An industrial robot tool setting and processing method for large gear chamfering

Abstract

The present invention provides an industrial robot tool setting and processing method for chamfering large gears, belonging to the field of robot application. One gear tooth is processed at a time, and the chamfering of the entire gear is completed through multiple processing on a turntable. The method mainly solves the problems of low accuracy, low efficiency and high risk factor of manual tool setting. The present invention uses a laser displacement sensor at the end of the robot to scan various positions of the gear workpiece to determine the coordinates of the workpiece center and the gear tooth vertex coordinates, thereby achieving accurate and stable tool setting and facilitating subsequent chamfering processing.

Description

Technical Field

[0001] The present invention relates to the field of robot applications, and in particular to a tool setting and processing method for large gear chamfering by an industrial robot. Background Art

[0002] Early industrial robots were primarily used in applications requiring low-precision motion control. However, with the continuous advancement of technology, they are now widely used in industries such as automotive manufacturing, home appliance manufacturing, casting production, and logistics warehousing. Now, with the continuous development of robotics and control technologies, and the increasing intersection of robotics with advanced intelligent control, vision, and force sensing, industrial robots are increasingly being used in manufacturing processes such as grinding, chamfering, deburring, and assembly. Replacing human labor with industrial robots not only improves productivity and quality, but also increases flexibility, reduces production costs, and eliminates dangerous and harsh labor positions. Industrial robots are now entering fields requiring high-precision control.

[0003] Larger gears are typically chamfered manually. Replacing manual chamfering with industrial robots not only ensures tool setting accuracy, but also improves chamfering efficiency and reduces risk. Tool setting requires accurate tool setting before chamfering. Accurate tool setting improves workpiece quality and extends tool life. Currently, tool setting for chamfering is mostly manual, relying entirely on visual inspection and experience. This results in low efficiency, poor accuracy, and difficulty ensuring quality. For industrial robots with multi-degree-of-freedom linkage structures, controlling tool setting is even more complex. Summary of the Invention

[0004] The purpose of the present invention is to provide an industrial robot tool setting and processing method for chamfering large gears. The method mainly uses a laser displacement sensor at the end of the robot to scan the large gear to obtain the workpiece center coordinates and gear tooth vertex coordinates, and calculates the eccentricity between the turntable and the workpiece to compensate for the processing point coordinates after the turntable rotates a certain angle.

[0005] To achieve the above objectives, the present invention provides the following technical solutions:

[0006] A tool setting and processing method for large gear chamfering by an industrial robot, characterized by comprising:

[0007] Step 1: Install the electric spindle, tool, and laser displacement sensor at the end of the robot through the connector. Use a level to level the turntable and the gear workpiece. Establish two tool coordinate systems: laser displacement sensor coordinate system A and tool coordinate system B.

[0008] Step 2: Adjust the robot's posture for the first time;

[0009] Step 3: Adjust the robot's posture again;

[0010] Step 4: Based on the coordinates of these discrete points, the least squares method is used to fit the rough positioning circle center coordinates O0 (x0, y0, z0) through MATLAB software;

[0011] Step 5: Adjust the robot end position in the user coordinate system U;

[0012] Step 6: Use the same pose as step 5 to move an arc around the tooth profile in the new user coordinate system U;

[0013] Step 7: Adjust the posture so that the X direction of the tool coordinate system B is perpendicular to the XOY plane of the U coordinate system;

[0014] Step 8: After teaching each point on the chamfering trajectory, rotate the turntable θ angle;

[0015] Step 9: Calculate the initial machining point P of gear tooth No. i from the eccentricity i Coordinates and processing trajectory, i≥3;

[0016] Step 10: Adjust the robot's posture and perform chamfering according to the machining trajectory of the corresponding gear tooth. After the operation is completed, rotate the turntable to chamfer the next gear tooth.

[0017] Step one also includes installing the electric spindle, tool and laser displacement sensor at the end of the robot through connecting parts, using a spirit level to level the turntable and gear workpiece; and establishing two tool coordinate systems: laser displacement sensor coordinate system A and tool coordinate system B.

[0018] Step 2 also includes adjusting the robot's posture for the first time so that the Y direction of coordinate system A is perpendicular to the XOY plane of world coordinate system W, and moving along the X-axis or Y-axis in the world coordinate system. If the sensor reading fluctuates greatly, it is necessary to establish a coordinate system U0 parallel to the gear workpiece; control the sensor readings to be the same, establish the user coordinate system U0 as the base coordinate system, and record the rotation angle WPR values ​​of each axis of the coordinate system as w0, p0, r0.

[0019] Step three also includes adjusting the robot posture again so that the Y direction of the sensor coordinate system A is perpendicular to the XOY plane of U0, that is, the upper end face H of the gear, and controlling the robot end to move on the XOY plane of the coordinate system U0. When the sensor I / O signal changes from OFF to ON, the coordinates of the sensor coordinate system A in the world coordinate system W are recorded and recorded as point a; this is repeated several times to obtain the coordinates of n discrete points, where n ≥ 3.

[0020] Step 4 also involves fitting the rough positioning circle center coordinates O0 (x0, y0, z0) using the least squares method in MATLAB software based on the coordinates of these discrete points. In the teach pendant, the user coordinate system U, or the workpiece coordinate system of the gear, is established using direct input: the coordinate origin is (x0, y0, z0), and the rotation angles W, P, and R of each axis are the same as those of the coordinate system U0: W = w0, P = p0, and R = r0.

[0021] Step five also includes adjusting the robot's end posture in the user coordinate system U so that the Y axis of the A coordinate system points to the center of the cross section, controlling the robot to move an arc around the outer circle of the gear and recording the coordinates and sensor readings to obtain more accurate fitting point coordinates and repeating the fitting center coordinates in step four to obtain the precise positioning center coordinates O (x, y, z), and re-enter the center O into the user coordinate system U.

[0022] Step six also includes using the same posture as step five to walk an arc around the tooth profile in the new user coordinate system U, receiving sensor data and recording the coordinates of the tool coordinate system A in the user coordinate system U. When the sensor reading suddenly changes or tends to be flat, the X-axis and Y-axis coordinates x1, y1 of the tool coordinate system A in the U coordinate system are recorded to obtain the initial processing point P1 (x1, y1) of gear No. 1.

[0023] Step 7 also includes adjusting the posture so that the X direction of the tool coordinate system B is perpendicular to the XOY plane of the U coordinate system, setting the chamfering tool to the end face of the gear tooth, and recording the Z axis coordinate z of the tool coordinate system B in the user coordinate system U. n , and thus obtain the coordinates of P1 in the user coordinate system U (x1, y1, z n ).

[0024] Step 8 also includes teaching each point on the chamfering trajectory, rotating the turntable by an angle of θ, θ = 360° / Z, where Z is the number of gear teeth; if the center of the gear circle O coincides with the center of the turntable circle O', then the machining starting point P of the No. 2 gear tooth is 20 The point P2 obtained after rotation should coincide with the initial processing point P1 of gear tooth No. 1; there is eccentricity during the actual installation process. Repeat steps 5 and 6 to obtain the processing position coordinates P2 (x2, y2) of gear No. 2. The eccentricity between the gear workpiece and the turntable can be inferred by the deviation from the P1 coordinates.

[0025] The specific method of fitting in step 4 is as follows:

[0026] The coordinates of the discrete points are known to be (xi,yi,zi), and the plane equation is

[0027] ax+by+cz-1=0 (1)

[0028] Written in matrix form as MA=L1, where A=(a,b,c) T ,L1=(1,1,1) T (2)

[0029] This is an overdetermined equation. According to the least squares method, we can solve A=(M T M) -1 M T L1, the normal vector of the plane;

[0030] Assuming that all discrete points are on the circle, the perpendicular bisector of the line connecting any two points must pass through the center of the circle O(x0, y0, z0). Take two points P1(x1, y1, z1) and P2(x2, y2, z2), then the vector vector1 connecting P1 and P2 is expressed as (x2-x1, y2-y1, z2-z1), and the coordinates of the midpoint P12 of the line connecting P1 and P2 are The vector vector2 connecting the center O and P12 is In order for P1 and P2 to be on the circle, vector1*vector2=0, that is, After sorting

[0031] Δx 12 ·x0+Δy 12 ·y0+Δz 12 z0-l1=0

[0032] Where Δx 12 =x2-x1,Δy 12 =y2-y1,Δz 12 =z2-z1,

[0033] All points are on the circle, so

[0034]

[0035] Written in matrix form BO = L2

[0036] The above equation is also an overdetermined equation;

[0037] Since the center O must be in the aforementioned controlled plane, ax+by+cz-1=0, that is,

[0038] A T O=1 (4)

[0039] A is the normal vector of the plane, through A=(M T M) -1 M TL1 can be obtained; therefore, the optimization problem under the constraint of formula (4) can be constructed to solve formula (3), that is,

[0040] f(O)=||BO-L2|| 2 +λ(AO-1) (5)

[0041] Where λ is the Lagrange multiplier;

[0042] Derivative f(O) with respect to O and λ, and set the derivative value to 0, the transformation is

[0043]

[0044] Then the coordinates of the circle center O and λ can be obtained, that is,

[0045] The radius of a circle can be determined by taking the average of the distances from all points to the center of the circle:

[0046]

[0047] Calculate the eccentricity in step 8 & calculate P in step 9 i The specific method of coordinates is as follows:

[0048] O is the center of the gear workpiece, O' is the center of the turntable; P1 is the initial processing point of gear tooth No. 1, P 20 is the initial processing point of gear tooth No. 2, P2 is P 20 The point after the turntable rotates;

[0049] The deviation between P2 and P1 on the X axis is Δx=x2-x1, and the deviation on the Y axis is Δy=y2-y1; let the component of the eccentricity O'O in the X axis direction be D x , the component on the Y axis is D y ;

[0050] O2 is obtained by rotating the workpiece's initial position center O around the turntable's center O' by an angle of θ. From the congruence relationship, the XY deviations of O2 and O are equal to the XY deviations of P2 and P1. Construct the rectangle shown in the figure. From O'O=O'O2 and ∠AO'O+∠O2O'C=π / 2-θ, we can get the equation group:

[0051]

[0052] Given Δx, Δy, and θ, we can deduce D x , D y ;

[0053] By D x , D y The initial processing point P after the i-th gear rotates (i-1)*θ angle can be calculated i coordinates of

[0054] Let P i The deviation from P1 in the X and Y directions is Δx i , Δy i ;

[0055]

[0056]

[0057] x i =x1+Δx i

[0058] y i =y1+Δy i .

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] It mainly solves the problems of low accuracy, low efficiency and high risk of manual tool setting. The present invention uses the laser displacement sensor at the end of the robot to scan various positions of the gear workpiece to determine the center coordinates of the workpiece and the coordinates of the tooth vertices, thereby achieving accurate and stable tool setting and facilitating subsequent chamfering processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] Figure 1 This is a schematic diagram of the tool setting and processing method for large gear chamfering by an industrial robot;

[0062] Figure 2 Schematic diagram of the robot tool coordinate system and the laser displacement sensor coordinate system;

[0063] Figure 3 A schematic diagram of the robot's posture to obtain discrete point coordinates;

[0064] Figure 4 Schematic diagram of the robot's posture when scanning the outer circle of the gear to obtain the coordinates of discrete points;

[0065] Figure 5 Schematic diagram of a robot scanning the surface of a gear tooth;

[0066] Figure 6 A schematic diagram of the robot obtaining the Z-axis coordinate of the gear teeth;

[0067] Figure 7 Schematic diagram of the eccentricity between the gear workpiece and the turntable;

[0068] Figure 8 Schematic diagram of the projection of the eccentricity and the coordinate offset after the turntable rotates on the X and Y axes;

[0069] Figure 9It is a schematic diagram of the geometric relationship between eccentricity and coordinate offset;

[0070] Figure 10 This is a schematic diagram of the rough positioning of the fitting circle center in the case;

[0071] Figure 11 This is a diagram showing the sensor reading changes when the robot rotates around the outer circle under coarse and fine positioning of the circle center in the case;

[0072] Figure 12 This is a graph showing changes in the readings of the sensor scanning the gear tooth surface in the case. DETAILED DESCRIPTION

[0073] The technical solutions in the embodiments of the present invention will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present invention.

[0074] like Figure 1 A tool setting and processing method for large gear chamfering by an industrial robot, characterized by comprising:

[0075] Step 1: Install the electric spindle, tool, and laser displacement sensor at the end of the robot through the connector. Use a level to level the turntable and the gear workpiece. Establish two tool coordinate systems: laser displacement sensor coordinate system A and tool coordinate system B.

[0076] Step 2: Adjust the robot's posture for the first time;

[0077] Step 3: Adjust the robot's posture again;

[0078] Step 4: Based on the coordinates of these discrete points, the least squares method is used to fit the rough positioning circle center coordinates O0 (x0, y0, z0) through MATLAB software;

[0079] Step 5: Adjust the robot end position in the user coordinate system U;

[0080] Step 6: Use the same pose as step 5 to move an arc around the tooth profile in the new user coordinate system U;

[0081] Step 7: Adjust the posture so that the X direction of the tool coordinate system B is perpendicular to the XOY plane of the U coordinate system;

[0082] Step 8: After teaching each point on the chamfering trajectory, rotate the turntable θ angle;

[0083] Step 9: Calculate the initial machining point P of gear tooth No. i from the eccentricity i Coordinates and processing trajectory, i≥3;

[0084] Step 10: Adjust the robot's posture and perform chamfering according to the machining trajectory of the corresponding gear tooth. After the operation is completed, rotate the turntable to chamfer the next gear tooth.

[0085] like Figure 2 Step one also includes installing the electric spindle, tool and laser displacement sensor at the end of the robot through the connecting parts, using the level to level the turntable and the gear workpiece; establishing two tool coordinate systems: laser displacement sensor coordinate system A and tool coordinate system B.

[0086] Step 2 also includes adjusting the robot's posture for the first time so that the Y direction of coordinate system A is perpendicular to the XOY plane of world coordinate system W, and moving along the X-axis or Y-axis in the world coordinate system. If the sensor reading fluctuates greatly, it is necessary to establish a coordinate system U0 parallel to the gear workpiece; control the sensor readings to be the same, establish the user coordinate system U0 as the base coordinate system, and record the rotation angle WPR values ​​of each axis of the coordinate system as w0, p0, r0.

[0087] like Figure 3 Step 3 also includes adjusting the robot posture again so that the Y direction of the sensor coordinate system A is perpendicular to the XOY plane of U0, that is, the upper end face H of the gear, and controlling the robot end to move on the XOY plane of the coordinate system U0. When the sensor I / O signal changes from OFF to ON, the coordinates of the sensor coordinate system A in the world coordinate system W are recorded and recorded as point a. This is repeated several times to obtain the coordinates of n discrete points, where n ≥ 3.

[0088] like Figure 4 , Figure 11 Step five also includes adjusting the robot's end posture in the user coordinate system U so that the Y axis of the A coordinate system points to the center of the cross section, controlling the robot to move an arc around the outer circle of the gear and recording the coordinates and sensor readings to obtain more accurate fitting point coordinates and repeating the fitting center coordinates in step four to obtain the precise positioning center coordinates O (x, y, z), and re-enter the center O into the user coordinate system U.

[0089] like Figure 5 、 Figure 12 Step 6 also includes using the same posture as step 5 to walk an arc around the tooth profile in the new user coordinate system U, receiving sensor data and recording the coordinates of the tool coordinate system A in the user coordinate system U. When the sensor reading suddenly changes or tends to be flat, the X-axis and Y-axis coordinates x1, y1 of the tool coordinate system A in the U coordinate system are recorded to obtain the initial processing point P1 (x1, y1) of gear No. 1.

[0090] like Figure 6 Step 7 also includes adjusting the posture so that the X direction of the tool coordinate system B is perpendicular to the XOY plane of the U coordinate system, setting the chamfering tool to the end face of the gear tooth, and recording the Z axis coordinate z of the tool coordinate system B in the user coordinate system U. n , and thus obtain the coordinates of P1 in the user coordinate system U (x1, y1, z n ).

[0091] like Figure 7 Step eight also includes teaching each point on the chamfering trajectory, rotating the turntable by an angle of θ, θ = 360° / Z, where Z is the number of gear teeth; if the center of the gear circle O coincides with the center of the turntable circle O', then the initial processing point P of the No. 2 gear tooth is 20 The point P2 obtained after rotation should coincide with the initial processing point P1 of gear tooth No. 1; there is eccentricity during the actual installation process. Repeat steps 5 and 6 to obtain the processing position coordinates P2 (x2, y2) of gear No. 2. The eccentricity between the gear workpiece and the turntable can be inferred by the deviation from the P1 coordinates.

[0092] The specific method of fitting in step 4 is as follows:

[0093] The coordinates of the discrete points are known to be (xi,yi,zi), and the plane equation is

[0094] ax+by+cz-1=0 (1)

[0095] Written in matrix form as MA=L1, where A=(a,b,c) T ,L1=(1,1,1) T (2)

[0096] This is an overdetermined equation. According to the least squares method, we can solve A=(M T M) -1 M T L1, the normal vector of the plane;

[0097] Assuming that all discrete points are on the circle, the perpendicular bisector of the line connecting any two points must pass through the center of the circle O(x0, y0, z0). Take two points P1(x1, y1, z1) and P2(x2, y2, z2), then the vector vector1 connecting P1 and P2 is expressed as (x2-x1, y2-y1, z2-z1), and the coordinates of the midpoint P12 of the line connecting P1 and P2 are The vector vector2 connecting the center O and P12 is In order for P1 and P2 to be on the circle, vector1*vector2=0, that is, After sorting

[0098] Δx 12 ·x0+Δy 12 ·y0+Δz 12 z0-l1=0

[0099] Where Δx 12 =x2-x1,Δy 12 =y2-y1,Δz 12 =z2-z1,

[0100] All points are on the circle, so

[0101]

[0102] Written in matrix form BO = L2

[0103] The above equation is also an overdetermined equation;

[0104] Since the center O must be in the aforementioned controlled plane, ax+by+cz-1=0, that is,

[0105] A T O=1 (4)

[0106] A is the normal vector of the plane, through A=(M T M) -1 M T L1 can be obtained; therefore, the optimization problem under the constraint of formula (4) can be constructed to solve formula (3), that is,

[0107] f(O)=|BO-L2|| 2 +λ(AO-1) (5)

[0108] Where λ is the Lagrange multiplier;

[0109] Derivative f(O) with respect to O and λ, and set the derivative value to 0, the transformation is

[0110]

[0111] Then the coordinates of the circle center O and λ can be obtained, that is,

[0112] The radius of a circle can be determined by taking the average of the distances from all points to the center of the circle:

[0113]

[0114] like Figure 8-Figure 9 , calculate the eccentricity in step 8 & calculate P in step 9 i The specific method of coordinates is as follows:

[0115] O is the center of the gear workpiece, O' is the center of the turntable; P1 is the initial processing point of gear tooth No. 1, P 20 is the initial processing point of gear tooth No. 2, P2 is P 20 The point after the turntable rotates;

[0116] The deviation between P2 and P1 on the X axis is Δx=x2-x1, and the deviation on the Y axis is Δy=y2-y1; let the component of the eccentricity O'O in the X axis direction be D x , the component on the Y axis is D y ;

[0117] O2 is obtained by rotating the workpiece's initial position center O around the turntable's center O' by an angle of θ. From the congruence relationship, the XY deviations of O2 and O are equal to the XY deviations of P2 and P1. Construct the rectangle shown in the figure. From O'O=O'O2 and ∠AO'O+∠O2O'C=π / 2-θ, we can get the equation group:

[0118]

[0119] Given Δx, Δy, and θ, we can deduce D x , D y ;

[0120] By D x , D y The initial processing point P after the i-th gear rotates (i-1)*θ angle can be calculated i coordinates of

[0121] Let P i The deviation from P1 in the X and Y directions is Δx i , Δy i ;

[0122]

[0123]

[0124] x i =x1+Δx i

[0125] y i =y1+Δy i .

[0126] like Figure 10 The robot used is a FANUC robot. The gear workpiece has a module of 12, 64 teeth, a tooth tip diameter of 792 mm, a pitch diameter of 768 mm, a tooth thickness of 230 mm, and an inner diameter of 550 mm. In step 2, the rotation angles of the base coordinate system U0 on each axis are W = -0.1°, P = -0.4°, and R = 0.

[0127] The coordinates of the discrete points in step 3 are:

[0128] (1294.046,-671.834,312.703),

[0129] (1667.082,-603.702,311.450),

[0130] (1666.817,-279.803,313.265);

[0131] The coordinates of the circle center O fitted in step 4 are (1444.802, -441.940, 313.330), and the radius r = 274.916 mm, as shown in the figure.

[0132] In step 5, the coordinate origin of the user coordinate system U is (1444.802, -441.940, 313.330), W = -0.1°, P = -0.4°, R = 0.

[0133] The fitting points obtained in step 6 are

[0134] (1084.660,-441.920,306.485),

[0135] (1444.998,-83.842,308.892),

[0136] (1802.629,-441.916,313.081);

[0137] The precise positioning center obtained by fitting is (1443.644, -442.839, 309.785).

[0138] The above shows and describes the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely preferred examples of the present invention and are not intended to limit the present invention. Various changes and improvements may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and improvements fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A tool setting and processing method for large gear chamfering by an industrial robot, characterized in that: include: Step 1: Install the electric spindle, tool, and laser displacement sensor at the end of the robot through the connector. Use a level to level the turntable and the gear workpiece. Establish two tool coordinate systems: laser displacement sensor coordinate system A and tool coordinate system B. Step 2: Adjust the robot's posture for the first time; Step 2 also includes the first adjustment of the robot's posture so that: the Y direction of the laser displacement sensor coordinate system A is perpendicular to the XOY plane of the world coordinate system W. If the robot moves along the X-axis or Y-axis under the world coordinate system W, if the sensor reading fluctuates greatly, it is necessary to establish a user coordinate system U0 that is parallel to the gear workpiece; control the sensor readings to be the same, establish the user coordinate system U0 as the base coordinate system, and record the rotation angle WPR values ​​of each axis of the coordinate system as w0, p0, r0; Step 3: Adjust the robot's posture again; Step 3 also includes adjusting the robot's posture again so that the Y direction of the laser displacement sensor coordinate system A is perpendicular to the XOY plane of the user coordinate system U0, that is, the upper end face H of the gear. The robot end is controlled to move on the XOY plane of the user coordinate system U0. When the sensor I / O signal changes from OFF to ON, the coordinates of the laser displacement sensor coordinate system A in the world coordinate system W are recorded and recorded as point a. This process is repeated several times to obtain the coordinates of n discrete points, where n ≥ 3. Step 4: Based on the coordinates of these discrete points, the least squares method is used to fit the rough positioning circle center coordinates O0 (x0, y0, z0) through MATLAB software; Step 4 also includes fitting the rough positioning circle center coordinates O0 (x0, y0, z0) using the least squares method in MATLAB software based on the coordinates of these discrete points; using the direct input method in the teach pendant to establish the user coordinate system U, that is, the workpiece coordinate system of the gear: the coordinate origin is (x0, y0, z0), and the rotation angles W, P, and R of each axis are the same as those of the user coordinate system U0, W=w0, P=p0, R=r0; Step 5: Adjust the robot end position in the user coordinate system U; Step 5 also includes adjusting the robot's end-user posture in the user coordinate system U so that the Y axis of the laser displacement sensor coordinate system A points to the center of the cross-section circle. The robot is then controlled to move an arc around the outer circle of the gear and the coordinates and sensor readings are recorded to obtain more accurate fitting point coordinates. The fitting center coordinates in step 4 are then repeated to obtain the precise positioning center coordinates O (x, y, z). The center O is then re-entered into the user coordinate system U. Step 6: Use the same pose as step 5 to move an arc around the tooth profile in the new user coordinate system U; Step 6 also includes using the same posture as step 5 to walk an arc around the tooth profile in the new user coordinate system U, receiving sensor data while recording the coordinates of the laser displacement sensor coordinate system A in the user coordinate system U. When the sensor reading suddenly changes or tends to be flat, the X-axis and Y-axis coordinates x1, y1 of the laser displacement sensor coordinate system A in the user coordinate system U are recorded to obtain the initial machining point P1 (x1, y1) of gear tooth No.

1. Step 7: Adjust the posture so that the X direction of the tool coordinate system B is perpendicular to the XOY plane of the user coordinate system U; Step 7 also includes adjusting the posture so that the X direction of the tool coordinate system B is perpendicular to the XOY plane of the user coordinate system U, setting the chamfering tool to the end face of the gear tooth, and recording the Z axis coordinate z of the tool coordinate system B in the user coordinate system U. n , and thus obtain the coordinates of P1 in the user coordinate system U (x1, y1, z n ); Step 8: After teaching each point on the chamfering trajectory, rotate the turntable θ angle; Step 8 also includes teaching each point on the chamfering trajectory, rotating the turntable by an angle of θ, θ=360° / Z, where Z is the number of gear teeth; if the center of the gear circle O coincides with the center of the turntable circle O', then the machining starting point P of the No. 2 gear tooth is 20 The point P2 obtained after rotation should coincide with the initial processing point P1 of gear No.

1. In the actual installation process, there is eccentricity. Repeat steps 5 and 6 to obtain the processing position coordinates P2 (x2, y2) of gear No.

2. The eccentricity between the gear workpiece and the turntable can be inferred by the deviation from the P1 coordinates. Step 9: Calculate the initial machining point P of gear tooth No. i from the eccentricity i Coordinates and processing trajectory, i≥3; Step 10: Adjust the robot's posture and perform chamfering according to the machining trajectory of the corresponding gear tooth. After the operation is completed, rotate the turntable to chamfer the next gear tooth.

2. The tool setting and processing method for large gear chamfering by an industrial robot according to claim 1, characterized in that: The specific method of fitting in step 4 is as follows: The coordinates of the discrete points are known to be (xi,yi,zi), and the plane equation is (1) Written in matrix form as , where , (2) This is an overdetermined equation. According to the least squares method, we can find , which is the normal vector of the plane; Assuming that all discrete points are on the circle, the perpendicular bisector of the line connecting any two points must pass through the center of the circle O(x0, y0, z0). Take two points P1(x1, y1, z1) and P2(x2, y2, z2), then the vector vector1 connecting P1 and P2 is expressed as (x2-x1, y2-y1, z2-z1), and the coordinates of the midpoint P12 of the line connecting P1 and P2 are , the vector vector2 connecting the center O and P12 is ; To make P1 and P2 on the circle, vector1*vector2=0, that is, , after sorting ， In the formula , , All points are on the circle, so （3） Written in matrix form In the formula , , , The above equation is also an overdetermined equation; Since the center O must be in the aforementioned controlled plane, ,Right now （4） is the normal vector of the plane, through Therefore, we can solve (3) by constructing an optimization problem under the constraints of (4), that is, （5） in, is the Lagrange multiplier; right About O and Take the derivative and set the derivative value to 0, and transform to get （6） Then we can get the coordinates of the center O and ,Right now , The radius of a circle can be determined by taking the average of the distances from all points to the center of the circle: 。 3. The tool setting and processing method for large gear chamfering by an industrial robot according to claim 1, characterized in that: Calculate the eccentricity in step 8 and P in step 9 i The specific method of coordinates is as follows: O is the center of the gear workpiece, O' is the center of the turntable; P1 is the initial processing point of gear tooth No. 1, P 20 is the initial processing point of gear tooth No. 2, P2 is P 20 The point after the turntable rotates; Deviation between P2 and P1 on the X axis , the deviation on the Y axis ; Let the component of eccentricity O'O in the X-axis direction be D x , the component on the Y axis is D y ; O2 is obtained by rotating the workpiece's initial position center O around the turntable's center O' by an angle of θ. From the congruence relationship, the XY deviations of O2 and O are equal to the XY deviations of P2 and P1, thus constructing a rectangle. From O'O=O'O2 and ∠AO'O+∠O2O'C=π / 2-θ, we can obtain the following equations: ， Given Δx, Δy, and θ, we can deduce D x , D y ; By D x , D y The initial processing point P after the i-th gear rotates by (i-1)*θ can be calculated. i coordinates of Let P i The deviation from P1 in the X and Y directions is Δx i , Δy i ; ， ， ， 。

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