Rapid calibration tool and rapid calibration method for tool coordinate system of palletizing robot

Abstract

The invention discloses a quick calibration tool and a quick calibration method for a tool coordinate system of a palletizing robot, and relates to the field of industrial robot control. According to the invention, through a plurality of reference points, such as a disc fixing device, a vertical guide rod, a stand column tip and a chuck center base, the coordinate system of the sucker tool is accurately calibrated. The offset and the angle offset on the X axis, the Y axis and the Z axis can be accurately measured. The device is provided with a plurality of guide rods with scales, such as an upper transverse guide rod, a lower transverse guide rod, a lower longitudinal guide rod, a vertical guide rod and the like, and the guide rods are used for measuring X-axis offset, Y-axis offset, Z-axis offset and angle offset respectively. The scale design on the guide rods can provide accurate data reading in each direction, so that the suction cup is ensured to be spatially aligned with the flange plate. The chuck is provided with four baffles, the periphery of the suction cup can be synchronously clamped, and it is guaranteed that the four faces of the suction cup are evenly attached to the tool. By means of the structure, the centering position and stability of the suction cup in the clamping process are guaranteed, and therefore offset errors are reduced.

Description

Technical Field

[0001] The present invention relates to the field of industrial robot control, and in particular to a rapid calibration tool and a rapid calibration method for a tool coordinate system of a palletizing robot. Background Art

[0002] In modern industrial production, palletizing robots are widely used due to their efficient and accurate automated stacking and handling capabilities. In order to ensure the accuracy of palletizing operations, the tool coordinate system (TCP) of the palletizing robot must accurately reflect the actual position and orientation of the tool. Although the traditional tool coordinate system calibration method, especially the three-point method, is widely used, it has certain limitations and errors in actual operation.

[0003] The three-point calibration process usually involves the following steps: First, adjust the robot's posture so that the center point of the end tool coincides with the reference top; then, teach three reference points at different angles, and use these points to calculate the offset of the tool coordinate system. This method relies on the precise alignment of the robot's end tool and the operator's manual adjustment, so it is susceptible to human error. Specifically, center point positioning error: During the three-point calibration process, a ruler is required to measure the center point of the tooling, but the ruler measurement has accuracy limitations, which can easily lead to center point positioning deviations. Even if the tooling is symmetrical, it is difficult to achieve ideal accuracy with a ruler measurement, and the center point error directly affects the accuracy of the tool coordinate system.

[0004] Three-time teaching error accumulation: The three-point method requires three times of teaching the tooling in different postures, but each operation may introduce errors. These errors gradually accumulate in the calculation, affecting the accuracy of the final tool coordinate system, especially in the palletizing scenario with high precision requirements, the accumulated errors will cause the stacking position to shift.

[0005] However, during the actual installation and production process, the palletizing robot's suction cups, fixtures and other tooling may deviate from the designed position. This deviation may cause center offset and direction deviation, thus affecting the accuracy of palletizing. In particular, when calibrating the direction, manual visual inspection is relied upon, which is prone to error accumulation, thus affecting the accuracy of the palletizing operation, causing the material stacking to be offset and uneven, and reducing production efficiency. In addition, the three-point test method requires the mobile robot to adjust its posture, and the calibration efficiency is low. Summary of the invention

[0006] In view of the shortcomings of the prior art, the present invention provides a rapid calibration tool and a rapid calibration method for the tool coordinate system of a palletizing robot. The device and method can solve the problems of low efficiency and poor precision of the traditional three-point method, and realize high-precision rapid calibration of the tool coordinate system of the palletizing robot. At the same time, the device and method are simple to operate and have strong applicability, which can effectively improve production efficiency and reduce human errors.

[0007] To achieve the above technical effects, the present application discloses a rapid calibration tool for a tool coordinate system of a palletizing robot, which is used to measure the coordinates of a palletizing tool fixed on a flange of the robot, including a disc fixing device, the disc fixing device being fixedly arranged on a cross-section of the flange parallel to the Y direction of the robot, an upper transverse guide rod being fixedly arranged on the disc fixing device, the upper transverse guide rod being consistent with the X direction of the robot, and further comprising a lower transverse guide rod parallel to the upper transverse guide rod, the lower transverse guide rod being connected to the upper transverse guide rod via a vertical guide rod, a lower longitudinal guide rod being further arranged on the lower transverse guide rod, the vertical guide rod being perpendicular to the upper transverse guide rod and being able to move on the upper transverse guide rod, The lower transverse guide rod is perpendicular to the vertical guide rod and can move on the vertical guide rod. The lower longitudinal guide rod is perpendicular to the lower transverse guide rod and can move on the lower transverse guide rod. The lower transverse guide rod is also provided with a column top. The lower longitudinal guide rod is provided with a chuck center base that can move along the length direction of the lower longitudinal guide rod. A chuck is provided on the chuck center base. The chuck is provided with two groups of baffle groups. Any baffle group consists of two opposite baffles, and it is arranged that when any baffle in the same baffle group moves, the opposite baffles will also move in the opposite direction at the same time, and the moving distances are equal.

[0008] Furthermore, the upper transverse guide rod, the lower transverse guide rod, the vertical guide rod and the lower longitudinal guide rod are all provided with scales.

[0009] Furthermore, a circular scale for measuring angles is provided on the center base of the chuck.

[0010] Furthermore, the stacking tool is selected as a suction cup or a gripper.

[0011] At the same time, the present invention also discloses a method for rapid calibration of a tool coordinate system of a palletizing robot. The rapid calibration of the tool coordinate system of the palletizing robot is performed by the above-mentioned tooling, and specifically comprises the following steps: (1) Initial alignment: Move the robot with the palletizing tooling to the initial zero position, fix the disc fixture above the flange, move the vertical guide rod horizontally to a position where the tooling does not affect the measurement, read the value X1 of the center of the vertical guide rod on the upper horizontal guide rod, and move the top of the column horizontally in the opposite direction to the position on the lower horizontal guide rod. The moving distance value is X1; (2) The chuck clamps the palletizing tooling, moves the lower longitudinal guide rod and the center base of the chuck to the bottom of the tooling, moves the lower transverse guide rod upward until the top of the center base of the chuck contacts the palletizing tooling, then stops, and slowly clamps the four baffles of the chuck respectively, so that the four sides of the baffle are tightly attached to the palletizing tooling, with no gaps in all directions. During the process of the baffles being close to the four sides, the transverse guide rod and the center base of the chuck will also move accordingly. After fixing the guide rods, chuck, base and other devices, read and record; (3) Read the numerical value and measure the angle offset A value: the rotation angle on the center base of the chuck, that is, the offset angle A of the tooling; Measure the X-direction offset: read the scale value X1 of the top of the column on the lower transverse guide rod, and read the scale value X2 of the lower longitudinal guide rod on the lower transverse guide rod. The offset value in the X-direction is X= X1-X2; Measure the Y-direction offset: read the value Y of the chuck center base on the lower longitudinal guide rod, which is the offset value in the Y direction; Measure the Z-direction offset: read the value Z1 of the lower transverse guide rod on the vertical guide rod. It is known that the height from the top of the chuck center base to the lower transverse guide rod in the designed tooling is Z2, and the offset value in the Z direction is Z=Z1-Z2; The tool coordinate system can be obtained as (X, Y, Z, A, 0, 0).

[0012] Beneficial effects of the technical solution of the present invention: High-precision calibration: Through physical alignment of multiple reference points, scale difference calculation and synchronous clamping design, the device can accurately measure the tool coordinate system offset of the suction cup, reduce the cumulative error in traditional calibration methods, and significantly improve the calibration accuracy.

[0013] Easy to operate: Multiple scaled guide rods and a clear calibration process allow operators to intuitively read the suction cup's X, Y, Z offset and angle offset (A value) without the need for complex calculations or additional equipment, reducing the difficulty of operation.

[0014] Strong applicability: The device is suitable for rapid calibration of suction cups and fixtures, especially for precise calibration of tool coordinate systems when the suction cup center is difficult to determine directly, to meet the calibration requirements of different tools.

[0015] Improve production efficiency: By reducing calibration time and errors, the robot's palletizing accuracy and work efficiency can be effectively improved, and the rework rate can be reduced, thereby improving the efficiency and stability of the entire production line.

[0016] Reducing human errors: This invention avoids the errors caused by traditional manual visual direction through standardized physical scale alignment and clamping design, and provides a stable tool coordinate system calibration method for high-precision application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a schematic diagram of the tooling structure of the present invention.

[0019] Figure 2 The test of the present invention is shown in FIG. Figure 1 .

[0020] Figure 3 The test of the present invention is shown in FIG. Figure 2 .

[0021] Among them: disc fixing device-1, upper horizontal guide rod-2, lower horizontal guide rod-3, vertical guide rod-4, lower longitudinal guide rod-5, column top-6, chuck-7, chuck center base-8, baffle-9, flange-100, stacking tooling-200. DETAILED DESCRIPTION

[0022] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0023] refer to Figure 1-3 A palletizing robot tool coordinate system rapid calibration tool, used for measuring the coordinates of a palletizing tool 200 fixed on a flange 100 of a robot, comprising a disc fixing device 1, wherein the disc fixing device 1 is fixedly arranged on a cross section of the flange 100 parallel to the Y direction of the robot, an upper transverse guide rod 2 is fixedly arranged on the disc fixing device 1, the upper transverse guide rod 2 is consistent with the X direction of the robot, and further comprising a lower transverse guide rod 3 parallel to the upper transverse guide rod 2, the lower transverse guide rod 3 is connected to the upper transverse guide rod 2 through a vertical guide rod 4, a lower longitudinal guide rod 5 is further arranged on the lower transverse guide rod 3, the vertical guide rod 4 is perpendicular to the upper transverse guide rod 2 and can move on the upper transverse guide rod 2, The lower transverse guide rod 3 is perpendicular to the vertical guide rod 4 and can move on the vertical guide rod 4. The lower longitudinal guide rod 5 is perpendicular to the lower transverse guide rod 3 and can move on the lower transverse guide rod 3. The lower transverse guide rod 3 is also provided with a column top 6. The lower longitudinal guide rod 5 is provided with a chuck center base 8 that can move along the length direction of the lower longitudinal guide rod. The chuck center base is provided with a chuck 7. The chuck 7 is provided with two groups of baffle groups. Any baffle group consists of two opposite baffles 9, and it is arranged that when any baffle in the same baffle group moves, the opposite baffles will also move in the opposite direction at the same time, and the moving distance is equal.

[0024] In a specific embodiment, reference Figure 1 , a disc fixing device 1, there is a cross-section on the mechanical body above the flange, and the cross-section is parallel to the Y direction of the robot. When the device is fixed, the cross-section inside the disc and the cross-section of the flange are locked, thereby ensuring that the direction of the connected lateral guide rod 2 is consistent with the coordinate system X of the robot.

[0025] The upper horizontal guide rod 2 is consistent with the X direction of the robot and has a ruler on it to measure the X offset between the center of the vertical guide rod 4 and the center of the flange.

[0026] The lower transverse guide rod 3 is parallel to the upper transverse guide rod 2 and is also provided with a ruler to measure the distances between the top 6 of the column and the lower longitudinal guide rod 5 and the center of the vertical guide rod 4 respectively.

[0027] The vertical guide rod 4 is mainly used to connect and fix the upper transverse guide rod 2 and the lower transverse guide rod 3, and is used to measure the Z offset between the top of the chuck center base 8 and the center of the flange 100.

[0028] The lower longitudinal guide rod 5 is fixed to the lower transverse guide rod 3 and is used to measure the Y-direction offset of the center of the chuck center base 8 from the center of the flange. The top of the column 6 can be moved to the bottom of the flange according to the scales on the upper and lower transverse guide rods 2 and 3. The chuck 7 has four baffles 9. When one baffle is moved, the opposite baffle will also move in the opposite direction at the same time, and the moving distance is equal. The chuck center base 8 is connected to the lower longitudinal guide rod 5, and the top of the base is connected to the chuck 7; it has a circular scale to measure the rotation angle of the chuck 7.

[0029] Preferably, the upper transverse guide rod 2, the lower transverse guide rod 3, the vertical guide rod 4 and the lower longitudinal guide rod 5 are provided with scales to facilitate reading of the scale numbers. The chuck center base 8 is provided with a circular scale for measuring angles.

[0030] The stacking tool is selected as a suction cup or a gripper. The suction cup is used as an example. When used, the following steps are specifically included: (1) Initial alignment: Move the robot with the palletizing tooling to the initial zero position, fix the disc fixture above the flange, move the vertical guide rod horizontally to a position where the tooling does not affect the measurement, read the value X1 of the center of the vertical guide rod on the upper horizontal guide rod, and move the top of the column horizontally in the opposite direction to the position on the lower horizontal guide rod. The moving distance value is X1; (2) The chuck clamps the palletizing tooling, moves the lower longitudinal guide rod and the center base of the chuck to the bottom of the tooling, moves the lower transverse guide rod upward until the top of the center base of the chuck contacts the palletizing tooling, then stops, and slowly clamps the four baffles of the chuck respectively, so that the four sides of the baffle are tightly attached to the palletizing tooling, with no gaps in all directions. During the process of the baffles being close to the four sides, the transverse guide rod and the center base of the chuck will also move accordingly. After fixing the guide rods, chuck, base and other devices, read and record; (3) Read the numerical value and measure the angle offset A value: the rotation angle on the center base of the chuck, that is, the offset angle A of the tooling; Measure the X-direction offset: read the scale value X1 of the top of the column on the lower transverse guide rod, and read the scale value X2 of the lower longitudinal guide rod on the lower transverse guide rod. The offset value in the X-direction is X= X1-X2; Measure the Y-direction offset: read the value Y of the chuck center base on the lower longitudinal guide rod, which is the offset value in the Y direction; Measure the Z-direction offset: read the value Z1 of the lower transverse guide rod on the vertical guide rod. It is known that the height from the top of the chuck center base to the lower transverse guide rod in the designed tooling is Z2, and the offset value in the Z direction is Z=Z1-Z2; The tool coordinate system can be obtained as (X, Y, Z, A, 0, 0).

[0031] The key points of the invention include: (1) Precise calibration of multiple reference points: The invention achieves precise calibration of the suction cup tool coordinate system through multiple reference points (such as the disc fixture, vertical guide rod, column top and chuck center base). The reference points work together to ensure that the offset and angle offset (A value) on the X, Y and Z axes can be accurately measured.

[0032] (2) All-round three-dimensional offset measurement: The device is equipped with multiple guide rods with scales, including upper and lower transverse guide rods, lower longitudinal guide rods and vertical guide rods, which are used to measure X, Y, Z axis offset and angular offset respectively. The scale design on these guide rods can provide accurate data reading in each direction to ensure the spatial alignment of the suction cup and the flange.

[0033] (3) Four-sided synchronous clamping structure: The chuck has four baffles that can synchronously clamp the suction cup around the four sides to ensure that the suction cup fits the tooling evenly on all four sides. This structure ensures the suction cup's center position and stability during clamping, thereby reducing offset errors.

[0034] The above key points reflect the following innovations: Multi-point calibration design for automatic flange alignment: By aligning the disc fixture and the cross-section of the flange, the X-axis of the measuring device is ensured to be consistent with the X-direction of the robot. This design reduces the reliance on traditional measurement methods and improves the accuracy and efficiency of coordinate system calibration.

[0035] Scale-based segmented offset calculation method: This device uses the superposition calculation method of the reference point scale difference to realize the calculation of the overall offset by reading multi-point offset data. Compared with the traditional single-point measurement or teaching method, this method greatly improves the measurement accuracy and calibration efficiency.

[0036] Multifunctional guide rod combination design: The guide rod system integrates the offset measurement of the X, Y, and Z axes, and has the functions of flexible adjustment and multi-directional reading. In particular, the combination of the vertical guide rod and the lower longitudinal guide rod can simultaneously measure the offset in different directions and provide three-dimensional precision calibration.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A palletizing robot tool coordinate system rapid calibration tool, used to measure the coordinates of a palletizing tool (200) fixed on a flange (100) of the robot, characterized in that: The invention comprises a disc fixing device (1), wherein the disc fixing device (1) is fixedly arranged on a cross-section of the flange (100) parallel to the Y direction of the robot, an upper transverse guide rod (2) is fixedly arranged on the disc fixing device (1), the upper transverse guide rod (2) is consistent with the X direction of the robot, and further comprises a lower transverse guide rod (3) parallel to the upper transverse guide rod (2), the lower transverse guide rod (3) is connected to the upper transverse guide rod (2) via a vertical guide rod (4), a lower longitudinal guide rod (5) is further arranged on the lower transverse guide rod (3), the vertical guide rod (4) is perpendicular to the upper transverse guide rod (2) and can move on the upper transverse guide rod (2), The lower transverse guide rod (3) is perpendicular to the vertical guide rod (4) and can move on the vertical guide rod (4). The lower longitudinal guide rod (5) is perpendicular to the lower transverse guide rod (3) and can move on the lower transverse guide rod (3). The lower transverse guide rod (3) is also provided with a column top (6). The lower longitudinal guide rod (5) is provided with a chuck center base (8) that can move along the length direction of the lower longitudinal guide rod. A chuck (7) is provided on the chuck center base. The chuck (7) is provided with two baffle groups. Any baffle group consists of two opposing baffles (9). When any baffle in the same baffle group moves, the opposing baffles will also move in the opposite direction at the same time and the moving distance is equal.

2. The rapid calibration tool for tool coordinate system of a palletizing robot according to claim 1, characterized in that: The upper transverse guide rod (2), the lower transverse guide rod (3), the vertical guide rod (4) and the lower longitudinal guide rod (5) are all provided with scales.

3. The rapid calibration tool for tool coordinate system of a palletizing robot according to claim 1, characterized in that: The chuck center base (8) is provided with a circular scale for measuring angles.

4. The rapid calibration tool for tool coordinate system of a palletizing robot according to claim 1, characterized in that: The stacking tool is selected as a suction cup or a gripper.

5. A rapid calibration method for a palletizing robot tool coordinate system, characterized in that: The rapid calibration of the tool coordinate system of the palletizing robot according to any one of claims 1 to 4 is performed, and specifically comprises the following steps: (1) Initial alignment: Move the robot with the palletizing tooling to the initial zero position, fix the disc fixture above the flange, move the vertical guide rod horizontally to a position where the tooling does not affect the measurement, read the value X1 of the center of the vertical guide rod on the upper horizontal guide rod, and move the top of the column horizontally in the opposite direction to the position on the lower horizontal guide rod. The moving distance value is X1; (2) The chuck clamps the palletizing tooling, moves the lower longitudinal guide rod and the center base of the chuck to the bottom of the tooling, moves the lower transverse guide rod upward until the top of the center base of the chuck contacts the palletizing tooling, then stops, and slowly clamps the four baffles of the chuck respectively, so that the four sides of the baffle are tightly attached to the palletizing tooling, with no gaps in all directions. During the process of the baffles being close to the four sides, the transverse guide rod and the center base of the chuck will also move accordingly. After fixing the guide rods, chuck, base and other devices, read and record; (3) Read the numerical value and measure the angle offset A value: the rotation angle on the center base of the chuck, that is, the offset angle A of the tooling; Measure the X-direction offset: read the scale value X1 of the top of the column on the lower transverse guide rod, and read the scale value X2 of the lower longitudinal guide rod on the lower transverse guide rod. The offset value in the X-direction is X= X1-X2; Measure the Y-direction offset: read the value Y of the chuck center base on the lower longitudinal guide rod, which is the offset value in the Y direction; Measure the Z-direction offset: read the value Z1 of the lower transverse guide rod on the vertical guide rod. It is known that the height from the top of the chuck center base to the lower transverse guide rod in the designed tooling is Z2, and the offset value in the Z direction is Z=Z1-Z2; The tool coordinate system can be obtained as (X, Y, Z, A, 0, 0).

Images