Multifunctional drilling end effector and working method

Abstract

The invention discloses a multifunctional drilling end effector and a working method, and relates to the technical field of machining, the multifunctional drilling end effector comprises a multi-degree-of-freedom robot and a multifunctional end effector, and the multifunctional end effector is connected to the execution tail end of the multi-degree-of-freedom robot; the multifunctional end effector comprises a machine head, a three-way driving mechanism and a laser scanning sensor, the laser scanning sensor is fixedly connected to one side of the machine head, the three-way driving mechanism is connected with the machine head and drives the machine head to conduct X / Y / Z axis three-way position adjustment, and the multifunctional drilling equipment further comprises a controller. According to the device, the multifunctional end effector and the laser scanning sensor are matched to obtain data information and position information of the circumference line of the to-be-formed hole site, so that accurate normal alignment and accurate positioning are achieved, and the controller can identify interferents according to the data information of the circumference line of the to-be-formed hole site and automatically remove the interferents. Compared with the prior art for normal vector measurement by acquiring surface data, the data calculation amount is effectively reduced, and the measurement efficiency is ensured.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and in particular to a multifunctional hole-making end effector and its working method. Background Technology

[0002] In high-precision hole-making processes, such as aircraft skin and frame assembly, the workpiece is often not planar. To ensure hole quality, the hole-making of increasingly variable curvature surface workpieces requires real-time detection of the normal direction. Traditional normal measurement methods use a four-point method, where four laser displacement sensors simultaneously acquire distance information from four points and quickly calculate the normal deviation. However, due to the complex surface structure of the workpiece and the presence of numerous interfering objects, the traditional four-point method cannot identify objects that lie on them, leading to measurement errors and affecting hole-making accuracy. As an improvement, existing hole-making processes employ a line laser scanning normal measurement method at the end of the hole-making process. This method obtains surface data, allowing for the identification and automatic removal of interfering objects, thus ensuring measurement accuracy. However, the large amount of data and long computation time affect measurement efficiency.

[0003] Meanwhile, high-precision hole-making is characterized by a wide variety of products and small batches. Fully automated hole-making requires pre-programming, simulation, and calibration of workpiece and robot coordinates, resulting in lengthy preparation time. It is often suitable for scenarios with a large number of holes to be made in a single operation, and also demands a high level of operator skill. In some cases, where only a few holes need to be machined, fully automated hole-making can lead to slow response, cumbersome operation, and a shortage of skilled personnel. Summary of the Invention

[0004] To address the aforementioned problems, this invention proposes a multifunctional end effector for hole making and its working method. The multifunctional end effector is mounted on a multi-degree-of-freedom robot for hole making. Specifically, the multifunctional end effector for hole making described in this invention adopts the following technical solution: The device includes a multi-degree-of-freedom robot and a multi-functional end effector. The multi-functional end effector is connected to the end of the multi-degree-of-freedom robot. The multi-functional end effector includes a head, a three-axis drive mechanism, and a laser scanning sensor. The laser scanning sensor is fixedly connected to one side of the head, and the three-axis drive mechanism is connected to the head and drives the head to adjust its position in the X, Y, and Z axes. The laser scanning sensor is used to detect the circumferential data of the position of the hole to be drilled on the curved workpiece and guide the multi-degree-of-freedom robot to drive the multi-functional end effector to perform normal alignment. The multi-functional hole-making equipment also includes a controller, which is communicatively connected to both the multi-degree-of-freedom robot and the multi-functional end effector.

[0005] A method for operating a multifunctional hole-making end effector, characterized by comprising the following steps: 1) The controller controls the movement of the three-way drive mechanism, so that the multi-functional end effector drives the laser scanning sensor to perform a circular scan around the hole to be processed with the axis of the hole as the center and the set distance as the radius, to obtain the circumferential line data information. 2) The controller uses a built-in algorithm to identify data values ​​with obvious anomalies in the distance data on the z-axis and removes the outliers; 3) The controller identifies and removes interference points from the circumferential line data based on its built-in algorithm; 4) The controller fits the plane where the hole to be made is located according to the built-in algorithm, and then obtains the plane parameters and the normal vector information of the hole to be made; 5) Based on the obtained normal vector information, the controller controls the multi-functional end effector to adjust the posture to complete the normal deviation compensation, thereby completing the accurate normal alignment.

[0006] Further, step 1) specifically includes: the laser scanning sensor performs circular motion on the plane with a radius of r, taking the center of the circle as the origin O, and marking points on the horizontal x-axis at intervals of length s. Points are marked from left to right on the upper half of the circle, resulting in a sequence of spatial coordinate points. The sequence of spatial coordinate points obtained by marking dots from right to left on the lower semicircle is as follows: This allows us to obtain information on 2N data points on the circumference.

[0007] Further, step 2) specifically includes: the controller identifies data values ​​with obvious abnormalities in the distance data on the z-axis, uses the sliding window box plot method to identify abnormal values, removes abnormal points, and marks the number as K.

[0008] Further, step 3) specifically includes: the controller uses the least squares method to fit the parameters of the plane ellipse, thereby identifying and removing interference point information contained in the circumferential line data information, the number of which is marked as H.

[0009] Further, step 4) specifically includes: the controller uses the singular value decomposition method to fit the plane where the workpiece is located. By performing singular value decomposition on the coordinate matrix of the point to be fitted after centroid removal, the plane parameters are obtained, and the normal information of the hole to be made is obtained.

[0010] Furthermore, when 2r / s is an integer, When 2r / s is not an integer, That is, the floor value of 2r / s.

[0011] Furthermore, the data According to fixed window size Divide into, and obtain Given a data segment, calculate the first quartile of each data segment. and the third and fourth quartiles Thus, the interquartile range (IQR) is obtained. The interquartile range is used to determine the upper bound of outliers. and the lower realm They are defined as follows: ; ; Where T is the number of data points, and data points outside the upper and lower bounds are marked as outliers; these are the points marked as outliers. Data The corresponding coordinate points are removed from the original coordinate point sequence, thus obtaining the coordinate point sequence after outlier removal. .

[0012] Furthermore, the general form for fitting an elliptic curve using the least squares method is... , obtain parameters ; Calculate the actual coordinates of the points and the coordinates of the point on the ellipse The difference between them, i.e. Set threshold Difference sequence The standard deviation, i.e. ; in, For sequence The mean. When At that time, the point was considered an interference point; the set of coordinate points obtained after removal is... .

[0013] Furthermore, calculate the centroid of the coordinate points. : ; Translate the data points to a point where the centroid is the origin: ; For the centroid-free matrix Perform singular value decomposition: ; in: yes The left singular vector matrix; yes A diagonal matrix, where the diagonal elements are singular values. ; yes The right singular vector matrix, whose column vectors Corresponding to the main direction; normal vector of a plane Minimum singular value The corresponding right singular vector : ; Using the center of mass and normal vector Calculate coefficients : ; Thus, the equation of the plane containing the coordinate point is obtained: ; The unit normal vector of the hole to be made is then obtained as: ; in .

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: 1) The multi-functional end effector of the present invention is equipped with a multi-degree-of-freedom robot for hole making. When facing non-standard hole processing requirements, the multi-functional end effector realizes three-way adjustment of X / Y / Z axis through the first to third servo motors, which can meet the high-precision complex structure hole processing of curved workpieces, and can realize automatic compensation of complex deviations, greatly enhancing its versatility and adaptability.

[0015] 2) This invention integrates the tool magazine onto a multi-functional end effector, which can complete multiple hole-making operations at once, avoiding the problems of low efficiency caused by long-distance tool changes and low processing quality caused by the accumulation of multiple positioning errors.

[0016] 3) This invention uses multiple auxiliary supports and main supports to support the AGV vehicle, improving the stability of the entire system and avoiding the problem of equipment center of gravity shifting due to large amplitude vibrations during the hole-making process.

[0017] 4) This invention uses a multi-functional end effector in conjunction with a laser scanning sensor set on the end of the hole to obtain the circumferential line data and position information of the hole to be made, thereby achieving accurate normal alignment and precise positioning. The controller can identify and automatically remove interference objects based on the circumferential line data of the hole to be made. Compared with the prior art, which obtains surface data for normal vector measurement, the amount of data calculation is effectively reduced, ensuring measurement efficiency.

[0018] 5) This invention can selectively perform large-batch and small-batch hole making. In small-batch processing, a human-machine collaborative mode is used, specifically a combination of manual rough positioning and automatic machine precise positioning to perform hole making, which simplifies the tedious operation of small-batch hole making and improves response speed. In large-batch processing, fully automated positioning, normal alignment and processing can be achieved, which improves processing efficiency. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram of the internal structure of the multifunctional end effector of the present invention; Figure 3 This is another schematic diagram of the internal structure of the multifunctional end effector of the present invention; Figure 4 This is a schematic diagram of the appearance of the multifunctional end effector of the present invention; Figure 5 This is a schematic diagram of the AGV vehicle structure of the present invention; Figure 6 This is a schematic diagram of the detection principle of the laser scanning sensor of the present invention; Figure 7 This is a schematic diagram of the laser scanning sensor of the present invention.

[0020] In the diagram: 1. AGV vehicle; 2. Multi-degree-of-freedom robot; 3. Multifunctional end effector; 4. Control cabinet; 5. Connecting base plate; 6. Head unit; 7. Tool magazine; 8. Laser scanning sensor; 9. Vision camera; 10. First guide rail; 11. First servo motor; 12. First connecting plate; 13. Second guide rail; 14. Second servo motor; 15. First side plate; 16. Third guide rail; 17. Third servo motor; 18. Base plate; 19. Fourth guide rail; 20. Fourth servo motor; 21. Second connecting plate; 22. Tool holder; 23. Front plate; 24. Second side plate; 25. Control panel; 26. Display screen; 27. Remote control handle; 28. Mecanum wheel; 29. ​​Main positioning; 30. Auxiliary positioning; 31. Base plate. Detailed Implementation

[0021] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0022] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0023] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0024] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0025] like Figure 1-5 As shown, this embodiment of the invention provides a mobile robot drilling device, including an AGV vehicle 1, a multi-degree-of-freedom robot 2, a multi-functional end effector 3, and a control cabinet 4. The multi-degree-of-freedom robot 2 and the control cabinet 4 are located on the top of the AGV vehicle 1. The multi-functional end effector 3 is connected to the end effector of the multi-degree-of-freedom robot 2 via a connecting base plate 5. The multi-functional end effector 3 includes a head unit 6, a three-way drive mechanism, a tool magazine 7, a laser scanning sensor 8, and a vision camera 9. The laser scanning sensor 8 and the vision camera 9 are fixedly connected to one side of the head unit 6. The tool magazine 7 is movably located at the rear of the other side of the head unit 6. The tool magazine 7 can be selected... The robot moves to the front of the head 6 and works with the head 6 to change the tool. The three-way drive mechanism is connected to the head 6 and drives the head 6 to adjust its position in the X / Y / Z axes. The laser scanning sensor 8 is used to indicate the position of the multi-functional end effector 3, detect the circular line data information of the position of the hole to be made on the curved workpiece, and guide the multi-degree-of-freedom robot 2 to drive the multi-functional end effector 3 to move for normal alignment. The vision camera 9 is used to identify the markers set on the hole to be made and guide the multi-degree-of-freedom robot 2 to accurately align with the markers. The control cabinet 4 is equipped with a controller, which is communicatively connected to the AGV 1, the multi-degree-of-freedom robot 2, and the multi-functional end effector 3.

[0026] The three-way drive mechanism of the present invention includes a base plate 31, a first guide rail 10, a first servo motor 11, a second guide rail 13, a second servo motor 14, a third guide rail 16, and a third servo motor 27. The first guide rail 10 is disposed on the upper end of the base plate 31 along the Y-axis. The first servo motor 11 is connected to a first slider through a first transmission mechanism, thereby driving the first slider to move along the first guide rail 10. A first connecting plate 12 is disposed above the first slider. The second guide rail 13 is disposed above the first connecting plate 12 along the X-axis. The second servo motor 14 is connected to a second slider through a second transmission mechanism, thereby driving the second slider to move along the second guide rail 13. A first side plate 15 is vertically disposed above the second slider. The third guide rail 16 is disposed on the side of the first side plate 15 facing the machine head 6 along the Z-axis. The third servo motor 27 is connected to a third slider through a third transmission mechanism, thereby driving the third slider to move along the third guide rail 16. The third slider is fixedly connected to the machine head 6. This invention uses a first servo motor 11, a second servo motor 14, and a third servo motor 27 to adjust the position of the machine head 6 along the X / Y / Z axes. During normal alignment, the controller controls the movement of the machine head 6 to drive the laser scanning sensor 8 to perform a circular scan around the hole to be machined with the axis of the hole as the center and a set distance as the radius r, thereby obtaining circumferential line data information. During hole making, the controller controls the machine head 6 to move according to a preset trajectory to complete the processing of complex structure holes, realizing automatic compensation for complex deviations, which greatly enhances its versatility and adaptability.

[0027] The tool magazine 7 of this invention includes a base plate 18 fixedly connected to a base plate 31. A fourth guide rail 19 is provided on the upper side of the base plate 18. The fourth guide rail 19, the first guide rail 10, and the second guide rail 13 are all inclined. A fourth servo motor 20 is provided on one side of the fourth guide rail 19. The fourth servo motor 20 is connected to a fourth slider through a fourth transmission mechanism, thereby driving the fourth slider to move along the fourth guide rail 19. A second connecting plate 21 is connected to the top of the fourth slider, and a tool holder 22 is connected to the fourth slider through the second connecting plate 21. Multiple tool fixing seats are provided on the tool holder 22. When a tool change is required, this invention controls the fourth servo motor 20 to drive the tool holder 22 forward to the tool change position to cooperate with the machine head 6 for tool change. After the tool change is completed, it retracts to a clearance position to prevent interference with the movement of the multi-functional end effector 3. This invention integrates the tool magazine 7 onto the multi-functional end effector 3, which can complete multiple hole-making operations at once, avoiding the problems of low efficiency caused by long-distance tool changes and low processing quality caused by the accumulation of multiple positioning errors.

[0028] The multi-functional end effector 3 of this invention also includes a housing disposed on the outer periphery of its main body. The housing includes a front plate 23 and a second side plate 24 disposed perpendicular to the front plate 23. A control panel 25 is fixedly connected to the outer side of the second side plate 24. The control panel 25 is provided with a display screen 26 and a remote control handle 27. The display screen 26 is used for human-machine interaction and displays various parameters of the control system. The specific parameter types can be defined according to actual needs. The remote control handle 27 includes a vertically disposed rocker arm A and a rocker arm B. Rocker arm A can swing in two directions and has two buttons, thereby controlling the end effector of the multi-degree-of-freedom robot 2 to translate along the X / Y / Z axes. Rocker arm B can swing in two directions and rotate around its own axis, thereby controlling the end effector of the multi-degree-of-freedom robot 2 to rotate along the X / Y / Z axes. This application allows manual control of the multi-degree-of-freedom robot 2 to drive the multi-functional end effector 3 to move and adjust its posture via the remote control handle 27.

[0029] The AGV 1 of this invention includes multiple Mecanum wheels 28 and a support structure located on the lower side of the vehicle body. Each Mecanum wheel 28 is an electrically controlled lifting suspension mechanism. When the AGV 1 moves, the Mecanum wheel 28 extends downward to support the vehicle body and move. After the AGV 1 moves to a designated position, the Mecanum wheel 28 retracts upward, and the vehicle body lands directly on the ground via the support structure. The support structure includes multiple main supports 29 and multiple auxiliary supports 30. The main supports 29 protrude downward along the bottom of the AGV 1's body. When the Mecanum wheels 28 of the AGV 1 retract and the vehicle body lands, the main supports 29 naturally touch the ground. The auxiliary supports 30 are detachably and fixedly mounted on the side of the AGV 1's body. A pressure sensor is installed inside the auxiliary support 30. During the downward extension of the auxiliary support 30, when the pressure sensor detects that the supporting force has reached a set value, the extension movement stops. This invention uses multiple auxiliary supports 30 and main supports 29 to support the AGV 1, improving the stability of the entire system and avoiding the problem of equipment center of gravity shifting due to large amplitude vibrations during hole-making operations.

[0030] Furthermore, the working method of the mobile robot hole-making device of the present invention includes the following steps: The processing mode is selected by the controller or display screen 26. The processing mode includes small batch mode and large batch mode. When performing small batch processing, proceed to step A-1. A-1. Mark all locations of holes to be made. Markers can be pre-drilled holes, scribing lines, stickers, etc. A-2. The operator determines the actual alignment position of the end of the hole by observing the laser emitted by the laser scanning sensor 8. A-3. The operator controls the movement of the multi-degree-of-freedom robot 2 through the remote control handle 27, so that the distance between the multi-functional end effector 3 and the workpiece is within the range of the laser scanning sensor 8, and the multi-functional end effector 3 is roughly aligned with the hole to be made for preliminary positioning; at the same time, the operator observes with the naked eye and manually controls the multi-degree-of-freedom robot 2 to drive the multi-functional end effector 3 to be roughly perpendicular to the surface of the workpiece for preliminary normal alignment. A-4. The operator transfers control of the multi-degree-of-freedom robot 2 to the controller. The controller uses the laser scanning sensor 8 to detect the normal of the hole to be made. Based on the detection results, the controller controls the multi-degree-of-freedom robot 2 to adjust its posture to complete the normal deviation compensation, thereby completing the accurate normal alignment. A-5. The controller uses the vision camera 9 to detect the accurate position of the marker for the hole to be made. After obtaining the accurate position, the controller controls the multi-degree-of-freedom robot 2 to adjust its posture so that the multi-functional end effector 3 is aligned with the hole to be made for precise positioning. A-6. After the posture adjustment is completed, the multi-degree-of-freedom robot 2 stops moving and remains stationary. The controller simultaneously controls the three-way drive mechanism and spindle movement of the multi-functional end effector 3 to complete the hole making process. A-7. The operator regains control of the multi-degree-of-freedom robot 2, moves to the next hole position to continue drilling, and repeats steps A-2 to A-6 until all holes to be drilled are completed.

[0031] Further, in step A-5, after the orientation adjustment is completed, the vision camera 9 is used to re-detect the accurate position of the marker for the hole to be drilled, and the detection result is compared with the theoretical data. If the positional error does not fall within the allowable error range, the controller controls the multi-degree-of-freedom robot 2 to readjust its orientation again, repeating the above inspection process until the positional error falls within the allowable error range. Then, the final distance between the multi-functional end effector 3 and the workpiece is fed back to the controller, which calculates the spindle feed amount and controls the spindle to perform axial feed.

[0032] When performing mass production, proceed to step B-1: B-1. The controller acquires the spatial coordinate system information of the multi-degree-of-freedom robot 2, AGV vehicle 1, multi-functional end effector 3, and the workpiece to be processed; B-2. The controller acquires the digital model information of the workpiece to be processed, including the coordinates, dimensions and types of all holes to be made, and generates the motion trajectory of the multi-degree-of-freedom robot 2 and the multi-functional end effector 3. B-3. ​​The controller, based on the spatial coordinate system information obtained in B-1 and the digital model information obtained in B-2, controls the multi-degree-of-freedom robot 2 to move to the position corresponding to the first hole to be made. B-4. The controller uses laser scanning sensor 8 to detect the normal orientation of the hole to be drilled. Based on the detection results, the controller controls the multi-degree-of-freedom robot 2 to adjust its posture and complete the precise normal orientation alignment. B-5. After the posture adjustment is completed, the multi-degree-of-freedom robot 2 stops moving and remains stationary. The controller simultaneously controls the three-way drive mechanism and spindle movement of the multi-functional end effector 3 to complete the hole making process. B-6. The controller controls the multi-degree-of-freedom robot 2 to move to the next hole position according to the motion trajectory. Repeat steps B-4 to B-5 to complete the processing of the remaining holes.

[0033] This invention can selectively perform large-batch and small-batch hole-making. In small-batch processing, a human-machine collaborative mode is used, specifically a combination of manual rough positioning and automatic precise positioning by the machine to perform hole-making, which simplifies the tedious operation of hole-making for small-batch parts and improves response speed. In large-batch processing, fully automated positioning, normal alignment and processing can be achieved, improving processing efficiency.

[0034] Furthermore, between steps A- and A-2, and between steps B-2 and B-3, there is also a tool change judgment step. Specifically, the controller determines whether a tool change is needed based on the size and type of the hole to be made. If a tool change is needed, the controller controls the tool magazine 7 to move forward to the tool change position to perform the tool change.

[0035] Furthermore, in steps A-4 and B-4, the laser displacement scanning sensor performs normal detection on the hole to be drilled, specifically including the following steps: 1) The controller controls the movement of the three-way drive mechanism, so that the multi-functional end effector 3 drives the laser scanning sensor 8 to perform a circular scan around the hole to be processed with the axis of the hole as the center and a set distance as the radius r, to obtain circumferential line data information. See Figure 6 , Figure 7 Specifically, this includes: the laser scanning sensor 8 performs circular motion on a plane with a radius of r, and the center of the circle is taken as the origin O. It marks a point every length s along the horizontal x-axis, and the data obtained at each point is the distance between the laser scanning sensor 8 and the workpiece. The trajectory of the laser scanning sensor 8 in circular motion is as follows: Figure 7 As shown. Points are marked on the upper semicircle from left to right, resulting in a sequence of spatial coordinate points. When 2r / s is an integer, When 2r / s is not an integer, That is, the floor value of 2r / s. Starting point. The coordinates on the x-axis are The coordinates on the y-axis are The coordinate on the z-axis represents the distance data obtained by the laser scanning sensor 8 when it hits the workpiece. Then, point by point is taken to the right in sequence until the last coordinate point of the upper part of the circular motion is obtained. Its coordinates on the x-axis are The coordinates on the y-axis are The coordinates on the z-axis represent the distance data at this point. .

[0036] Similarly, by marking points from right to left on the lower semicircle, the resulting sequence of spatial coordinate points is as follows: Starting point The coordinates on the x-axis are The coordinates on the y-axis are The coordinates on the z-axis represent distance data. Continue taking points to the left in sequence until you reach the last coordinate point of the lower half of the circular motion. Its coordinates on the x-axis are The coordinates on the y-axis are The coordinate on the z-axis represents the distance data obtained by the sensor hitting the workpiece at this moment. Thus, information on 2N data points on the circumference is obtained.

[0037] 2) The controller identifies data values ​​with obvious anomalies in the distance data on the z-axis, and uses the sliding window box plot method to identify and remove outliers; Specifically, this includes: taking into account factors such as sensor detection anomalies, and taking appropriate measures to address any obvious anomalies in the data. For example, regarding the coordinate point sequence... If there are obvious outliers in the distance data on the z-axis, outlier handling is the first step. A sliding window box plot method is used to identify outliers. According to fixed window size To divide the data, T is usually set to 30, resulting in... There are several data segments; the details of each data segment are as follows: ; G represents the specific data segment interval, and l represents the number of data segments; For each data segment, a box plot method is used. Specifically, the first quartiles of the two key statistics in each data segment are calculated. and the third and fourth quartiles Thus, the interquartile range (IQR) is obtained. ; Use the interquartile range to determine the range of outliers, the upper bound ( ) and lower bound ( They are defined as follows: ; ; Where T represents the number of data points, and data points outside the upper and lower bounds are marked as outliers. These are then labeled as outliers. Data The corresponding coordinate points are removed from the original coordinate point sequence, thus obtaining the coordinate point sequence after outlier removal. .

[0038] 3) The controller uses the least squares method to fit the parameters of the plane ellipse, thereby identifying and removing interference points contained in the circumferential line data. Specifically, this includes: considering the roughness of the workpiece surface and interference from impurities, and processing the data to address potential interference. The least squares method is used to fit the parameters of the plane ellipse, thereby identifying the interference points it contains. Specifically, based on the coordinate point sequence... The general form of fitting the following elliptic curve using the least squares method is given. , obtain parameters Since the sequence of coordinate points does not all lie on the elliptic curve, it is necessary to calculate the actual coordinates of the points. and the coordinates of the point on the ellipse The difference between them, i.e. Set threshold Difference sequence The standard deviation, i.e. ; in, For sequence The mean. When At that time, the point is considered an interference point. The H marked interference points are... The set of coordinate points obtained after removal is .

[0039] 4) The controller uses the singular value decomposition method to fit the plane where the workpiece is located. By performing singular value decomposition on the coordinate matrix of the point to be fitted after centroid removal, the plane parameters are obtained and the normal information of the hole to be made is obtained.

[0040] Specifically, this includes: coordinate points on a plane in known space. ; Calculate the centroid of the coordinate point: ; Translate the data points to a point where the centroid is the origin: ; For the centroid-free matrix Perform singular value decomposition: ; in: yes The left singular vector matrix; yes A diagonal matrix, where the diagonal elements are singular values. ; yes The right singular vector matrix, whose column vectors Corresponding to the main direction.

[0041] normal vector of a plane Minimum singular value The corresponding right singular vector : ; Using the center of mass and normal vector Calculate coefficients : ; Thus, the equation of the plane containing the coordinate point is obtained: ; The unit normal vector of the hole to be made is then obtained as: ; in .

[0042] In summary, this invention uses a multi-functional end effector 3 in conjunction with a laser scanning sensor 8 mounted on the end of the hole to acquire circumferential line data and position information of the hole to be made, thereby achieving precise normal alignment and accurate positioning. The controller can identify and automatically remove interference objects based on the circumferential line data of the hole to be made. Compared with the prior art, which obtains surface data for normal vector measurement, the amount of data calculation is effectively reduced, ensuring measurement efficiency.

[0043] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0044] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A multifunctional hole-making end effector, characterized in that, The device includes a multi-degree-of-freedom robot and a multi-functional end effector. The multi-functional end effector is connected to the end of the multi-degree-of-freedom robot. The multi-functional end effector includes a head, a three-axis drive mechanism, and a laser scanning sensor. The laser scanning sensor is fixedly connected to one side of the head, and the three-axis drive mechanism is connected to the head and drives the head to adjust its position in the X, Y, and Z axes. The laser scanning sensor is used to detect the circumferential data of the position of the hole to be drilled on the curved workpiece and guide the multi-degree-of-freedom robot to drive the multi-functional end effector to perform normal alignment. The multi-functional hole-making device also includes a controller, which is communicatively connected to both the multi-degree-of-freedom robot and the multi-functional end effector.

2. A method for operating a multifunctional hole-making end effector, characterized in that, The multifunctional hole-making end effector as described in claim 1 includes the following steps: 1) The controller controls the movement of the three-way drive mechanism, so that the multi-functional end effector drives the laser scanning sensor to perform a circular scan around the hole to be processed with the axis of the hole as the center and the set distance as the radius, to obtain the circumferential line data information. 2) The controller uses a built-in algorithm to identify data values ​​with obvious anomalies in the distance data on the z-axis and removes the outliers; 3) The controller identifies and removes interference points from the circumferential line data based on its built-in algorithm; 4) The controller fits the plane where the hole to be made is located according to the built-in algorithm, and then obtains the plane parameters and the normal vector information of the hole to be made; 5) Based on the obtained normal vector information, the controller controls the multi-functional end effector to adjust the posture to complete the normal deviation compensation, thereby completing the accurate normal alignment.

3. The working method of the multifunctional hole-making end effector according to claim 2, characterized in that, Step 1) specifically includes: the laser scanning sensor performs circular motion on a plane with a radius of r. Taking the center of the circle as the origin O, it marks points along the horizontal x-axis at intervals of length s. Points are marked from left to right on the upper half of the circle, resulting in a sequence of spatial coordinate points. The sequence of spatial coordinate points obtained by marking dots from right to left on the lower semicircle is as follows: This allows us to obtain information on 2N data points on the circumference.

4. The working method of the multifunctional hole-making end effector according to claim 3, characterized in that, Step 2) specifically includes: the controller identifies data values ​​with obvious abnormalities in the distance data on the z-axis, uses the sliding window box plot method to identify abnormal values, removes abnormal points, and marks the number as K.

5. The working method of a multifunctional hole-making end effector according to claim 4, characterized in that, Step 3) specifically includes: the controller uses the least squares method to fit the parameters of the plane ellipse, thereby identifying and removing interference point information contained in the circumferential line data information, and the number is marked as H.

6. The working method of the multifunctional hole-making end effector according to claim 5, characterized in that, Step 4) Specifically includes: The controller uses the singular value decomposition method to fit the plane where the workpiece is located. By performing singular value decomposition on the coordinate matrix of the point to be fitted after centroid removal, the plane parameters are obtained, and the normal information of the hole to be made is obtained.

7. The working method of the multifunctional hole-making end effector according to claim 3, characterized in that, When 2r / s is an integer When 2r / s is not an integer, That is, the floor value of 2r / s.

8. The working method of a multifunctional hole-making end effector according to claim 6, characterized in that, Data According to fixed window size Divide into, and obtain Given a data segment, calculate the first quartile of each data segment. and the third and fourth quartiles Thus, the interquartile range (IQR) is obtained. The interquartile range is used to determine the upper bound of outliers. and the lower realm They are defined as follows: ； ； Where T is the number of data points, and data points outside the upper and lower bounds are marked as outliers; these are the points marked as outliers. Data The corresponding coordinate points are removed from the original coordinate point sequence, thus obtaining the coordinate point sequence after outlier removal. .

9. The working method of a multifunctional hole-making end effector according to claim 8, characterized in that, General formula for fitting elliptic curves using the least squares method , obtain parameters ; Calculate the actual coordinates of the points and the coordinates of the point on the ellipse The difference between them, i.e. Set threshold Difference sequence The standard deviation, i.e. ； in, For sequence The mean. When At that time, the point was considered an interference point; the set of coordinate points obtained after removal is... .

10. The working method of a multifunctional hole-making end effector according to claim 9, characterized in that, Calculate the centroid of the coordinate point : ； Translate the data points to a point where the centroid is the origin: ； For the centroid-free matrix Perform singular value decomposition: ； in: yes The left singular vector matrix; yes A diagonal matrix, where the diagonal elements are singular values. ; yes The right singular vector matrix, whose column vectors Corresponding to the main direction; normal vector of a plane Minimum singular value The corresponding right singular vector : ； Using the center of mass and normal vector Calculate coefficients : ; Thus, the equation of the plane containing the coordinate point is obtained: ; The unit normal vector of the hole to be made is then obtained as: ； in .

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