Visual calibration method and device of visual assembly system and medium

Abstract

The invention relates to the technical field of visual guidance, and provides a visual calibration method and device of a visual assembly system and a medium, and the visual assembly system comprises a camera, a motion control platform and a clamping device. The motion control platform at least comprises a first moving mechanism for driving the clamping device to move in a first direction and a second moving mechanism for driving the clamping device to move in a second direction, the first direction is perpendicular to the second direction, and the camera is used for observing a calibration object clamped by the clamping device. The method comprises the following steps: acquiring first coordinates of a plurality of preset calibration points in a platform coordinate system of the motion control platform; obtaining a deviation angle of a product coordinate system relative to a platform coordinate system; compensating the first coordinate according to the deviation angle to obtain a second coordinate of the calibration point position; and according to the second coordinates, calibrating a conversion relation between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera.

Description

Technical Field

[0001] The embodiments of the present disclosure relate to the field of vision guidance technology, and more specifically, to a vision calibration method, device and medium for a vision assembly system. Background Art

[0002] One of the main features of industrial robots is that they are good at performing repetitive precision labor. However, in practical applications, robots are often required to accurately locate randomly placed workpieces through sensors before they can perform subsequent precision labor. Area array cameras in visual sensors are widely used in robot vision guidance technology because of their mature technology and low price. The key to the accuracy of robot vision guidance positioning is the accuracy of the coordinate transformation formula from the camera pixel coordinate system to the robot world coordinate system. The process of establishing the coordinate transformation formula is commonly referred to as "hand-eye calibration."

[0003] In conventional visual positioning projects, the camera and the motion mechanism are usually calibrated at nine points to establish a relationship. If there is a rotation axis, a rotation calibration is also performed to calculate the new coordinates of the feature points after rotation, so as to calculate the actual offset.

[0004] However, if there is an angle between the product coordinate system and the coordinate system of the motion mechanism, a large calibration error will occur, affecting the processing effect. Summary of the invention

[0005] An objective of the embodiments of the present disclosure is to provide a visual calibration method, device and medium for a visual assembly system.

[0006] According to a first aspect of an embodiment of the present disclosure, a visual calibration method for a visual assembly system is provided, wherein the visual assembly system comprises a camera, a motion control platform and a clamping device, wherein the motion control platform comprises at least a first moving mechanism for driving the clamping device to move in a first direction and a second moving mechanism for driving the clamping device to move in a second direction, wherein the first direction and the second direction are perpendicular to each other, and the camera is used to observe a calibration object clamped by the clamping device, and the method comprises: Acquire first coordinates of a plurality of preset calibration points in a platform coordinate system of the motion control platform; Obtaining a deviation angle of a product coordinate system relative to the platform coordinate system; Compensating the first coordinate according to the deviation angle to obtain the second coordinate of the calibration point; According to the second coordinates, a conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera is calibrated.

[0007] Optionally, compensating the first coordinate according to the deviation angle to obtain the second coordinate of the calibration point includes: According to the deviation angle and the first coordinate, the coordinate of the calibration point in the platform coordinate system after rotating around the reference point by the deviation angle is determined as the second coordinate.

[0008] Optionally, the second coordinate is determined by the following formula:

[0009]

[0010] in, represents the second coordinate, represents the deviation angle, represents the first coordinate, Represents the coordinates of the reference point in the platform coordinate system.

[0011] Optionally, calibrating the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera according to the second coordinates includes: Traverse multiple calibration points; According to the second coordinate of the currently traversed calibration point, control the first moving mechanism and the second moving mechanism to drive the clamping device to move the clamped calibration object to the currently traversed calibration point, and obtain the third coordinate of the calibration object in the camera coordinate system; Determine whether the multiple calibration points have been traversed, and if so, continue traversing; if not, calibrate the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system according to the second coordinates and the third coordinates.

[0012] Optionally, the motion control platform further includes a third moving mechanism for driving the clamping device to move in a third direction, and a rotating mechanism for driving the clamping device to rotate around the third direction, the third direction is perpendicular to the first direction and the second direction, and the rotating mechanism is arranged on the third moving mechanism; the calibrating the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera according to the second coordinate also includes: The rotation center in the camera coordinate system is calibrated according to the second coordinate.

[0013] Optionally, calibrating the rotation center in the camera coordinate system according to the second coordinate includes: According to the second coordinate, the first moving mechanism and the second moving mechanism are controlled to drive the clamping device to move the clamped calibration object to a selected calibration point, and obtain a fourth coordinate of the calibration object in the camera coordinate system; wherein the selected calibration point is any calibration point except the reference point; Controlling the rotating mechanism to drive the clamping device to rotate the clamped calibration object by a first angle, and obtaining a fifth coordinate of the calibration object in the camera coordinate system; Controlling the rotating mechanism to drive the clamping device to rotate the clamped calibration object by a second angle, and obtaining a sixth coordinate of the calibration object in the camera coordinate system; The rotation center in the camera coordinate system is calibrated according to the fourth coordinate, the fifth coordinate, and the sixth coordinate.

[0014] Optionally, the method further includes: Determining whether the deviation angle is greater than a set angle; In the case where the deviation angle is greater than the set angle, the step of compensating the first coordinate according to the deviation angle to obtain the second coordinate of the calibration point is performed.

[0015] According to a second aspect of the present disclosure, a visual calibration device of a visual assembly system is provided, the visual assembly system comprising a camera, a motion control platform and a clamping device, the motion control platform at least comprising a first moving mechanism for driving the clamping device to move in a first direction, and a second moving mechanism for driving the clamping device to move in a second direction, the first direction and the second direction being perpendicular to each other, the camera being used to observe a calibration object clamped by the clamping device, and the device comprising: A coordinate acquisition module, used to acquire first coordinates of a plurality of preset calibration points in the platform coordinate system of the motion control platform; A deviation acquisition module, used to acquire a deviation angle of a product coordinate system relative to the platform coordinate system; A coordinate compensation module, used to compensate the first coordinate according to the deviation angle to obtain a second coordinate of the calibration point; A coordinate calibration module is used to calibrate the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera according to the second coordinates.

[0016] According to a third aspect of the present disclosure, an electronic device is provided, comprising a processor and a memory, wherein the memory is used to store a computer program, and the processor is used to execute the method described in the first aspect of the present disclosure under the control of the computer program.

[0017] According to a fourth aspect of the present disclosure, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the method described in the first aspect of the present disclosure is implemented.

[0018] Through the embodiments of the present disclosure, the first coordinates of multiple calibration points in the platform coordinate system are compensated according to the deviation angle of the product coordinate system relative to the platform coordinate system of the motion control platform to obtain the second coordinates of the calibration points. According to the second coordinates, the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera is calibrated, which can reduce the calibration error, improve the calibration efficiency, and thus improve the qualified rate of product assembly.

[0019] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0021] Figure 1 is a flow chart of a visual calibration method for a visual assembly system according to an embodiment of the present disclosure; Figure 2 is a block diagram of a visual calibration device of a visual assembly system according to an embodiment of the present disclosure; Figure 3 is a block diagram of a vision calibration device of a vision assembly system according to another embodiment of the present disclosure. DETAILED DESCRIPTION

[0022] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0023] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0024] Technologies, methods and equipment known to persons of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods and equipment should be considered part of the specification.

[0025] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0026] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0027] <Method Example> The present disclosure provides a vision calibration method for a vision assembly system, which can be implemented by a vision calibration device for the vision assembly system.

[0028] In this embodiment, the visual assembly system includes a camera, a motion control platform and a clamping device. The motion control platform includes at least a first moving mechanism that drives the clamping device to move in a first direction and a second moving mechanism that drives the clamping device to move in a second direction. The first direction and the second direction are perpendicular to each other. The camera is used to observe the calibration object clamped by the clamping device.

[0029] In this embodiment, the first moving mechanism and the second moving mechanism may both be electric cylinders, and the clamping device may be a clamp or a suction nozzle.

[0030] Furthermore, the visual assembly system may include one or more cameras, which is not limited here.

[0031] The visual assembly system of this embodiment can assemble materials with semi-finished products in tooling located at specific positions through visual guidance.

[0032] Specifically, the clamping device is used to fix the material. The tooling is used to place the semi-finished product. The first moving mechanism and the second moving mechanism are controlled to move so that when the material on the clamping device and the semi-finished product on the tooling are aligned, the material and the semi-finished product can be assembled. Therefore, it is necessary to accurately calibrate the visual guidance device to ensure that the material on the clamping device and the semi-finished product on the tooling can be accurately aligned and meet the gap requirements for assembly.

[0033] Figure 1 The figure is a flow chart of a vision calibration method for a vision assembly system according to an embodiment of the present disclosure.

[0034] like Figure 1 As shown, the method includes steps S1100 to S1400 as shown below: Step S1100 , obtaining first coordinates of a plurality of preset calibration points in the platform coordinate system of the motion control platform.

[0035] In this embodiment, the first coordinates of the multiple calibration points may be pre-set according to application scenarios or specific requirements.

[0036] In this embodiment, the platform coordinate system may be a rectangular coordinate system, that is, two coordinate axes (X axis and Y axis) of the platform coordinate system are perpendicular to each other.

[0037] Further, the X-axis of the platform coordinate system is parallel to the first direction, and the Y-axis of the platform coordinate system is parallel to the second direction.

[0038] In one embodiment, the multiple calibration points may include 9 calibration points, and the coordinates of the 9 calibration points may be shown in Table 1 below.

[0039] Table 1

[0040] Here, k may be set in advance according to the size of the camera's shooting field of view. For example, k may be 5 mm.

[0041] Step S1200, obtaining the deviation angle of the product coordinate system relative to the platform coordinate system.

[0042] In this embodiment, the product coordinate system may be a coordinate system set based on the product to be assembled.

[0043] In this embodiment, the deviation angle may be obtained in advance through an actual angle measurement tool or a drawing.

[0044] In an embodiment where the product coordinate system is a rectangular coordinate system, the deviation angle of the product coordinate system relative to the platform coordinate system can be obtained, which can be the angle between the X-axis of the product coordinate system and the X-axis of the platform coordinate system, or the angle between the Y-axis of the product coordinate system and the Y-axis of the platform coordinate system.

[0045] Step S1300, compensating the first coordinate according to the deviation angle to obtain the second coordinate of the calibration point.

[0046] In this embodiment, the first coordinate is compensated according to the deviation angle, and the first coordinate in the platform coordinate system may be converted into the product coordinate system to obtain the second coordinate.

[0047] In one embodiment of the present disclosure, the first coordinate is compensated according to the deviation angle to obtain the second coordinate of the calibration point, including: determining the coordinate of the calibration point in the platform coordinate system after rotating the calibration point by the deviation angle around the reference point according to the deviation angle and the first coordinate, as the second coordinate.

[0048] The reference point in this embodiment may be any point in the platform coordinate system. For example, the reference point may be the origin of the platform coordinate system.

[0049] In one embodiment of the present disclosure, the second coordinate may be determined by the following formula:

[0050]

[0051] in, represents the second coordinate, Indicates the deviation angle, represents the first coordinate, Indicates the coordinates of the reference point in the platform coordinate system.

[0052] Step S1400: calibrate the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera according to the second coordinates.

[0053] In this embodiment, according to the second coordinates, the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera is calibrated, including the following steps S1410 to S1440: Step S1410, traverse multiple calibration points.

[0054] Step S1420, according to the second coordinate of the currently traversed calibration point, control the first moving mechanism and the second moving mechanism to drive the clamping device to move the clamped calibration object to the currently traversed calibration point, and obtain the third coordinate of the calibration object in the camera coordinate system.

[0055] In this embodiment, when the calibration object is moved to the currently traversed calibration point, the camera is controlled to take a picture of the calibration object to obtain the third coordinate of the calibration object in the camera coordinate system.

[0056] Step S1430, determine whether all calibration points have been traversed. If so, continue to execute step S1410 and continue to traverse; if not, execute step S1440.

[0057] Step S1440: calibrate the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system according to the second coordinates and the third coordinates.

[0058] In this embodiment, the second coordinates and the third coordinates of the multiple calibration points can be substituted into the calibration algorithm to solve the internal and external parameters of the camera, so as to calibrate the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system. Among them, the commonly used calibration algorithm can be, for example, the Zhang Zhengyou calibration method.

[0059] In one embodiment of the present disclosure, the motion control platform also includes a third moving mechanism that drives the clamping device to move in a third direction, and a rotating mechanism that drives the clamping device to rotate around the third direction. The third direction is perpendicular to the first direction and the second direction, and the rotating mechanism is arranged on the third moving mechanism.

[0060] In this embodiment, calibrating the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera according to the second coordinates also includes: calibrating the rotation center in the camera coordinate system according to the second coordinates.

[0061] In one embodiment of the present disclosure, calibrating the rotation center in the camera coordinate system according to the second coordinate includes steps S1450 to S1480 as shown below: Step S1450, according to the second coordinate, control the first moving mechanism and the second moving mechanism to drive the clamping device to move the clamped calibration object to the selected calibration point, and obtain the fourth coordinate of the calibration object in the camera coordinate system.

[0062] The selected calibration point is any calibration point other than the reference point. For example, the selected calibration point may be point 6.

[0063] Step S1460: Control the rotating mechanism to drive the clamping device to rotate the clamped calibration object by a first angle, and obtain the fifth coordinate of the calibration object in the camera coordinate system.

[0064] In this embodiment, the first angle may be an angle pre-set according to an application scenario or specific requirements. For example, the first angle may be any angle between [30 degrees, 90 degrees].

[0065] Step S1470: Control the rotating mechanism to drive the clamping device to rotate the clamped calibration object by a second angle, and obtain the sixth coordinate of the calibration object in the camera coordinate system.

[0066] In this embodiment, the second angle may be an angle pre-set according to an application scenario or specific requirements. For example, the second angle may be any angle between [-30 degrees, -90 degrees].

[0067] In one example, the motion control platform may be such that the camera obtains the fourth coordinate of the calibration object, and the rotation mechanism is controlled to drive the clamping device to rotate the clamped calibration object to the second angle. On this basis, the first angle and the second angle are not equal.

[0068] In another example, the motion control platform may be such that the camera obtains the fifth coordinate of the calibration object, and the rotation mechanism is controlled to drive the clamping device to rotate the clamped calibration object by the second angle. On this basis, after the rotation mechanism is controlled to drive the clamping device to rotate the clamped calibration object by the second angle, the position of the calibration object is different from the position of the calibration object when the camera obtains the fourth coordinate.

[0069] Step S1480, calibrating the rotation center in the camera coordinate system according to the fourth coordinate, the fifth coordinate and the sixth coordinate.

[0070] In this embodiment, the fourth coordinate, the fifth coordinate and the sixth coordinate are all different. Then, the method based on fitting the center of the circle at three points can be used to obtain the mapping coordinates of the rotation center of the platform coordinate system in the camera coordinate system according to the fourth coordinate, the fifth coordinate and the sixth coordinate, that is, to calibrate the rotation center in the camera coordinate system.

[0071] Through the embodiments of the present disclosure, the first coordinates of multiple calibration points in the platform coordinate system are compensated according to the deviation angle of the product coordinate system relative to the platform coordinate system of the motion control platform to obtain the second coordinates of the calibration points. According to the second coordinates, the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera is calibrated, which can reduce the calibration error, improve the calibration efficiency, and thus improve the qualified rate of product assembly.

[0072] In one embodiment of the present disclosure, the method further includes: determining whether the deviation angle is greater than a set angle; when the deviation angle is greater than the set angle, executing step S1400, compensating the first coordinate according to the deviation angle to obtain a second coordinate of the calibration point.

[0073] Further, when the deviation angle is less than or equal to the set angle, the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera is calibrated directly according to the first coordinates.

[0074] In this embodiment, the set angle may be an angle pre-set according to an application scenario or specific requirements. For example, the set angle may be zero.

[0075] Through this embodiment, when the deviation angle is less than or equal to the set angle, an accurate calibration result can be obtained more quickly.

[0076] <Device Example> The present embodiment provides a visual calibration device for a visual assembly system, wherein the visual assembly system includes a camera, a motion control platform and a clamping device, wherein the motion control platform includes at least a first moving mechanism for driving the clamping device to move in a first direction and a second moving mechanism for driving the clamping device to move in a second direction, wherein the first direction and the second direction are perpendicular to each other, and the camera is used to observe the calibration object clamped by the clamping device.

[0077] On the one hand, Figure 2 As shown, the vision calibration device 2000 of the vision assembly system may include a coordinate acquisition module 2100 , a deviation acquisition module 2200 , a coordinate compensation module 2300 and a coordinate calibration module 2400 .

[0078] The coordinate acquisition module 2100 is used to acquire first coordinates of a plurality of preset calibration points in the platform coordinate system of the motion control platform.

[0079] The deviation acquisition module 2200 is used to acquire the deviation angle of the product coordinate system relative to the platform coordinate system.

[0080] The coordinate compensation module 2300 is used to compensate the first coordinate according to the deviation angle to obtain the second coordinate of the calibration point.

[0081] The coordinate calibration module 2400 is used to calibrate the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera according to the second coordinates.

[0082] In one embodiment of the present disclosure, the coordinate compensation module 2300 is specifically used for: According to the deviation angle and the first coordinate, the coordinate of the calibration point in the platform coordinate system after rotating around the reference point by the deviation angle is determined as the second coordinate.

[0083] In one embodiment of the present disclosure, the second coordinate is determined by the following formula:

[0084]

[0085] in, represents the second coordinate, represents the deviation angle, represents the first coordinate, Represents the coordinates of the reference point in the platform coordinate system.

[0086] In one embodiment of the present disclosure, the coordinate calibration module 2400 is used to: Traverse multiple calibration points; According to the second coordinate of the currently traversed calibration point, control the first moving mechanism and the second moving mechanism to drive the clamping device to move the clamped calibration object to the currently traversed calibration point, and obtain the third coordinate of the calibration object in the camera coordinate system; Determine whether the multiple calibration points have been traversed, and if so, continue traversing; if not, calibrate the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system according to the second coordinates and the third coordinates.

[0087] In one embodiment of the present disclosure, the motion control platform also includes a third moving mechanism that drives the clamping device to move in a third direction, and a rotating mechanism that drives the clamping device to rotate around the third direction, the third direction is perpendicular to the first direction and the second direction, and the rotating mechanism is arranged on the third moving mechanism; the coordinate calibration module 2400 is also used to: calibrate the rotation center in the camera coordinate system according to the second coordinate.

[0088] In one embodiment of the present disclosure, calibrating the rotation center in the camera coordinate system according to the second coordinate includes: According to the second coordinate, the first moving mechanism and the second moving mechanism are controlled to drive the clamping device to move the clamped calibration object to a selected calibration point, and obtain a fourth coordinate of the calibration object in the camera coordinate system; wherein the selected calibration point is any calibration point except the reference point; Controlling the rotating mechanism to drive the clamping device to rotate the clamped calibration object by a first angle, and obtaining a fifth coordinate of the calibration object in the camera coordinate system; Controlling the rotating mechanism to drive the clamping device to rotate the clamped calibration object by a second angle, and obtaining a sixth coordinate of the calibration object in the camera coordinate system; The rotation center in the camera coordinate system is calibrated according to the fourth coordinate, the fifth coordinate, and the sixth coordinate.

[0089] In one embodiment of the present disclosure, the visual calibration device 2000 of the visual assembly system further includes: A module for determining whether the deviation angle is greater than a set angle; The coordinate compensation module 2300 is used to execute the step of compensating the first coordinate according to the deviation angle to obtain the second coordinate of the calibration point when the deviation angle is greater than the set angle.

[0090] On the other hand, Figure 3 As shown, the visual calibration device 3000 of the visual assembly system may include a processor 3100 and a memory 3200, the memory 3200 is used to store a computer program, and the processor 3100 is used to control the visual calibration device 3000 of the visual assembly system to execute the method of any embodiment of the present disclosure under the control of the computer program.

[0091] <Readable Storage Medium Embodiment> This embodiment provides a computer-readable storage medium, in which a computer program is stored. When the computer program is executed by a processor, the method described in any method embodiment of the present disclosure is executed.

[0092] The present invention may be a system, a method and / or a computer program product. The computer program product may include a computer-readable storage medium carrying computer-readable program instructions for causing a processor to implement various aspects of the present invention.

[0093] A computer-readable storage medium may be a tangible device that can hold and store instructions used by an instruction execution device. A computer-readable storage medium may be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any suitable combination of the above. More specific examples (a non-exhaustive list) of computer-readable storage media include: a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a static random access memory (SRAM), a portable compact disk read-only memory (CD-ROM), a digital versatile disk (DVD), a memory stick, a floppy disk, a mechanical encoding device, such as a punch card or a raised structure in a groove on which instructions are stored, and any suitable combination of the above. The computer-readable storage medium used herein is not to be interpreted as a transient signal itself, such as a radio wave or other freely propagating electromagnetic wave, an electromagnetic wave propagating through a waveguide or other transmission medium (e.g., a light pulse through a fiber optic cable), or an electrical signal transmitted through a wire.

[0094] The computer-readable program instructions described herein can be downloaded from a computer-readable storage medium to each computing / processing device, or downloaded to an external computer or external storage device via a network, such as the Internet, a local area network, a wide area network, and / or a wireless network. The network can include copper transmission cables, optical fiber transmissions, wireless transmissions, routers, firewalls, switches, gateway computers, and / or edge servers. The network adapter card or network interface in each computing / processing device receives the computer-readable program instructions from the network and forwards the computer-readable program instructions for storage in the computer-readable storage medium in each computing / processing device.

[0095] The computer program instructions for performing the operation of the present invention may be assembly instructions, instruction set architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state setting data, or source code or object code written in any combination of one or more programming languages, including object-oriented programming languages, such as Smalltalk, C++, etc., and conventional procedural programming languages, such as "C" language or similar programming languages. The computer-readable program instructions may be executed entirely on the user's computer, partially on the user's computer, as a separate software package, partially on the user's computer, partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., using an Internet service provider to connect through the Internet). In some embodiments, by using the state information of the computer-readable program instructions to personalize an electronic circuit, such as a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), the electronic circuit may execute the computer-readable program instructions, thereby implementing various aspects of the present invention.

[0096] Various aspects of the present invention are described herein with reference to the flowcharts and / or block diagrams of the methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each box of the flowchart and / or block diagram and the combination of the boxes in the flowchart and / or block diagram can be implemented by computer-readable program instructions.

[0097] These computer-readable program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing device, thereby producing a machine, so that when these instructions are executed by the processor of the computer or other programmable data processing device, a device that implements the functions / actions specified in one or more boxes in the flowchart and / or block diagram is generated. These computer-readable program instructions can also be stored in a computer-readable storage medium, and these instructions cause the computer, programmable data processing device, and / or other equipment to work in a specific manner, so that the computer-readable medium storing the instructions includes a manufactured product, which includes instructions for implementing various aspects of the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0098] Computer-readable program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other device so that a series of operating steps are performed on the computer, other programmable data processing apparatus, or other device to produce a computer-implemented process, thereby causing the instructions executed on the computer, other programmable data processing apparatus, or other device to implement the functions / actions specified in one or more boxes in the flowchart and / or block diagram.

[0099] The flow charts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the systems, methods and computer program products according to multiple embodiments of the present invention. In this regard, each box in the flow chart or block diagram can represent a part of a module, a program segment or an instruction, and a part of the module, a program segment or an instruction contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flow chart, and the combination of the boxes in the block diagram and / or flow chart can be implemented by a dedicated hardware-based system that performs the specified function or action, or can be implemented by a combination of dedicated hardware and computer instructions. It is well known to those skilled in the art that it is equivalent to implement it by hardware, implement it by software, and implement it by combining software and hardware.

[0100] Embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles of the embodiments, practical applications, or technical improvements in the marketplace, or to enable other persons of ordinary skill in the art to understand the embodiments disclosed herein. The scope of the present invention is defined by the appended claims.

Claims

1. A visual calibration method for a visual assembly system, characterized in that: The visual assembly system comprises a camera, a motion control platform and a clamping device, wherein the motion control platform comprises at least a first moving mechanism for driving the clamping device to move in a first direction and a second moving mechanism for driving the clamping device to move in a second direction, wherein the first direction and the second direction are perpendicular to each other, and the camera is used to observe the calibration object clamped by the clamping device. The method comprises: Acquire first coordinates of a plurality of preset calibration points in a platform coordinate system of the motion control platform; Obtaining a deviation angle of a product coordinate system relative to the platform coordinate system; Compensating the first coordinate according to the deviation angle to obtain the second coordinate of the calibration point; According to the second coordinates, a conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera is calibrated.

2. The method according to claim 1, characterized in that The compensating the first coordinate according to the deviation angle to obtain the second coordinate of the calibration point includes: According to the deviation angle and the first coordinate, the coordinate of the calibration point in the platform coordinate system after rotating around the reference point by the deviation angle is determined as the second coordinate.

3. The method according to claim 2, characterized in that The second coordinate is determined by the following formula: in, represents the second coordinate, represents the deviation angle, represents the first coordinate, Represents the coordinates of the reference point in the platform coordinate system.

4. The method according to claim 1, characterized in that: The step of calibrating the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera according to the second coordinates includes: Traverse multiple calibration points; According to the second coordinate of the currently traversed calibration point, control the first moving mechanism and the second moving mechanism to drive the clamping device to move the clamped calibration object to the currently traversed calibration point, and obtain the third coordinate of the calibration object in the camera coordinate system; Determine whether the multiple calibration points have been traversed, and if so, continue traversing; if not, calibrate the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system according to the second coordinates and the third coordinates.

5. The method according to claim 4, characterized in that The motion control platform further includes a third moving mechanism for driving the clamping device to move in a third direction, and a rotating mechanism for driving the clamping device to rotate around the third direction, wherein the third direction is perpendicular to the first direction and the second direction, and the rotating mechanism is arranged on the third moving mechanism; the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera is calibrated according to the second coordinate, and further includes: The rotation center in the camera coordinate system is calibrated according to the second coordinate.

6. The method according to claim 5, characterized in that The step of calibrating the rotation center in the camera coordinate system according to the second coordinate includes: According to the second coordinate, the first moving mechanism and the second moving mechanism are controlled to drive the clamping device to move the clamped calibration object to a selected calibration point, and obtain a fourth coordinate of the calibration object in the camera coordinate system; wherein the selected calibration point is any calibration point except the reference point; Controlling the rotating mechanism to drive the clamping device to rotate the clamped calibration object by a first angle, and obtaining a fifth coordinate of the calibration object in the camera coordinate system; Controlling the rotating mechanism to drive the clamping device to rotate the clamped calibration object by a second angle, and obtaining a sixth coordinate of the calibration object in the camera coordinate system; The rotation center in the camera coordinate system is calibrated according to the fourth coordinate, the fifth coordinate, and the sixth coordinate.

7. The method according to claim 1, characterized in that The method further comprises: Determining whether the deviation angle is greater than a set angle; In the case where the deviation angle is greater than the set angle, the step of compensating the first coordinate according to the deviation angle to obtain the second coordinate of the calibration point is performed.

8. A visual calibration device for a visual assembly system, characterized in that: The visual assembly system comprises a camera, a motion control platform and a clamping device, wherein the motion control platform comprises at least a first moving mechanism for driving the clamping device to move in a first direction and a second moving mechanism for driving the clamping device to move in a second direction, wherein the first direction and the second direction are perpendicular to each other, and the camera is used to observe the calibration object clamped by the clamping device, and the device comprises: A coordinate acquisition module, used to acquire first coordinates of a plurality of preset calibration points in the platform coordinate system of the motion control platform; A deviation acquisition module, used to acquire a deviation angle of a product coordinate system relative to the platform coordinate system; A coordinate compensation module, used to compensate the first coordinate according to the deviation angle to obtain a second coordinate of the calibration point; A coordinate calibration module is used to calibrate the conversion relationship between the coordinates in the platform coordinate system and the coordinates in the camera coordinate system of the camera according to the second coordinates.

9. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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