Displacement control method for friction stir welding

Abstract

The invention relates to the technical field of friction stir welding, and provides a friction stir welding displacement control method which comprises the following steps: displacement teaching: controlling the press-in amount of friction stir welding performed on a teaching workpiece by a stirring tool to be consistent according to a first preset mode, or simulating and controlling the press-in amount on the teaching workpiece to be consistent according to a second preset mode, or simulating and controlling the press-in amount on the teaching workpiece to be consistent according to a second preset mode; measuring the surface information of the teaching workpiece according to a third preset mode to obtain a displacement superposition value capable of enabling the press-in amount to be consistent; in displacement teaching, according to the accumulated running length of the teaching workpiece, a plurality of recording points on the welding seam and displacement superposition values corresponding to the recording points are determined; and friction stir welding displacement control is conducted on the to-be-welded workpiece based on the displacement superposition values corresponding to the multiple recording points, and the to-be-welded workpiece has the surface characteristics of the teaching workpiece. The problem that friction stir welding in the related technology is poor in adaptability with two-dimensional track welding while it is guaranteed that the press-in amount of each workpiece is consistent is solved. Automatic press-in amount control is achieved, and the consistency of the press-in amount of each workpiece is guaranteed.

Description

Technical Field

[0001] The invention relates to the technical field of stir friction welding, and in particular to a displacement control method for stir friction welding. Background Art

[0002] Friction stir welding is a solid-phase joining technology. The workpiece is stirred and rubbed by a high-speed rotating stirring tool. The metal material reaches a plastic state under the action of the stirring tool shoulder and the stirring needle, flows in the direction of rotation, and forms a dense solid-phase weld under the extrusion of the welding tool.

[0003] Due to the surface error of the workpiece or the height error of the tooling, the surface of the workpiece is usually not completely horizontal and there will be height changes. Therefore, during stir friction welding, it is necessary to control the Z displacement or the amount of pressure in accordance with the height of the workpiece surface to ensure the welding quality. Existing control methods include constant displacement control with constant Z displacement, constant pressure control with pressure sensors installed, and constant pressure control with displacement sensors installed. However, constant displacement control cannot automatically control the amount of pressure, which will lead to inconsistent pressure at different positions, and more materials need to be removed in subsequent processes such as milling; constant pressure control requires the installation of pressure sensors, and can only control the amount of pressure within a certain range, and cannot ensure that each workpiece has a consistent amount of pressure; constant pressure control requires the installation of displacement sensors, and since the point actually detected by the displacement sensor is a certain distance from the center of the stirring tool, it is poorly compatible with two-dimensional trajectory welding.

[0004] Currently, no effective solution has been proposed to meet the requirements of automatic pressure-input control of friction stir welding, ensuring the consistency of pressure-input amount for each workpiece, and adapting to two-dimensional trajectory welding. Summary of the invention

[0005] The present invention provides a displacement control method for friction stir welding, the purpose of which is to achieve automatic pressure-in amount control without installing a sensor and solve the problem of inconsistent pressure-in amount.

[0006] The present invention provides a displacement control method for stir friction welding, including: displacement teaching: stir friction welding is performed on a teaching workpiece according to a first preset method, wherein the first preset method controls the pressing amount of the stirring tool on the teaching workpiece to be consistent, or, according to the second preset method, simulates and controls the pressing amount on the teaching workpiece to be consistent, or, according to the third preset method, measures the surface information of the teaching workpiece to obtain a displacement superposition value that can make the pressing amount on the teaching workpiece consistent; during the displacement teaching process, according to the cumulative running length of the teaching workpiece, determines multiple recording points on the weld and the displacement superposition value corresponding to each recording point; welding displacement control: based on the displacement superposition values ​​corresponding to the multiple recording points, displacement control is performed on the stir friction welding of the workpiece to be welded, wherein the workpiece to be welded has the surface characteristics of the teaching workpiece.

[0007] The displacement control method for stir friction welding provided by the embodiment of the present invention, before stir friction welding is performed on the teaching workpiece according to the first preset method, the method further includes: recording the starting coordinates of the weld; before simulating and controlling the pressing amount on the teaching workpiece to be consistent according to the second preset method, the method further includes: recording the starting coordinates of the weld; before measuring the surface information of the teaching workpiece according to the third preset method and obtaining the displacement superposition value that can make the pressing amount consistent, the method further includes: recording the initial value of the sensor at the starting point of the weld, wherein the sensor is used to detect the surface information of the teaching workpiece in real time during the displacement teaching process.

[0008] The displacement control method of friction stir welding provided by the embodiment of the present invention determines multiple recording points on the weld and the displacement superposition value corresponding to each recording point according to the cumulative running length of the teaching workpiece, including: starting from the starting coordinates of the weld, collecting and calculating the running trajectory of the weld according to the preset collection cycle, and obtaining the collection point coordinates corresponding to the current collection cycle, wherein the starting coordinates of the weld are determined in the machine tool coordinate system or the workpiece coordinate system of the friction stir welding equipment; based on the sum of the trajectory length of the current collection cycle and the cumulative running length of the previous collection cycle, the cumulative running length of the current collection cycle is determined, wherein the trajectory length of the current collection cycle is calculated based on the collection point coordinates of the current collection cycle and the previous collection cycle; when the cumulative running length of the current collection cycle is greater than or equal to the corresponding preset sampling length, the collection point corresponding to the current collection cycle is used as the current recording point; and the corresponding displacement superposition value is determined according to the recording point coordinates.

[0009] The displacement control method of stir friction welding provided by the embodiment of the present invention, when the collection point corresponding to the current collection cycle is used as the current recording point, a length interval is added to the current preset sampling length to obtain the next preset sampling length; the collection calculation is continued according to the preset collection cycle, and when the cumulative running length of the new current collection cycle is greater than or equal to the next preset sampling length, the collection point corresponding to the new current collection cycle is used as the new current recording point, and the new next preset sampling length is obtained until the running trajectory on the teaching workpiece is completed, wherein the initial value of the preset sampling length is 0; after determining the corresponding displacement superposition value according to the coordinates of the recording point, the above method also includes: recording the displacement superposition values ​​corresponding to all recording points in a recording table in an ascending order of the corresponding preset sampling lengths by means of variable index.

[0010] The displacement control method of friction stir welding provided by the embodiment of the present invention performs displacement control on the friction stir welding of the workpiece to be welded based on the displacement superposition value corresponding to multiple recording points, including: determining the acquisition point coordinates, cumulative welding length, reading length and data reading points of the workpiece to be welded in a manner of determining the acquisition point coordinates, cumulative running length, preset sampling length and recording points of the teaching workpiece, wherein the data reading points correspond to the corresponding recording points of the preset sampling length from small to large in a one-to-one manner according to the corresponding reading length from small to large; when the cumulative welding length of the current acquisition cycle of the workpiece to be welded is greater than or equal to the current reading length, the current data reading point and the next data reading point are obtained respectively The displacement superposition value of the corresponding recording point; according to the displacement superposition values ​​of the recording points corresponding to the current data reading point and the next data reading point, respectively, and the real-time accumulated welding length of the workpiece to be welded within the current length interval, calculate the displacement superposition value change value between the current data reading point and the collection point corresponding to the current collection period of the workpiece to be welded, wherein the current length interval is the length interval between the current data reading point and the next data reading point, and the size of the current length interval is equal to the size of the length interval of the preset sampling length; according to the displacement superposition value change value, determine the real-time superposition value of the collection point corresponding to the current collection period of the workpiece to be welded; perform real-time displacement control on the stir friction welding of the workpiece to be welded according to the real-time superposition value.

[0011] The displacement control method of friction stir welding provided by the present invention is to calculate the displacement superposition value change value between the current data reading point and the collection point corresponding to the current collection period of the workpiece to be welded according to the displacement superposition value and the real-time cumulative welding length of the workpiece to be welded within the current length interval, including: obtaining a real-time ratio according to the ratio of the cumulative welding length of the workpiece to be welded from the current data reading point to the length interval of the preset sampling length; subtracting the displacement superposition value of the record point corresponding to the current data reading point from the displacement superposition value of the record point corresponding to the next data reading point to obtain the displacement superposition difference between the next data reading point and the current data reading point; multiplying the real-time ratio by the displacement superposition difference to obtain the displacement superposition value change value between the current data reading point and the collection point corresponding to the current collection period of the workpiece to be welded; determining the real-time superposition value of the collection point corresponding to the current collection period of the workpiece to be welded according to the displacement superposition value change value, including: adding the displacement superposition value of the record point corresponding to the current data reading point to the displacement superposition value change value to obtain the real-time superposition value of the collection point corresponding to the current collection period of the workpiece to be welded.

[0012] The displacement control method of friction stir welding provided by the embodiment of the present invention performs displacement control on the friction stir welding of the workpiece to be welded between the current data reading point and the next data reading point based on the displacement superposition value of the recording point corresponding to the current data reading point and the control speed in a point control manner when the current length interval is less than a preset threshold value, wherein the control speed is determined according to the current moving speed of the stirring tool.

[0013] The displacement control method of stir friction welding provided by the embodiment of the present invention, in the displacement teaching process, the above method also includes: calculating the characteristic value of the teaching workpiece based on the displacement superposition value corresponding to the current recording point and all previous recording points, wherein the characteristic value of the teaching workpiece includes the displacement value and the cumulative weld length corresponding to the current recording point, the maximum displacement value and the corresponding operating position, and the minimum displacement value and the corresponding operating position; based on the characteristic value of the teaching workpiece, displaying the surface features of the current position of the teaching workpiece during the displacement teaching process, and displaying the overall surface features of the teaching workpiece after the displacement teaching is completed; in the welding displacement control process, the above method also includes: calculating the characteristic value of the workpiece to be welded based on the displacement superposition value of each acquisition cycle, wherein the characteristic value of the workpiece to be welded includes the displacement value and the cumulative weld length corresponding to the current data reading point, the maximum displacement value and the corresponding welding position, and the minimum displacement value and the corresponding welding position; based on the characteristic value of the workpiece to be welded, displaying the surface features of the current position of the workpiece to be welded during the welding displacement control process, and displaying the overall surface features of the workpiece to be welded after the welding displacement control is completed.

[0014] The displacement control method for friction stir welding provided by the embodiment of the present invention performs the same welding displacement control on the friction stir welding of multiple workpieces to be welded based on one displacement teaching.

[0015] The present invention provides a displacement control method for friction stir welding, wherein the displacement control is displacement control in the Z-axis direction, the X-axis direction, or the Y-axis direction in the machine tool coordinate system or the workpiece coordinate system of the friction stir welding equipment, or a combination of displacement controls in multiple of the above directions.

[0016] The present invention provides a displacement control method for friction stir welding, which obtains a displacement superposition value through displacement teaching control, and can realize automatic pressure control without installing a pressure sensor, and can ensure the consistency of the pressure amount; in the welding displacement control process, the friction stir welding of the workpiece to be welded is displacement controlled based on the displacement superposition value corresponding to a plurality of recording points, so that the workpiece to be welded and the teaching workpiece have a consistent pressure amount, and there is no need to use a sensor. This can solve the problem of poor compatibility of friction stir welding in related technologies with two-dimensional trajectory welding while ensuring the consistency of the pressure amount of each workpiece. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention, and for those skilled in the art, other embodiments can be obtained based on these drawings without creative work.

[0018] Figure 1 It is a flow chart of the overall steps of a displacement control method for stir friction welding in an embodiment of the present invention.

[0019] Figure 2 It is a specific working principle diagram of a displacement control method of stir friction welding in an embodiment of the present invention.

[0020] Figure 3 It is a structural schematic diagram of an electronic device in an embodiment of the invention. DETAILED DESCRIPTION

[0021] The embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided to provide a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0022] When performing friction stir welding, it is necessary to control the Z displacement or the amount of pressure according to the surface error of the workpiece to ensure the welding quality.

[0023] Existing control methods include constant displacement control with constant Z displacement, constant pressure control with pressure sensors installed, and constant pressure-in amount control with displacement sensors installed. Among them, constant displacement control will result in inconsistent pressure-in amounts for each workpiece, requiring more material to be removed in subsequent processes such as milling. Constant pressure control requires the installation of pressure sensors, and can only control the pressure-in amount within a certain range, and cannot ensure that each workpiece has a consistent pressure-in amount. Constant pressure-in amount control requires the installation of displacement sensors. Since the detection point of the displacement sensor is at a certain distance from the center of the stirring tool, the detection point will not always be on the weld trajectory during two-dimensional trajectory welding, i.e., it has poor compatibility with two-dimensional trajectory welding.

[0024] To do this, please refer to Figure 1As shown in the step flow chart, the present invention provides a displacement control method for stir friction welding, including: step S101, displacement teaching: stir friction welding is performed on a teaching workpiece according to a first preset method, wherein the first preset method controls the pressing amount of the stirring tool on the teaching workpiece to be consistent, or, according to the second preset method, simulates and controls the pressing amount on the teaching workpiece to be consistent, or, according to the third preset method, measures the surface information of the teaching workpiece to obtain a displacement superposition value that can make the pressing amount on the teaching workpiece consistent.

[0025] Step S102, during the displacement teaching process, multiple recording points on the weld and the displacement superposition value corresponding to each recording point are determined according to the accumulated running length of the teaching workpiece.

[0026] It can be understood that step S101 and step S102 are performed synchronously.

[0027] Step S103, welding displacement control: performing displacement control on the friction stir welding of the workpiece to be welded based on the displacement superposition values ​​corresponding to the multiple recording points, wherein the workpiece to be welded has the surface features of the teaching workpiece.

[0028] Optionally, the first preset mode is manual control, and the operator adjusts the displacement of the stirring tool based on his own experience during the welding process to ensure that the amount of pressure on the teaching workpiece is consistent.

[0029] The second preset method is meter control, where a dial gauge or micrometer is installed on the tool handle, and the probe of the dial gauge or micrometer is placed on the rotation center axis of the stirring tool and in contact with the surface of the teaching workpiece. During the trajectory operation, the operator adjusts the displacement and keeps the reading of the dial gauge or micrometer unchanged to ensure that the pressing amount on the teaching workpiece is consistent during the entire operation process using the dial gauge or micrometer to simulate the control. Among them, the tool handle refers to the component that connects the stirring tool and the main shaft of the welding equipment.

[0030] The third preset method is automatic detection. A displacement sensor is installed on the machine head, and the detection point of the displacement sensor is set on the rotation center axis of the stirring tool. During the trajectory operation, the displacement sensor will continuously measure the height position change on the weld trajectory of the teaching workpiece and transmit the measurement data to the controller. The controller calculates the displacement superposition value based on the measurement data representing the position change information, which is used to control the consistent amount of pressure on the workpiece to be welded during subsequent welding displacement control. Among them, the machine head refers to the component on which the stirring tool is installed, which can drive the stirring tool to rotate and move. Specifically, the pressure amount refers to the depth of pressure of the shoulder or stirring needle of the stirring head into the workpiece. Controlling the consistent pressure amount of the stirring tool on the teaching workpiece means that the pressure depth of the stirring tool at each welding position on the teaching workpiece can be kept within a certain error range, so that the welding process is stable and the uniformity and consistency of the weld quality are guaranteed. The same applies to the consistent pressure amount of the stirring tool on the workpiece to be welded.

[0031] The running length of the stirring tool on the teaching workpiece increases with the running time. The cumulative running length can be determined based on the distance between the current running position and the initial position; the cumulative running length of the current acquisition cycle can also be determined based on the sum of the trajectory length of the current acquisition cycle and the cumulative running length of the previous acquisition cycle.

[0032] Considering that the shape of the weld includes but is not limited to a straight line, in order to ensure the accuracy of the cumulative running length, this embodiment preferably determines the cumulative running length of the current acquisition cycle by taking the sum of the trajectory length of the current acquisition cycle and the cumulative running length of the previous acquisition cycle as the preferred method, and will be described in detail later. The cumulative running length refers to the total length of the trajectory from the weld start point to the current running position.

[0033] It can be understood that, when the first preset mode is adopted for displacement teaching, the cumulative running length refers to the total length of the track from the starting point of the weld of the teaching workpiece to the current welding position of the stirring tool.

[0034] When the second preset mode is used for displacement teaching, the cumulative running length refers to the total length of the track from the starting point of the weld of the teaching workpiece to the current running position corresponding to the probe of the dial indicator or micrometer.

[0035] When the third preset method is used for displacement teaching, the cumulative running length refers to the total length of the track from the starting point of the weld of the teaching workpiece to the current running position corresponding to the detection point of the displacement sensor.

[0036] When the first preset mode is an equivalent mode of manual control, or the second preset mode is an equivalent mode of meter control, or the third preset mode is an equivalent mode of automatic detection, a person skilled in the art may refer to the above content to determine the corresponding cumulative running length.

[0037] Those skilled in the art can determine the length interval between adjacent recording points according to a priori values ​​or controller parameters, and sample and record the total length of the weld track of the teaching workpiece according to this length interval. When the cumulative running length of the current acquisition cycle is greater than or equal to the corresponding preset sampling length, the acquisition point corresponding to the current acquisition cycle is used as the recording point, and the recording time and accuracy are improved by determining the recording points one by one. This method will be described in detail later.

[0038] It is understandable that the displacement superposition value of the stirring tool can be calculated based on the coordinate values ​​of the above-mentioned recording points, and the displacement superposition value is the displacement superposition value in the Z-axis direction, the X-axis direction, or the Y-axis direction in the machine tool coordinate system or the workpiece coordinate system of the stir friction welding equipment. Obviously, the corresponding description of XYZ is in accordance with the coordinate rules of most equipment, and does not exclude special coordinate naming situations. It is illustrative and cannot be understood as limiting the scope of protection of the embodiments of the present invention.

[0039] Based on the displacement superposition values ​​corresponding to multiple recording points, the stir friction welding of the workpiece to be welded can be displacement controlled, wherein the above-mentioned displacement control is displacement control in the Z-axis direction, X-axis direction or Y-axis direction in the machine tool coordinate system or the workpiece coordinate system of the stir friction welding equipment, or a combination of displacement controls in multiple of the above directions.

[0040] The following description of this embodiment is made by taking the calculation of the vertical displacement superposition value of the stirring tool in the height direction of the teaching workpiece surface based on the coordinate values ​​of the above-mentioned recording points, that is, the Z displacement superposition value in the Z-axis direction as an example.

[0041] The workpiece to be welded has the surface features of the teaching workpiece, which means that the welded portion of the workpiece to be welded and the welded portion of the teaching workpiece are similar in shape and size in a preset direction and the error is within a preset range. The preset direction includes but is not limited to the above-mentioned Z-axis direction, X-axis direction, and Y-axis direction.

[0042] For example, in practical applications, for the same batch of workpieces with fixed errors, one of the workpieces is used as a teaching workpiece, and the other workpieces are workpieces to be welded. The displacement superposition values ​​corresponding to the various recording points on the weld of the teaching workpiece can reflect the running profile of the teaching workpiece in the preset direction. By welding the workpiece to be welded according to the above running profile, it can be ensured that the welding profile on the workpiece to be welded is the same as the running profile on the teaching workpiece, and the pressing amount of the welded workpiece is consistent, and the same batch of workpieces have a consistent pressing amount.

[0043] Fixed error is understood as each workpiece having the same or similar error. The welding contour on the workpiece to be welded and the running contour on the teaching workpiece are the same, which means that the shapes and sizes of the two are similar and the error is within a preset range, wherein the more recording points there are, the more accurate the running contour of the teaching workpiece in the preset direction reflected by the above displacement superposition value, and the more similar the welding contour on the workpiece to be welded is to the running contour on the teaching workpiece and the smaller the error. At the same time, too many recording points will lead to too frequent adjustments, so the technician needs to select an appropriate recording point length interval based on a priori values ​​or controller parameters. In this embodiment, it is preferred to set the length interval of the preset sampling length to determine the appropriate number of recording points, which will be described in detail later.

[0044] It is understandable that those skilled in the art can directly use the displacement superposition values ​​corresponding to the multiple recording points to perform displacement control on the friction stir welding of the workpiece to be welded, or can perform corresponding processing on the displacement superposition values ​​to improve the accuracy and efficiency of subsequent displacement control. In this embodiment, displacement control is preferably performed on the friction stir welding of the workpiece to be welded after the displacement superposition values ​​are processed accordingly, which will be described in detail later.

[0045] The displacement control method of the friction stir welding provided in this embodiment obtains the displacement superposition value through displacement teaching control, and can realize automatic pressure control without installing a pressure sensor, and can ensure the consistency of the pressure; based on the displacement superposition value corresponding to multiple recording points, the friction stir welding of the workpiece to be welded is displacement controlled, so that the workpiece to be welded is welded according to the running contour on the teaching workpiece, with a consistent pressure. The method provided in this embodiment can realize automatic control of the pressure without installing a sensor, and ensure the consistency of the pressure. Since there is no need to use a displacement sensor when performing friction stir welding on the workpiece to be welded, the method can better adapt to two-dimensional trajectory welding while ensuring the consistency of the pressure of each workpiece.

[0046] When manual welding mode displacement teaching is used, after the starting point is in place and before the trajectory is run, the starting point coordinates are recorded and the initial Z is collected.

[0047] When the meter is manually controlled, adjust the meter to 0 before running the trajectory at the starting point and collect the initial Z.

[0048] In automatic detection mode, the initial sensor values ​​are collected before running the track at the starting point.

[0049] It is understandable that the above starting point coordinates or initial values ​​are used to subsequently calculate the height difference of each acquisition point relative to the weld starting point, and record the height change of the teaching workpiece surface starting from the weld starting point.

[0050] Preferably, in step S102, based on the cumulative running length of the teaching workpiece, multiple recording points on the weld and the displacement superposition value corresponding to each recording point are determined and recorded, including: step S1021, starting from the starting point of the weld, the running trajectory of the weld is collected and calculated according to a preset collection cycle to obtain the collection point coordinates corresponding to the current collection cycle.

[0051] The starting point coordinates and the acquisition point coordinates of the weld are determined in the machine tool coordinate system or workpiece coordinate system of the friction stir welding equipment. The starting point coordinates are three-dimensional coordinates (x 0 ,y 0 , z 0 ).

[0052] Step S1022, determining the cumulative running length of the current acquisition cycle based on the sum of the trajectory length of the current acquisition cycle and the cumulative running length of the previous acquisition cycle, wherein the trajectory length of the current acquisition cycle is calculated based on the acquisition point coordinates of the current acquisition cycle and the previous acquisition cycle.

[0053] Specifically, the cumulative running length of the current collection cycle for: ; in, is the cumulative running length of the previous acquisition cycle, x, y are the coordinate values ​​of the plane where the teaching workpiece surface is located corresponding to the acquisition point coordinates (x, y, z) of the current acquisition cycle, , is the acquisition point coordinates of the previous acquisition cycle ( , , ) corresponds to the coordinate value of the plane where the teaching workpiece surface is located.

[0054] Step S1023: When the accumulated running length of the current acquisition cycle is greater than or equal to the corresponding preset sampling length, the acquisition point corresponding to the current acquisition cycle is used as the current recording point. The displacement superposition value corresponding to each recording point is calculated and determined according to the coordinates of each recording point.

[0055] Step S1024, the displacement superposition values ​​corresponding to all the recording points are recorded in a recording table in an ascending order of the corresponding preset sampling lengths by means of variable index.

[0056] For example, when manual control or meter control is used, the z coordinate value of the recording point (x, y, z) is subtracted from the starting point of the weld (x 0 ,y 0 , z 0 ) 0 Coordinate value, then we get the displacement superposition value corresponding to the recorded point (x, y, z) : ; in, The initial z value of the weld start point.

[0057] When the automatic detection method is adopted, when sampling, the sensor output value p of the recorded point is subtracted from the initial value to obtain the corresponding displacement superposition value : ; in, is the initial value of the sensor at the start of the weld.

[0058] Exemplarily, the displacement superposition value is recorded in the record table in the form of variable index, and each time the recording is completed, the variable index is increased by 1.

[0059] Preferably, when the collection point corresponding to the current collection period is used as the current recording point, a length interval is added to the current preset sampling length to obtain the next preset sampling length, wherein the initial value of the preset sampling length is 0.

[0060] The formula for updating the preset sampling length is: ; in, For the next preset sampling length, is the current preset sampling length, is the length interval.

[0061] Those skilled in the art can select an appropriate length interval according to the length of the teaching workpiece in the advancing direction of the stirring tool in actual application, or the surface error of the teaching workpiece. For example, if the surface height of the workpiece being taught varies greatly, a smaller length interval is selected, and the number of recorded points is greater to obtain a more accurate running profile.

[0062] Preferably, in step S103, displacement control is performed on the friction stir welding of the workpiece to be welded based on the displacement superposition values ​​corresponding to multiple recording points, including: step S1031, determining the collection point coordinates, cumulative welding length, reading length and data reading points of the workpiece to be welded in a manner of determining the collection point coordinates, cumulative running length, preset sampling length and recording points of the teaching workpiece, wherein the data reading points correspond one-to-one to the recording points with corresponding preset sampling lengths in ascending order according to the corresponding reading lengths.

[0063] Step S1032, when the cumulative welding length of the current acquisition cycle of the workpiece to be welded is greater than or equal to the current reading length, the displacement superposition values ​​of the recording points corresponding to the current data reading point and the next data reading point are obtained.

[0064] Step S1033, based on the displacement superposition values ​​of the recording points corresponding to the current data reading point and the next data reading point, respectively, and the real-time accumulated welding length of the workpiece to be welded within the current length interval, calculate the displacement superposition value change value between the current data reading point and the collection point corresponding to the current collection period of the workpiece to be welded, wherein the current length interval is the length interval between the current data reading point and the next data reading point, and the size of the current length interval is equal to the size of the length interval of the preset sampling length.

[0065] For example, according to the cumulative welding length of the workpiece to be welded from the current data reading point , and the length interval of the preset sampling length The ratio is obtained by multiplying the values ​​by the real-time ratio.

[0066] The cumulative welding length from the current data reading point The calculation method includes but is not limited to: using the real-time cumulative welding length of the current acquisition cycle minus the last preset sampling length to obtain Or, from the current data reading point, calculate the accumulated welding length of each preset acquisition cycle to obtain .

[0067] The displacement superposition value of the recording point corresponding to the next data reading point , minus the displacement superposition value of the recording point corresponding to the current data reading point , and obtain the displacement superposition difference between the next data reading point and the current data reading point.

[0068] Multiply the real-time ratio by the displacement superposition difference to obtain the displacement superposition value change between the current data reading point and the collection point corresponding to the current collection cycle of the workpiece to be welded. .

[0069] Step S1034, determining the real-time superposition value of the acquisition point corresponding to the current acquisition period of the workpiece to be welded according to the displacement superposition value change value.

[0070] Exemplarily, the displacement superposition value of the recording point corresponding to the current data reading point is added to the displacement superposition value change value to obtain the real-time superposition value of the collection point corresponding to the current collection period of the workpiece to be welded.

[0071] ; in, It indicates the real-time superposition value of the acquisition points corresponding to the current acquisition cycle of the workpiece to be welded.

[0072] Step S1035: performing real-time displacement control on the friction stir welding of the workpiece to be welded according to the real-time superposition value.

[0073] Each time a data reading point is reached, the displacement superposition value of the corresponding recording point is read from the recording table in the same variable indexing manner, and the index is incremented by 1 when the reading is completed. The index reading method facilitates reading the displacement superposition value of the recording point corresponding to the current data reading point and the next data reading point. It can be understood that the above-mentioned real-time displacement control method is to control between points with a length interval of d, which belongs to a linear interpolation method and has high motion stability.

[0074] Furthermore, when the current length interval is less than a preset threshold, based on the displacement superposition value of the recording point corresponding to the current data reading point and the control speed, the friction stir welding of the workpiece to be welded between the current data reading point and the next data reading point is displacement controlled in a point control manner, wherein the control speed is determined according to the current moving speed of the stirring tool. In this point control method, the displacement superposition value of the corresponding recording point is directly read at the data reading point, and the displacement superposition value is used to perform displacement control according to the speed. The friction stir welding between the data reading points is smoothed by setting the displacement speed control.

[0075] It can be understood that the point control method when the current length interval is less than the preset threshold has the characteristics of simple calculation while meeting the control accuracy.

[0076] Preferably, during the displacement teaching process, the method provided in this embodiment further includes: calculating the characteristic value of the teaching workpiece based on the displacement superposition value corresponding to the current recording point and all previous recording points, wherein the characteristic value of the teaching workpiece includes the displacement value and cumulative weld length corresponding to the current recording point, the maximum displacement value and the corresponding operating position, and the minimum displacement value and the corresponding operating position. Based on the characteristic value of the teaching workpiece, the surface features of the current position of the teaching workpiece are displayed during the displacement teaching process, and the overall surface features of the teaching workpiece are displayed after the displacement teaching is completed.

[0077] During the welding displacement control process, the method provided in this embodiment further includes: calculating the characteristic value of the workpiece to be welded based on the displacement superposition value of each acquisition cycle, wherein the characteristic value of the workpiece to be welded includes the displacement value and the cumulative weld length corresponding to the current data reading point, the maximum displacement value and the corresponding welding position, and the minimum displacement value and the corresponding welding position. Based on the characteristic value of the workpiece to be welded, the surface features of the current position of the workpiece to be welded are displayed during the welding displacement control process, and the overall surface features of the workpiece to be welded are displayed after the welding displacement control is completed.

[0078] Exemplarily, during the displacement teaching process, two variables are set to store the maximum displacement superposition value and the minimum displacement superposition value corresponding to the teaching workpiece. Each time the sampling length is reached, the displacement superposition value of the current acquisition cycle is compared with the stored displacement superposition value. When the displacement superposition value of the current acquisition cycle is greater than the stored maximum displacement superposition value, the maximum displacement superposition value and the corresponding operating position are refreshed; when the displacement superposition value of the current acquisition cycle is less than the stored minimum displacement superposition value, the minimum displacement superposition value and the corresponding operating position are refreshed.

[0079] Exemplarily, during the welding displacement control process, two variables are set to store the maximum displacement superposition value and the minimum displacement superposition value corresponding to the workpiece to be welded. In each acquisition cycle, the displacement superposition value of the current acquisition cycle is compared with the stored displacement superposition value. When the displacement superposition value of the current acquisition cycle is greater than the stored maximum displacement superposition value, the maximum displacement superposition value and the corresponding welding position are refreshed; when the displacement superposition value of the current acquisition cycle is less than the stored minimum displacement superposition value, the minimum displacement superposition value and the corresponding welding position are refreshed.

[0080] It can be understood that by displaying the current position surface features and overall surface features of the teaching workpiece and the current position surface features and overall surface features of the workpiece to be welded, it helps those skilled in the art to understand the characteristic data of the workpiece surface.

[0081] For example, the specific working principle of the above method provided in this embodiment can be referred to Figure 2 As shown, for the displacement teaching process, the initial value is first collected at the starting point of the weld of the teaching workpiece, and then the Z displacement data is collected during the displacement teaching process to calculate the Z displacement superposition value, and the Z displacement superposition value is recorded in the record table.

[0082] Based on one displacement teaching, the same welding displacement control is performed on the friction stir welding of multiple workpieces to be welded.

[0083] During the welding displacement control process, the corresponding Z displacement superposition value is read from the record table, the real-time superposition value is calculated, and the displacement control of the friction stir welding of the workpiece to be welded is performed based on the real-time superposition value.

[0084] Among them, the characteristic values ​​of the corresponding workpiece can be calculated and recorded and displayed during the displacement teaching process and the welding displacement control process.

[0085] The present invention also provides a non-transitory machine-readable medium storing a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to execute the method of the present invention.

[0086] The present invention also provides a computer program product, including a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to execute the method of the present invention.

[0087] The present invention also provides an electronic device, comprising: at least one processor; and a memory connected to the at least one processor. The memory stores a computer program executable by the at least one processor, and the computer program is used to enable the electronic device to perform the method of the present invention when executed by the at least one processor.

[0088] refer to Figure 3 , a block diagram of an electronic device that can be used as an embodiment of the invention will now be described, which is an example of a hardware device that can be applied to various aspects of the invention. The electronic device is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers and other suitable computers, numerical control systems, PLCs, various forms of controllers. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the invention described and / or claimed herein.

[0089] like Figure 3 As shown, the electronic device includes a computing unit 301, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 302 or a computer program loaded from a storage unit 308 into a random access memory (RAM) 303. In the RAM 303, various programs and data required for the operation of the electronic device can also be stored. The computing unit 301, the ROM 302, and the RAM 303 are connected to each other via a bus 304. An input / output (I / O) interface 305 is also connected to the bus 304.

[0090] Multiple components in the electronic device are connected to the I / O interface 305, including: an input unit 306, an output unit 307, a storage unit 308, and a communication unit 309. The input unit 306 can be any type of device that can input information to the electronic device, and the input unit 306 can receive input digital or character information, and generate key signal input related to user settings and / or function control of the electronic device. The output unit 307 can be any type of device that can present information, and can include but is not limited to a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 308 can include but is not limited to a disk, an optical disk. The communication unit 309 allows the electronic device to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks, and can include but is not limited to a modem, a network card, an infrared communication device, and / or a wireless communication transceiver, such as a Bluetooth device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0091] The computing unit 301 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 301 include, but are not limited to, a CPU, a graphics processing unit (GPU), various special artificial intelligence (AI) computing units, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 301 performs the various methods and processes described above. For example, in some embodiments, the method embodiments created by the present invention may be implemented as a computer program, which is tangibly contained in a machine-readable medium, such as a storage unit 308. In some embodiments, part or all of the computer program may be loaded and / or installed on an electronic device via a ROM 302 and / or a communication unit 309. In some embodiments, the computing unit 301 may be configured to perform the above-described method in any other appropriate manner (e.g., by means of firmware).

[0092] The computer program for implementing the method of the present invention can be written in any combination of one or more programming languages. These computer programs can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the computer program, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The computer program can be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0093] In the context of the present invention, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or apparatus. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable signal medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, or infrared systems, devices, or equipment, or any suitable combination of the foregoing. More specific examples of machine-readable storage media may include electrical connections based on one or more lines, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disk read-only memories (CD-ROMs), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing.

[0094] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative and not restrictive. Those skilled in the art should understand that unless otherwise clearly indicated in the context, they should be understood as "one or more". The descriptions of the terms "first", "second", etc. are for descriptive purposes only and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of technical features indicated.

[0095] The user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in the embodiments of the present invention are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with the relevant laws, regulations and standards of relevant countries and regions, and provide corresponding operation entrances for users to choose to authorize or refuse.

[0096] The various steps described in the method implementation methods provided by the embodiments of the present invention can be performed in different orders and / or in parallel. In addition, the method implementation methods may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0097] The term "embodiment" in this specification refers to specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same and similar parts between the various embodiments refer to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0098] The above-described embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of protection. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A displacement control method for friction stir welding, characterized in that: include: Displacement teaching: Stir friction welding is performed on the teaching workpiece according to a first preset method, wherein the first preset method controls the pressing amount of the stirring tool on the teaching workpiece to be consistent, or simulates and controls the pressing amount on the teaching workpiece to be consistent according to a second preset method, or measures the surface information of the teaching workpiece according to a third preset method to obtain a displacement superposition value that can make the pressing amount on the teaching workpiece consistent; During the displacement teaching process, a plurality of recording points on the weld and a displacement superposition value corresponding to each of the recording points are determined according to the accumulated running length of the teaching workpiece; Welding displacement control: Based on the displacement superposition values ​​corresponding to the plurality of recording points, the friction stir welding of the workpiece to be welded is displacement controlled, wherein the workpiece to be welded has the surface features of the teaching workpiece.

2. The method according to claim 1, characterized in that Before performing friction stir welding on the teaching workpiece according to the first preset mode, the method further includes: recording the starting point coordinates of the weld; Before simulating and controlling the pressing amount on the teaching workpiece to be consistent according to the second preset mode, the method further includes: recording the starting point coordinates of the weld; Before measuring the surface information of the teaching workpiece in accordance with a third preset method and obtaining a displacement superposition value that can make the pressing amount consistent, the method also includes: recording an initial value of the sensor at the starting point of the weld, wherein the sensor is used to detect the surface information of the teaching workpiece in real time during the displacement teaching process.

3. The method according to claim 1, characterized in that According to the cumulative running length of the teaching workpiece, a plurality of recording points on the weld and a displacement superposition value corresponding to each of the recording points are determined, including: Starting from the starting point coordinates of the weld, the running trajectory of the weld is collected and calculated according to a preset collection cycle to obtain the collection point coordinates corresponding to the current collection cycle, wherein the starting point coordinates of the weld are determined in the machine tool coordinate system or the workpiece coordinate system of the friction stir welding equipment; Determine the cumulative running length of the current acquisition cycle based on the sum of the trajectory length of the current acquisition cycle and the cumulative running length of the previous acquisition cycle, wherein the trajectory length of the current acquisition cycle is calculated based on the acquisition point coordinates of the current acquisition cycle and the previous acquisition cycle; When the accumulated running length of the current acquisition cycle is greater than or equal to the corresponding preset sampling length, the acquisition point corresponding to the current acquisition cycle is used as the current recording point; Determine the corresponding displacement superposition value according to the coordinates of the recorded points.

4. The method according to claim 3, characterized in that: In the case where the acquisition point corresponding to the current acquisition period is used as the current recording point, a length interval is added to the current preset sampling length to obtain a next preset sampling length; Continue to perform acquisition calculation according to the preset acquisition cycle. When the cumulative running length of the new current acquisition cycle is greater than or equal to the next preset sampling length, use the acquisition point corresponding to the new current acquisition cycle as the new current recording point, and obtain the new next preset sampling length until the running track on the teaching workpiece is completed, wherein the initial value of the preset sampling length is 0; After determining the corresponding displacement superposition value according to the recorded point coordinates, the method further includes: The displacement superposition values ​​corresponding to all recording points are recorded in the recording table by variable index in the order from small to large according to the corresponding preset sampling length.

5. The method according to claim 4, characterized in that Based on the displacement superposition values ​​corresponding to the plurality of recording points, the friction stir welding of the workpiece to be welded is subjected to displacement control, including: According to the method of determining the acquisition point coordinates, cumulative running length, preset sampling length and recording points of the teaching workpiece, the acquisition point coordinates, cumulative welding length, reading length and data reading points of the workpiece to be welded are determined, wherein the data reading points correspond to the recording points of the preset sampling lengths from small to large in the order of the corresponding reading lengths from small to large one by one; When the accumulated welding length of the workpiece to be welded in the current acquisition cycle is greater than or equal to the current reading length, obtaining the displacement superposition values ​​of the recording points corresponding to the current data reading point and the next data reading point respectively; According to the displacement superposition values ​​of the recording points corresponding to the current data reading point and the next data reading point, respectively, and the real-time accumulated welding length of the workpiece to be welded within the current length interval, the displacement superposition value change value between the current data reading point and the collection point corresponding to the current collection period of the workpiece to be welded is calculated, wherein the current length interval is the length interval between the current data reading point and the next data reading point, and the size of the current length interval is equal to the size of the length interval of the preset sampling length; Determine the real-time superposition value of the collection point corresponding to the current collection period of the workpiece to be welded according to the displacement superposition value change value; The friction stir welding of the workpiece to be welded is subjected to real-time displacement control according to the real-time superposition value.

6. The method according to claim 5, characterized in that According to the displacement superposition value and the real-time accumulated welding length of the workpiece to be welded within the current length interval, a displacement superposition value change value between the current data reading point and the collection point corresponding to the current collection period of the workpiece to be welded is calculated, including: obtaining a real-time ratio according to a ratio of the accumulated welding length of the workpiece to be welded from the current data reading point to the length interval of the preset sampling length; Subtract the displacement superposition value of the recording point corresponding to the current data reading point from the displacement superposition value of the recording point corresponding to the next data reading point to obtain the displacement superposition difference between the next data reading point and the current data reading point; Multiplying the real-time ratio by the displacement superposition difference to obtain a displacement superposition value change value between the current data reading point and the collection point corresponding to the current collection period of the workpiece to be welded; Determining the real-time superposition value of the collection point corresponding to the current collection period of the workpiece to be welded according to the displacement superposition value change value includes: The displacement superposition value of the recording point corresponding to the current data reading point is added to the displacement superposition value change value to obtain the real-time superposition value of the collection point corresponding to the current collection period of the workpiece to be welded.

7. The method according to claim 5, characterized in that When the current length interval is less than a preset threshold, based on the displacement superposition value of the recording point corresponding to the current data reading point and the control speed, the friction stir welding of the workpiece to be welded between the current data reading point and the next data reading point is displacement controlled in a point control manner, wherein the control speed is determined according to the current moving speed of the stirring tool.

8. The method according to claim 1, characterized in that During the displacement teaching process, the method further includes: Calculating the characteristic value of the teaching workpiece based on the displacement superposition value corresponding to the current recording point and all previous recording points, wherein the characteristic value of the teaching workpiece includes the displacement value and cumulative weld length corresponding to the current recording point, the maximum displacement value and the corresponding operating position, and the minimum displacement value and the corresponding operating position; Based on the characteristic value of the teaching workpiece, the surface characteristics of the current position of the teaching workpiece are displayed during the displacement teaching process, and the overall surface characteristics of the teaching workpiece are displayed after the displacement teaching is completed; During the welding displacement control process, the method further comprises: Calculating the characteristic value of the workpiece to be welded based on the displacement superposition value of each acquisition cycle, wherein the characteristic value of the workpiece to be welded includes the displacement value and the cumulative weld length corresponding to the current data reading point, the maximum displacement value and the corresponding welding position, and the minimum displacement value and the corresponding welding position; Based on the characteristic value of the workpiece to be welded, the surface characteristics of the workpiece to be welded at the current position are displayed during the welding displacement control process, and the overall surface characteristics of the workpiece to be welded are displayed after the welding displacement control is completed.

9. The method according to claim 1, characterized in that: Based on one displacement teaching, the same welding displacement control is performed on the friction stir welding of multiple workpieces to be welded.

10. The method according to claim 1, characterized in that The displacement control is displacement control in the Z-axis direction, X-axis direction or Y-axis direction in the machine tool coordinate system or the workpiece coordinate system of the friction stir welding equipment, or a combination of displacement controls in multiple directions.

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