JPH03144862A - Relative position measuring device - Google Patents

Abstract

PURPOSE:To simplify and miniaturize constitution by measuring distance to an object to be detected on which a member to be detected is fixed by one set of an image pickup means provided with a light source, a reflecting mirror and a camera. CONSTITUTION:The member 3 to be detected is fixed on the flat surface 2 of the object 1 to be detected, and the object 4 opposite to the object 1 to be detected is provided with the image pickup means 5, and the image pickup means 5 is provided with the light source 8, the reflecting mirror 9 of a half mirror and the camera 10. The object 1 to be detected is irradiated with light from the light source 8, and the reflecting mirror 9 transmits the light from the light source 8, and bends and reflects the reflected light reflected from the member 3 to be detected, and the camera 10 receives this light, and images it on an image pickup element 16. Then, output from the camera 10 is inputted to a processing circuit 35, and the distance between the object 4 and the object 1 to be detected is calculated and obtained. Thus, the constitution can be simplified and miniaturized.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a device for measuring a relative position to a detected object, that is, a distance to the detected object and an attitude of the detected object. .

2. Description of the Related Art In a typical prior art, an object to be detected is imaged by a pair of television cameras installed at different positions, and the distance to the object to be detected is measured.

Problems to be Solved by the Invention This prior art requires two television cameras and is therefore obviously complex and bulky in construction.

An object of the present invention is to provide a relative position measuring device that can be made smaller by simplifying the i-precept.

Means for Solving the Problems The present invention provides (a) a member to be detected that is fixed to an object to be detected and reflects light in a direction parallel to the incident light; (b) imaging means; a light source that irradiates light toward the detection member; (b2) a reflecting mirror that is provided on the optical axis of the light source, transmits the light from the light source, and bends the optical path of the reflected light from the detected object; b3) an imaging means having a camera that receives light from a reflecting mirror to take an image of the detected member; and (c) processing for calculating and calculating the distance between the detected member and the camera in response to the output of the camera. A relative position measuring device characterized in that it includes means.

Further, the present invention is characterized in that the imaging means are provided in at least three locations with different positions, and the processing means calculates and obtains the attitude of the object to be detected from the distance obtained from the output of each camera. .

According to the present invention, the distance to the object to be detected to which the member to be detected is fixed can be measured by one imaging means having a light source, a reflecting mirror, and a camera. This simplifies the cross flow and allows for compactness.

Furthermore, according to the present invention, the object to be detected has a configuration that reflects light in a direction parallel to the incident light, and therefore, it is possible to prevent false detection due to ambient light.

Furthermore, according to the present invention, imaging means are provided at at least 31 locations, and the attitude of the detected object is calculated and determined from the distance to the detected member determined by the output of the camera provided in each imaging means. be able to.

Example FIG. 1 is a system diagram of one embodiment of the present invention.

A member to be detected 3 is fixed to a flat surface 2 of an object to be detected 1 called a target. An object 4 that faces the detected object 1 and can be called a chaser has a total of three imaging means 5 and 6, as shown in the front in FIG.
．． 7 is provided. One of the imaging means 5 includes a light source 8, a reflecting mirror 9 which is a half mirror, and a camera 10, and is a so-called camera with coaxial falling illumination. A light source 8 emits light toward an object 1 to be detected along an optical axis 11. A reflecting mirror 9 is provided on the optical axis 11.
The transmitted light is guided to the detected object 1 as shown by reference numeral 12, and the reflected light reflected from the detected member 3 of the detected object 1 is shown by reference numeral 13.14. Bend and reflect as shown. The camera 10 receives light indicated by an optical path 14 from the reflecting mirror 9, and forms an image on an image sensor 16 such as a charge storage device (abbreviated as C0D) via a focusing lens 15. Another imaging means 6.7 has a similar tlIt, and includes a reflector 17.18 and a camera 19.
．． 20 and a light source (not shown). Optical axis 12, 21.2 in each imaging means 5, 6.7
2 is located at the apex position of an equilateral triangle within a plane perpendicular to their optical axis 122122, and the center of gravity of the virtual equilateral triangle is indicated by reference numeral 23.

FIG. 3 is a front view of the object to be detected 1. FIG. Detected member 3
In addition, detection members 24 and 25 are provided, all of which have the same dimensions and shape, and which are connected to the three optical axes 1.
2, 21, and 22 are placed at each vertex of an equilateral triangle, and the center of gravity of the virtual equilateral triangle is indicated by reference numeral 26.

FIG. 4 is a front view of the member to be detected 3, and FIG. 5 is a cross-sectional view taken along the section line ``---'' in FIG.

With reference to these drawings, the detected member 3 is the detected object 1.
The reference mark 28 is arranged symmetrically on the left and right sides of FIG. 4 with respect to the plane of symmetry 27 perpendicular to the surface 2 on the surface 2, and has a central reference mark 28 and two scale marks of 510I on each side thereof. The diameter of the reference mark 28 is, for example, 15 mmφ, and the length of the two scale marks in the left and right direction is 1.
1 is 15 mm, its width W1 is 10 mm, the distance l1li12 between the center of the reference mark 28 and the center of the adjacent scale mark 29 is 20 mm, and each center of gravity of two adjacent scale marks The distance between 13 is 20m
m, and the distance l4 between the scale marks 29 at both ends is 200
It is mm.

Such a mark 29 is affixed to the surface 2 of the detected object 1 with an adhesive 30, which means that the reference mark 28
The same applies to

FIG. 6 is an enlarged plan view of marks 28,29.

These marks 28 and 29 have a tank bottom in which a large number of square pyramid prisms 31 in the shape of glass beads are arranged adjacent to each other. As shown in FIG. 7, this prism 31 is a so-called retroreflective sheet that reflects and guides the optical path of reflected light in parallel with the incident light when light is incident from the imaging means 5 through the optical axis 12. Configure. Therefore, disturbance light is prevented from entering the imaging means 5 via the optical path 13, and erroneous detection due to disturbance light can be prevented.

FIG. 8 is an enlarged plan view of another embodiment of the markings 28,29. In this embodiment, a large number of glass beads 32 are arranged, and the glass beads 32 are partially embedded in the sheet 33 as shown in FIG. Aluminum R34 is deposited on the surface of the glass beads 32 embedded in the sheet 33. Therefore, when incident light enters through the optical axis 12, the reflected light follows the optical path 13 and is reflected in parallel to the incident light 12.

The outputs from the cameras 10, 19, 20 of the imaging means 5, 6, 7 are input to a processing circuit 35 realized by a microcomputer or the like as shown in FIG. The distance between the object and the object to be detected and the attitude of the object to be detected are calculated and calculated.

FIG. 10 shows a state in which an image is captured by the image sensor 16 of the camera 10 used in the image capture means 5. Images 28a and 29a of marks 28 and 29 on the detected member 3 are partially captured on the imaging surface 36 of the image sensor 16 in accordance with the distance between the imaging means 5 and the detected member 3. . In this embodiment, the image 28a of the reference mark 28 is captured by the image sensor 1 of the camera 10.
The position of the object 4, and hence the image pickup means 5, is determined in advance so that the object 4, and hence the image pickup means 5, are present in the image pickup surface 36 of 6. At this time, the number of images 29 of the mark 29 included in the image pickup surface 36 is This corresponds to the distance from the detected member 3. Therefore, by counting the number of marks 29a, the distance between the imaging means 5 and the detected member 3 can be roughly determined.

The operation of the processing circuit 35 will be explained with reference to FIG.

Moving from step n1 to step n2, the output from the image pickup device 16 provided in the camera 10 of the image pickup means 5 is transferred to the processing F.
It is inputted as an input signal C1 to one circuit 35, and is binarized into a digital signal.

Similarly, the output of the camera 19.20 of the imaging means 6.7 is sent to the processing circuit 35 as input signals C2, C3 in step ri3. given at r+4.

In step n5, in response to the input signal C1 from the image sensor 16 of the camera 10, labeling is performed to identify circles and triangles, and feature parameters such as area are extracted and compared with predetermined values in step n6. The shape of the mark 2829 is thereby identified. step n
3, the two-dimensional position of the center of gravity of the marks 28 and 29 which are each figure is calculated and found, in other words, the marks 28 and 29
The shapes of the captured images 28a and 29a (see FIG. 1 above) are determined respectively. In step n8, the image sensor 1
Image 28 of mark 28 and 29 captured on imaging surface 36 of 6
a, the distance 1i h between the centers of gravity at both ends of 29a is calculated, and thereby the three-dimensional X a - Y a of the imaging means 5 is calculated.
- Calculate the distance X 1 a in the Z a coordinate system.

FIG. 12 is a diagram schematically showing an optical system for imaging the member 3 to be detected by the camera 10 of the imaging means 5. As shown in FIG. The focal length of the focusing lens 15 is F, the distance on the image sensor 16 is 1"l, and the actual length of the detected member 3 is Hl.
When , the first equation holds true.

Therefore, the distance N between the detected member 3 and the focusing lens 15
X 1 a is determined based on the first equation.

Steps 09 to n12 explain the operation of the processing circuit 35 in response to the output of one camera of the imaging means 6, and these steps 19 to n12 are the same as steps 05 to n8 described above. Furthermore, based on the output from the camera 20 of the imaging means 7, operations similar to the above steps n5 to n8 are performed in steps n13 to n16.The distances Xla, X2a, and X3a thus determined are , the attitude of the detected object 1 is calculated and determined as follows.
As shown in Figure 3, the Euler angle (ψ.

The coordinate transformation matrix generated by θ, P) is expressed by the second equation.

Here, first, in order to calculate the amount of parallel movement, the second
Expressed as a vector as in the equation.

xa=M-x+xO-(3) Let the coordinates of the detected object 1 be xi, x2. x3, and the tfifi detection results by those cameras 10, 19.20 are xal, xi2. Let it be xi3.

xal = M-xi + xo
・−(4)xi2 = M−x2 + xo
−<5) xi3 = M−x3 + x
o (6) Calculating the sums of both sides of Equations 4 to 6 yields Equation 7.

Here, reference numeral 23.2 shown in FIGS. 2 and 3
6 is the center of gravity, and the first term on the right side of Equation 7 is zero, so Equations 8 and 9 hold true.

xO=, Σ xai/3
(9) 1=1 Also, based on the output of each camera 10, 19, and 20, the attitude of the detected object 1 is calculated as follows.

and xbl = xal - x.

Then, xbL=sinθ・Rybl=5in9)−cosθ−Rzb1=
cogp-cosθ・R...<11>...(12)...<13>...(14) Therefore, sinθ=-xb 1/R-(15) sinp=
yb 1/cos θ-R-, (1B) From the 15th and 16th equations, θ and ψ can be calculated.

The optical axes 12, 21, 22 are located at the vertices of an equilateral triangle,
Moreover, the detected members 3, 24, and 25 are located at each vertex of an equilateral triangle of the same shape, and therefore, xb2=coaθ・sinp(J葎2>+sin
θ・R/2 − (19)xb3=aosθ・sin
p (-7 = 1/2) 10 sin θ, R/2-
(20) xb2- xb3 = cosθ・sinpA
Page - <21> Therefore, sinψ= (xb2-xb3) /cosθ-1fi
−(22) From this 22nd equation, sinψ
can be found. In this way, the attitude of the detected object 1 can be detected.

The imaging means 5, 6.7 and the detected member 3.2425 are
In the above-described embodiment, three in total are provided, but in other embodiments of the present invention, a larger number may be provided, and in order to measure the distance Xla,
It is sufficient that one imaging means 5 and one detected member 3 are provided in correspondence.

Effects of the Invention As described above, according to the present invention, the distance to the object to be detected to which the member to be detected is fixed can be measured using one imaging means, so the configuration is simple and the size is reduced. becomes possible. Moreover, since the detected member is configured to reflect light in a direction parallel to the incident light, erroneous detection due to disturbance light can be prevented. Furthermore, by providing these imaging means at least at least 3f1 locations, it becomes possible to calculate and determine the attitude of the object to be detected from the distance determined by the output of the camera provided in each imaging means.

[Brief explanation of the drawing]

FIG. 1 is an overall system diagram of an embodiment of the present invention, FIG. 2 is a front view of an object 4 equipped with an imaging means 5.6.7, FIG. 3 is a front view of an object to be detected 1, and FIG. The figure is a front view of the member to be detected 3, FIG. 5 is a partial sectional view taken from section line 4 (2I) - is a perspective view showing the prism 31 in FIG.
9 is an enlarged cross-sectional view of the vicinity of the glass beads 32 shown in FIG. 8, and FIG. 11 is a flowchart for explaining the operation of the processing circuit 35, and FIG. 12 is a front view showing the state in which the distance 111i is
Diagram 1 for explaining the principle for measuring X1a
FIG. 3 is a diagram for explaining Euler angles. 1... Object to be detected, 3, 24. 25... Member to be detected,
4...Object, 5,6.7...Imaging means, 8...Light source, 98...Reflector, 0. 20...Camera, 28...Reference mark, 9...Scale mark

Claims (2)

[Claims] (1) (a) A member to be detected that is fixed to the object to be detected and reflects light in a direction parallel to the incident light, (b) an imaging means, and (b1) irradiates light toward the member to be detected. (b2) a reflector provided on the optical axis of the light source, which transmits the light from the light source and bends the optical path of the reflected light from the object to be detected; (b3) a reflector that reflects the light from the reflector. (c) processing means that responds to the output of the camera and calculates the distance between the detected member and the camera by calculating the distance between the detected member and the camera; relative position measuring device. (2) The imaging means is provided at at least three locations, and the processing means calculates and determines the attitude of the object to be detected from the distance determined by the output of each camera. The relative position measuring device according to item 1.