JP3514029B2 - Two-dimensional position and orientation measurement method and apparatus, control apparatus for image recording apparatus, and control apparatus for manipulator - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two- dimensional position / orientation measuring method and device, a controller for an image recording device, and a controller for a manipulator, and in particular, simplification and cost reduction can be achieved in measuring the position and orientation in two dimensions. , can improve handling properties, constant method measuring accuracy measurement have dependent <br/> Shinano on the speed of the mark forming media and apparatus, and a control device for controlling an image recording apparatus and the manipulator using them.

[0002]

2. Description of the Related Art In recent years, two-dimensional positions and postures have been changed at high speed with the advancement and complexity of work by robots and the like.
It is required to measure with high accuracy. For example, it is necessary to measure the position and orientation of a target object at high speed and with high accuracy when gripping an object with a manipulator or placing the gripped object at an appropriate place.

As a conventional two-dimensional position / orientation measuring apparatus, there is one using an image pickup means such as a television camera as an external sensor for performing visual feedback control.
According to this two-dimensional position / orientation measuring device, an image of an object to be measured is picked up by an image pickup means such as a television camera to generate position and attitude information of the object to be measured, and the position and attitude obtained from this information are used as an external environment. The coordinate value is converted into a fixed coordinate system, and the position and orientation of the measuring object is measured according to the difference between the target coordinate value of this coordinate system and the detected coordinate value obtained by the coordinate conversion.

However, according to this two-dimensional position / orientation measuring apparatus, a two-dimensional sensor such as a CCD is used as an image pickup means such as a television camera, and the data capturing speed of one screen is 1/30 seconds or 1/60. Seconds. This is extremely slow compared to the fact that the feedback cycle time of the motor control device of the manipulator is generally 1/1000 second or less, and cannot cope with high-speed positioning work. Also,
Since the number of pixels on one screen is about 500 × 500, the resolution is not sufficient, and since the amount of information to be processed is large, a dedicated processing circuit is required for speeding up, resulting in an increase in cost.

As a two-dimensional position and orientation measuring device or a two-dimensional position measuring device for solving these problems, for example,
JP-A-3-17503 and JP-A-64-180
There is one disclosed in Japanese Patent Publication No. 01.

2 disclosed in Japanese Patent Laid-Open No. 17503/1993
The dimensional position / orientation measuring apparatus has a four-sided square one-dimensional optical sensor arranged on each side of the square, and reads a grid-shaped cut-off line formed on a semiconductor wafer by the sensor. The position and orientation of the semiconductor wafer are measured based on the received light level distribution and the difference therebetween.

Further, the two-dimensional position measuring device disclosed in Japanese Patent Laid-Open No. 64-18001 is equipped with a point light source such as a miniature bulb on the object to be measured, and the point light source is condensed by a condensing optical system to collect the light. The emitted light beam is split by a beam splitter, and the split light beam is divided into two orthogonal directions 1
The dimension sensor detects the position and inputs the sensor signal to the corresponding position detection circuit to measure the position of the measuring object.

On the other hand, as a control device for an image recording apparatus for detecting an error in registration of a plurality of color images formed on a recording medium of the image recording apparatus, Japanese Patent Laid-Open No. 6-11
There is one disclosed in Japanese Patent No. 8735. This control device for an image recording device is provided with first and second inverted V-shaped patterns.
And a mark detection timing signal output from the first and second mark detectors are input to perform a predetermined calculation, and the calculation result is obtained. And an arithmetic circuit for detecting an error in registration of a plurality of color images based on the above. In this control device for an image recording device, a first mark having two sides of an inverted V-shaped pattern in a first color and an inverted V-shaped pattern are formed on a recording medium that moves at a predetermined speed. A second mark whose side is a second color, and a third mark whose first side of the inverted V-shaped pattern is a first color and whose second side is a second color are respectively It is formed at a predetermined timing. The first to third marks are detected by the first and second mark detectors by the movement of the recording medium. When detecting the first to third marks, the first and second mark detectors output detection timing signals to the arithmetic circuit. The arithmetic circuit inputs the detection timing signal to perform a predetermined arithmetic operation, and based on the arithmetic result, the first and second
The registration error of the color image of.
The image recording device adjusts the registration of the color image based on the detected error.

[0009]

However, Japanese Patent Laid-Open No. 3-1 is used.
According to the two-dimensional position-and-orientation measuring device disclosed in Japanese Patent No. 7503, since the one-dimensional sensor is arranged on each side of the square, at least four one-dimensional sensors are required, resulting in high cost. On the other hand, according to the two-dimensional position measuring device disclosed in Japanese Patent Laid-Open No. 64-18001, various optical components including an imaging lens, a kamaboko lens, and a beam splitter are required, which complicates the configuration and increases the cost. . In addition, since a point light source such as a miniature bulb is required, care must be taken in handling to prevent breakage. Further, according to the color registration error detection device disclosed in Japanese Patent Laid-Open No. 6-118735, the mark detection timing signal is substituted into an arithmetic expression in which the speed of the recording medium is constant to detect the registration error. If the speed of the recording medium fluctuates, the detection accuracy decreases.

It is therefore an object of the present invention is to provide two-dimensional position Ru Hakare simplification of cost and construction orientation measuring method and apparatus, an image recording apparatus control unit, and the manipulator control device.

Another object of the present invention is to provide required such have 2D pay particular attention to the handling position and orientation measuring method and apparatus, and a manipulator control device.

Another object of the present invention lies in that the measurement accuracy rate-dependent, such has two-dimensional position and orientation measuring method and apparatus of the mark forming medium, and to provide a manipulator control system.

[0013]

[0014]

According to a first aspect of the problem-solving means for the present invention, for achieving the above object, the two-dimensional position and orientation measuring method for measuring the position and orientation of the measuring object displacing the first upper plane In the first and second line segments, and two intersections between the second line segment and the third line segment, the angle formed by the first and second line segments, A mark having a known angle between the second and third line segments and the distance between the two intersections is formed on the measurement object, and at least one one-dimensional sensor is arranged on the second plane and included in the mark. A light-receiving signal representing the light-receiving intensity distribution in the longitudinal direction on the at least one one-dimensional photosensor by forming three line-segment images of the first, second, and third line segments on the second plane. to generate, at least one of the primary of the three line segments images on the basis of the received light signal Calculating a position on the optical sensor, and based on the position on the at least one one-dimensional optical sensor, one position of the two intersections of the mark and the first, second, and third positions of the mark. There is provided a two-dimensional position and orientation measuring method characterized by calculating the inclination of one line segment.

According to a second aspect of the present invention, in order to achieve the above object, in a two-dimensional position / orientation measuring apparatus for measuring the position and orientation of a measuring object displaced on a first plane,
Formed on the measurement object, providing two intersections between the first and second line segments and the second and third line segments;
The angle formed by the first and second line segments, the second and third
An angle formed by the line segments and the distance between the two intersections are known, and three line segment images of the first, second, and third line segments included in the marks on the second plane. An image forming unit to be formed, at least one one-dimensional optical sensor which is arranged on the second plane and outputs a light receiving signal representing a light receiving intensity distribution in the length direction based on the three line segment images; The at least one of the three line segment images based on the received light signal
One of the first calculating means for calculating a position on the one-dimensional optical sensor, and one position of the two intersections of the mark based on a position on the at least one one-dimensional optical sensor, wherein the mark first There is provided a two-dimensional position-and-orientation measuring apparatus characterized by comprising a second calculating means for calculating an inclination of one of the first, second, and third line segments.

According to a third aspect of the present invention, in order to achieve the above object, an image recording apparatus for forming a color image by superposing toner images of different colors is provided.
2 between the second line segment and the third line segment
An image that provides two intersections and generates an image signal of a mark whose angle is formed by the first and second line segments, the angle formed by the second and third line segments, and the distance between the two intersections is known. Signal generation means, and first toner image forming means for inputting the image signal of the mark and forming a toner image of the mark in a first color on a first position of an image carrier such as paper or a belt, Second toner image forming means for inputting an image signal of the mark and forming a toner image of the mark in a second color at a second position adjacent to the first position of the image carrier; The three line segment images included in the first and second color toner images are formed on a predetermined plane.
And the mark image forming means to be formed on the predetermined surface.
Based on the above three line segment images, the received light intensity in the length direction
At least one of the one-dimensional optical sensor, a first calculating means for calculating a position on the at least one one-dimensional optical sensor of the three line segments images on the basis of the light reception signal for outputting a light reception signal representing a cloth Of the toner image of the mark based on the position on the at least one one-dimensional photosensor.
Second computing means for computing the position of one intersection and the inclination of one of the first , second and third line segments of the Toter image of the mark for each of the first and second colors. And an error in registration of the toner image of the second color with respect to the toner image of the first color is calculated based on the calculation result of the second calculation means, and a control signal for correcting the error is output. Provided is a control device for an image recording apparatus, which is equipped with a control means.

[0017] According to a fourth aspect of the present invention, for achieving the above object, the manipulator control device for controlling the position and orientation of the Target article, the target table of the target object
A first and second line segment formed on the surface, and the second line
Providing two points of intersection between the line segment and the third line segment,
The angle formed by the first and second line segments, the second and third line segments
A mark whose angle is known and the distance between the two intersections is known.
And the first, second, and third included in the mark
Form three line segment images on a predetermined surface of the manipulator
Image forming means and the predetermined surface of the manipulator
Are arranged in the vertical direction, and based on the three line segment images,
At least one that outputs a received light signal that represents a light intensity distribution
A one-dimensional optical sensor, and the first based on the received light signal,
The at least one one-dimensional optical sensor of the second and third line segments.
The first calculation means for calculating the position on the sensor,
And the marker based on the position on one one-dimensional optical sensor.
Position of one of the two intersections of the
Calculate the slope of one of the first, second and third line segments
And a second computing means for performing computation by the second computing means.
Based on the one position and the slope of the one line segment
Providing manipulator control apparatus characterized by comprising a control means for the position and the orientation of the predetermined position and a predetermined posture of the target object by controlling the manipulator Te.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION A two-dimensional position and orientation measuring mark, a two-dimensional position and orientation measuring method and apparatus, an image recording apparatus control apparatus, and a manipulator control apparatus according to the present invention will be described in detail below with reference to the accompanying drawings. explain.

FIG. 1A shows a first embodiment of a two-dimensional position / orientation measuring apparatus of the present invention. This two-dimensional position-and-orientation measuring apparatus is illuminated by a measurement object 1 that is displaced on a plane parallel to the object surface 2, a light source (not shown) that illuminates the object surface 2 of the measurement object 1, and a light source. Imaging unit 5 for imaging the target surface 2, and imaging unit 5
The calculation unit 9 is configured to calculate the position and orientation of the measurement target 1 based on the sensor signal output from the display unit 17 and display the calculated position and orientation on the display unit 17.

The image pickup unit 5 comprises an image forming lens 4 and an image forming surface 7, and a one-dimensional optical sensor described later is arranged on the image forming surface 7.

The arithmetic unit 9 is a microcomputer or the like having an interface function with the image pickup unit 5, and has a processor such as a memory and ALU.

The mark 3 formed on the target surface 2 is shown in FIG. 1 (b). This mark 3 provides an intersection P ₂ between the first and second straight line L _1, the intersection point P _1, and the second and third linear L _2, L ₃ between L _2, intersection P
₁ and the distance g between P ₂ and the angle α formed by the straight lines L ₁ and L ₂ ,
And the angle β formed by the straight lines L ₂ and L ₃ is known.

The mark 3 is formed by applying a paint having a reflectance different from that of the target surface 2 to the target surface 2, or by sticking a mark or the like printed with ink on the target surface 2, or by applying the mark to the target surface 2. Alternatively, members made of different materials may be attached.
In this embodiment, the mark 3 is marked on the white target surface 2 with black paint. There may be four or more straight lines, and attention should be paid to three that satisfy the condition. Further, these straight lines may be continuous lines or discontinuous lines, and a line segment having a predetermined length may be defined.

In FIG. 1C, the image plane 7 of the image pickup unit 5 is shown. As described above, the one-dimensional optical sensor 6 is arranged on the image plane 7, and the straight lines L _{1 to} L ₃ of the mark 3 on the target surface 2 intersect the intersections P ₁ ′ and P ₂ ′ on the image plane 7. It is imaged as mark image 3 made of linear L ₁ '~L _3' 'having. h-v indicates a two-dimensional coordinate system.

FIG. 2 shows a system of the image pickup unit 5 and the arithmetic unit 9. This system includes a drive circuit 11 that drives the one-dimensional photosensor 6, an amplifier 12 that amplifies the sensor signal of the one-dimensional photosensor 6, and an A / D converter 13 that converts the amplified sensor signal into digital data. , A memory 14 for storing a digital sensor signal output from the A / D converter 13, and a control signal from a processor 16 to be described later to write / write in the memory 14.
A memory control circuit 1 that outputs a read signal and controls writing and reading of a sensor signal in the memory 14.
5 and the sensor signal read from the memory 14, the position and orientation of the measuring object 1 are calculated, and the result is displayed on the display unit 1.
7 is provided with a processor 16 for displaying.
The processor 16 calculates the positions of the straight lines L ₁ ′ to L ₃ ′ on the one-dimensional optical sensor 6 and the intersections P ₁ and P ₂ based on the calculation result of the first calculation circuit 16 a. having a second arithmetic circuit 16b for calculating at least one position, at least one slope of the straight line L ₁ ~L _3.

The operation of the above configuration will be described.

First, the target surface 2 is illuminated by a light source (not shown).
When the irradiation is performed, the reflected light from the target surface 2 including the mark 3 is condensed by the imaging lens 4, and the intersection P ₁ ′,
'Mark image 3 made of' ~L ₃ is imaged 'straight line L ₁ has a' to P _2.

When the mark image 3'is formed on the image plane 7, 1
The three-dimensional photosensor 6 outputs a sensor signal indicating the light intensity distribution. The sensor signal is amplified by the amplifier 12, then A / D converted by the A / D converter 13, and transferred to the memory 14 as digital data. The transferred digital sensor signal is written in the memory 14 according to the write signal output from the memory control circuit 15, and is read from the memory 14 to the processor 16 according to the read signal output from the memory control circuit 15. Be done.
The processor 16 calculates the position of the mark image 3'on the one-dimensional optical sensor 6 by the first calculation circuit 16a, and calculates the position and orientation of the measurement object 1 in two dimensions by the second calculation circuit 16b. Then, the result is displayed on the display unit 17.

A method of calculating the two-dimensional position and orientation performed by the processor 16 will be described below.

FIG. 3 shows the position and orientation of the mark 3 in the two-dimensional coordinate system indicated by xy. In this figure there is a reading line 18 on the target surface 2 detected by the one-dimensional photosensor 6 on the x-axis.

FIG. 4 shows the one-dimensional optical sensor 6 on the image plane 7.
And the positional relationship between the straight lines L ₁ 'to L ₃ ' of the mark image 3 '.

In FIG. 3, the equation of the straight line of the reading line 18 in the two-dimensional coordinate system uses the pixel number q of the one-dimensional photosensor 6, [x, y] ^t = q [a, b] ^t + [c , D] ^t ... (1)

Here, [] ^t represents a transposed matrix.
[A, b] ^t is the direction vector of the reading line 18, and c and d are the positions of the center of the 0th pixel in the two-dimensional coordinate system. The size of the belt [a, b] ^{t is} the size per pixel of the one-dimensional photosensor 6 in the two-dimensional coordinate system.

Before the measurement is performed, the equation of the straight line of the read line 18 is obtained. a and b are generally constants,
When the target surface 2 and the image plane 7 are not parallel to each other or the lens distortion is large and the error is large when approximated as a constant, a and b may be expressed as a function of q.

First, in FIG. 4, the one-dimensional optical sensor 6
Position q of the straight line of the mark image 3'in ₁~ Q₃Ask for.
Straight line L of mark 3₁~ L₃Is a line with a constant width
And its image L₁'~ L₃', The sensor signal output level
Le becomes low. Therefore, the straight line L of the mark image 3 '₁'~ L₃'
Position q_j(J = 1 to 3), as shown in FIG.
By using the pixel data in the range below an appropriate threshold value I,
For example, it is obtained as the position of the center of gravity of the shaded portion. That
Barycentric position q_jIs calculated by, for example, formula (2).

[Equation 1]

[0036] In the above equation, D (q) is the output value of the pixel q, D _b represents the background level.

In this way, the first arithmetic circuit 16a
Straight line L of mark image 3 '₁’～ L₃’Position q₁~ Q₃To
Ask. The second arithmetic circuit 16b uses the calculated position q₁~
q₃Substituting into equation (1), the mark in the two-dimensional coordinate system
Straight line 3₁~ L₃Position A ₁(X₁, 0) to A₃(X
₃, 0) is calculated.

In the calculation of the second calculation circuit 16b,
Straight line L of mark 3 shown by 3₁And L ₂Intersection P of
₁(P_1x, P_1y) Is the position of mark 3, the straight line L of mark 3
₂When is parallel to the y-axis, the reference posture of mark 3
Line L₂The inclination θ of is the posture of the mark 3.

In FIG. 3, the intersection of the straight lines L ₂ and L ₃ is P ₂
And the circumscribed circle of the triangle A ₁ P ₁ A ₂ is π ₁ , and the triangle A ₂
The circumscribed circle of P ₂ A ₃ is π ₂ . In the circles π ₁ and π ₂ , the lengths of the line segments A ₁ A ₂ and A ₂ A ₃ and ∠A ₁ P
_Since the angles α and β of ₁ A ₂ and ∠A ₂ P ₂ A ₃ are obtained respectively, the radii R ₁ and R ₂ of each circle and the center C ₁ (c _1x , c _1y ) of each circle are calculated from the sine law. The coordinates of C ₂ (c _2x , c _2y ) are obtained, and the equation of each circle is as follows. π ₁ : (x-c _1x ) ² + (y-c _1y ) ² = R ₁ R ₁ = (x ₂ −x ₁ ) / 2 / sin (α) c _1x = x ₂ − (x ₂ −x _{1 ) / 2 c 1y = R 1} cos (α) ····· (3) π 2: (x-c 2x) 2 + (y-c 2y) 2 = R 2 R 2 = (x 3 -x 2 ) / 2 / sin (β) c _2x = x ₂ − (x ₃ −x ₂ ) / 2 c _2y = R ₂ cos (β) (4) Here, the equation of the straight line of the straight line L ₂ Where x−x ₂ = ky (5), the position P ₁ (P _1x , P _1y ) of the mark 3 is obtained as the intersection of the circumscribed circle π ₁ and the straight line L ₂ , and the value of k If is found, from equations (3) and (5)

[Equation 2] It can be obtained as p _1x = x ₂ + k p _1y (7) Further, the posture of the mark 3 can be obtained as θ = tan ⁻¹ (−k) (8).

Then, k is obtained as follows, for example. When the coordinates of the point P ₂ are (P _2x , P _2y ), from equations (4) and (5)

[Equation 3] It is expressed as p _2x = x ₂ + k p _2y (10), and the following equation is obtained using the lengths g of the points P ₁ and P ₂ . ^{_{(P 1x -p 2x) 2 +}} (p 1y -p 2y) 2 = g 2 ·····
(11A) and equations (6), (7), (9), and (10) are substituted and rearranged to obtain the following quadratic equation. ^{_{((X 3 -x 1) 2}} -g 2) k 2 -2 (x 3 -x 1) Fk + F 2 -g 2 = 0 ····· (11B) F = (x 3 -x 2) cos ( β) / sin (β) + (x
₂₋ x ₁ ) cos (α) / sin (α) Expression (11) is an equation that always has a solution, as is clear from the fact that the line segment P ₁ P ₂ can be actually illustrated in FIG. And when x ₃ −x ₁ = g, k is

[Equation 4] Is. When x ₃ −x ₁ = g, k is

[Equation 5] And k has two solutions, k ₁ and k ₂ . In this case, it is necessary to use only the range of k in which the mark is displaced in the measurement and determine whether k ₁ or k ₂ corresponds to the k of the true mark. However, this determination is made, for example, when the angles α and β of ∠A ₁ P ₁ A ₂ and ∠A ₂ P ₂ A ₃ are both 90 deg, the relationship between k ₁ and k ₂ is k ₁ = −k ₂ . This can be easily done simply by discriminating whether the k is positive or negative. When α and β have other values, the range of k is k _a
If the measurement is performed as <k <k _b (where k _a and k _b are certain constants), the determination can be easily performed. In practice, no particular difficulty has been recognized in the above discrimination.

By calculating by the procedure described above,
It is possible to obtain the position and orientation in two dimensions. FIG. 6 is a flowchart showing the calculation performed by the processor 16. Here, position data is obtained in steps S ₁ , S ₂ , S ₃ , and S ₄ , and posture data is obtained in steps S ₁ , S ₂ , and S ₅ .

As for the shape of the mark 3, as shown in FIG. 7A, the straight lines L _{1 to} L ₃ of the mark ₃ may be separated from each other and the intersections P ₁ and P ₂ may be located on the extended line. Further, in addition to the method described above, the mark 3 may be formed by cutting out the target surface 2 to form straight lines L _{1 to} L ₃ in addition to the method described above. Further, as shown in (c) of FIG.
The contour line may be used a mark 3, the straight line L ₁ ~L _3.

FIG. 8 shows a case where the mark 3 shown in FIG. 7 (c) is used, the mark image 3'formed on the image forming surface 7, the intensity distribution of the sensor signal detected by the one-dimensional optical sensor 6, and the threshold value. The relationship with I is shown. Here, since the same reference numerals and reference symbols are given to the same parts as those in FIG. 4, duplicate description will be omitted.

FIGS. 9A and 9B show another modification of the mark 3. As shown in FIG. 9A, the intersection points P ₁ and P ₂
Are on the same side of the read line 18,
Calculation can be performed by the flow shown in FIG. Further, as shown in FIG. 9B, the mark may be a case where the intersections of the straight lines L _{1 to} L ₃ intersect at one place P ₁ . In this case, when the distance g between the points P ₁ and P ₂ is zero in the above description of the calculation, the relational expression of p ₁ y = p ₂ y and the expression (6)
From (9),

[Equation 6] As a result, k can be obtained. In the flowchart shown in FIG. 6, step S ₃ is replaced with the equation (14), and the position and orientation are calculated in the same manner.

Further, the mark 3 may be formed by a groove or a convex portion, or may be formed by using a linear light source or by applying a fluorescent paint. If the measurement target 1 is light transmissive, it may be formed of materials having different light transmissivities.

Further, if the object to be measured is a thin member such as a plate, an opening is provided in place of the mark 3, the object to be measured 1 is sandwiched, and light is emitted from the side opposite to the image pickup unit 5 to leak. Incoming light may be detected.

Furthermore, as shown in FIG.
To the target surface 2 of the
a, to form a straight line L ₂ so as to connect 2b, a mark 3 by utilizing the two opposite sides of the edges of the object surface 2 as a straight line L _1, L _3, has a straight line L ₁ '~L _3' The mark image 3 ′ may be formed on the image forming surface 7 of the image pickup unit 5.

FIG. 11 shows a modification of the one-dimensional photosensor 6 of the image pickup unit 5, in which three one-dimensional photosensors 6a, 6b and 6c are arranged on the same line and straight lines L ₁ 'to L of the mark image 3 are arranged.
₃ 'is detected. Of course, the number is not limited to three, and a plurality may be arranged on the same line.

FIG. 12 shows a modification of the image pickup unit 5.
The image pickup unit 5 uses, instead of the imaging lens, a Selfox lens array 26 that forms an erecting equal-magnification real image. In this case, even if the target surface 2 moves up and down a little, an erecting equal-magnification real image can be obtained, so that the two-dimensional position and orientation can be measured within the focused range. Also, three straight lines L ₁ ~
The reading of L ₃ may be performed using a separate SELFOX lens and a one-dimensional photosensor. At this time, each one-dimensional optical sensor may be arranged on separate parallel planes having a step.

In each of the modified examples described above, the position and orientation can be measured by the flow shown in FIG.

FIG. 13 shows a first embodiment of the control device for the image recording apparatus of the present invention. The control device for the image recording device includes yellow (Y), magenta (M), cyan (C),
Further, the image pickup unit 5 is provided in the conveyance path 210 that conveys the paper sheet 200 on which the image in which the color of black (K) is superimposed is recorded, and the output of the image pickup unit 5 is connected to the control unit 300. The imaging unit 5 has the SELFOC lens array 26 and the one-dimensional optical sensor 6, and the control unit 300 has the memory 14, the memory control circuit 15, the processor 16 and the like described in FIG. Transport path 21
The platen roll 2 on the opposite side of the imaging unit 5 with respect to 0.
20 are provided.

In the above structure, the paper 200 is formed by the image forming bodies of respective colors provided upstream of the conveying path 210.
A black and magenta mark 3 is formed on.

FIG. 14A shows the marks 3 formed on the central portion of the paper sheet 200 and on both left and right sides.

FIG. 14 (b) is an enlarged view of portion A of FIG. 14 (a).
The black (K) mark 3 is extended.
Intersection P on the line_K1, P_K23 straights (not shown)
Line L _K1, L_K2, L_K3And has a magenta (M) mark 3
Is another intersection point P on the extension line_M1, P_M2(Not shown)
Three straight lines L_M1, L_M2, L_M3Have.

When the sheet of paper 200 reaches the position of the detection line 18 of the image pickup unit 5, the portion of the mark 3 indicated by f passes through the SELFOC lens array 26 and the one-dimensional optical sensor 6 is detected.
Read by When the one-dimensional optical sensor 6 reads the black (K) and magenta (M) marks 3,
The read signal is output to the control unit 300. When the control unit 300 inputs the read signal, the control unit 300 inputs black (K) and magenta (M) according to the flowchart of FIG.
The position and orientation of the mark 3 of the
With reference to, the error in registration of magenta (M) is calculated by equation (15).

[Equation 7] C _L : Magenta (M) lateral direction registration error C _p : Magenta (M) process direction registration error x ₁ : black (K) mark 3 x coordinate y ₂ : black (K) mark 3 y coordinate x ₂ : magenta (M) mark 3 x coordinate y ₂ : magenta (M) mark 3 y coordinate θ: black (K) mark 3 posture a: black ( Ideal displacement b in the x direction with respect to the mark 3 of magenta (M) when the reference posture of the mark 3 of K) (θ = 0): when the reference posture (θ = 0) of the mark 3 of black (K) Ideal displacement in the y direction with respect to the magenta (M) mark 3 of

When the portion of the mark 3 indicated by g and the portion of the mark 3 indicated by h next reach the detection line 18 by the movement of the sheet 200 in the conveying direction, the portion indicated by f of the mark 3 is reached. And the registration error of the magenta (M) mark 3 with respect to the black (K) mark 3 is detected. In this way, the registration error of about 30 portions of f, g, h, ... Is detected, and the average value thereof is taken as the registration error of magenta (M). The control unit 300 outputs a control signal based on this error to control the magenta (M) image forming body and correct the magenta (M) registration error. There are various correction methods. For example, the exposure timing of the magenta (M) image signal is controlled, and the speed of the magenta (M) photoconductor is controlled.

In the same manner, a registration error with respect to yellow (Y) and cyan (C) with respect to black (K) is detected and corrected based on the detection result.

Generally, in an electrophotographic recording apparatus, one of the criteria for evaluating the quality of a color image is a registration error. This is often kept commercially below 125 microns. When the pixel density is 400 DPI,
The outline of the color image becomes wavy with an amplitude of 10 microns or more.

Therefore, according to the control device for an image recording apparatus of the present invention, for example, it is not possible to correct the registration error within 10 microns by reading the f portion of the mark 3 only once. From this point of view, in the above-described embodiment, the portions f, g, h at about 30 places,
The mark 3 is read at ... and the registration error is detected based on the average value of the detection results. As a result, it has been confirmed that the registration error can be detected with an accuracy of 3 microns or less when the detection is performed using the 400-DPI one-dimensional optical sensor.

FIG. 15 shows a modified example of the first embodiment of the control device for an image recording apparatus of the present invention, and the same parts as those in FIG. 13 are shown by the same reference numerals, and therefore the duplicated description will be omitted. But black (K) and magenta (M) mark 3
Are formed on the intermediate transfer belt 250. The intermediate transfer belt 250 is stretched around a drive roll 230 and a support roll 240, and black (K), yellow (Y), magenta (M), and cyan ( Photosensitive drums 260, 270, 280, and 290 on which the toner image of C) is formed are provided.

In the above configuration, the operation is as shown in FIGS.
This is performed in the same manner as the operation described in 4 (a) and (b). Instead of forming the mark 3 on the paper 200,
The only difference is the operation formed on the intermediate transfer belt 250.

FIG. 16 shows a first embodiment of the manipulator control device of the present invention. The manipulator control device controls the robot 40, and an image pickup unit 5 that reads a mark 3 (not shown) on the target surfaces 2A and 2B of the target articles 1A and 1B and outputs a read signal.
2, a control unit 300 including the memory 14, the memory control circuit 15, the processor 16 and the like shown in FIG. 2, and a robot controller 400 for inputting a control signal output from the control unit 300 to control the robot 40. The image pickup unit 5 has the configuration shown in FIG. 1A or FIG. 5, and the target surfaces 2A and 2B are shown in FIG. 1B, FIG. 7A, FIG. 7B, and FIG. The mark 3 indicated by the symbol etc. is formed. Further, the robot 40 rotates on a vertical post 41 fixed to a base 47, a first rotating arm 42 that rotates about the vertical post 41 as an axis, and a support shaft (not shown) of the first rotating arm 42. The second rotating arm 43, the vertical arm 44 that moves up and down while being supported by the second rotating arm 43, and the band 4 provided at the lower end of the vertical arm 44.
5 and grippers 46a and 46b provided on the band 45
Have.

In the above structure, the image pickup unit 5 reads the mark 3 on the target surface 2A of the target article 1A and supplies a read signal to the control unit 300. Control unit 3
00 indicates the position and orientation of the mark 3 based on the flowchart shown in FIG.
Output to 00. The robot controller 400 includes a first rotation arm 42, a second rotation arm 43, and a vertical arm 4.
4, controlling the grippers 46a and 46b to control the gripper 46
The target article 1A is held by a and 46b. When the grippers 46 a and 46 b grip the target article 1 </ b> A, the robot controller 400 causes the first and second rotating arms 42 and 4 to move.
3 is controlled to move the imaging unit 5 directly above the target surface 2B of the target article 1B. The imaging unit 5 is the target article 1
When it reaches directly above the target surface 2B of B, the mark 3 on the target surface 2B is read and the read signal is sent to the control unit 300.
Supply to. The control unit 300 detects the position and orientation of the mark 3 based on the flowchart shown in FIG. 6 and outputs it to the robot controller 400. The robot controller 400 includes the first and second rotating arms 42,
43, the vertical arm 44, and the grippers 46a and 46b are controlled to connect the target article 1A to the target article 1A in a predetermined relationship. Although the operation of coupling the target article 1A to the target article 1B has been described in the above embodiment, the operation is not limited to this. For example, from the first position of the target article to the second
It can be applied to various applications such as moving to a position of, a disassembly of a bonded article, and the like.

FIG. 17 shows the two-dimensional position / orientation measurement of the present invention.
A second embodiment of the device is shown and is identical to FIG.
Since the same reference numerals and reference signs are attached to the parts,
A duplicate description will be omitted. This two-dimensional position and orientation measuring device
Is a straight line L with a constant width ₁~ L₃Mark consisting of 3
Towards the measurement object 1 in the form of a plate provided with
A light source 21 that emits light and a light source 2 that sandwiches the measurement target 1
1-dimensional image unit 19 on the opposite side of
Based on the sensor signal from the original image unit 19,
Calculation unit 9 for calculating the two-dimensional position and orientation of the ark 3.
It consists of

The mark 3 is the first and second straight lines L.₁, L
₂Intersection P with₁, And the second and third straight lines L₂, L
₃Intersection P with₂And the intersection distance g, and
L₁, L ₂Angle α and L₂, L₃Angle β
Is known. The light source 21 is, for example, from a lamp 22.
The light is collimated by the light projecting lens 23 to the measuring object 1.
Irradiate. The one-dimensional image unit 19 includes a light receiving surface 20.
The one-dimensional optical sensor 6 is arranged in the. This unit 19
The straight line L of the mark image 3'on the light receiving surface 20 of₁'~ L₃'Is the primary
It is formed so as to cross the original light sensor 6.

The arithmetic unit 9 is composed of a microcomputer having an interface function with the one-dimensional image unit 19. Now, the measuring object 1 is displaced parallel to a certain plane, and when measuring the two-dimensional position and orientation of this measuring object 1 on a certain plane, a two-dimensional coordinate system is set on the plane to be measured, The light source 21 and the one-dimensional image unit 19 are arranged so that the optical path of the irradiation light from the light source 21 is orthogonal to the plane provided with the two-dimensional coordinate system. In addition, the light receiving surface should be perpendicular to the optical path of the irradiation light, that is, 1
The one-dimensional image unit 19 is arranged so that the three-dimensional photosensor 6 is orthogonal to the optical path of the irradiation light. The one-dimensional image unit 19 and the arithmetic unit 9 are the same as the imaging unit 5 and the arithmetic unit 9 in FIG.

Next, a method of calculating a two-dimensional position and orientation according to the second embodiment will be described.

First, the straight line L of the projected mark image 3 '
Determining the position of the one-dimensional optical sensor 6 ₁ '~L _3'.

FIG. 18 shows the positional relationship between the one-dimensional photosensor 6 and the straight lines L ₁ 'to L ₃ ' of the mark image 3 '. As described above, the straight lines L _{1 to} L ₃ are openings having a constant width, and the sensor signal output level of the one-dimensional optical sensor 6 is large at the portions of the straight lines L ₁ ′ to L ₃ ′ of the mark image 3 ′. Has become. Therefore, the j-th mark image 3'on the one-dimensional optical sensor 6
The positions q _j (j = 1 to 3) of the straight lines L ₁ ′ to L ₃ ′ of the line are pixel data q in the vicinity of an appropriate threshold I or more, for example.
Is calculated using equation (16).

[Equation 8] Here, D (q) is an output value in the pixel q.

In the two-dimensional coordinate system, the one-dimensional optical system
Sensor 6 uses pixel number q   [X, y]^t= Q [a, b]^t+ [C, d]^t    (17) It can be expressed as. Where [a, b]^tIs the size
Direction vector of pixel pitch, [c, d]^tIs the 0th picture
The center coordinates of the element. At this time, on the one-dimensional optical sensor 6
Straight line L of mark image 3 '₁'~ L₃Position q₁~ Q₃Is the expression
Due to (7), the straight line L of the opening in the two-dimensional coordinate system₁~ L
₃Position A₁~ A₃Is converted to. Got this way
Straight line L of the opening₁~ L₃Position A₁~ A₃Based on
Straight line L of the mouth ₁, L₂Intersection P of₁Target position (x, y)
Position, straight line L₂Is parallel to the y-axis, the reference posture (θ
= 0), first of all, as in the above-described embodiment, the straight line L
₂Determine the slope k of and measure from equations (6), (7), (8)
The two-dimensional position and orientation of the object 1 can be obtained.

In FIG. 19, the procedure described above is performed.
A flow chart of the operation is shown, step S₁,
S₂, S₃, S_FourPosition data is obtained by
S ₁, S₂, S₃, S_FiveAttitude data is obtained by
It

Further, the mark 3 composed of the straight lines L _{1 to} L ₃ of the opening may have a triangular shape as shown in FIG. 7C, and its contour line may be used as a straight line for detection. If the measurement object 1 is a transparent member, a mark may be printed on the member in place of the opening, using a material having a different transmittance. For example, if the mark is written with black paint having a low transmittance, the mark image 3'is detected as shown in FIG. 4, and the position and orientation can be measured in the same manner as described above.

For the mark 3, it is sufficient that the mark image 3'projected on a plane having a two-dimensional coordinate system is a straight line at the portion detected by the one-dimensional photosensor 6, and L ₁ , L ₂ and L ₃ are It does not have to be a straight line. Therefore, measurement is possible even if the measurement target is other than a plate. In FIG. 17, the straight line L ₁ ′ of the mark image 3 ′-
L ₃ 'may be detected using a separate one-dimensional photosensor. At this time, each one-dimensional optical sensor may be arranged on a different plane having a step.

[0074]

As described above, according to the two-dimensional position / orientation measuring apparatus and method of the present invention, only the one-dimensional optical sensor is used, so that the structure can be simplified and the cost can be reduced. Further, since it is not necessary to provide a point light source such as a miniature electric bulb as a bright spot, the object to be measured can be easily handled. Furthermore, according to the control device for an image recording apparatus of the present invention, the measurement accuracy does not depend on the speed of the medium such as the paper and the intermediate transfer belt, so that the measurement result with a predetermined accuracy can be obtained. Further, according to the manipulator control device of the present invention, since the target article is handled while detecting the position and orientation in real time, the amount of information to be stored can be reduced, and the software can be simplified.

[Brief description of drawings]

1A and 1B show a first embodiment of a two-dimensional position / orientation measuring apparatus of the present invention, (a) is an overall explanatory view, and (b) is an explanation of a mark on a target surface viewed from below (a). FIG. 6 (c) is an explanatory view of the one-dimensional optical sensor on the image plane as viewed from the lower side of FIG.

FIG. 2 is a block diagram showing a system of an imaging unit and an arithmetic unit in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 3 is an explanatory diagram showing the positions and orientations of marks in the two-dimensional coordinate system in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 4 is an explanatory diagram showing a positional relationship between the one-dimensional optical sensor and the straight line of the mark image on the image plane in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 5 is an explanatory diagram showing an output waveform of the one-dimensional photosensor in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 6 is a flowchart showing a calculation procedure in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 7 is an explanatory diagram showing a modified example of the mark in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 8 is an explanatory diagram showing the positional relationship between the one-dimensional optical sensor and the straight line of the mark image on the image plane in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 9 is an explanatory diagram showing another modification of the marks in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 10 is an explanatory view showing still another modified example of the mark in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 11 is an explanatory view showing a modified example of the one-dimensional optical sensor in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 12 is an explanatory diagram showing a modified example of the imaging lens in the first embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 13 is an explanatory diagram showing a first embodiment of a control device for an image recording apparatus of the present invention.

FIG. 14 is an explanatory diagram showing marks formed on a sheet in the first embodiment of the control device for the image recording apparatus of the present invention.

FIG. 15 is an explanatory diagram showing a modification of the first embodiment of the control device for the image recording apparatus of the present invention.

FIG. 16 is an explanatory diagram showing a first embodiment of a manipulator control device of the present invention.

FIG. 17 is an explanatory diagram showing a second embodiment of a two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 18 is an explanatory view showing the positional relationship between the one-dimensional optical sensor and the straight line of the mark image on the image plane in the second embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

FIG. 19 is a flowchart showing a calculation procedure in the second embodiment of the two-dimensional position and orientation measuring apparatus of the present invention.

[Explanation of symbols]

1 measurement object 1A, 1B object article 2, 2A, 2B object surface 3 mark 4 imaging lens 5 imaging unit 6, 6a, 6b, 6c one-dimensional optical sensor 7 imaging surface 11 drive circuit 12 amplifier 13 A / D conversion 14 memory 15 memory control circuit 16 processor 17 display section 18 reading line 19 one-dimensional image unit 20 light receiving surface 21 light source 22 lamp 23 light projecting lens 26 selfoc lens array 40 robot 41 vertical post 42, 43 rotating arm 44 vertical arm 45 Bands 46a, 46b Gripper 47 Base 200 Paper 210 Paper transport path 220 Platen roll 230 Drive roll 240 Support roll 250 Intermediate transfer belts 260, 270, 280, 290 Photosensitive drum 300 Control unit 400 Robot controller L _{1 to} L ₃ Mark straight line L ₁ '~L _3' linear P _1, P ₂ marks the intersection P ₁ of the mark image ', P _2' intersection mark images

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-7-72930 (JP, A) JP-A-52-29250 (JP, A) JP-B-58-49070 (JP, B2) Patent 3111869 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01B 11/00-11/30 B25J 13/08 G01B 11/26 G06T 7/60

Claims (12)

(57) [Claims] 1. A two-dimensional position / orientation measuring method for measuring the position and orientation of a measuring object which is displaced on a first plane, comprising: a first and a second line segment; and a second line segment and a third line segment. Two intersections are provided, and the angle formed by the first and second line segments, the angle formed by the second and third line segments, and the distance between the two intersections are known. Forming a mark on the measurement object, arranging at least one one-dimensional sensor on a second plane,
Three line segment images of the first, second, and third line segments included in the mark are formed on the second plane, and the at least one one-dimensional photosensor has a light receiving intensity distribution in the longitudinal direction. Is generated, and the position of the three line segment images on the at least one one-dimensional photosensor is calculated based on the received light signal, and based on the position on the at least one one-dimensional photosensor. Two-dimensional position and orientation measurement, characterized in that the position of one of the two intersections of the mark and the inclination of one of the first, second, and third line segments of the mark are calculated. Method. 2. The mark is formed by forming an edge or a profile of the object to be measured with the first, second and third marks.
The two-dimensional position / orientation measuring method according to claim 1 , wherein the two-dimensional position / orientation measuring method is defined as at least one line segment. Wherein formation of said mark, the measurement object the first openings provided in, according to claim 1, wherein performing defined as at least one segment of the second and third line segments Two
Dimensional position and orientation measurement method. 4. The mark is formed by using a material having a reflectance or a transmittance different from that of the measuring object, which is provided on the measuring object, to reduce the first, second, and third line segments. 1
The two-dimensional position and orientation measuring method according to claim 1 , wherein the two-dimensional position and orientation is defined as one line segment. 5. A two-dimensional position / orientation measuring apparatus for measuring the position and orientation of a measuring object which is displaced on a first plane, comprising: first and second line segments formed on the measuring object; and Provide two intersections between the second and third line segments,
The angle formed by the first and second line segments, the second and third
An angle formed by the line segments and the distance between the two intersections are known, and three line segment images of the first, second, and third line segments included in the mark are formed on a second plane. An image forming unit to be formed; and at least one one-dimensional optical sensor which is arranged on the second plane and outputs a light receiving signal representing a light receiving intensity distribution in the length direction based on the three line segment images, the mark on the basis of the first calculating means for calculating a position on the at least one one-dimensional optical sensor of the three line segments images on the basis of the received light signal, a position on the at least one one-dimensional optical sensor to the one position of the two intersections of the first of the mark, characterized by comprising a second calculating means for calculating the slope of one line of the second and third line segments Two-dimensional position and orientation measuring device. 6. The mark includes the first, second and third marks.
At least one line segment of the object to be measured edge line segment, or claim 5 Symbol constituted by profiles
2-dimensional position and orientation measurement apparatus of the mounting. 7. The mark includes the first, second and third marks.
The two-dimensional position-and-orientation measuring device according to claim 5, wherein at least one of the line segments is defined by an opening for light transmission formed in the measurement object. 8. The mark comprises the first, second and third marks.
2. The two-dimensional position-and-orientation measuring apparatus according to claim 5, wherein at least one line segment of the line segment is made of a material having a reflectance or a transmittance different from that of the measurement object provided on the measurement object. 9. An image recording apparatus for forming color images by superimposing toner images of different colors, between a first line segment and a second line segment, and between the second line segment and a third line segment. Providing two intersections and generating an image signal of a mark whose angle between the first and second line segments, the angle between the second and third line segments, and the distance between the two intersections is known. An image signal generating means, and a first toner image forming means for inputting the image signal of the mark and forming a toner image of the mark in a first color on a first position of an image carrier such as a sheet or a belt. Second toner image forming means for inputting the image signal of the mark and forming a toner image of the mark in a second color at a second position adjacent to the first position of the image carrier, The first and the second contained in the first and second color toner images,
Forming three line segment images of the second and third line segments on a predetermined surface
And a mark image forming unit that is arranged on the predetermined surface and is based on the three line segment images.
At least one one-dimensional optical sensor, a position on the at least one one-dimensional optical sensor of the three line segments images on the basis of the photodetection signal operation for outputting a light reception signal representing the received light intensity distribution in the longitudinal direction A first calculating means, one position of the two intersections of the toner image of the mark based on the position on the at least one one-dimensional optical sensor, and the first and second positions of the toter image of the mark . and second calculating means for calculating the slope of one line of the third segment to the first and second each color, result to said first color based on said second calculation means An image recording apparatus control device comprising: a control unit for calculating an error in registration of the toner image of the second color with respect to the toner image and outputting a control signal for correcting the error. 10. The first and second toner image forming means form a plurality of the marks at a predetermined pitch in the process direction on the image carrier, and the first and second calculating means include: 10. The image recording apparatus according to claim 9 , wherein a plurality of calculations are performed for each of the plurality of marks, and the control unit calculates the error based on an average value of the calculation results of the plurality of times. Control device. 11. A pair manipulator control device for controlling the position and orientation of the elephants article, is formed on the target surface of the target object, the first and second lines
And two between the second line segment and the third line segment
Providing an intersection point, the angle formed by the first and second line segments,
The angle formed by the second and third line segments, and the intersection of the two
Of a known distance and the first, second and third line segments included in the mark
Form three line segment images of on the predetermined surface of the manipulator
The image forming means and the manipulator are disposed on the predetermined surface, and
Receiving intensity distribution in the longitudinal direction based on two line segment images
At least one one-dimensional optical sensor that outputs an optical signal, and the first, second, and third line segments based on the received light signal
A position on the at least one one-dimensional photosensor of
First calculating means for, based on the position on the at least one one-dimensional optical sensor
Position of one of the two intersections of the mark and the mark
Inclination of one of the first, second and third line segments of the ark
Second calculating means for calculating the oblique, the one position that is calculated by the second arithmetic means
Manipulator control, characterized by that a control means for the position and the orientation of the predetermined position and a predetermined posture of the target object by controlling the manipulator based on the slope of said one line segment apparatus. 12. The aboveAt least one one-dimensional optical sensor
Is a predetermined distance from the first point where the target article is located
Target surface of another target article located at a second point having
Formed inThe abovemarkAbout light receptionOutput signal, before
The calculation means is the above-mentioned mark of the other target article.Receiving
lightA signal is input to separate the target article and the other target article from each other.
The control means for calculating the relative position and the relative attitude,
Is based on the relative position and the relative posture.
There is a configuration for assembling the target article to the other target article
Claim11 descriptionControl device for manipulator.