A gantry platform calibration method and a gantry platform

Abstract

The present invention discloses a calibration method for a gantry platform and a gantry platform. The method includes: obtaining the first planar coordinates of a first calibration point and the second planar coordinates of a second calibration point; obtaining the third planar coordinates of the first calibration point and the fourth planar coordinates of the second calibration point; determining the offset angle of the calibration point according to the first planar coordinates, the second planar coordinates, the third planar coordinates, and the fourth planar coordinates; obtaining the reference geometric position relationship between the first calibration point and the second calibration point; taking the third planar coordinates as a reference, and determining the fifth planar coordinates of the second calibration point according to the offset angle of the calibration point and the reference geometric position relationship; determining the motion compensation amount of the gantry platform according to the second planar coordinates and the fifth planar coordinates; or, taking the fourth planar coordinates as a reference, determining the sixth planar coordinates of the first calibration point according to the offset angle of the calibration point and the reference geometric position relationship; determining the motion compensation amount of the gantry platform according to the first planar coordinates and the sixth planar coordinates.

Description

Technical Field

[0001] The embodiments of the present invention relate to motion control technology, and in particular to a calibration method for a gantry platform and a gantry platform. Background Art

[0002] The dual-drive gantry platform is driven by dual encoders, has high positioning accuracy and repeat positioning accuracy, and is commonly used in processes such as positioning and picking of materials, visual inspection, etc., and is widely used in high-precision and high-speed application environments such as semiconductor packaging, visual inspection, and laser cutting.

[0003] Limited by the long-term movement of the dual-drive gantry platform at a relatively high speed and acceleration, the generated heat will affect the performance of the dual-drive grating scale, causing the linear motor to have a temperature drift phenomenon, which in turn affects the motion accuracy of the entire gantry platform. Therefore, it is very necessary to regularly verify and calibrate the motion accuracy of the gantry platform, and judge and feedback the generated temperature drift error. However, there is a lack of research solutions in this regard in the industrial applications. Summary of the Invention

[0004] The present invention provides a calibration method for a gantry platform and a gantry platform to achieve the purpose of automatically verifying and calibrating the motion accuracy of the gantry platform.

[0005] In a first aspect, an embodiment of the present invention provides a calibration method for a gantry platform, including:

[0006] Obtain the first planar coordinates of the first calibration point at the first moment, and obtain the second planar coordinates of the second calibration point at the first moment;

[0007] Obtain the third planar coordinates of the first calibration point at the second moment, and obtain the fourth planar coordinates of the second calibration point at the second moment;

[0008] Determine the calibration point offset angle according to the first planar coordinates, the second planar coordinates, the third planar coordinates, and the fourth planar coordinates;

[0009] Obtain the reference geometric position relationship between the first calibration point and the second calibration point;

[0010] Taking the third planar coordinates as a reference, determine the fifth planar coordinates of the second calibration point according to the calibration point offset angle and the reference geometric position relationship;

[0011] Determine the motion compensation amount of the gantry platform according to the second planar coordinates and the fifth planar coordinates;

[0012] Alternatively, taking the fourth planar coordinates as a reference, determine the sixth planar coordinates of the first calibration point according to the calibration point offset angle and the reference geometric position relationship;

[0013] Determine the motion compensation amount of the gantry platform according to the first plane coordinate and the sixth plane coordinate.

[0014] Optionally, it further includes:

[0015] Determine the first offset amount of the first calibration point between the first moment and the second moment according to the first plane coordinate and the third plane coordinate;

[0016] Determine the second offset amount of the second calibration point between the first moment and the second moment according to the second plane coordinate and the fourth plane coordinate;

[0017] If the first offset amount is greater than the first offset threshold and the second offset amount is greater than the second offset threshold, then calculate the motion compensation amount of the gantry platform.

[0018] Optionally, it further includes:

[0019] Obtain the first tilt characteristic angle of the first calibration point at the second moment, and determine the first plane coordinate orthogonality of the gantry platform according to the first tilt characteristic angle;

[0020] Obtain the second tilt characteristic angle of the second calibration point at the second moment, and determine the second plane coordinate orthogonality of the gantry platform according to the second tilt characteristic angle;

[0021] If the first offset amount is greater than the first offset threshold, the second offset amount is greater than the second offset threshold, the first plane coordinate orthogonality of the gantry platform is greater than the first orthogonality threshold, and the second plane coordinate orthogonality of the gantry platform is greater than the second orthogonality threshold, then calculate the motion compensation amount of the gantry platform.

[0022] Optionally, it further includes:

[0023] After calculating the fifth plane coordinate with the third plane coordinate as the reference, or after calculating the sixth plane coordinate with the fourth plane coordinate as the reference, it further includes;

[0024] Output and display the fifth plane coordinate, the sixth plane coordinate, and the offset angle of the calibration point.

[0025] Optionally, the formula for determining the first offset amount includes:

[0026] Δx1 = x1 ′ - x1

[0027] Δy1 = y1 ′ - y1

[0028] The formula for determining the second offset amount includes:

[0029] Δx2 = x2′ -x2

[0030] Δy2 = y2 ′ -y2

[0031] Wherein, (Δx1, Δy1) represents the first offset, (x1, y1) represents the first planar coordinate, (x1 ′ , y1 ′ ) represents the third planar coordinate;

[0032] (Δx2, Δy2) represents the second offset, (x2, y2) represents the second planar coordinate, (x2 ′ , y2 ′ ) represents the fourth planar coordinate.

[0033] Optionally, the formula for determining the motion compensation amount of the gantry platform includes:

[0034]

[0035] Or;

[0036]

[0037] Wherein, l represents the motion compensation amount of the gantry platform, p1 represents the first planar coordinate, p1″ represents the sixth planar coordinate, p2 represents the second planar coordinate, and p2″ represents the fifth planar coordinate.

[0038] Optionally, the motion compensation amount of the gantry platform includes a first motion axis compensation amount and a second motion axis compensation amount;

[0039] The first motion axis compensation amount is used for compensating the control amount of the first motion motor in the direction of the first motion axis of the gantry platform;

[0040] The second motion axis compensation amount is used for compensating the control amount of the second motion motor in the direction of the second motion axis of the gantry platform.

[0041] In a second aspect, an embodiment of the present invention further provides a gantry platform, including a controller, and the controller is configured with an executable program, and when the executable program runs, it is used to implement any one of the gantry platform calibration methods described in the embodiments of the present invention.

[0042] Optionally, it is further configured with a first calibration point and a second calibration point;

[0043] The first calibration point is arranged on the workbench of the gantry platform, and the second calibration point is arranged on the marble platform on which the gantry platform is installed.

[0044] Optionally, a motor lead screw module and a vision camera are also configured.

[0045] The vision camera is fixedly connected to the motor lead screw module, and the motor lead screw module is fixedly connected to the crossbeam slider of the gantry platform.

[0046] The vision camera is used to obtain images of the first calibration point and the second calibration point, and the images are used as the basis for determining the planar coordinates of the first calibration point and the second calibration point.

[0047] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention proposes a gantry platform calibration method, which includes obtaining the first planar coordinates and the second planar coordinates of the first calibration point and the second calibration point set at different positions on the gantry platform at the first moment, obtaining the third planar coordinates and the fourth planar coordinates of the first calibration point and the second calibration point at the second moment, determining the position offset of the first calibration point and the second calibration point at the first moment and the first calibration point and the second calibration point at the second moment according to the geometric relationship, determining the motion error of the gantry platform according to the offset, and generating a gantry platform motion compensation amount (for the gantry platform motor) for compensating the motion error, realizing automatic periodic verification and calibration of the motion accuracy of the gantry platform. Description of the Drawings

[0048] Figure 1 is the flow chart of the gantry platform calibration method in the embodiment;

[0049] Figure 2 is another flow chart of the gantry platform calibration method in the embodiment;

[0050] Figure 3 is the schematic diagram of the calibration point in the embodiment;

[0051] Figure 4 is the schematic diagram of the gantry platform in the embodiment. Detailed Embodiments

[0052] The present invention will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that, for the sake of description, only parts related to the present invention are shown in the drawings, rather than all the structures.

[0053] Embodiment 1

[0054] Figure 1 is the flow chart of the gantry platform calibration method in the embodiment, referring to Figure 1 , the gantry platform calibration method includes:

[0055] S101. Obtain the first planar coordinates of the first calibration point at the first moment, and obtain the second planar coordinates of the second calibration point at the first moment.

[0056] Exemplarily, in this embodiment, the gantry platform calibration method is applicable to compensating the motor control quantity for driving the gantry (or corresponding moving components) in the gantry platform to ensure the repeated motion accuracy of the gantry platform.

[0057] Exemplarily, in this embodiment, the first calibration point and the second calibration point have the same shape, where one calibration point is set on the workbench of the gantry platform, and the other calibration point is located on the base on which the gantry platform is installed.

[0058] Exemplarily, in this embodiment, the method for determining the first planar coordinates and the second planar coordinates is not limited. For example, the first planar coordinates and the second planar coordinates of the first calibration point (center point) and the second calibration point (center point) in the specified coordinate system can be determined by machine vision or other means.

[0059] Exemplarily, in this embodiment, the first planar coordinates and the second planar coordinates are set as the coordinates in the gantry platform device coordinate system. If the first planar coordinates and the second planar coordinates are determined by machine vision, the first planar coordinates and the second planar coordinates can be determined in the following manner;

[0060] Before determining the first planar coordinates and the second planar coordinates, determine the conversion relationship between the camera coordinate system and the gantry platform device coordinate system, denoted as the first conversion relationship (for example, determine the above conversion relationship by calibrating the external parameters of the camera);

[0061] Denote the image obtained by the camera at the first moment and containing the first calibration point as the first image, and determine the first image coordinates of the first calibration point in the first image coordinate system;

[0062] Determine the conversion relationship between the first image coordinate system and the camera coordinate system according to the first image, denoted as the second conversion relationship;

[0063] Convert the first image coordinates into the first planar coordinates in the gantry platform device coordinate system according to the first conversion relationship and the second conversion relationship;

[0064] Denote the image obtained by the camera at the first moment and containing the second calibration point as the second image, and determine the second image coordinates of the second calibration point in the second image coordinate system;

[0065] Determine the conversion relationship between the second image coordinate system and the camera coordinate system according to the second image, denoted as the third conversion relationship;

[0066] Convert the second image coordinates into the second planar coordinates in the gantry platform device coordinate system according to the first conversion relationship and the third conversion relationship.

[0067] Exemplarily, in this embodiment, the coordinate system of the gantry platform device is set according to requirements, and the methods of calibrating the external parameters of the camera, determining the image coordinates, and determining the conversion relationship between the image coordinates and the camera coordinates are the same as those in the prior art, and the specific content will not be elaborated here.

[0068] Exemplarily, in this embodiment, the controller can be set to receive the first planar coordinates and the second planar coordinates at the first moment sent by the machine vision module, or the controller can be configured to directly calculate the above-mentioned first planar coordinates and second planar coordinates.

[0069] S102. Obtain the third planar coordinates of the first calibration point at the second moment, and obtain the fourth planar coordinates of the second calibration point at the second moment.

[0070] In this solution, on the basis of the content recorded in step S101, before determining the third planar coordinates and the fourth planar coordinates, determine the conversion relationship between the camera coordinate system and the coordinate system of the gantry platform device, denoted as the fourth conversion relationship;

[0071] Record the image containing the first calibration point obtained by the camera at the second moment as the third image, and determine the third image coordinates of the first calibration point in the third image coordinate system;

[0072] Determine the conversion relationship between the third image coordinate system and the camera coordinate system according to the third image, denoted as the fifth conversion relationship;

[0073] Convert the third image coordinates into the third planar coordinates in the coordinate system of the gantry platform device according to the fourth conversion relationship and the fifth conversion relationship;

[0074] Record the image containing the second calibration point obtained by the camera at the second moment as the fourth image, and determine the fourth image coordinates of the second calibration point in the fourth image coordinate system;

[0075] Determine the conversion relationship between the fourth image coordinate system and the camera coordinate system according to the fourth image, denoted as the sixth conversion relationship;

[0076] Convert the fourth image coordinates into the fourth planar coordinates in the coordinate system of the gantry platform device according to the fourth conversion relationship and the sixth conversion relationship.

[0077] Exemplarily, in this embodiment, it is set that when calibrating the external parameters of the camera at the first moment and the second moment, the positions of the calibration points used for calibration are fixed in the coordinate system of the gantry platform device;

[0078] It is set that the positions of the camera when obtaining the first image, the second image, the third image, and the fourth image in the coordinate system of the gantry platform device can be the same or different.

[0079] S103. Determine the calibration point offset angle based on the first planar coordinate, the second planar coordinate, the third planar coordinate, and the fourth planar coordinate.

[0080] In this embodiment, the calibration point offset angle is specifically set as follows: Denote the vector from the first planar coordinate to the second planar coordinate as the first vector, and denote the unit vector in the same direction as the first vector as the first unit vector;

[0081] Denote the vector from the third planar coordinate to the fourth planar coordinate as the second vector, and denote the unit vector in the same direction as the second vector as the second unit vector;

[0082] Denote the included angle between the first unit vector and the second unit vector as the calibration point offset angle.

[0083] Exemplarily, in this embodiment, the specific method for determining the calibration point offset angle is not limited, and it can be freely selected according to design requirements.

[0084] S104. Obtain the reference geometric position relationship between the first calibration point and the second calibration point.

[0085] In this embodiment, the reference geometric position relationship is specifically set as follows: At the initial moment (i.e., before the gantry platform is put into operation), the geometric distance between the setting positions of the first calibration point and the second calibration point.

[0086] S105. Taking the third planar coordinate as the reference, determine the fifth planar coordinate of the second calibration point according to the calibration point offset angle and the reference geometric position relationship.

[0087] Exemplarily, in this embodiment, the method for determining the fifth planar coordinate according to the calibration point offset angle and the reference geometric position relationship is not specifically limited;

[0088] For example, taking the third planar coordinate as the origin and the first unit vector as the initial direction, place the first end of the line segment corresponding to the reference geometric position relationship at the above origin, rotate the line segment in the direction of the second unit vector, and the rotation angle is the calibration point offset angle. Set the position where the second end of the rotated line segment is located as the fifth planar coordinate.

[0089] S106. Determine the motion compensation amount of the gantry platform according to the second planar coordinate and the fifth planar coordinate.

[0090] Exemplarily, in this embodiment, the method for determining the motion compensation amount of the gantry platform according to the second planar coordinate and the fifth planar coordinate can be as follows:

[0091] Determine the third vector from the second planar coordinate to the fifth planar coordinate, determine the first projection length of this third vector in the X-axis direction of the (gantry platform device coordinate system), and determine the second projection length of this third vector in the Y-axis direction of the (gantry platform device coordinate system);

[0092] Take the first projection length as the motion compensation amount of the gantry platform corresponding to the X-axis direction of the gantry platform, and / or take the second projection length as the motion compensation amount of the gantry platform corresponding to the Y-axis direction of the gantry platform.

[0093] S107. Alternatively, based on the fourth plane coordinates, determine the sixth plane coordinates of the first calibration point according to the calibration point offset angle and the reference geometric position relationship.

[0094] Exemplarily, in this embodiment, based on steps S105 and S106, the method for determining the sixth plane coordinates according to the calibration point offset angle and the reference geometric position relationship is not specifically limited;

[0095] For example, taking the fourth plane coordinates as the origin and the first unit vector as the initial direction, place the second end of the line segment corresponding to the reference geometric position relationship at the above origin, rotate the line segment in the direction of the second unit vector, and the rotation angle is the calibration point offset angle. Set the position where the first end of the rotated line segment is located as the sixth plane coordinates.

[0096] S108. Determine the motion compensation amount of the gantry platform according to the first plane coordinates and the sixth plane coordinates.

[0097] Exemplarily, in this embodiment, the method for determining the motion compensation amount of the gantry platform according to the first plane coordinates and the sixth plane coordinates may be:

[0098] Determine the fourth vector from the first plane coordinates to the sixth plane coordinates, determine the third projection length of the fourth vector in the X-axis direction of the (gantry platform device coordinate system), and determine the fourth projection length of the fourth vector in the Y-axis direction of the (gantry platform device coordinate system);

[0099] Take the third projection length as the motion compensation amount of the gantry platform corresponding to the X-axis direction of the gantry platform, and / or take the fourth projection length as the motion compensation amount of the gantry platform corresponding to the Y-axis direction of the gantry platform.

[0100] Exemplarily, in this embodiment, steps S101 to S108 are the gantry platform calibration methods within one calibration cycle. During the operation of the gantry platform, there may be multiple calibration cycles, and the calibration methods within each calibration cycle are the same.

[0101] This embodiment proposes a gantry platform calibration method, which includes obtaining the first plane coordinates and the second plane coordinates of the first calibration point and the second calibration point set at different positions on the gantry platform at the first moment, obtaining the third plane coordinates and the fourth plane coordinates of the first calibration point and the second calibration point at the second moment, determining the position offset of the first calibration point and the second calibration point at the first moment and the first calibration point and the second calibration point at the second moment according to the geometric relationship, determining the motion error of the gantry platform according to the offset, and generating a gantry platform motion compensation amount (for the gantry platform motor) for compensating the motion error, thereby realizing the automatic periodic verification and calibration of the motion accuracy of the gantry platform.

[0102] Based on the Figure 1 scheme shown, in an implementable scheme, after obtaining the first plane coordinates and the third plane coordinates, it further includes:

[0103] Determining a first offset of the first calibration point between the first moment and the second moment according to the first plane coordinates and the third plane coordinates.

[0104] Exemplarily, in this scheme, the formula used to determine the first offset includes:

[0105] Δx1 = x1 ′ - x1

[0106] Δy1 = y1 ′ - y1

[0107] where (Δx1, Δy1) represents the first offset, (x1, y1) represents the first plane coordinates, and (x1 ′ , y1 ′ ) represents the third plane coordinates;

[0108] After obtaining the second plane coordinates and the fourth plane coordinates, it further includes:

[0109] Determining a second offset of the second calibration point between the first moment and the second moment according to the second plane coordinates and the fourth plane coordinates.

[0110] Exemplarily, in this scheme, the formula used to determine the second offset includes:

[0111] Δx2 = x2 ′ - x2

[0112] Δy2 = y2 ′ - y2

[0113] where (Δx2, Δy2) represents the second offset, (x2, y2) represents the second plane coordinates, and (x2 ′ , y2 ′ ) represents the fourth plane coordinates.

[0114] After determining the above first offset and second offset, it further includes:

[0115] If the first offset is greater than the first offset threshold and the second offset is greater than the second offset threshold, calculate the motion compensation amount of the gantry platform.

[0116] Exemplarily, in this solution, the first offset threshold and the second offset threshold are determined according to experience or calibration tests. If the above conditions are met, calculate the motion compensation amount of the gantry platform (i.e., execute steps S103 - S108), otherwise, do not continue to calculate the motion compensation amount of the gantry platform.

[0117] In this solution, calculating the motion compensation amount of the gantry platform only when the first offset is greater than the first offset threshold and the second offset is greater than the second offset threshold can reduce the calculation load of the arithmetic unit and improve the working stability of the gantry platform.

[0118] Further, on the basis of determining whether the first offset is greater than the first offset threshold and whether the second offset is greater than the second offset threshold, in an implementable solution, the gantry platform calibration method further includes:

[0119] Obtain the first tilt characteristic angle of the first calibration point at the second moment, and determine the first gantry platform plane coordinate orthogonality according to the first tilt characteristic angle.

[0120] Exemplarily, in this solution, the first tilt characteristic angle is determined based on machine vision. The specific method for determining the first tilt characteristic angle is not limited. For example, the first tilt characteristic angle can be determined in the following way:

[0121] At the second moment, use the first calibration point to calibrate the camera to determine the external parameters of the camera, and take the (θ x1 , θ y1 , θ z1 ) in the external parameters as the first tilt characteristic angle;

[0122] Among them, θ x1 , θ y1 , θ z1 respectively represent: the angles that need to be rotated in the X, Y, and Z axis directions when the calibration coordinate system established with the midpoint of the first calibration point as the origin coincides with the camera coordinate system;

[0123] Among them, it is set that the plane formed by the X and Y axes is parallel to the motion plane of the gantry platform, and the Z axis is perpendicular to the plane formed by the X and Y. Take θ z1 as the first gantry platform plane coordinate orthogonality.

[0124] Exemplarily, in this solution, the method for calibrating the camera using the first calibration point is not limited, which is the same as the prior art and will not be elaborated in detail.

[0125] Obtain the second tilt feature angle of the second calibration point at the second moment, and determine the second orthogonal quantity of the gantry platform plane coordinates according to the second tilt feature angle.

[0126] At the second moment, use the second calibration point to calibrate the camera to determine the external parameters of the camera, and take (θ x2 , θ y2 , θ z2 ) in the external parameters as the second tilt feature angle;

[0127] Among them, θ x2 , θ y2 , θ z2 respectively represent: the angles that need to be rotated in the X, Y, and Z axis directions when the calibration coordinate system established with the midpoint of the second calibration point as the origin coincides with the camera coordinate system;

[0128] Among them, it is set that the plane formed by the X and Y axes is parallel to the movement plane of the gantry platform, and the Z axis is perpendicular to the plane formed by the X and Y. Take θ z2 as the first orthogonal quantity of the gantry platform plane coordinates.

[0129] If the first offset is greater than the first offset threshold, the second offset is greater than the second offset threshold, the first orthogonal quantity of the gantry platform plane coordinates is greater than the first orthogonal quantity threshold, and the second orthogonal quantity of the gantry platform plane coordinates is greater than the second orthogonal quantity threshold, then calculate the movement compensation amount of the gantry platform.

[0130] Exemplarily, in this solution, the first orthogonal quantity threshold and the second orthogonal quantity threshold are determined through experience or calibration tests.

[0131] Exemplarily, in this solution, when the above conditions are met, then calculate the movement compensation amount of the gantry platform (that is, execute steps S103 to S108), otherwise do not continue to calculate the movement compensation amount of the gantry platform.

[0132] In this solution, if the first offset is greater than the first offset threshold, the second offset is greater than the second offset threshold, the first orthogonal quantity of the gantry platform plane coordinates is greater than the first orthogonal quantity threshold, and the second orthogonal quantity of the gantry platform plane coordinates is greater than the second orthogonal quantity threshold, then calculate the movement compensation amount of the gantry platform. Combining multiple conditions to judge whether movement compensation of the gantry platform is required can improve the accuracy of the judgment result and further improve the movement and control stability of the gantry platform.

[0133] On the basis of the solution shown in Figure 1 , in an implementable solution, the gantry platform calibration method further includes:

[0134] After calculating the fifth plane coordinate based on the third plane coordinate, or after calculating the sixth plane coordinate based on the fourth plane coordinate, output and display the fifth plane coordinate, the sixth plane coordinate, and the calibration point offset angle.

[0135] Exemplarily, in this solution, the purpose of outputting and displaying the fifth plane coordinate, the sixth plane coordinate, and the calibration point offset angle is: based on the above parameters, manually determine the motion compensation amount of the gantry platform.

[0136] In Figure 1 Based on the solution shown, in an implementable solution, the formula for determining the motion compensation amount of the gantry platform includes:

[0137]

[0138] Or;

[0139]

[0140] In the formula, l represents the motion compensation amount of the gantry platform, p1 represents the first plane coordinate, p1″ represents the sixth plane coordinate, p2 represents the second plane coordinate, and p2″ represents the fifth plane coordinate.

[0141] Further, when determining the motion compensation amount of the gantry platform through the above formula for determining l, the motion compensation amount of the gantry platform includes the first motion axis compensation amount and the second motion axis compensation amount;

[0142] The first motion axis compensation amount is used for compensating the control amount of the first motion motor in the first motion axis direction of the gantry platform;

[0143] The second motion axis compensation amount is used for compensating the control amount of the second motion motor in the second motion axis direction of the gantry platform.

[0144] Exemplarily, in this solution, the gantry platform is set as a dual-drive gantry platform, and the motion directions of the dual-drive gantry platform include the X-axis direction and the Y-axis direction;

[0145] Specifically, the projected length of l in the X-axis direction is used as the first motion axis compensation amount, and the projected length of l in the Y-axis direction is used as the second motion axis compensation amount.

[0146] In this embodiment, the solutions corresponding to any of the above gantry platform calibration methods can be freely combined. Figure 2 It is another flowchart of the gantry platform calibration method in the embodiment. Refer to Figure 2 In an implementable solution, the gantry platform calibration method includes:

[0147] S201. Obtain the first planar coordinates of the first calibration point at the first moment, and obtain the second planar coordinates of the second calibration point at the first moment.

[0148] S202. Obtain the third planar coordinates of the first calibration point at the second moment, and obtain the fourth planar coordinates of the second calibration point at the second moment.

[0149] S203. Determine the first offset of the first calibration point between the first moment and the second moment according to the first planar coordinates and the third planar coordinates.

[0150] S204. Determine the second offset of the second calibration point between the first moment and the second moment according to the second planar coordinates and the fourth planar coordinates.

[0151] S205. Obtain the first tilt characteristic angle of the first calibration point at the second moment, and determine the first orthogonal quantity of the gantry platform planar coordinates according to the first tilt characteristic angle.

[0152] S206. Obtain the second tilt characteristic angle of the second calibration point at the second moment, and determine the second orthogonal quantity of the gantry platform planar coordinates according to the second tilt characteristic angle.

[0153] S207. If the first offset is greater than the first offset threshold, the second offset is greater than the second offset threshold, the first orthogonal quantity of the gantry platform planar coordinates is greater than the first orthogonal quantity threshold, and the second orthogonal quantity of the gantry platform planar coordinates is greater than the second orthogonal quantity threshold, then calculate the motion compensation quantity of the gantry platform.

[0154] S208. Determine the offset angle of the calibration point according to the first planar coordinates, the second planar coordinates, the third planar coordinates, and the fourth planar coordinates.

[0155] S209. Obtain the reference geometric position relationship between the first calibration point and the second calibration point.

[0156] S210. Based on the third planar coordinates, determine the fifth planar coordinates of the second calibration point according to the offset angle of the calibration point and the reference geometric position relationship.

[0157] S211. Determine the motion compensation quantity of the gantry platform according to the second planar coordinates and the fifth planar coordinates.

[0158] S212. Or, based on the fourth planar coordinates, determine the sixth planar coordinates of the first calibration point according to the offset angle of the calibration point and the reference geometric position relationship.

[0159] S213. Determine the motion compensation quantity of the gantry platform according to the first planar coordinates and the sixth planar coordinates.

[0160] In this solution, the formula used to determine the first offset includes:

[0161] Δx1 = x1′ - x1

[0162] Δy1 = y1 ′ -y1

[0163] The formulas for determining the second offset include:

[0164] Δx2 = x2 ′ -x2

[0165] Δy2 = y2 ′ -y2

[0166] The formulas for determining the motion compensation amount of the gantry platform include:

[0167]

[0168] Or;

[0169]

[0170] The motion compensation amount of the gantry platform includes the compensation amount of the first motion coordinate axis (X-axis) and the compensation amount of the second motion coordinate axis (Y-axis);

[0171] The compensation amount of the first motion coordinate axis is used for compensating the control amount of the first motion motor in the direction of the first motion coordinate axis of the gantry platform;

[0172] The compensation amount of the second motion coordinate axis is used for compensating the control amount of the second motion motor in the direction of the second motion coordinate axis of the gantry platform;

[0173] The projected length of l in the X-axis direction is used as the compensation amount of the first motion coordinate axis, and the projected length of l in the Y-axis direction is used as the compensation amount of the second motion coordinate axis.

[0174] In this solution, the rest of the content is the same as that recorded in the corresponding previous solution, and the specific content will not be elaborated here.

[0175] Example 2

[0176] This example proposes a gantry platform, including a controller, and the controller is configured with an executable program, which is used to implement any one of the gantry platform calibration methods recorded in Example 1 when the executable program is running.

[0177] In this example, the implementation process of the gantry platform calibration method is the same as the corresponding content recorded in Example 1, and will not be elaborated here.

[0178] Figure 3 It is a schematic diagram of the calibration points in the example. Refer to Figure 3 , the gantry platform is also configured with a first calibration point and a second calibration point;

[0179] The first calibration point is set on the workbench of the gantry platform, and the second calibration point is set on the marble platform where the gantry platform is installed.

[0180] Exemplarily, in this solution, it is set that the shapes of the first calibration point and the second calibration point are the same, and when the gantry platform is working, there is no relative movement between the workbench and the marble platform.

[0181] Exemplarily, in this solution, the images including the first calibration point and the second calibration point are used as the basis for determining the planar coordinates of the first calibration point and the second calibration point;

[0182] In addition, the single-image calibration of the camera (vision camera) can also be realized by using the first calibration point / or the second calibration point.

[0183] Exemplarily, in this solution, the method of using the first calibration point and / or the second calibration point to determine the above planar coordinates and calibrate the camera is the same as the prior art, and the specific content will not be elaborated here.

[0184] Figure 4 It is a schematic diagram of the gantry platform in the embodiment. Refer to Figure 4 , in an implementable solution, the gantry platform is further configured with a motor screw module 101 and a vision camera 102;

[0185] The vision camera 102 is fixedly connected to the motor screw module 101, and the motor screw module 101 is fixedly connected to the crossbeam mover 103 of the gantry platform;

[0186] The vision camera 102 is used to acquire the images of the first calibration point 201 and the second calibration point 202, and the images are used as the basis for determining the planar coordinates of the first calibration point 201 and the second calibration point 202.

[0187] Exemplarily, in this solution, it is set that the gantry platform is a dual-drive gantry platform, and the vision camera 102 can move along the crossbeam (of the dual-drive gantry platform) driven by the crossbeam mover 103;

[0188] It is set that the vision camera 102 can move along the X, Y, and Z axes of the camera (vision camera) coordinate system driven by the motor screw module 101.

[0189] Note that the above is only a preferred embodiment of the present invention and the technical principles applied. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments, and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments. Without departing from the concept of the present invention, more other equivalent embodiments can be included, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. A gantry platform calibration method, characterized in that, Including: Obtain the first planar coordinate of the first calibration point at the first moment, and obtain the second planar coordinate of the second calibration point at the first moment; Obtain the third planar coordinate of the first calibration point at the second moment, and obtain the fourth planar coordinate of the second calibration point at the second moment; Determine the calibration point offset angle according to the first planar coordinate, the second planar coordinate, the third planar coordinate, and the fourth planar coordinate; Obtain the reference geometric position relationship between the first calibration point and the second calibration point; Taking the third planar coordinate as a reference, determine the fifth planar coordinate of the second calibration point according to the calibration point offset angle and the reference geometric position relationship; Determine the motion compensation amount of the gantry platform according to the second planar coordinate and the fifth planar coordinate; Alternatively, taking the fourth planar coordinate as a reference, determine the sixth planar coordinate of the first calibration point according to the calibration point offset angle and the reference geometric position relationship; Determine the motion compensation amount of the gantry platform according to the first planar coordinate and the sixth planar coordinate.

2. The gantry platform calibration method according to claim 1, characterized in that, Also including: Determine the first offset amount of the first calibration point between the first moment and the second moment according to the first planar coordinate and the third planar coordinate; Determine the second offset amount of the second calibration point between the first moment and the second moment according to the second planar coordinate and the fourth planar coordinate; If the first offset amount is greater than the first offset threshold and the second offset amount is greater than the second offset threshold, then calculate the motion compensation amount of the gantry platform.

3. The gantry platform calibration method according to claim 2, wherein, Also including: Obtain the first tilt characteristic angle of the first calibration point at the second moment, and determine the first gantry platform planar coordinate orthogonality according to the first tilt characteristic angle; Obtain the second tilt characteristic angle of the second calibration point at the second moment, and determine the second gantry platform planar coordinate orthogonality according to the second tilt characteristic angle; If the first offset amount is greater than the first offset threshold, the second offset amount is greater than the second offset threshold, the first gantry platform planar coordinate orthogonality is greater than the first orthogonality threshold, and the second gantry platform planar coordinate orthogonality is greater than the second orthogonality threshold, then calculate the motion compensation amount of the gantry platform.

4. The gantry platform calibration method according to claim 1, wherein Also including: After calculating the fifth planar coordinate with the third planar coordinate as a reference, or after calculating the sixth planar coordinate with the fourth planar coordinate as a reference, it further includes; Output and display the fifth planar coordinate, the sixth planar coordinate, and the calibration point offset angle.

5. The gantry platform calibration method according to claim 2, characterized in that, The formula for determining the first offset amount includes: Δx1 = x1 ′ -x1 Δy1 = y1 ′ -y1 The formula for determining the second offset amount includes: Δx2 = x2 ′ -x2 Δy2 = y2 ′ -y2 where (Δx1, Δy1) represents the first offset, (x1, y1) represents the first planar coordinate, and (x1 ′ , y1 ′ ) represents the third planar coordinate; (Δx2, Δy2) represents the second offset, (x2, y2) represents the second plane coordinates, and (x2 ′ , y2 ′ ) represents the fourth plane coordinates.

6. The gantry platform calibration method according to claim 1, characterized in that The formula for determining the motion compensation amount of the gantry platform includes: Or; Wherein, l represents the motion compensation amount of the gantry platform, p1 represents the first plane coordinate, p1 ″ represents the sixth plane coordinate, p2 represents the second plane coordinate, and p2″ represents the fifth plane coordinate.

7. The gantry platform calibration method according to claim 6, characterized in that, The motion compensation amount of the gantry platform includes a first motion axis compensation amount and a second motion axis compensation amount; The first motion axis compensation amount is used for compensating the control amount of the first motion motor in the first motion axis direction of the gantry platform; The second motion axis compensation amount is used for compensating the control amount of the second motion motor in the second motion axis direction of the gantry platform.

8. A gantry platform, characterized in that, It includes a controller, and the controller is configured with an executable program which is used to implement the gantry platform calibration method according to any one of claims 1 to 7 when the executable program runs.

9. The gantry platform according to claim 8, wherein It is further configured with a first calibration point and a second calibration point; The first calibration point is arranged on the workbench of the gantry platform, and the second calibration point is arranged on the marble platform where the gantry platform is installed.

10. The gantry platform according to claim 8, characterized in that, It is further configured with a motor lead screw module and a vision camera; The vision camera is fixedly connected to the motor lead screw module, and the motor lead screw module is fixedly connected to the crossbeam mover of the gantry platform; The vision camera is used to acquire images of the first calibration point and the second calibration point, and the images are used as the basis for determining the planar coordinates of the first calibration point and the second calibration point.

Images