A robot clamping calibration method based on CAD model

Abstract

The present invention provides a robot clamping calibration method based on a CAD model, comprising the following steps: Step 1: building a robot workstation, importing a CAD model and defining a clamping coordinate system, and selecting a calibration mode according to the geometric features of the calibration object; Step 2: calibration data acquisition: acquiring data including data in the CAD model and data in the actual model; Step 3: creating a calibration coordinate system: creating local coordinate systems for the CAD model and the actual model respectively, obtaining a transformation matrix through registration between the two local coordinate systems, and finally mapping the clamping coordinate system defined in the CAD model to obtain the clamping coordinate system of the actual model. The calibration method proposed by the present invention does not rely on the posture relationship between the clamping coordinate system to be calibrated and the model, and the clamping coordinate system can be defined at any position on the model, which is conducive to rapid implementation in the processing scene; it has strong versatility and can cover most clamping calibration application scenarios of simple parts.

Description

Technical Field

[0001] The invention belongs to the field of industrial robot clamping calibration, and in particular relates to a robot clamping calibration method based on a CAD model. Background Art

[0002] Industrial robots are widely used in complex operations such as assembly, handling, welding, spraying, laser cutting, cutting, 3D printing, etc. due to their compact structure and high flexibility. The trajectory execution accuracy of the robot is related to the robot's clamping calibration accuracy. The purpose of clamping calibration is to determine the posture relationship between the robot body and external tools and workpieces. Due to the complexity and diversity of tools and workpieces in the actual working environment of the robot, the simple calibration method currently provided in the robot control system is difficult to apply to the actual working environment. Therefore, providing a clamping calibration method with wide applicability and simple operation is of great significance to establish a high-precision closed-loop operation of the robot.

[0003] At present, the most classic method of tool calibration is the multi-point cusp tool calibration method. This method teaches the end point of the tool to contact a fixed point in space with different postures, and then establishes a constraint relationship to solve the tool coordinate system origin (TCP). This type of method is simple in theory, but the actual operation is relatively complicated. Another type of tool calibration method is the tool coordinate system calibration method based on spherical, distance or plane constraints. This type of method requires expensive measuring equipment and has a limited scope of use. The simplest calibration method for the workpiece coordinate system is the three-point method, which is suitable for the calibration of workpiece coordinate systems with simple shapes and specified coordinate systems. However, the actual application scenarios are complex, especially when using complex trajectory operations using offline programming, the definition of the workpiece coordinate system is not specific, so the above method cannot accurately and easily implement the calibration of any workpiece coordinate system.

[0004] In view of the above problems, the present invention proposes a calibration method for the robot's arbitrary clamping coordinate system based on simple geometric features and CAD models. Summary of the invention

[0005] In view of the problems existing in the prior art, the present invention intends to provide a fast and effective clamping and calibration method for tools or workpieces with simple geometric features relative to a robot. The calibration method is simple and the clamping coordinate system can be defined at any position on the geometry to be calibrated.

[0006] The technical solution adopted by the present invention to solve the problems existing in the prior art is as follows:

[0007] A robot clamping calibration method based on a CAD model, characterized by comprising the following steps:

[0008] Step 1: Build a robot workstation, import the CAD model and define the clamping coordinate system. Set the robot base coordinate system as RCS, the workpiece coordinate system as WCS, the tool attachment coordinate system as ECS, and the tool processing coordinate system as TCS. At the same time, select the calibration mode according to the geometric characteristics of the calibration object. There are six calibration modes: 1) three-plane method mode, 2) one point plus a straight line method mode, 3) one point plus two planes method mode, 4) two points plus one plane method mode, 5) three-point method mode and 6) two-line method mode;

[0009] Step 2: Calibration data acquisition: The data collected includes the data in the CAD model and the data in the actual model. The data in the CAD model is obtained by selecting features in the software, and the data in the actual model is obtained by actual measurement with the measuring equipment.

[0010] Step 3: Create a calibration coordinate system: Create local coordinate systems for the CAD model and the actual model respectively, obtain the transformation matrix through the registration between the two local coordinate systems, and finally map the clamping coordinate system defined in the CAD model to obtain the clamping coordinate system of the actual model.

[0011] The step one is specifically as follows: a robot workstation is built in an offline programming software (such as HiperMOS), a CAD model of a robot, a processing tool and a processing workpiece consistent with the actual scene is imported, a clamping relationship between the tool, the workpiece and the robot is established in the software, and then the following simple geometric features are observed in the object to be calibrated: point, straight line, plane, circular surface, spherical surface, cylindrical surface, and one of the six calibration modes is selected according to the geometric features in the model. The features in each mode need to meet relevant rules to create a calibration coordinate system, among which: 1) the three-plane method mode requires that the three planes can intersect at one point; 2) the one-point plus a straight line method mode requires that a point is not on a straight line; 3) the one-point plus two-plane method mode requires that the two planes intersect and a point is not located on the intersection line; 4) the two-point plus one-plane method mode requires that the straight line formed by the two points intersects with the plane; 5) the three-point method mode requires that the three points do not overlap with each other and are not collinear; 6) the two-line method mode requires that the two lines are not parallel.

[0012] The step 2 is specifically as follows: respectively selecting features on the CAD model in the software, and collecting features in the actual model in the actual model, wherein the features in the CAD model are obtained by selecting features in the theoretical model, and the features in the actual model are actually collected by external measuring equipment, and when collecting straight line data, two points on the straight line need to be collected, when collecting plane data, three or more non-collinear points need to be collected, when collecting spherical data, four or more non-coplanar points need to be collected, when collecting cylindrical data, six or more non-coplanar points need to be collected, and when collecting circular surface data, three or more non-overlapping points on the circle need to be collected.

[0013] The step three specifically includes the following steps:

[0014] S31: Extract the simplest features: If the collected data has plane, circular, spherical or cylindrical features, use the fitting method to extract point or line features. The plane model is fitted into the simplest form of point and normal representation; the circular or spherical data is fitted into a circle center or sphere center as a point feature, and the cylindrical data can be fitted into an axis as a line feature;

[0015] S32: Establishing a local coordinate system: Establishing local coordinate systems for the CAD model and the actual model respectively, and establishing the local coordinate system based on the simplest features according to one of the six calibration modes selected in step 1:

[0016] S33: Calculate the transformation matrix: Let the local coordinate system constructed by the CAD model data be The local coordinate system constructed by the actual model data is recorded as Create a transformation matrix between two local coordinate systems:

[0017]

[0018] S34: Get the clamping coordinate system of the actual model: Assume that the clamping coordinate system in the theoretical model is The clamping coordinate system in the actual model is According to T * Calculate the actual clamping coordinate system to be calibrated:

[0019] In step S32, when the three-plane calibration mode is selected in step 1, the calibration method is suitable for the calibration of the coordinate system with the simplest feature having three plane features. 1 、f 2 、f 3 For three non-parallel planes, the specific rules for establishing the coordinate system of this method are as follows: 1-1) The intersection of the three planes is taken as the origin O of the coordinate system; 1-2) The plane f 1 The normal of the plane f is taken as the Z axis; 1-3) 1 and f 2 The intersection line of is taken as the X axis;

[0020] The specific steps to express the coordinate system to be determined using mathematical expressions according to the above rules are as follows: i (i=1,2,3) respectively adopt the point method (P i , n i ) means: where P i Represents the plane f i Previous point, n i Represents the plane f i The normal of , calculate the local coordinate system based on the above rules: The calculation steps are as follows:

[0021] 1-a) Calculate the unit vector z of the Z axis of the coordinate system Dir :z Dir =n 1 ;

[0022] 1_b) Calculate the unit vector x of the X axis of the coordinate system Dir :

[0023] 1-c) Calculate the unit vector y of the Y axis of the coordinate system Dir :

[0024] 1-d) Solve the intersection of the three planes as the origin of the coordinate system O: According to the points, establish the following equation system on the plane, and obtain the intersection of the three planes as the origin of the coordinate system by solving the following linear equation system;

[0025]

[0026] In step S32, when the one-point-plus-a-line calibration mode is selected in step 1, the calibration method is suitable for determining the coordinate system with the simplest feature having a point feature and a straight line feature. Suppose the straight line l 1 (Q 1 Q 2 ) is the center axis extracted after cylindrical surface fitting or the straight line determined by two points, P l，1 For a point outside the straight line, the rules for establishing the coordinate system of this method are as follows: 2-1) Straight line l 1 Determines the Z axis of the coordinate system; 2-2)P l，1 Located on the X-axis of the coordinate system; 2-3)P l，1 Towards straight line l 1 The projection point is taken as the origin O of the coordinate system;

[0027] Calculate the coordinate system based on the above rules The calculation steps are as follows:

[0028] 2-a) Calculate the unit vector z of the Z axis of the coordinate system Dir :

[0029] 2-b) Calculate P l，1 Towards straight line Q 1 Q 2 The projection point is taken as the origin of the coordinate system O;

[0030] 2-c) Calculate the unit vector x of the x-axis of the coordinate system Dir :

[0031] 2-d) Calculate the unit vector y of the Y axis of the coordinate systemDir :

[0032] In step S32, when the one-point plus two-plane calibration mode is selected in step 1, the calibration method is suitable for determining the coordinate system with the simplest feature having one point and two plane features. s，1 is a point or the center of a sphere, f s，1 and f s，2 are two non-parallel planes, and their normals are denoted by n s，1 and n s，2 The rules for establishing the coordinate system of this method are as follows: 3-1) The normal of the first plane determines the Z axis of the coordinate system; 3-2) The plane f s，1 and f s，2 The intersection line of is taken as the X axis; 3-3)P s，1 As the origin of the coordinate system O;

[0033] Calculate the coordinate system based on the above rules The calculation steps are as follows:

[0034] 3-a) Calculate the unit vector z of the Z axis of the coordinate system Dir :z Dir =n s，1 ;

[0035] 3-b) Calculate the unit vector x of the X axis of the coordinate system Dir :

[0036] 3-c) Calculate the unit vector y of the Y axis of the coordinate system Dir :

[0037] 3-d)P s，1 As the origin O of the coordinate system.

[0038] In step S32, when the two-point plus one-plane calibration mode is selected in step 1, the calibration method is suitable for determining the workpiece coordinate system with the simplest feature having two point features and one plane feature. p，1 , P p，2 are two non-coincident points; f p，1 is a plane, and the straight line formed by the two points is not perpendicular to the plane. The rules for establishing the coordinate system of this method are as follows: 4-1) Plane The normal direction determines the Z axis of the coordinate system; 4-2) The projection vectors of the two points on the plane determine the X axis; 4-3) P p，1 The projection point on the plane is taken as the origin O of the coordinate system;

[0039] Calculate the coordinate system based on the above rules The calculation steps are as follows:

[0040] 4-a) Calculate two points P p，1 , P p，2 In plane f p，1 Projection point on

[0041] 4-b) Calculate the unit vector x of the X axis of the coordinate system Dir :

[0042] 4-c) Calculate the unit vector z of the Z axis of the coordinate system Dir :z Dir =n, n is the plane f p，1 The normal direction of

[0043] 4-d) Calculate the unit vector y of the Y axis of the coordinate system Dir :

[0044] 4-e) Calculate the origin of the coordinate system:

[0045] In step S32, when the three-point calibration mode is selected in step 1, the calibration method is suitable for determining the coordinate system with the simplest feature having three point features. c，1 , P c，2 , P c，3 For three points that are not coincident and not collinear, the rules for establishing the coordinate system by this method are as follows: 5-1) The first point P c，1 is the origin of the coordinate system O; 5-2) vector P c，1 P c，2 Determines the X-axis of the coordinate system; 5-3) The third point P c，3 Located on the XOY plane of the coordinate system (first quadrant);

[0046] Calculate the coordinate system based on the above rules The calculation steps are as follows:

[0047] 5-a) Calculate the unit vector x of the X axis of the coordinate system Dir :

[0048] 5-b) Calculate the unit vector z of the Z axis of the coordinate system Dir :

[0049] 5-c) Calculate the unit vector y of the Y axis of the coordinate system Dir :

[0050] 5-d) Calculate the origin of the coordinate system: O = P c，1 .

[0051] In step S32, when the two-line calibration mode is selected in step 1, the calibration method is applicable to the workpiece whose simplest feature has two straight line features. l，1 , Q l，2 For the straight line l l，1 Two points on Q l，3 , Q l，4 For the straight line l l，2 The rules for establishing a coordinate system for two points on a line are as follows: 6-1) The direction perpendicular to both lines determines the Z axis; 6-2) The direction of the first line determines the X axis of the coordinate system; 6-3) If the two lines are coplanar, the point of intersection is the origin of the coordinate system O; if the two lines are not coplanar, the point of intersection of the common perpendicular line and the first line is the origin of the coordinate system;

[0052] Calculate the coordinate system based on the above rules: The calculation steps are as follows:

[0053] 6-a) Calculate the unit vector x of the x-axis of the coordinate system Dir :

[0054] 6-b) Calculate the unit vector z of the Z axis of the coordinate system Dir :

[0055] 6-c) Calculate the unit vector y of the Y axis of the coordinate system Dir :

[0056] 6-d) Use the method of finding the intersection point or common perpendicular line of two straight lines to calculate the origin O of the coordinate system.

[0057] The present invention has the following advantages:

[0058] 1. The method of the present invention can solve the problem of machining work point deviation caused by the inconsistency between the tool or workpiece shape and the theoretical model. It has a wide range of applications and can be used for rapid and effective calibration of parts such as automotive parts, 3C workpieces, and metal components.

[0059] 2. The calibration method proposed in the present invention does not rely on the posture relationship between the clamping coordinate system to be calibrated and the model. The clamping coordinate system can be defined at any position on the model, which can reduce the complexity of actual calibration and is conducive to rapid implementation in processing scenarios.

[0060] 3. The six calibration methods proposed in the present invention are independent of each other and have strong versatility, and can cover most simple parts clamping calibration application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 Schematic diagram of active processing by a robot in an embodiment of the present invention.

[0062] Figure 2 Schematic diagram of the local coordinate system transformation for clamping and calibration in an embodiment of the present invention. DETAILED DESCRIPTION

[0063] The technical solution of the present invention is further specifically described below through embodiments and in combination with the accompanying drawings. The present invention provides a simple clamping calibration method based on a CAD model. The clamping coordinate system refers to a coordinate system defined on a tool or workpiece installed on a robot or outside the robot. The clamping coordinate system can be defined at any position on the geometry to be calibrated. Specifically, the following steps are included:

[0064] Step 1: Build the robot workstation, import the CAD model and define the clamping coordinate system, such as Figure 1 As shown, the robot clamps the processing tool to process the external workpiece. Assume that the robot base coordinate system is RCS, the workpiece coordinate system is WCS, the tool attachment coordinate system is ECS, and the tool processing coordinate system is TCS. The method provided by the present invention can be used to calibrate the posture relationship between TCS and ECS, and between WCS and RCS.

[0065] Select the calibration mode according to the geometric features of the calibration object. There are six calibration modes: 1) three-plane method mode, 2) one-point plus one-line method mode, 3) one-point plus two-plane method mode, 4) two-point plus one-plane method mode, 5) three-point method mode and 6) two-line method mode; Figure 1 The workpiece has three non-parallel plane features, and the three-plane method mode can be used for calibration.

[0066] Step 2: Calibration data collection: The data collected includes the data in the CAD model and the data in the actual model. The data in the CAD model is obtained by selecting features in the software, and the data in the actual model is obtained by actual measurement with the measuring equipment. Figure 1 Take the three-plane method mode shown in the figure as an example: First, import the workpiece CAD model consistent with the actual workpiece in the simulation environment, select three surface features f on the CAD model 1 ′,f 2 ′, f′ 3 , get the representation of the surface features in the RCS coordinate system, then collect point data in the RCS coordinate system on the corresponding three planes in the actual environment, and fit the three planes f of the actual model 1 , f 2 , f 3 .

[0067] Step 3: Create a calibration coordinate system: Create local coordinate systems for the CAD model and the actual model respectively, obtain the transformation matrix through the registration between the two local coordinate systems, and finally map the clamping coordinate system defined in the CAD model to obtain the clamping coordinate system of the actual model.

[0068] The step three specifically includes the following steps:

[0069] Step S31: Extracting the simplest features: If the collected data has plane, circular, spherical or cylindrical features, a fitting method is used to extract point or line features. The plane model is fitted into the simplest form of point and normal representation; the circular or spherical data is fitted into a circle center or sphere center as a point feature, and the cylindrical data can be fitted into an axis as a line feature;

[0070] Step S32: Establishing a local coordinate system: Establishing local coordinate systems for the CAD model and the actual model respectively, and establishing the local coordinate system based on the simplest features according to one of the six calibration modes selected in step 1:

[0071] This embodiment takes the three-plane method as an example, assuming f 1 、f 2 、f 3 For three non-parallel planes, the specific rules for establishing the coordinate system of this method are as follows: 1-1) The intersection of the three planes is taken as the origin O of the coordinate system; 1-2) The plane f 1 The normal of the plane f is taken as the Z axis; 1-3) 1 and f 2 The intersection line of is taken as the X-axis.

[0072] The three planes f i (i=1,2,3) respectively adopt the point method (P i , n i ) means: where P i Represents the plane f i Previous point, n i Represents the plane f i The normal direction of , based on the above rules, the local coordinate system can be calculated: The calculation steps are as follows:

[0073] 1-a) Calculate the unit vector z of the Z axis of the coordinate system Dir :z Dir =n 1 ;

[0074] 1-b) Calculate the unit vector x of the X axis of the coordinate system Dir :

[0075] 1-c) Calculate the unit vector y of the Y axis of the coordinate system Dir :

[0076] 1-d) Solve the intersection of the three planes as the origin of the coordinate system O: According to the points, establish the following equation system on the plane, and obtain the intersection of the three planes as the origin of the coordinate system by solving the following linear equation system;

[0077]

[0078] Step S33: Calculate the transformation matrix: Figure 2 As shown in the figure, assuming that in the robot offline programming environment, the theoretical workpiece coordinate system is recorded as WCS′, and its position and posture relationship relative to the base coordinate system RCS is recorded as The robot offline programming trajectory is defined in the WCS′ coordinate system. In the actual application environment, the actual workpiece coordinate system is denoted as WCS, and its actual position relative to the robot base coordinate system is denoted as is the coordinate system to be calibrated. Establish the transformation matrix between the two local coordinate systems:

[0079]

[0080] Step S34: Obtain the clamping coordinate system of the actual model: Since the transformation relationship between the theoretical workpiece and the actual workpiece is fixed, converting WCS to WCS′ is equivalent to converting CS to CS′. * Calculate the actual workpiece coordinate system to be calibrated:

[0081] Based on the above steps, it can be seen that no matter how the actual workpiece coordinate system WCS is set, the actual workpiece coordinate system can be obtained by aligning the CAD model with the actual model. This idea can be used for the six methods of defining coordinate systems introduced in this invention, and the other five methods will not be described in detail here.

[0082] Similarly, for robot gripping object calibration, the only difference is that the pose data of the ECS based on the same reference point under the RCS is collected. In order to calibrate the relationship between TCS and ECS, the data must first be converted into TCS relative to ECS data based on the reference point. Then, a calibration solution method similar to that of external object calibration can be used.

[0083] The protection scope of the present invention is not limited to the above-mentioned embodiments. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the scope and spirit of the present invention. If these changes and modifications fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include these changes and modifications.

Claims

1. A robot clamping calibration method based on a CAD model, characterized in that: The steps include: Step 1: Build a robot workstation, import the CAD model and define the clamping coordinate system, set the robot base coordinate system as RCS, the workpiece coordinate system as WCS, the tool attachment coordinate system as ECS, and the tool processing coordinate system as TCS. At the same time, select the calibration mode according to the geometric characteristics of the calibration object. There are six calibration modes: 1) three-plane method mode, 2) one point plus a straight line method mode, 3) one point plus two planes method mode, 4) two points plus one plane method mode, 5) three-point method mode and 6) two straight line method mode; among them: 1) the three-plane method mode requires that the three planes can intersect at one point; 2) the one point plus a straight line method mode requires that the point is not on the straight line; 3) the one point plus two planes method mode requires that the two planes intersect and the point is not on the intersection line; 4) the two points plus one plane method mode requires that the straight line formed by the two points intersects with the plane; 5) the three-point method mode requires that the three points do not overlap and are not collinear; 6) the two straight line method mode requires that the two straight lines are not parallel; Step 2: Calibration data acquisition: The data collected includes the data in the CAD model and the data in the actual model. The data in the CAD model is obtained by selecting features in the software, and the data in the actual model is obtained by actual measurement with the measuring equipment. Step 3: Create a calibration coordinate system: Create local coordinate systems for the CAD model and the actual model respectively, obtain the transformation matrix through the registration between the two local coordinate systems, and finally map the clamping coordinate system defined in the CAD model to obtain the clamping coordinate system of the actual model.

2. A robot clamping calibration method based on a CAD model as claimed in claim 1, characterized in that: The step one is specifically as follows: building a robot workstation in the offline programming software, importing the CAD models of the robot, processing tools and processing workpieces that are consistent with the actual scene, establishing the clamping relationship between the tool, workpiece and robot in the software, and then observing whether the object to be calibrated has the following simple geometric features: point, straight line, plane, circular surface, spherical surface, cylindrical surface, and selecting one of the six calibration modes according to the geometric features in the model. The features in each mode need to meet the relevant rules to create a calibration coordinate system.

3. A robot clamping calibration method based on a CAD model as claimed in claim 1, characterized in that: The step 2 is specifically as follows: respectively selecting features on the CAD model in the software, and collecting features in the actual model in the actual model, wherein the features in the CAD model are obtained by selecting features in the theoretical model, and the features in the actual model are actually collected by external measuring equipment, and when collecting straight line data, two points on the straight line need to be collected, when collecting plane data, three or more non-collinear points need to be collected, when collecting spherical data, four or more non-coplanar points need to be collected, when collecting cylindrical data, six or more non-coplanar points need to be collected, and when collecting circular surface data, three or more non-overlapping points on the circle need to be collected.

4. A robot clamping calibration method based on a CAD model as claimed in claim 1, characterized in that: The step three specifically includes the following steps: S31: Extract the simplest features: If the collected data has plane, circular, spherical or cylindrical features, use the fitting method to extract point or line features. The plane model is fitted into the simplest form of point and normal representation; the circular or spherical data is fitted into a circle center or sphere center as a point feature, and the cylindrical data is fitted into an axis as a line feature; S32: Establishing a local coordinate system: Establishing local coordinate systems for the CAD model and the actual model respectively, and establishing the local coordinate system based on the simplest features according to one of the six calibration modes selected in step 1: S33: Calculate the transformation matrix: Let the local coordinate system constructed by the CAD model data be The local coordinate system constructed by the actual model data is recorded as Create a transformation matrix between two local coordinate systems: S34: Get the clamping coordinate system of the actual model: Assume that the clamping coordinate system in the theoretical model is The clamping coordinate system in the actual model is According to T * Calculate the actual clamping coordinate system to be calibrated: In step S32, when the three-plane calibration mode is selected in step 1, the calibration method is applicable to the calibration of a coordinate system with three plane features as the simplest feature, assuming that f1, f2, and f3 are three non-parallel planes, and the specific rules for establishing the coordinate system in this method are as follows: 1-1) the intersection of the three planes is used as the origin O of the coordinate system; 1-2) the normal of plane f1 is used as the Z axis; 1-3) the intersection line of planes f1 and f2 is used as the X axis; The three planes f i (i=1,2,3) respectively adopt the point method (P i , n i ) means: where P i Represents the plane f i Previous point, n i Represents the plane f i The normal of , calculate the local coordinate system based on the above rules: The calculation steps are as follows: 1-a) Calculate the unit vector z of the Z axis of the coordinate system Dir :z Dir =n1; 1-b) Calculate the unit vector x of the X axis of the coordinate system Dir : 1-c) Calculate the unit vector y of the Y axis of the coordinate system Dir : 1-d) Solve the intersection of the three planes as the origin of the coordinate system O: According to the points, establish the following equation system on the plane, and obtain the intersection of the three planes as the origin of the coordinate system by solving the following linear equation system; In step S32, when the one-point-plus-a-line calibration mode is selected in step 1, the calibration method is applicable to the coordinate system determination with the simplest feature having a point feature and a straight line feature. Assume that the straight line l1 is the center axis extracted after cylindrical surface fitting or the straight line determined by two points, P l，1 For a point outside the line, the rules for establishing the coordinate system by this method are as follows: 2-1) Line l1 determines the Z axis of the coordinate system; 2-2) P l，1 Located on the X-axis of the coordinate system; 2-3)P l，1 The projection point onto the line l1 is taken as the origin O of the coordinate system; Calculate the coordinate system based on the above rules The calculation steps are as follows: 2-a) Calculate the unit vector z of the Z axis of the coordinate system Dir : 2-b) Calculate the projection point of Pl, 1-axis straight line Q1Q2 as the origin O of the coordinate system; 2-c) Calculate the unit vector x of the X axis of the coordinate system Dir : 2-d) Calculate the unit vector y of the Y axis of the coordinate system Dir : In step S32, when the one-point plus two-plane calibration mode is selected in step 1, the calibration method is suitable for determining the coordinate system with the simplest feature having one point and two plane features. s，1 is a point or the center of a sphere, f s，1 and f s，2 are two non-parallel planes, and their normals are denoted by n s，1 and n s，2 The rules for establishing the coordinate system of this method are as follows: 3-1) The normal of the first plane determines the Z axis of the coordinate system; 3-2) The plane f s，1 and f s，2 The intersection line of is taken as the X axis; 3-3)P s，1 As the origin of the coordinate system O; Calculate the coordinate system based on the above rules The calculation steps are as follows: 3-a) Calculate the unit vector z of the Z axis of the coordinate system Dir :z Dir =n s，1 ; 3-b) Calculate the unit vector x of the X axis of the coordinate system Dir : 3-c) Calculate the unit vector y of the Y axis of the coordinate system Dir : 3-d)P s，1 As the origin of the coordinate system O; In step S32, when the two-point plus one-plane calibration mode is selected in step 1, the calibration method is suitable for determining the workpiece coordinate system with the simplest feature having two point features and one plane feature. p，1 , P p，2 are two non-coincident points; f p，1 is a plane, and the straight line formed by the two points is not perpendicular to the plane. The rules for establishing the coordinate system of this method are as follows: 4-1) Plane The normal direction determines the Z axis of the coordinate system; 4-2) The projection vectors of the two points on the plane determine the X axis; 4-3) P p，1 The projection point on the plane is taken as the origin O of the coordinate system; Calculate the coordinate system based on the above rules The calculation steps are as follows: 4-a) Calculate two points P p，1 , P p，2 In plane f p，1 Projection point on 4-b) Calculate the unit vector x of the X axis of the coordinate system Dir : 4-c) Calculate the unit vector z of the Z axis of the coordinate system Dir :z Dir =n, n is the plane f p，1 The normal direction of 4-d) Calculate the unit vector y of the Y axis of the coordinate system Dir : 4-e) Calculate the origin of the coordinate system: In step S32, when the three-point calibration mode is selected in step 1, the calibration method is suitable for determining the coordinate system with the simplest feature having three point features. c，1 , P c，2 , P c，3 For three points that are not coincident and not collinear, the rules for establishing the coordinate system by this method are as follows: 5-1) The first point P c，1 is the origin of the coordinate system O; 5-2) vector P c，1 P c，2 Determines the X-axis of the coordinate system; 5-3) The third point P c，3 Located on the XOY plane of the coordinate system; Calculate the coordinate system based on the above rules The calculation steps are as follows: 5-a) Calculate the unit vector x of the X axis of the coordinate system Dir : 5-b) Calculate the unit vector z of the Z axis of the coordinate system Dir : 5-c) Calculate the unit vector y of the Y axis of the coordinate system Dir : 5-d) Calculate the origin of the coordinate system: O = P c，1 ; In step S32, when the two-line calibration mode is selected in step 1, the calibration method is applicable to the workpiece whose simplest feature has two straight line features. l，1 , Q l，2 For the straight line l l，1 Two points on Q l，3 , Q l，4 For the straight line l l，2 The rules for establishing a coordinate system for two points on a line are as follows: 6-1) The direction perpendicular to both lines determines the Z axis; 6-2) The direction of the first line determines the X axis of the coordinate system; 6-3) If the two lines are coplanar, the point of intersection is the origin of the coordinate system O; if the two lines are not coplanar, the point of intersection of the common perpendicular line and the first line is the origin of the coordinate system; Calculate the coordinate system based on the above rules: The calculation steps are as follows: 6-a) Calculate the unit vector x of the X axis of the coordinate system Dir : 6-b) Calculate the unit vector z of the Z axis of the coordinate system Dir : 6-c) Calculate the unit vector y of the Y axis of the coordinate system Dir : 6-d) Use the method of finding the intersection point or common perpendicular line of two straight lines to calculate the origin O of the coordinate system.

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