured at the respective photographing positions by the distance measuring means. Calculating means for calculating the relative position and angle between the shooting position and the second shooting position.

Thus, two positions (relative positions) and relative angles (directions) of the three-dimensional measuring device can be determined without placing a reference scale.

Further, in the three-dimensional measuring apparatus according to a second aspect of the present invention, the second feature point designating means captures the feature point designated by the first feature point designating means. The apparatus is provided with a capturing and following means that follows as the dimension measuring device moves.

[0013] This makes it possible to automatically specify a feature point at the second photographing position, so that three-dimensional measurement can be easily performed. Further, the three-dimensional measuring apparatus according to a third aspect of the present invention is the three-dimensional measuring apparatus according to the first or second aspect, wherein the feature points designated by the first feature point designating means are mutually different. There are at least three different points.

[0014]

FIG. 1 is an overall view showing an outline of a three-dimensional measuring apparatus according to the present invention.

The three-dimensional measuring device comprises a photographing / ranging device 1 and an arithmetic device 2. The photographing / ranging device 1
Further, it is composed of a photographing unit 3 and a distance measuring unit 4.

The photographing section 3 is a digital photographing apparatus, and is provided with a CCD (Charge Coupled Device) for reading an image of incident light through a photographing lens of a photographing window 5. Also,
A monitor display 9 and an operation unit 10 are provided on the back surface of the imaging unit 3.

The distance measuring unit 4 comprises a point distance measuring device.
In order to measure the distance to a point on the object to be measured by the time-of-flight method, a light projection window 7 and a light receiving window 8 are provided.

The time of flight (TIME OF FLIGHT)
In the FLIGHT method, a light beam emitted from a light beam projection window 7 is applied to an object, and light reflected by the object enters a light receiving window 8 and is detected. At this time, by measuring the round trip time of the light beam, the distance from the distance measuring unit 4 to one point on the object hit by the light beam is obtained. From this distance and the direction of the light beam, three-dimensional data of one point of the object can be obtained.

An image photographed by the photographing section 3 and a distance measuring section 4
In addition to the measurement data measured in step (1), data such as photographing conditions and measurement conditions are sent to the arithmetic unit 2 via the recording medium 11. Instead of mediating the recording medium 11, these data can be sent to the arithmetic unit 2 via a communication line.

The arithmetic unit 2 includes a monitor display 1
2, an operation unit 13 and an operation unit 14.
A personal computer can be used for the operation unit 13, and a keyboard, a mouse, and the like can be used for the operation unit 14.

FIG. 2 is a perspective view showing the usage of the photographing / ranging apparatus 1 of the present invention. The photographing / ranging device 1 is placed on a road leading to the intersection 20, and photographs and measures the intersection 20. In FIG. 2, two photographing / ranging devices 1 are illustrated, but these are the same photographing / ranging devices 1.
Is used twice in different places. A dotted line 22 indicates the angle of view of an image shot when the photographing / ranging device 1 is located at the right position.
Reference numeral 3 denotes an angle of view of an image photographed when the photographing / ranging device 1 is located at the left position. The photographing / ranging device 1 is supported by a support device 21.

When the photographing / ranging device 1 is placed at the left position, the distances (arrows 24, 25, 26) from the photographing / ranging device 1 to the points A, B, and C are measured by the distance measuring unit 4. Is done.

FIG. 3 is a conceptual diagram for explaining three-dimensional measurement performed by the stereo method. In the stereo method, an object to be measured is photographed from first and second photographing positions, and a distance to the object to be measured is obtained from these two pieces of image data according to the so-called triangulation principle.

For this purpose, it is necessary to know the first and second photographing positions (x, y, z) and photographing directions (θx, θy, θz). In FIG. 3, the x, y, and z coordinate axes are appropriately determined, and the x, y, and z coordinates (X ₀ , Y ₀ , Z) of the first shooting position are determined.
₀ ), rotation angles about the x, y, and z coordinate axes (θx ₀ , θ
y ₀ , θz ₀ ), x, y, z coordinates (X
₁ , Y ₁ , Z ₁ ), rotation angles (θ) about x, y, z coordinate axes
x ₁ , θy ₁ , θz ₁ ). This is determined as follows.

FIG. 4 is an explanatory view showing a state where an object to be measured is photographed by one digital camera. M is a point on the object to be measured, which corresponds to a point m on the image plane. When the XYZ coordinate axes are appropriately determined, the XYZ coordinates of the point M are obtained by the distance measuring unit 4. Now

(Equation 1)

Since the matrix P has an arbitrary scale, it has 11 degrees of freedom. Here, when the parameter s is eliminated from the above equation (1),

(Equation 2)

(Equation 3) Is obtained.

The eleven degrees of freedom include the camera's external parameters (Xc, Yc, Zc, θx, θy, θz, external parameters: numerical values that take different values depending on the situation where the camera is placed) and internal parameters (Xc, Yc, θx, θy, θz). φ, u ₀ , v ₀ ,
Internal parameter: a value that is specific to the camera and does not change wherever this camera is placed). Here, φ: the angle between the coordinate axes of the image plane, (u ₀ , v ₀ ): the coordinates of the optical axis, α _u : focal length * horizontal of the image pixel, α _v : focal length * vertical of the image pixel. If these internal parameters are known, P is

(Equation 4) become that way.

Here, P ₀ indicates a matrix for projecting from the three-dimensional coordinates having the optical axis as the origin, the XY axes being parallel to the image plane and the X axis being parallel to the u axis on the image plane, to the image plane, It can be described only with internal parameters. R is a rotation matrix, t is a translation vector, and

(Equation 5)

(Equation 6) Can be described as follows.

Substituting equations (5) and (6) into equation (4),
Further, when the parameter s is deleted from the equation substituted into the equation (1), Xc, Yc, Zc, θx, θy, and θz become variables (unknown numbers).
Are obtained. Therefore, in order to solve this equation, it is sufficient to obtain the above-mentioned arithmetic expression for three points.

The above is for one photographing, and when photographing twice at different positions for the stereo method, the same processing is performed for each photographing position. However, since the XYZ coordinate axes need to be common in the two shootings, the same point on the measured object used for the calculation is used.

The contents of the above description will be described in further words. FIG. 9 is a three-dimensional drawing in which points A, B, and C in FIG. 2 and two positions P and Q of the photographing / ranging device 1 are extracted and represented.

The distance and the direction from point P to point A, and the distance and the direction from point P to point B when measured on the three-dimensional coordinates fixed to the photographing / ranging device 1 by the measurement at the first photographing position. , The distance and the direction from the point P to the point C are obtained, so that the position of the point A, the position of the point B, and the position of the point C are determined in this coordinate system. Therefore, distance AB, distance B
C and the distance CA are obtained. Here, a viewpoint is set in another coordinate system fixed to a plane including the points A, B, and C (this coordinate system is referred to as a measurement object coordinate system for convenience). When the distance device 1 is viewed, the coordinate position of the point P is determined.

Similarly, when looking at the second photographing position, the coordinate position of the point Q in the coordinate system of the object to be measured is determined. Since the coordinate positions of the points P and Q are known in the common coordinate system, the distance between the points P and Q is obtained.

Based on the same idea, each of the directions (directions and angles) of the photographing / ranging device 1 placed at the first photographing position and the second photographing position when viewed on the coordinate system of the object to be measured is determined. Therefore, the relative directions of the photographing / ranging device 1 at the two positions can be obtained. As a result, the relative position and the relative angle of the photographing / ranging device 1 at the first photographing position and the second photographing position are obtained.

FIG. 5 shows a case where the photographing / ranging device 1 is a GPS (Glo
bal Positioning System). The GPS can measure the position of this device on the earth, and use this to determine Xc, Yc, Zc
Can be obtained, and the number of unknowns is three. Therefore, the above-mentioned arithmetic expression may be obtained for two points.

FIG. 6 shows an example in which the photographing / ranging device 1 has three GPS antennas. Antenna receiving point 3
Since the XYZ coordinates of the points are known and one plane including the three receiving points is determined, this is the same as determining θx, θy, and θz, and the above calculation is unnecessary.

FIG. 7 is a flowchart showing a flow up to creation of a sketch according to the present invention. First, in step # 1, the photographing / ranging device 1 is placed at the first photographing position, and the photographing unit 3 performs the first photographing of the measured object. In step # 2, appropriate three points are designated on the first image obtained by the first photographing. Step #
In step 3, the distance measuring unit 4 measures the distance at the three points designated in the previous step # 2.

Next, in step # 4, the photographing / ranging device 1 is moved to the second photographing position to perform the second photographing.
On the image obtained by the second shooting, the first
Points corresponding to the three points specified in the image are designated (step # 5).

Then, the photographed image data, the distance measurement data, and the corresponding point information obtained in the above steps are stored in the arithmetic unit 2 via the recording medium 11 (see FIG. 1) or the communication line.
Send to In step # 6, based on these data and information, the arithmetic unit 2 performs the above-described arithmetic operation, and obtains X, Y, Z, θx, and θx at the first and second photographing positions.
θy and θz are calculated. In step # 7, three-dimensional data of the object to be measured is created by a stereo method based on the calculated data and the preceding two captured image data.
Further, in step # 8, a sketch (for example, a bird's eye view) is created based on the obtained three-dimensional data.

In step # 5, the method of designating three points designated in the first image and corresponding points in the second image is such that two images are displayed on the monitor display 9 (FIG. 1) and used. One example is a method in which a user operates the operation unit 10 to specify. Also, the following method can be used.

FIG. 8 is a flowchart showing the method. In this method, a camera that can shoot a moving image is used as the shooting unit 3.

First, in step # 21, the first image is photographed at the first photographing position. Step # 22
In, three points are designated on the first image. Step #
At 23, the designated three points are captured, and the photographing / ranging device 1 is moved to the second photographing position. During the movement, the three points are continuously captured and followed, so that when the second imaging position is reached, these three points do not need to be specified again, but are specified automatically. In step # 24, shooting is performed at the second shooting position, and three corresponding points on the second shot image are determined.

The above-mentioned capturing / following is performed, for example, by capturing a characteristic such as contrast or edge information of the captured point and performing a tracking based on the characteristic, or by providing an acceleration sensor in the photographing unit 3 and using the photographing / ranging device 1. It is possible to employ a method of integrating the acceleration associated with the movement twice in time to obtain the movement amount.

[0044]

According to the present invention, as in the prior art,
Since there is no need to place a reference scale with known dimensions on site, there is no restriction that there is no room for placing the reference scale or that it cannot be placed in an appropriate direction (orientation).
In addition, there is an effect that there is no need to handle a large scale and troublesome transportation to the site.

Further, according to another aspect of the present invention, the point designated in the first photographing is automatically followed as the photographing / ranging device moves, so that the corresponding point is newly re-established at the second photographing position. There is no need to specify the, so that three-dimensional measurement can be easily performed.

[Brief description of the drawings]

FIG. 1 is an overall view showing an outline of a three-dimensional measuring apparatus of the present invention.

FIG. 2 is a perspective view showing a usage state of the photographing / ranging apparatus 1 of the present invention.

FIG. 3 is a conceptual diagram for describing three-dimensional measurement performed by a stereo method.

FIG. 4 is an explanatory diagram showing a state where an object to be measured is photographed by one digital camera.

FIG. 5 is a diagram illustrating an example in which the photographing / ranging device 1 includes a GPS.

FIG. 6 is a diagram illustrating an example in which the photographing / ranging device 1 includes three GPS antennas.

FIG. 7 is a flowchart showing a flow until a sketch is created according to the present invention.

FIG. 8 is a flowchart for explaining an example of a method of designating corresponding points in a second image of three points designated in a first image.

FIG. 9 shows points A, B and C in FIG.
3 is a three-dimensional drawing that extracts and represents the two positions P and Q of FIG.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 photographing / ranging device 2 computing device 3 photographing unit 4 distance measuring unit 5 photographing window 7 ray projection window 8 light receiving window 9, 12 monitor display 10, 14 operating unit 11 recording media 13 computing unit 20 intersection 21 support device

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takuto Ueko 2-3-1-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka Inside Osaka International Building Minolta Co., Ltd. (72) Inventor Yuji Taguchi Azuchi, Chuo-ku, Osaka-shi, Osaka 2-3-1, Machi, Osaka International Building Minolta Co., Ltd. F-term (reference) 2F065 AA04 AA06 AA12 AA53 CC11 CC14 FF04 FF05 FF31 HH04 JJ01 JJ03 JJ05 JJ26 QQ21 QQ28 SS13 5B057 AA16 CA13 DA07 DB03 DC07 DC08 5J06 CC

Claims (3)

[Claims] 1. A three-dimensional measuring apparatus, comprising: an image pickup means for photographing an object to be measured; and a feature point on an image obtained by photographing the object to be measured by the image pickup means. A first feature point designating means for measuring a distance to a feature point on the object specified by the feature point designating means; A point on the object to be measured corresponding to the characteristic point on the image of the object photographed as the characteristic point on the image of the object to be measured at the second photographing position by the imaging means. A second feature point designating unit, each feature point on an image of the object to be measured at the first shooting position and the second shooting position, and a distance measured at each shooting position by the distance measuring unit. From the distance to each feature point Three-dimensional measurement apparatus characterized by comprising calculating means for determining the relative position and angle of the shadow position and a second imaging position. 2. The three-dimensional measuring apparatus according to claim 1, wherein the second feature point designating means captures a feature point designated by the first feature point designating means, and performs the three-dimensional measurement. A three-dimensional measuring apparatus comprising a capturing and following means for following as the apparatus moves. 3. The three-dimensional measuring apparatus according to claim 1, wherein the at least three feature points designated by the first feature point designation means are different from each other. Three-dimensional measuring device.