CN114527471A - Non-contact type layering positioning instrument positioning method - Google Patents

Abstract

The invention discloses a positioning method of a non-contact type layering positioning instrument, and belongs to the technical field of composite material part manufacturing. When the workpiece is positioned, whether the workpiece has a cooperative target mark point is judged according to the type of the workpiece, if the workpiece has a cooperative target, a binocular vision system is adopted to identify the mark point, and a coordinate point converted by the target is input into a layering locator control computer by combining a laser ranging system to complete the spatial positioning of the workpiece to be measured. If no cooperation target exists, the laser ranging module and the galvanometer scanning mechanism are adopted to carry out laser projection, characteristic points of the workpiece to be detected are searched and matched with the imported workpiece model, and therefore positioning information is obtained. The positioning method of the layering positioning instrument has high intelligent degree, can solve the problem of space positioning of zero contact with workpieces, and realizes the space positioning of all the workpieces to be measured with different shapes in the measuring range of the layering positioning instrument by using one positioning method.

Description

Non-contact type layering positioning instrument positioning method

Technical Field

The invention relates to a non-contact type positioning method for a layering positioning instrument, and belongs to the technical field of composite material part manufacturing.

Background

The laying locator is one of advanced intelligent manufacturing equipment widely used in the field of composite material part manufacturing, and is mainly used for work such as composite material laying, workpiece positioning, welding and the like. When the laser processing system works, firstly, a tested workpiece model is led into a control system of the instrument, the control system projects laser on the surface of a processed workpiece, and other equipment or personnel are assisted to complete related processing work. For the coupling of the model and the real workpiece, the real workpiece to be processed needs to be spatially positioned first, and then the workpiece and the model coordinate are aligned in an instrument control system, so that an accurate laser projection position is obtained. Therefore, the space positioning precision of the workpiece to be measured is an important factor influencing the accuracy degree of the overlay positioning instrument.

The existing measured workpiece positioning technology mainly depends on a special optical material tool, the tool is placed on the edge of the measured workpiece, and the tool is searched through a layer positioning instrument to position the measured workpiece. However, this method is not suitable for all shapes of workpieces, does not resist high temperature, requires removal before thermal processing of the workpiece, and has low repeatability of placement. Therefore, the problem to be solved urgently is to provide an accurate non-contact type workpiece positioning method for the overlay positioning instrument.

Disclosure of Invention

The invention discloses a non-contact type positioning method of a layer positioning instrument, aiming at solving the problem that the existing workpiece space positioning technology depends on a tool, and aiming at meeting the space positioning requirements of all workpieces to be measured with different shapes in the measuring range of the layer positioning instrument.

The purpose of the invention is realized by the following technical scheme:

the invention discloses a non-contact type layer positioning instrument positioning method which adopts two positioning modes of a binocular vision system and a laser ranging system. Firstly, judging whether the workpiece has a cooperative target mark point according to the type of the workpiece, if the workpiece has the cooperative target, adopting a binocular vision system to identify the mark point, and inputting a coordinate point converted from the target into a layering locator control computer by combining a laser ranging system to complete the spatial positioning of the measured workpiece. If no cooperation target exists, the laser ranging module and the galvanometer scanning mechanism are adopted to carry out laser projection, the characteristic points of the workpiece to be detected are searched and matched with the imported workpiece model, and therefore positioning information is obtained.

The invention discloses a non-contact type positioning method of a layering positioning instrument, which comprises the following steps:

the method comprises the following steps: judging whether the workpiece has a cooperative target mark point;

step two: accurately positioning a workpiece based on a binocular vision system or a laser ranging system;

if the workpiece has the cooperative target mark points, identifying the mark points by adopting a binocular vision system:

obtaining image coordinates of a target point by a camera, measuring the coordinates of the target point by a binocular vision system, measuring the distance of the target point by a laser distance measuring module according to needs, substituting distance information into calculation, and providing position information of the target point for a layer positioning instrument so as to determine the position of a processed workpiece;

if the workpiece has no cooperative target mark point, positioning by adopting a laser ranging system:

and emitting laser through a vibrating mirror carried by the layering positioning instrument, slowly scanning the edge characteristic points of the workpiece, performing laser ranging and light return power recording while scanning, and performing matching comparison with an introduced workpiece model through data analysis to obtain information of the spatial position of the obvious characteristic points of the workpiece, thereby determining the position of the processed workpiece.

Step three: the system calculates to obtain a target space position or a contour space position;

the three-dimensional coordinates of a plurality of target points or characteristic points of the workpiece are accurately measured through the positioning system, and the position coordinates of the target points or the characteristic points in the workpiece are combined and are registered through a coordinate system, so that the position and posture relation between a paving layer locator coordinate system and a workpiece coordinate system is obtained, and the preparation work of projecting laser patterns on the workpiece by the three-dimensional laser projection system is completed.

Step four: three-dimensional laser projection based on a high-speed galvanometer;

transmitting the positioning information acquired in the third step to a control computer of the layer positioning instrument, wherein the layer positioning instrument aligns with the real workpiece and the model coordinates: the method comprises the steps of introducing a three-dimensional model of a workpiece into a layering locator control computer, defining a position to be projected and a pattern in the computer, generating three-dimensional point cloud of the pattern under a workpiece coordinate system in computer software, converting the three-dimensional point cloud into three-dimensional coordinates under the layering locator coordinate system through the pose relation between the layering locator coordinate system and the workpiece coordinate system, planning a path by the computer software, generating galvanometer rotation angle information corresponding to the three-dimensional point cloud information, sending an angle information instruction to a galvanometer controller by the computer, controlling the galvanometer to rotate by the controller to form a laser pattern, accurately projecting laser to a part to be processed, and completing layering positioning three-dimensional laser projection work.

Has the advantages that:

1. the invention discloses a non-contact type layer positioning instrument positioning method which does not need to be in contact with a processed workpiece, and avoids the processed workpiece from being collided and scratched.

2. The invention discloses a non-contact type layer positioning instrument positioning method, which is characterized in that a workpiece is positioned by utilizing a binocular vision system and a laser ranging system, the workpiece can be accurately positioned with or without a cooperative target, the application range is wide, and the intelligent degree is high.

Drawings

FIG. 1 is a flow chart of a method of non-contact ply locator positioning;

FIG. 2 is a schematic diagram of the positioning operation of the binocular vision system of the method of the present invention;

FIG. 3 is a schematic diagram of the positioning operation of the laser ranging system of the method of the present invention;

wherein the reference numbers:

the system comprises a camera 1, a window 2, a cooperative target mark point 3, a target-containing workpiece 4, an image processing card 5, a data processing unit 6, a laser ranging module 7, a numerical control unit 8, a galvanometer system 9 and a non-target workpiece 10.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and examples. The technical problems and the advantages solved by the technical solutions of the present invention are also described, and it should be noted that the described embodiments are only intended to facilitate the understanding of the present invention, and do not have any limiting effect.

In the embodiment 1, when a workpiece is positioned, whether the workpiece has a cooperative target mark point is judged according to the type of the workpiece, if the workpiece has the cooperative target, the visual system is adopted to identify the mark point to obtain the image coordinate of the target point, the binocular visual system is used for measuring, meanwhile, the laser ranging module is adopted to range the target point according to the requirement, the distance information is substituted and calculated to provide the position information of the target point for a layer positioning instrument, and therefore the position of the workpiece to be processed is determined; the identification method of the mark point image comprises the steps of obtaining a coded mark point image, adopting edge contour extraction in an image identification algorithm in view of the fact that a target mark point is designed into a known coding form, matching based on a graph shape and a contour to obtain a current mark point number, calculating the center image coordinate of the mark point by combining the actual position relation of the target mark point, and further calculating a space three-dimensional coordinate by a binocular vision system. And the three-dimensional coordinates of the mark points are used as common points to realize the registration of the coordinate system of the workpiece and the coordinate of the positioning system.

If the cooperative target exists, the system operates according to the method of fig. 2, namely, the target workpiece 4 in the measuring range contains the cooperative target mark point 3. Firstly, the power supply of a binocular vision system and a laser ranging system is turned on, two cameras 1 are used for shooting a target mark point through window glass 2, the image coordinate of the target mark is converted into the direction of the mark relative to the coordinate system of a layer positioning instrument system through an image processing card 5, a galvanometer system 9 in the layer positioning instrument is used for driving a laser ranging module 7 to irradiate the target mark point, and therefore distance information of the target mark point is obtained. From the information, the three-dimensional coordinate information of the target mark point can be solved and input into the layering positioning instrument.

In embodiment 2, for a workpiece without a target mark point, a laser range finder is used to emit laser through a galvanometer carried by a layer locator, slow scanning is performed on characteristic points of the edge of the workpiece, such as the edge of the workpiece, a round hole, a square hole, and the like, laser range finding and return light power recording are performed while scanning, and matching comparison is performed between data analysis and a guided workpiece model to obtain information of a spatial position of an obvious characteristic of the workpiece, so that positioning information of the whole workpiece is obtained. The non-cooperative target mark point image identification method includes the steps of obtaining the outline of the edge or the special feature of a workpiece through laser ranging scanning, obtaining point cloud data of the feature, comparing the point cloud data with the feature in a workpiece three-dimensional model to achieve feature matching, combining the point cloud data with design data of the feature in the workpiece to obtain three-dimensional coordinates of specific points on the feature, and achieving registration of a workpiece coordinate system and a positioning system coordinate through the fact that the three-dimensional coordinates of the specific points are used as common points.

If there is no target marker point, the system proceeds according to the method of FIG. 3. Firstly, edge feature points of the non-target workpiece 10, such as the hexahedron edge or the ring inflection point of 10 shown in fig. 3, need to be found, the laser ranging module 7 is controlled by the numerical control unit 8, and the laser ranging module irradiates onto the obvious features of the processed non-target workpiece 10 through the galvanometer system 9 and performs slow scanning. During scanning, two parameters, namely the distance detected by the laser ranging module 7 and the return light power measured by the galvanometer system, are transmitted to the data processing unit 6 for data analysis, and after the profile is obtained, the profile is compared with a digital model led in the layer positioning instrument to determine the real space position of the workpiece to be measured.

Positioning information of the two systems is transmitted to a control computer of the layering positioning instrument so as to help the layering positioning instrument align with real workpiece and model coordinates, laser is projected to a position needing to be processed accurately, and layering positioning work is completed.

The method comprises the steps of introducing a three-dimensional model of a workpiece into a layering locator control computer, defining a position to be projected and a pattern in the computer, generating three-dimensional point cloud of the pattern under a workpiece coordinate system in computer software, converting the three-dimensional point cloud into three-dimensional coordinates under the layering locator coordinate system through the pose relation between the layering locator coordinate system and the workpiece coordinate system, planning a path by the computer software, generating galvanometer rotation angle information corresponding to the three-dimensional point cloud information, sending an angle information instruction to a galvanometer controller by the computer, controlling the galvanometer to rotate by the controller to form a laser pattern, accurately projecting laser to a part to be processed, and completing layering positioning three-dimensional laser projection work.

The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (4)

1. A non-contact type positioning method of a layering positioning instrument is characterized by comprising the following steps: the method comprises the following steps:

the method comprises the following steps: judging whether the workpiece has a cooperative target mark point;

step two: accurately positioning a workpiece based on a binocular vision system or a laser ranging system;

step three: the system calculates to obtain a target space position or a contour space position;

step four: three-dimensional laser projection based on a high-speed galvanometer.

2. The non-contact type overlay locator positioning method according to claim 1, wherein: the implementation method of the second step is as follows:

if the workpiece has the cooperative target mark points, identifying the mark points by adopting a binocular vision system:

obtaining image coordinates of a target point by a camera, measuring the coordinates of the target point by a binocular vision system, measuring the distance of the target point by a laser distance measuring module according to needs, substituting distance information into calculation, and providing position information of the target point for a layer positioning instrument so as to determine the position of a processed workpiece;

if the workpiece has no cooperative target mark point, positioning by adopting a laser ranging system:

and emitting laser through a vibrating mirror carried by the layering positioning instrument, slowly scanning the edge characteristic points of the workpiece, performing laser ranging and light return power recording while scanning, and performing matching comparison with an introduced workpiece model through data analysis to obtain information of the spatial position of the obvious characteristic points of the workpiece, thereby determining the position of the processed workpiece.

3. The non-contact type overlay locator positioning method according to claim 1, wherein: the third step is realized by the following steps:

the three-dimensional coordinates of a plurality of target points or characteristic points of the workpiece are accurately measured through the positioning system, and the position coordinates of the target points or the characteristic points in the workpiece are combined and are registered through a coordinate system, so that the position and posture relation between a paving layer locator coordinate system and a workpiece coordinate system is obtained, and the preparation work of projecting laser patterns on the workpiece by the three-dimensional laser projection system is completed.

4. The non-contact type overlay locator positioning method according to claim 1, wherein: the implementation method of the fourth step is as follows:

transmitting the positioning information acquired in the third step to a control computer of the layer positioning instrument, wherein the layer positioning instrument aligns with the real workpiece and the model coordinates: the method comprises the steps of introducing a three-dimensional model of a workpiece into a layering locator control computer, defining a position to be projected and a pattern in the computer, generating three-dimensional point cloud of the pattern under a workpiece coordinate system in computer software, converting the three-dimensional point cloud into three-dimensional coordinates under the layering locator coordinate system through the pose relation between the layering locator coordinate system and the workpiece coordinate system, planning a path by the computer software, generating galvanometer rotation angle information corresponding to the three-dimensional point cloud information, sending an angle information instruction to a galvanometer controller by the computer, controlling the galvanometer to rotate by the controller to form a laser pattern, accurately projecting laser to a part to be processed, and completing layering positioning three-dimensional laser projection work.

Images