CN103273310B - An automatic alignment method of micro parts based on multi-channel micro vision - Google Patents

Abstract

The invention discloses a micro-part automatic alignment device and method based on multi-channel micro vision. The device comprises a first micro vision system, a second micro vision system, a third micro vision system, a first motion platform, a second motion platform and a computer. First, use the multiple relative movements of the first micro-part in the clear imaging plane to realize the calibration between the multi-channel microscopic vision system and the first motion platform; then, use the multiple times of the second micro-part in the clear imaging plane Relative movement realizes the calibration between the multi-channel microscopic vision system and the second motion platform; finally, based on the calibrated image Jacobian matrix, the PD control law is used to realize the motion control of the first micro-part and the second micro-part, thereby The pose alignment of the first micro-part and the second micro-part is realized. The invention has the advantages of convenient operation, short assembly time and high assembly precision, realizes the automatic alignment of millimeter-level complex structure micro parts, has wide application prospects and considerable social and economic benefits.

Description

An automatic alignment method of micro parts based on multi-channel micro vision

technical field

The invention belongs to microscopic vision measurement and control in the technical field of micro-assembly, in particular to a three-dimensional automatic alignment method of micro parts based on multi-channel microscopic vision.

Background technique

With the rapid development of micro-electro-mechanical systems, it often involves product assembly of different processing techniques, complex geometric shapes, and different processing materials. Advanced micro-miniature parts assembly technology can improve the manufacturing quality of micro-miniature products, shorten cycle times, and reduce product costs. It is of great significance, therefore, micro vision is widely used in the field of micro assembly. However, due to the small depth of field of the microscopic vision system, each microscopic vision has almost no common field of view, so it is difficult to form a traditional stereoscopic vision system, which makes the assembly automation of micro parts difficult.

Current micro-assembly processes are often complex and generally not highly automated. Among the commonly used micro-assembly technologies, one class uses microscopic vision systems with different magnifications to achieve micro-assembly, but the assembly process is complex and requires high system hardware (see literature: S.J.Ralis, B.Vikramadiya, B.J.Nelson.Micropositioning of a weakly calibrated microassembly system using coarse-to-fine visual servoing strategies. IEEE Transactions on Electronics Packaging Manufacturing, 2000, 23(2): 123-131); another type of assembly method using coarse-to-fine combination, but also faces low assembly efficiency Low problem (see literature: X.Tao, H.Cho, Y.Cho.Visually guided microassembly with activezooming. Robotics and Mechatronics, 2006,18(6):787-794).

Contents of the invention

In order to solve the problem of complex assembly process and low assembly efficiency of micro-parts in the prior art, the purpose of the present invention is to provide a method for automatic alignment of micro-parts in three-dimensional space based on multi-channel microscopic vision, which can meet the needs of rapid and automatic alignment of micro-parts in three-dimensional space. alignment requirements.

The outstanding features of the present invention are: 1) the automatic alignment of the three-dimensional space pose of the micro parts is realized; 2) the automatic alignment method of the present invention is simple and easy to implement, has high assembly efficiency, and can achieve high control precision.

According to one aspect of the present invention, an automatic alignment device for micro parts based on multi-channel micro vision is proposed, the device includes: a first micro vision system 1, a second micro vision system 2, and a third micro vision system 3, the first motion platform 4, the second motion platform 5, the computer 13, wherein:

The first microscopic vision system 1, the second microscopic vision system 2 and the third microscopic vision system 3 are arranged approximately orthogonally in space, wherein the optical axis of one microscopic vision system is approximately parallel to the X axis, and one path The optical axis of the microscopic vision system is approximately parallel to the Y axis, and the optical axis of the microscopic vision system along the way is approximately parallel to the Z axis. The first, second and third microscopic vision systems all point to the first microscopic vision system to be aligned. The part 6 and the second micro part 7 are used to collect the microscopic visual images of the first micro part 6 and the second micro part 7;

The first motion platform 4 is installed near the first, second and third micro vision systems, and it is used to carry the first micro parts 6, and make the first micro parts 6 in the Within the field of view of the first, second and third microscopic vision systems;

The first micro-part 6 is installed on the first motion platform 4, and it moves together with the first motion platform 4;

The second motion platform 5 is installed in the space below the microscopic vision system whose optical axis is approximately parallel to the Z axis, and it is used to carry the second micro parts 7 and make the second micro parts 7 in the first position. 1. Within the field of view of the second and third microscopic vision systems;

The second micro-part 7 is installed on the second motion platform 5, and it moves together with the second motion platform 5;

The first micro vision system 1 is connected to the computer 13 by the first visual connection line 8; the second micro vision system 2 is connected to the computer 13 by the second visual connection line 9; the third micro vision system 3 is connected to the computer 13 through the third visual connection line 10; the first motion platform 4 is connected to the computer 13 through the first control line 11; the second motion platform 5 is connected to the computer 13 through the second control line 12;

The computer 13 is used to receive the microscopic vision images collected by the first microscopic vision system 1, the second microscopic vision system 2, and the third microscopic vision system 3, and The micro-vision image controls the movement of the first moving platform 4 and the second moving platform 5, so that the first micro-part 6 and the second micro-part 7 are automatically aligned.

According to another aspect of the present invention, a method for automatic alignment of micro parts based on multi-channel microscopic vision is also proposed, the method includes the following steps:

Step S1: Adjusting the first motion platform 4 to drive the first micro-component 6 into the field of view of the multi-channel micro-vision system, and located in the clear imaging plane of the multi-channel micro-vision system, the multi-channel micro-vision system includes The first microscopic vision system 1, the second microscopic vision system 2 and the third microscopic vision system 3 arranged approximately orthogonally in space, the first, second and third microscopic vision systems all point to the Describe the first micro-part 6 and the second micro-part 7;

Step S2: Adjusting the first motion platform 4 to drive the first micro-part 6 to perform multiple relative movements in the clear imaging plane of the multi-channel microscopic vision system, and calculating each time of the first micro-part 6 The amount of change of the first image feature parameter before and after the second movement, according to the amount of change of the image feature parameter and the corresponding relative displacement of the first motion platform 4, the least square method is used to calculate the motion control of the first micro part 6 Image Jacobian matrix, that is, get J ₁₁ ~ J ₆₃ parameters;

Step S3: Adjusting the second motion platform 5 to drive the second micro part 7 into the field of view of the multi-channel micro-vision system, and to be located in the clear imaging plane of the multi-channel micro-vision system;

Step S4: Adjusting the second motion platform 5 to drive the second micro part 7 to perform multiple relative movements within the clear imaging planes of the first micro vision system 1 and the second micro vision system 2 , respectively calculate the variation of the second image characteristic parameter before and after each movement, according to the variation of the second image characteristic parameter and the corresponding relative displacement of the second motion platform 5, calculate the second The image Jacobian matrix of the motion control of the micro-part 7, that is, the J ₁₁ ~ J ₂₂ parameters are obtained;

Step S5: Extract the third image features of the first micro-part 6 and the second micro-part 7 in the multi-channel microscopic vision system, and calculate the first micro-part 6 and the second micro-part 7 The posture deviation of the micro-part 7 in the image space, and then, through the visual servo control method based on the image Jacobian matrix, the posture and posture adjustment of the second micro-part 7 is realized, so that it is consistent with the posture of the first micro-part 6 The attitude deviation is less than the given range;

Step S6: Extract the fourth image features of the first micro-part 6 and the second micro-part 7 in the multi-channel microscopic vision system, and calculate the first micro-part 6 and the second micro-part 6 For the positional deviation of the micro-part 7 in the image space, the position adjustment of the first micro-part 6 is realized through the visual servo control method based on the image Jacobian matrix, so that the positional deviation between the second micro-part 7 and the second micro-part 7 is less than a given range , completing the automatic alignment of the first micro-component 6 and the second micro-component 7 .

The invention is based on a multi-channel microscopic vision motion control model, and realizes the relative pose measurement of the part in three-dimensional space by using the coordinate increment of the clear image of the part. The multi-channel microscopic vision-based automatic alignment method for micro-parts of the present invention has the characteristics of simplicity and high assembly efficiency, and can conveniently and efficiently realize the automatic assembly of micro-parts in three-dimensional space. With the rapid development of MEMS (Micro-electro-mechanical systems), the application prospect and social and economic benefits of the present invention are considerable.

Description of drawings

FIG. 1 is a schematic diagram of the structure of an automatic alignment device for micro parts based on multi-channel micro vision according to the present invention.

Fig. 2 is a flow chart of the method for automatic alignment of micro parts based on multi-channel micro vision in the present invention.

Fig. 3 is a flow chart of the visual servo motion control method based on the image Jacobian matrix of the present invention.

FIG. 4 is a schematic diagram of a motion control error result of a second micro-component according to an embodiment of the present invention.

FIG. 5 is a schematic diagram of a motion control error result of a first micro-component according to an embodiment of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be described in further detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

Figure 1 is a schematic structural diagram of the micro-parts automatic alignment device based on multi-channel micro-vision in the present invention. As shown in Figure 1, the micro-parts automatic alignment device includes: a first micro-vision system 1, a second micro-vision system System 2, the third micro vision system 3, the first motion platform 4, the second motion platform 5, and the computer 13, wherein:

The first microscopic vision system 1, the second microscopic vision system 2 and the third microscopic vision system 3 are arranged approximately orthogonally in space, wherein the optical axis of one microscopic vision system is approximately parallel to the X axis, and one path The optical axis of the microscopic vision system is approximately parallel to the Y axis, and the optical axis of the microscopic vision system along the way is approximately parallel to the Z axis. The first, second and third microscopic vision systems all point to the first microscopic vision system to be aligned. The part 6 and the second micro part 7 are used to collect the microscopic visual images of the first micro part 6 and the second micro part 7;

The first motion platform 4 is installed near the first, second and third micro vision systems, and it is used to carry the first micro parts 6, and make the first micro parts 6 in the Within the field of view of the first, second and third microscopic vision systems, preferably, the installation position of the first motion platform 4 is such that the plane of the upper surface of the first micro part 6 is approximately perpendicular to the Z axis;

The first micro-part 6 is installed on the first motion platform 4, and it moves together with the first motion platform 4;

The second motion platform 5 is installed in the space below the microscopic vision system whose optical axis is approximately parallel to the Z axis, and it is used to carry the second micro parts 7 and make the second micro parts 7 in the first position. 1. Within the field of view of the second and third microscopic vision systems, preferably, the installation position of the second motion platform 5 is such that the upper surface plane of the second micro part 7 is approximately perpendicular to the Z axis;

The second micro-part 7 is installed on the second motion platform 5, and it moves together with the second motion platform 5;

The first micro vision system 1 is connected to the computer 13 by the first visual connection line 8; the second micro vision system 2 is connected to the computer 13 by the second visual connection line 9; the third micro vision system 3 is connected to the computer 13 through the third visual connection line 10; the first motion platform 4 is connected to the computer 13 through the first control line 11; the second motion platform 5 is connected to the computer 13 through the second control line 12;

The computer 13 is used to receive the microscopic vision images collected by the first microscopic vision system 1, the second microscopic vision system 2, and the third microscopic vision system 3, and The micro-vision image controls the movement of the first moving platform 4 and the second moving platform 5, so that the first micro-part 6 and the second micro-part 7 are automatically aligned.

In one embodiment of the present invention, the first motion platform 4 has three degrees of freedom in translation; Translational degree of freedom; the first, second and third microscopic vision systems 1, 2, and 3 are all composed of a GC2450 camera and a Navitar microscope lens; the computer 13 adopts Dell Inspiron 545S; the end of the first micro part 6 is a sheet An annular structure with a height of about 1 mm and an outer diameter of about 10 mm; the second micro-part 7 is a hollow cylindrical structure with a height of about 6 mm and an outer diameter of about 7 mm.

Fig. 2 is a flowchart of the automatic alignment method of micro parts based on multi-channel micro-vision in the present invention, which can realize the first micro-part 6 and the second micro-part 6 according to the motion control model based on multi-channel micro-vision Automatic alignment of part 7. As shown in Figure 2, the automatic alignment method includes the following steps:

Step S1: Adjusting the first motion platform 4 to drive the first micro-component 6 into the field of view of the multi-channel micro-vision system, and located in the clear imaging plane of the multi-channel micro-vision system;

Wherein, the multi-channel micro-vision system includes a first micro-vision system 1, a second micro-vision system 2 and a third micro-vision system 3 which are approximately orthogonally arranged in space. Both the second and third microscopic vision systems point to the first micro-part 6 and the second micro-part 7;

Step S2: Adjusting the first motion platform 4 to drive the first micro-part 6 to perform multiple relative movements in the clear imaging plane of the multi-channel microscopic vision system, and calculating each time of the first micro-part 6 The amount of change of the first image feature parameter before and after the second movement, according to the amount of change of the image feature parameter and the corresponding relative displacement of the first motion platform 4, the least square method is used to calculate the motion control of the first micro part 6 Image Jacobian matrix, that is, get J ₁₁ ~ J ₆₃ parameters;

Wherein, the first image characteristic parameter of the first micro-part 6 in the first micro-vision system 1 and the second micro-vision system 2 is the vertical edge line and the horizontal edge of the first micro-part 6 The coordinates of the line intersection point, the first image characteristic parameter in the third micro vision system 3 is the coordinates of the center of the upper surface of the first micro part 6 .

Step S3: Adjusting the second motion platform 5 to drive the second micro part 7 into the field of view of the multi-channel micro-vision system, and to be located in the clear imaging plane of the multi-channel micro-vision system;

In the process of adjusting the pose of the first micro-part 6 and the second micro-part 7 in the steps S1 and S3, the automatic focusing of the multi-channel microscopic vision system is used to ensure that the first micro-part 6 The feature extraction area of the first image and the feature extraction area of the second micro-part 7 remain clear. The first image feature extraction area of the first micro part 6 is the intersection area of vertical edge lines and horizontal edge lines in the first micro vision system 1 and the second micro vision system 2, and in the third In the micro vision system 3, it is the upper surface area; the second image feature extraction area of the second micro part 7 is a vertical edge line in the first micro vision system 1 and the second micro vision system 2 your region.

Step S4: Adjusting the second motion platform 5 to drive the second micro part 7 to perform multiple relative movements within the clear imaging planes of the first micro vision system 1 and the second micro vision system 2 , respectively calculate the variation of the second image characteristic parameter before and after each movement, according to the variation of the second image characteristic parameter and the corresponding relative displacement of the second motion platform 5, calculate the second The image Jacobian matrix of the motion control of the micro-part 7, that is, the J ₁₁ ~ J ₂₂ parameters are obtained;

Among them, when the moving platform drives the target to move relative to each other, the image of the end of the part remains clear in the multi-channel microscopic vision system.

The second image characteristic parameter of the second micro component 7 in the first micro vision system 1 and the second micro vision system 2 is the angle of the vertical edge line.

Step S5: Extract the third image features of the first micro-part 6 and the second micro-part 7 in the multi-channel microscopic vision system, and calculate the first micro-part 6 and the second micro-part 7 The posture deviation of the micro-part 7 in the image space, and then, through the visual servo control method based on the image Jacobian matrix, the posture and posture adjustment of the second micro-part 7 is realized, so that it is consistent with the posture of the first micro-part 6 The attitude deviation is less than the given range;

Wherein, the third image feature of the first micro part 6 is the vertical edge line in the first micro vision system 1 and the second micro vision system 2, and the first micro part 7 of the second micro part 7 Three image features are vertical edge lines in the first microvision system 1 and the second microvision system 2 .

The calculation formula of the attitude deviation is shown in the following formula:

$\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; e</span>}}_{\mathrm{<span\; class="notranslate">\; ang</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; k</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\\ {\mathrm{<span\; class="notranslate">\; e</span>}}_{\mathrm{<span\; class="notranslate">\; ang</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; k</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&alpha;</span>}\end{array}\right.$

Wherein, e _ang1 and e _ang2 respectively refer to the image angle difference between the first micro-part 6 and the second micro-part 7 in the first and second microscopic vision systems, k ₁ and k ₂ are respectively The slope of the vertical edge line of the first micro part 6 in the first and second micro vision systems, β and α are respectively the slopes of the second micro parts 7 in the first and second micro vision systems The vertical edge line angle of .

Step S6: Extract the fourth image features of the first micro-part 6 and the second micro-part 7 in the multi-channel microscopic vision system, and calculate the first micro-part 6 and the second micro-part 6 For the positional deviation of the micro-part 7 in the image space, the position adjustment of the first micro-part 6 is realized through the visual servo control method based on the image Jacobian matrix, so that the positional deviation from the second micro-part 7 is less than a given range , completing the automatic alignment of the first micro-component 6 and the second micro-component 7 .

Wherein, the fourth image feature of the first micro component 6 is the vertical edge line and the horizontal edge line in the first micro vision system 1 and the second micro vision system 2, and in the third micro vision system The center of the upper surface in the micro vision system 3, the fourth image feature of the second micro part 7 is the vertical and horizontal edges in the first micro vision system 1 and the second micro vision system 2 Line, the center of the upper surface in the third microscopic vision system 3 .

The position deviation is calculated by subtracting the fourth image feature coordinates of the first micro-part 6 and the second micro-part 7 .

In the steps S5 and S6, the visual servo control method based on the image Jacobian matrix can be expressed as the following motion control model for the position or attitude adjustment of the micro-parts. The variation of the image feature parameters controls the variation of the relative pose of the part in the three-dimensional space:

$\left[\begin{array}{c}\mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; T</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; \&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}{\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; no</span>}}\\ {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}}\\ <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\\ {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; mn</span>}}\end{array}\right]\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; \&Delta;p</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\\ <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\\ \mathrm{<span\; class="notranslate">\; \&Delta;</span>}{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}\end{array}\right]<span\; class="notranslate">\; ,</span>$

Among them, ΔT _x , ΔT _y , ΔT _z are the relative position changes of the parts along the X, Y, and Z axes in the three-dimensional space, respectively, and Δθ _x , Δθ _y , and Δθ _z are the relative position changes of the parts around the X, Y, and Z axes in the three-dimensional space, respectively. Δp _i is the variation of the image feature parameters of the clear image in the i-th microscopic vision system of the part, i=1, 2,...n, J ₁₁ ～J _mn is the image Jacobian that controls the movement of the part elements of the matrix.

Fig. 3 is a flow chart of the visual servo motion control based on the image Jacobian matrix of the present invention, taking the visual servo motion control of the first micro-part 6 as an example, the motion control method includes the following steps:

1) extracting the fourth image feature of the first micro-part 6 in the multi-channel micro-vision system, the fourth image feature refers to the first micro-part 6 in the first micro-vision system 1 And the vertical edge line and the horizontal edge line in the second micro vision system 2, the upper surface circle center in the third micro vision system 3;

2) dividing the fourth image feature area of the first micro-component 6 in the multi-channel micro-vision system;

3) Extracting the fourth image feature parameter of the first micro-part 6 in the fourth image feature area, the fourth image feature parameter is the first micro-part 6 in the first micro vision system 1 The coordinates of the intersection of the vertical edge line and the horizontal edge line in the second micro vision system 2, and the coordinates of the center of the upper surface in the third micro vision system 3;

4) calculating the fourth image feature parameter difference between the first micro-part 6 and the second micro-part 7, and converting it into a pose error in three-dimensional space based on the calibrated image Jacobian matrix;

5) Judging whether the pose error is less than a given error range, if yes, end the control process, if not, adopt PD (Proportion derivative) control law to control and adjust the pose of the first micropart 6, and repeat process 3 )~5).

In summary, in the method of the present invention, at first, adjust the position of the first micro-part 6 according to step S1; secondly, realize the calibration of the image Jacobian matrix of the motion control of the first micro-part 6 according to step S2; again, according to step S3 Adjust the position of the second micro-part 7; then, realize the calibration of the image Jacobian matrix for the motion control of the second micro-part 7 according to step S4. In one embodiment of the present invention, step S2 carries out 3 relative translational movements, step S4 carries out 2 relative rotational movements, the image Jacobian matrix of the calibrated first micropart 6 movement control and the second micropart 7 movement control The image Jacobian matrix looks like this:

${\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; T</span>}}<span\; class="notranslate">\; =</span>\left[\begin{array}{cc}\mathrm{<span\; class="notranslate">\; 1.0</span>}& \mathrm{<span\; class="notranslate">\; 0.0</span>}\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.2</span>}& \mathrm{<span\; class="notranslate">\; 1.2</span>}\end{array}\right]<span\; class="notranslate">\; ,</span>$

${\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; G</span>}}<span\; class="notranslate">\; =</span>\left[\begin{array}{ccc}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.0010</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.2070</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.0070</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.0010</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.1990</span>}\\ \mathrm{<span\; class="notranslate">\; 0.3210</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}& \mathrm{<span\; class="notranslate">\; 0</span>}\\ \mathrm{<span\; class="notranslate">\; 0.0040</span>}& \mathrm{<span\; class="notranslate">\; 0.0030</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.3270</span>}\\ \mathrm{<span\; class="notranslate">\; 0.2550</span>}& \mathrm{<span\; class="notranslate">\; 0.0140</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.0110</span>}\\ <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.0040</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.1950</span>}& <span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; 0.0010</span>}\end{array}\right]<span\; class="notranslate">\; ,</span>$

Wherein, J _T is the image Jacobian matrix of the motion control of the second micro-component 7 , and J _G is the image Jacobian matrix of the motion control of the first micro-component 6 .

Based on the calibration result of the image Jacobian matrix, firstly, control the attitude adjustment of the second micro-part 7 according to step S5, and then control the position adjustment of the first micro-part 6 according to step S6. In step S5, the parameters of the PD controller are respectively selected as 0.5 and 0.1, and the given error is set to 0.2 degrees. The result of the motion control error is shown in Figure 4. In step S6, the parameters of the PD controller are 0.7 and 0.12 respectively, and the given error is 5 μm. The result of the motion control error is shown in Fig. 5 .

It can be seen from Fig. 4 and Fig. 5 that the pose error of the first micro-part 6 and the second micro-part 7 can quickly converge to a given error range, which has a good control effect and meets the requirements of micro-assembly applications.

Based on the three-way microscopic vision system, the invention realizes the automatic alignment of the three-dimensional space pose of the micro parts, and the automatic alignment method is simple and easy, the assembly efficiency is high, and high control precision can be achieved.

The specific embodiments described above have further described the purpose, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (6)

1. A method for automatic alignment of micro parts based on multi-channel micro vision, characterized in that the method may further comprise the steps: Step S1: By adjusting the first motion platform (4), the first micro-part (6) enters the field of vision of the multi-channel microscopic vision system, and is located in the clear imaging plane of the multi-channel microscopic vision system. The micro vision system comprises a first micro vision system (1), a second micro vision system (2) and a third micro vision system (3) arranged approximately orthogonally in space, the first and second and the third microscopic vision system all point to the first micro-part (6) and the second micro-part (7); Step S2: by adjusting the first motion platform (4) to drive the first micro-component (6) to perform multiple relative movements in the clear imaging plane of the multi-channel microscopic vision system, respectively calculate the first The change amount of the first image characteristic parameter before and after each movement of the micro-part (6), according to the change amount of the image characteristic parameter and the corresponding relative displacement of the first motion platform (4), the least squares method is used to calculate the The image Jacobian matrix of the motion control of the first micro-part (6), that is, the elements J ₁₁ to J ₆₃ of the image Jacobian matrix are obtained; Step S3: Adjusting the second motion platform (5) to drive the second micro part (7) into the field of view of the multi-channel microscopic vision system, and to be located in the clear imaging plane of the multi-channel microscopic vision system ; Step S4: adjusting the second motion platform (5) to drive the clarity of the second micro parts (7) in the first micro vision system (1) and the second micro vision system (2) Carry out multiple relative movements in the imaging plane, respectively calculate the variation of the second image characteristic parameter before and after each movement, and according to the variation of the second image characteristic parameter and the corresponding relative displacement of the second motion platform (5), Calculating the image Jacobian matrix of the motion control of the second micro-part (7) by using the least square method, that is, obtaining the elements J ₁₁ -J ₂₂ of the image Jacobian matrix; Step S5: Extract the third image features of the first micro-part (6) and the second micro-part (7) in the multi-channel microscopic vision system, and calculate the first micro-part (6) ) and the attitude deviation of the second micro-part (7) in the image space, and then realize the adjustment of the pose and attitude of the second micro-part (7) through the visual servo control method based on the image Jacobian matrix, so that it is consistent with The posture posture deviation of the first micro-part (6) is smaller than a given range; Step S6: extracting the fourth image features of the first micro-part (6) and the second micro-part (7) in the multi-channel micro vision system, and calculating the first micro-part (6) ) and the position deviation of the second micro-part (7) in the image space, the position adjustment of the first micro-part (6) is realized through the visual servo control method based on the image Jacobian matrix, so that it is different from the second micro-part (7) The position deviation of the micro part (7) is less than a given range, and the automatic alignment of the first micro part (6) and the second micro part (7) is completed. 2. The method according to claim 1, characterized in that, the first micro part (6) in the first micro vision system (1) and the second micro vision system (2) The first image feature parameter is the coordinates of the intersection of the vertical edge line and the horizontal edge line of the first micro-part (6), and the first image feature parameter in the third microscopic vision system (3) is the first The coordinates of the center of circle on the upper surface of the micropart (6); The second image characteristic parameter of the second micro part (7) in the first micro vision system (1) and the second micro vision system (2) is the angle of the vertical edge line; The third image feature of the first micropart (6) is a vertical edge line in the first microscopic vision system (1) and the second microscopic vision system (2), the second microscopic vision system (2) a third image feature of the part (7) is a vertical edge line in said first microvision system (1) and said second microvision system (2); The fourth image feature of the first micro part (6) is the vertical edge line and the horizontal edge line in the first micro vision system (1) and the second micro vision system (2), in The upper surface circle center in the third microscopic vision system (3), the fourth image feature of the second micro part (7) is that it is in the first microscopic vision system (1) and the second display The vertical and horizontal edge lines in the micro vision system (2), the upper surface circle center in the third micro vision system (3). 3. method according to claim 1, is characterized in that, utilizes following formula to calculate described posture deviation: $\left\{\begin{array}{c}{\mathrm{<span\; class="notranslate">\; e</span>}}_{\mathrm{<span\; class="notranslate">\; ang</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; k</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&beta;</span>}\\ {\mathrm{<span\; class="notranslate">\; e</span>}}_{\mathrm{<span\; class="notranslate">\; ang</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; =</span>\mathrm{<span\; class="notranslate">\; arctan</span>}<span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; k</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}<span\; class="notranslate">\; )</span><span\; class="notranslate">\; +</span>\mathrm{<span\; class="notranslate">\; \&pi;</span>}<span\; class="notranslate">\; /</span>\mathrm{<span\; class="notranslate">\; 2</span>}<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; \&alpha;</span>}\end{array}\right.<span\; class="notranslate">\; ,</span>$ Wherein, e _ang1 , e _ang2 respectively refer to the image angle difference between the first micro-part (6) and the second micro-part (7) in the first and second microscopic vision systems, k ₁ and k ₂ are respectively the vertical edge line slopes of the first micro-part (6) in the first and second microscopic vision systems, β and α are the slopes of the second micro-part (7) in the first , the vertical edge line angle in the second microscopic vision system. 4. The method according to claim 1, wherein the position deviation is calculated by subtracting the fourth image feature coordinates of the first micro-part (6) and the second micro-part (7). 5. The method according to claim 1, wherein the visual servo control method based on the image Jacobian matrix can be expressed as the following motion control model for the position or attitude adjustment of micro parts: $\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&Delta;T</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&Delta;\&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; x</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&Delta;\&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; the\; y</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&Delta;\&theta;</span>}}_{\mathrm{<span\; class="notranslate">\; z</span>}}\end{array}\right]<span\; class="notranslate">\; =</span>\left[\begin{array}{cccc}{\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; 11</span>}}& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; 12</span>}}& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}\mathrm{<span\; class="notranslate">\; no</span>}}\\ {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; one</span>}}& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; twenty\; two</span>}}& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}\mathrm{<span\; class="notranslate">\; no</span>}}\\ <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\\ {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 1</span>}}& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; m</span>}\mathrm{<span\; class="notranslate">\; 2</span>}}& <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>& {\mathrm{<span\; class="notranslate">\; J</span>}}_{\mathrm{<span\; class="notranslate">\; mn</span>}}\end{array}\right]\left[\begin{array}{c}{\mathrm{<span\; class="notranslate">\; \&Delta;p</span>}}_{\mathrm{<span\; class="notranslate">\; 1</span>}}\\ {\mathrm{<span\; class="notranslate">\; \&Delta;p</span>}}_{\mathrm{<span\; class="notranslate">\; 2</span>}}\\ <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\\ {\mathrm{<span\; class="notranslate">\; \&Delta;p</span>}}_{\mathrm{<span\; class="notranslate">\; i</span>}}\\ <span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span><span\; class="notranslate">\; .</span>\\ {\mathrm{<span\; class="notranslate">\; \&Delta;p</span>}}_{\mathrm{<span\; class="notranslate">\; no</span>}}\end{array}\right]$ Among them, ΔT _x , ΔT _y , ΔT _z are the relative position changes of the parts along the X, Y, and Z axes in the three-dimensional space, respectively, and Δθ _x , Δθ _y , and Δθ _z are the relative position changes of the parts around the X, Y, and Z axes in the three-dimensional space, respectively. Δp _i is the variation of the image feature parameters of the clear image of the part in the i-th microscopic vision system, i=1,2,...n, J ₁₁ ~ J _mn are the images that control the movement of the part Elements of the Jacobian matrix. 6. method according to claim 1, is characterized in that, based on the visual servo motion control method of image Jacobian matrix, comprises the following steps: 1) respectively extracting the fourth image feature of a micro part in the multi-channel micro vision system; 2) dividing the fourth image characteristic area of the micro-part in the multi-channel micro-vision system; 3) extracting the fourth image feature parameter of the micro-part in the fourth image feature area; 4) calculating the fourth image feature parameter difference between the micro-part and another micro-part, and converting it into a pose error in three-dimensional space based on the calibrated image Jacobian matrix; 5) Judging whether the pose error is smaller than a given error range, if yes, end the control process, if not, control and adjust the pose of the micro-part, and repeat steps 3) to 5).