Synchronous ranging online trajectory planning robot arc material addition method, device and medium

Abstract

The present invention relates to a method, device and medium for arc additive by a synchronous ranging online trajectory planning robot, belonging to the field of additive manufacturing technology. The method comprises: after the arc additive of the current layer is completed, based on the first height of the current layer additive and the preset layer thickness, determining the second height corresponding to the next layer of slicing; when the second height is less than the preset threshold, performing trajectory planning at the second height to obtain an additive path; based on the additive path, performing arc additive on the next layer. The method for arc additive by a synchronous ranging online trajectory planning robot provided by the present invention, after each layer of additive is completed, determines the second height corresponding to the next layer of slicing according to the first height of the current layer additive and the preset layer thickness, performs layered slicing trajectory planning on the current height of the three-dimensional model, and then transmits it to the arc welding robot for additive trajectory movement, thereby reducing the cumulative error of multiple layers, achieving a better additive effect, and ensuring the precise parameters and excellent quality of the formed workpiece.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a synchronous ranging online trajectory planning robot arc additive method, device and medium. Background Art

[0002] Additive manufacturing, or 3D printing technology, can achieve overall forming and save materials well, providing a new solution for aerospace and military products from material design, manufacturing, repair, and remanufacturing. Wire Arc Additive Manufacturing (WAAM) uses metal wire as raw material and electric arc as heat source to quickly melt the wires fed in synchronously, deposit them layer by layer according to the preset path, achieve good metallurgical bonding, and quickly realize the integrated forming of large components. It has many process advantages: high efficiency, low cost, integrated forming, large-scale production, etc. Compared with other metal additive manufacturing technologies, it has certain advantages in material utilization, forming size, cost and efficiency.

[0003] In traditional additive manufacturing technology, the layered slicing thickness, scanning speed and overlap spacing are pre-set, and the slicing trajectory of the three-dimensional model is planned at one time, and the parameters remain unchanged during the additive process. Due to fluctuations in equipment process parameters and heat accumulation during the additive process, the actual additive layer thickness deviates from the preset layer thickness, and as the number of additive layers increases, the actual size deviation between the workpiece and the three-dimensional model increases, and the difference becomes more obvious. If it is not adjusted during the additive process, it will also cause great inconvenience to subsequent processing and use. For example, when the actual layer thickness of a single layer is higher than the preset layer thickness, the distance between the deposition head and the additive layer becomes smaller and smaller, and continuous accumulation will cause interference collision damage to the equipment until it cannot continue to form; conversely, when the actual layer thickness of a single layer is lower than the preset layer thickness, the distance between the deposition head and the additive layer becomes larger and larger, resulting in poor gas protection of the additive melt pool, increased spatter, and continuous accumulation resulting in forming failure due to excessive distance.

[0004] That is, the existing arc additive manufacturing technology has a large cumulative error, resulting in a poor additive effect. Summary of the invention

[0005] In view of this, it is necessary to provide a synchronous ranging online trajectory planning robot arc additive method, device and medium to solve the problems of large cumulative error and poor additive effect of existing arc additive manufacturing technology.

[0006] In order to solve the above problems, the present invention provides a synchronous ranging online trajectory planning robot arc additive method, comprising:

[0007] After the current layer of arc additive is completed, based on the first height of the current layer of additive and the preset layer thickness, a second height corresponding to the next layer of slices is determined; the next layer of slices is obtained by performing layered slicing processing on the three-dimensional model of the component to be additively manufactured;

[0008] When the second height is less than a preset threshold, performing trajectory planning at the second height to obtain an additive path;

[0009] Based on the additive path, arc additive is performed on the next layer.

[0010] In a possible implementation, when the second height is less than a preset threshold, performing trajectory planning at the second height to obtain an additive path includes:

[0011] Slicing the three-dimensional model of the component to be added with material in layers according to the second height to determine a cross-sectional contour line;

[0012] Based on a preset number of offsets, adjacent outer contour lines in the cross-sectional contour line are offset inwardly by a target distance to determine a first intersection point after the offset, and adjacent inner contour lines in the cross-sectional contour line are offset outwardly by a target distance to determine a second intersection point after the offset;

[0013] Determine a curve sequence set based on the first intersection point and the second intersection point;

[0014] Based on the set of curve sequences, an additive path is determined.

[0015] In a possible implementation manner, the first height of the first additive layer is equal to the preset layer thickness.

[0016] In a possible implementation, the first height of the current layer of additive material is determined by:

[0017] Determine a plurality of test points on the additive surface of the current layer;

[0018] Perform median filtering and Gaussian smoothing filtering on the height data corresponding to each test point to obtain processed height data;

[0019] Based on the processed height data, the first height is determined.

[0020] In a possible implementation, before performing median filtering and Gaussian smoothing filtering on the height data corresponding to each test point to obtain the processed height data, the method further includes:

[0021] A template window of a preset size is established with each test point as the center; the template window includes a plurality of grids;

[0022] The height data corresponding to the center of each grid is used as the height data corresponding to each test point.

[0023] In a possible implementation, the expression of the first height is as follows:

[0024]

[0025] Among them, h i represents the first height, t represents the number of test points, Represents the height data of the i-th test point after processing, Represents the minimum value in the processed height data, Indicates the maximum value in the processed height data.

[0026] The present invention also provides a synchronous ranging online trajectory planning robot arc material adding device, comprising:

[0027] Arc welding robot, welding gun, laser distance sensor, host computer, work platform, additive substrate, control cabinet and laser distance measurement execution robot;

[0028] The welding gun is arranged at the end of the arc welding robot;

[0029] The laser distance sensor is arranged at the end of the laser distance measurement execution robot;

[0030] The laser ranging execution robot is arranged on the working platform;

[0031] The laser beam emitted by the laser distance sensor is perpendicular to the additive substrate;

[0032] The control cabinet is connected to the host computer;

[0033] The host computer is wirelessly connected to the arc welding robot and the laser ranging execution robot respectively.

[0034] In a possible implementation, the laser distance sensor is a direct line laser distance sensor;

[0035] The laser ranging execution robot is a six-axis industrial robot.

[0036] On the other hand, the present invention also provides an electronic device, including a memory and a processor, wherein:

[0037] The memory is used to store programs;

[0038] The processor is coupled to the memory and is used to execute the program stored in the memory to implement the synchronous ranging online trajectory planning robot arc additive method described in any of the above implementations.

[0039] On the other hand, the present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the synchronous ranging online trajectory planning robot arc additive method described in any of the above-mentioned implementation methods.

[0040] The beneficial effects of the present invention are as follows: the synchronous ranging online trajectory planning robot arc additive method provided by the present invention determines the second height corresponding to the next layer of slicing according to the first height of the current layer of additive and the preset layer thickness after each layer of additive is completed, performs layered slicing trajectory planning on the current height of the three-dimensional model, and then transmits it to the arc welding robot for additive trajectory movement, thereby reducing the multi-layer cumulative error, ensuring the precise parameters and excellent quality of the formed workpiece, and solves the shortcomings of traditional one-time slicing by introducing real-time ranging slicing, realizing refined control of the WAAM process, obtaining a more stable forming process and improving the amount of formed parts, thereby better improving the accuracy of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 A method flow chart of an embodiment of a synchronous ranging and online trajectory planning robot arc material addition method provided by the present invention;

[0043] Figure 2 A schematic diagram of an algorithm for offsetting intersection coordinates provided by the present invention;

[0044] Figure 3 A schematic diagram of a template window centered on a test point provided by the present invention;

[0045] Figure 4 A schematic diagram of the installation structure provided by the present invention;

[0046] Figure 5 A schematic structural diagram of an embodiment of a synchronous ranging and online trajectory planning robot arc material adding device provided by the present invention;

[0047] Figure 6 A method flow chart of the robot online planning and arc additive forming method based on laser distance sensor provided by the present invention;

[0048] Figure 7 A schematic structural diagram of an embodiment of an electronic device provided by the present invention.

[0049] Reference numerals:

[0050] 510: arc welding robot; 520: welding gun; 530: laser distance sensor; 540: host computer; 550: working platform; 560: additive substrate; 570: control cabinet; 580: laser ranging execution robot; 590: additive parts. DETAILED DESCRIPTION

[0051] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0052] In the description of the embodiments of the present invention, unless otherwise specified, "multiple" means two or more than two. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" may mean: A exists alone, A and B exist at the same time, and B exists alone.

[0053] The descriptions of "first", "second", etc. involved in the embodiments of the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the technical features defined as "first" or "second" may explicitly or implicitly include at least one of the features.

[0054] Figure 1 A method flow chart of an embodiment of the synchronous ranging online trajectory planning robot arc material addition method provided by the present invention is as follows Figure 1 As shown, the synchronous ranging online trajectory planning robot arc additive method includes:

[0055] S101, after the current layer of arc additive is completed, based on the first height of the current layer of additive and the preset layer thickness, determining the second height corresponding to the next layer of slices; the next layer of slices is obtained by performing layered slicing processing on the three-dimensional model of the component to be additively added;

[0056] S102, when the second height is less than a preset threshold, performing trajectory planning at the second height to obtain an additive path;

[0057] S103 . Based on the additive path, perform arc additive on the next layer.

[0058] Compared with the prior art, the synchronous ranging online trajectory planning robot arc additive method provided by the embodiment of the present invention determines the second height corresponding to the next layer of slicing according to the first height of the current layer of additive and the preset layer thickness after each layer of additive is completed, and performs layered slicing trajectory planning on the current height of the three-dimensional model, which is then transmitted to the arc welding robot for additive trajectory movement, thereby reducing the multi-layer cumulative error, ensuring the accurate parameters and excellent quality of the formed workpiece, and solving the shortcomings of traditional one-time slicing by introducing real-time ranging slicing, realizing refined control of the WAAM process, obtaining a more stable forming process and improving the amount of formed parts, thereby better improving the precision of the product.

[0059] In some embodiments of the present invention, the first height of the first layer of additive material is equal to the preset layer thickness.

[0060] In some embodiments of the present invention, when the second height is less than a preset threshold, performing trajectory planning at the second height to obtain an additive path includes:

[0061] Slicing the three-dimensional model of the component to be added with material in layers according to the second height to determine a cross-sectional contour line;

[0062] Based on a preset number of offsets, adjacent outer contour lines in the cross-sectional contour line are offset inwardly by a target distance to determine a first intersection point after the offset, and adjacent inner contour lines in the cross-sectional contour line are offset outwardly by a target distance to determine a second intersection point after the offset;

[0063] Determine a curve sequence set based on the first intersection point and the second intersection point;

[0064] Based on the set of curve sequences, an additive path is determined.

[0065] By setting the initial layer thickness to the preset layer thickness d, the trajectory planning for the first layer of layered slicing is completed, and the trajectory file is transmitted online to the robot system to complete the first layer of additive forming.

[0066] The trajectory planning adopts the contour offset path strategy, and along the STL model layering, the outer contour of the cross-section contour line is offset inward, and the inner contour is offset outward by a certain distance. A cluster of curve sequences are obtained, and the contour offset path is converted into an offset for the polygon path. Figure 2 The schematic diagram of the algorithm for offset intersection coordinates provided by the present invention is shown in FIG. Figure 2 , calculate the intersection points of adjacent line segments after offset, and take L i The unit vector l in the xoy coordinate system i =a i i+b i j and L i+1 The unit vector l in the xoy coordinate system i+1 =ai+1 i+b i+1 j, then the line segment L i , L i+1 The equation of the straight line after deviating outward (in the direction of decreasing x and y axes) by a certain distance D is:

[0067]

[0068] Then line segment L i , L i+1 The equation of the line after shifting inward (in the direction of increasing x and y axes) a certain distance D is:

[0069]

[0070] Due to L i and L i+1 are not collinear, so a i b i+1 -a i+1 b i ≠0, solving the above equations will give the line segment L i , L i+1 The new intersection point H after the offset distance D i , the coordinate expression in the coordinate system xoy:

[0071]

[0072]

[0073] Then the intersection point H is expressed in the coordinate system XOY as:

[0074]

[0075] By calculating the intersection points of each adjacent line segment of the cross-sectional contour line after the STL model is layered and offset by a certain distance D, the discrete points of the offset contour line can be obtained. The corresponding offset times can be set according to demand, and a cluster of curve sequences after the cross-sectional contour line is offset can be obtained.

[0076] in:

[0077]

[0078]

[0079]

[0080]

[0081] The curve sequence can be used for path planning to guide the robot to move on the workpiece surface and complete the additive task.

[0082] After the current layer is added, the actual height of each test point is read by the laser distance sensor, and then the actual height h of the added surface is calculated by the filtering algorithm in the host computer. i .

[0083] The host computer sets the next slice height to h ii =h i +d, slicing software in h ii The height is sliced ​​in layers, and trajectory planning and additive forming are completed according to the method in the above steps. The height is read in real time and sliced ​​synchronously to eliminate the cumulative error. The trajectory file is transmitted to the robot control system to complete the additive forming of the next layer and calculate the actual height h of the additive surface. i , until h ii >Model height, stop printing.

[0084] After each layer of material is added, the laser distance sensor reads the current layer height and sends it to the synchronous trajectory planning system. The next layer height is sliced ​​and the trajectory is planned, and then sent to the robot to add the next layer until the part is printed.

[0085] The synchronous ranging online trajectory planning robot arc additive method provided by the present invention, after each layer of additive is completed, the height data is fed back to the host computer through the laser sensor, the layered slicing trajectory planning is performed for the current height of the three-dimensional model, and then it is transmitted to the arc welding robot for additive trajectory movement, thereby reducing the multi-layer cumulative error as much as possible, ensuring the accuracy of the parameters and excellent quality of the formed workpiece. The present invention solves the shortcomings of traditional one-time slicing by introducing real-time ranging slicing, and realizes the refined control of the WAAM process through real-time monitoring of the additive layer height by sensors and online planning of the host computer, obtaining a more stable forming process and improving the amount of formed parts, better improving the accuracy of the product, and reflecting the superiority of laser ranging online planning.

[0086] In some embodiments of the present invention, the first height of the current layer of additive material is determined by:

[0087] Determine a plurality of test points on the additive surface of the current layer;

[0088] Perform median filtering and Gaussian smoothing filtering on the height data corresponding to each test point to obtain processed height data;

[0089] Based on the processed height data, the first height is determined.

[0090] In some embodiments of the present invention, before performing median filtering and Gaussian smoothing filtering on the height data corresponding to each test point to obtain the processed height data, the method further includes:

[0091] A template window of a preset size is established with each test point as the center; the template window includes a plurality of grids;

[0092] The height data corresponding to the center of each grid is used as the height data corresponding to each test point.

[0093] In some embodiments of the present invention, the expression of the first height is as follows:

[0094]

[0095] Among them, h i represents the first height, t represents the number of test points, Represents the height data of the i-th test point after processing, Represents the minimum value in the processed height data, Indicates the maximum value in the processed height data.

[0096] Multiple test points can be determined on the additive surface of the current layer, recorded as t test points. The height data corresponding to each test point is read by the laser distance sensor, and then the actual height h of the additive surface is calculated by the filtering algorithm in the host computer. i , which is the first height.

[0097] In order to suppress the interference of noise and other factors on the ranging of the laser sensor, ensure the accuracy of reading the height, and minimize the error, the height data needs to be filtered. The host computer performs median filtering and Gaussian smoothing filtering on each test point.

[0098] Median filter: For any test point, a template window of a preset size is established with it as the center. The preset size can be (2k+1)×(2k+1). The template window includes multiple grids. Figure 3 This is a schematic diagram of a template window centered on a test point provided by the present invention, referring to Figure 3 , the height data of each grid center is recorded as h[i][j].

[0099] When the laser sensor measures a grid height value greater than μ times the sum of the heights in the template, it is considered a noise grid, and the height value of the noise grid is replaced by the mean of the remaining grids:

[0100]

[0101] In order to smooth the height data and further suppress noise interference, the host computer performs Gaussian smoothing filtering:

[0102]

[0103] The larger σ is, the larger the neighborhood range for Gaussian filtering is; the smaller G is, the smoother the filtering is.

[0104] Then the average height of each grid in the window is:

[0105]

[0106] According to the above method, measure the height of all test points in turn:

[0107] Then the expression of the first height of the current additive surface is as follows:

[0108]

[0109] Among them, h i represents the first height, t represents the number of test points, Represents the height data of the i-th test point after processing, Represents the minimum value in the processed height data, Indicates the maximum value in the processed height data.

[0110] The synchronous ranging online trajectory planning robot arc additive method provided by the present invention performs median filtering and Gaussian smoothing filtering on each test point to suppress the interference of noise and other factors on the ranging of the laser sensor, ensure the accuracy of the reading height, and reduce the error as much as possible.

[0111] Figure 4 A schematic diagram of the installation structure provided by the present invention, Figure 5 The schematic diagram of the structure of an embodiment of the synchronous ranging and online trajectory planning robot arc material adding device provided by the present invention is as follows Figure 5 As shown, the synchronous ranging online trajectory planning robot arc material adding device provided by the present invention comprises:

[0112] Arc welding robot 510, welding gun 520, laser distance sensor 530, host computer 540, work platform 550, additive substrate 560, control cabinet 570 and laser distance measurement execution robot 580;

[0113] The welding gun 520 is disposed at the end of the arc welding robot 510;

[0114] The laser distance sensor 530 is disposed at the end of the laser distance measurement execution robot 580;

[0115] The laser ranging execution robot 580 is arranged on the working platform 550;

[0116] The laser beam emitted by the laser distance sensor 530 is perpendicular to the additive substrate 560;

[0117] The control cabinet 570 is connected to the host computer 540;

[0118] The host computer 540 is wirelessly connected to the arc welding robot 510 and the laser ranging execution robot 580 respectively.

[0119] In some embodiments of the present invention, the laser distance sensor 530 is a direct line laser distance sensor;

[0120] The laser ranging execution robot 580 is a six-axis industrial robot.

[0121] Figure 6 A method flow chart of the robot online planning and arc additive forming method based on laser distance sensor provided by the present invention, such as Figure 6 As shown, the workflow of the synchronous ranging online trajectory planning robot arc additive device provided by the present invention includes:

[0122] Step 1: Platform installation and integration.

[0123] Install the laser distance sensor, connect the robot controller and the laser distance sensor through the upper control computer, and access the online slicing trajectory planning software system.

[0124] Platform installation and integration requires arc welding robot (additive action execution robot); welding gun; laser distance sensor; laser distance measurement execution robot; host computer; work platform; additive substrate; control cabinet (welding power supply), refer to Figure 4 .

[0125] The laser distance sensing system is installed on the working platform of the robot arc additive system, which consists of a laser rangefinder and a laser rangefinder execution robot. The laser rangefinder is installed at the end of the laser rangefinder execution robot, and its posture can be controlled by the mechanical arm of the laser rangefinder execution robot. During the additive process, the laser beam emitted by the sensor is always kept perpendicular to the additive substrate.

[0126] The arc welding robot is installed on the ground, the welding gun is installed at the end of the arc welding robot, and the welding gun posture can be controlled by the arc welding robot.

[0127] The control cabinet is installed on the ground and connected to the host computer. It can receive various parameter settings from the host computer to control the wire delivery speed, welding gun temperature, etc.

[0128] The laser distance sensor uses a direct line laser distance sensor, which can be ABB laser displacement sensor LR-X100, with a measuring distance of 25.0~100.0mm, a standard detection step difference of 1.0mm, and a display resolution of 0.1mm. It is integrated and installed at the end of the mechanical arm of the laser ranging execution robot. The laser ranging execution robot uses a six-axis industrial robot, which can be ABB IRB 1200-7 / 0.7 six-axis industrial robot, with a working range of 703mm, a payload of 7kg, and an arm load of 0.3kg.

[0129] The host computer online trajectory planning software realizes Bluetooth connection with the laser ranging through the BLE protocol stack, so that the host computer can obtain the laser ranging sensor data in real time.

[0130] The host computer uses Android to communicate with the robot via Bluetooth. The Bluetooth adapter converts the wired serial port connection into a wireless Bluetooth serial port connection through the serial linear simulation protocol to achieve wireless communication, and calls the GeoCOM interface through the Android program to send ASCⅡ instructions to achieve control of the robot.

[0131] Step 2: Initialize hardware and software.

[0132] The height of the working platform is read by the laser distance sensor and initialized to 0 height.

[0133] The spatial posture of the laser distance sensor is corrected by a six-axis industrial robot using the D4PG algorithm to ensure that the laser probe is perpendicular to the additive substrate.

[0134] Software initialization includes the connection and identification of the equipment, that is, establishing communication with the arc welding robot and laser distance sensor system.

[0135] Step 3: Set various parameters in the slicing software system.

[0136] Such as appropriate intra-layer scanning spacing and scanning speed; setting the appropriate expected layer thickness d in the slicing software; setting the appropriate wire feeding speed of the welding power supply.

[0137] The host computer synchronous trajectory planning system serves as the control center of the entire system. It can import the model, plan the trajectory according to the current layer height, and send it to the robot for material addition. At the same time, the robot can control the welding power supply to output the appropriate current, voltage, and wire feeding speed. The welding current is 100-250A, the wire feeding speed is 3-8m / min, the welding speed is 5-12mm / s, and the layer thickness is 1.5-3mm.

[0138] Step 4: Perform the first layer of additive manufacturing.

[0139] The first layer of layered slicing trajectory planning is completed through the initial layer thickness, and the trajectory file is transmitted to the robot system online to complete the first layer of additive forming.

[0140] The trajectory planning adopts the contour offset path strategy, and along the STL model layering, the outer contour of the cross-section contour line is offset inward, and the inner contour is offset outward by a certain distance to obtain a cluster of curve sequences.

[0141] To further convert the contour offset path into an offset for a polygon path, refer to Figure 2 Next, calculate the intersection of adjacent line segments after offset, and take L i The unit vector l in the xoy coordinate system i =a i i+b i j and L i+1 The unit vector l in the xoy coordinate system i+1 =a i+1 i+b i+1 j, then the line segment L i , L i+1 The equation of the straight line after deviating outward (in the direction of decreasing x and y axes) by a certain distance D is:

[0142]

[0143] Then line segment L i , L i+1 The equation of the line after shifting inward (in the direction of increasing x and y axes) a certain distance D is:

[0144]

[0145] Due to L i and L i+1 are not collinear, so a i b i+1 -a i+1 b i ≠0, solving the above equations will give the line segment L i , L i+1 The new intersection point H after the offset distance D i , the coordinate expression in the coordinate system xoy:

[0146]

[0147]

[0148] Then the intersection point H is expressed in the coordinate system XOY as:

[0149]

[0150] By calculating the intersection points of each adjacent line segment of the cross-sectional contour line after the STL model is layered and offset by a certain distance D, the discrete points of the offset contour line can be obtained. The corresponding offset times can be set according to demand, and a cluster of curve sequences after the cross-sectional contour line is offset can be obtained.

[0151] in:

[0152]

[0153]

[0154]

[0155]

[0156] After completing the trajectory planning, the data after filling the path planning is converted into Gcode instructions through the Slic3r software, and the Gcode instructions are parsed accordingly through the 3D Print plug-in of the RoboDK robot software. After parsing, the path information of the print head is converted into a MoveJ instruction file that can be recognized by the robotic arm. Finally, the welding machine is controlled to perform additive forming until the first layer of additive forming is completed.

[0157] Step 5: Read the current layer additive height.

[0158] The upper computer controls the mechanical arm of the laser distance measurement execution robot to move the laser sensor to the corresponding test point. The upper computer issues a sampling instruction to read the actual height of each test point through the laser distance sensor, and then the filtering algorithm in the upper computer calculates the actual height h of the additive surface. i .

[0159] The host computer sends a sampling command from the IO port, and the height data read by the laser ranging sensor is transmitted to the digital-to-analog conversion module of the host computer as a current signal of 10-20mA.

[0160] In order to suppress the interference of noise and other factors on the ranging of the laser sensor, ensure the accuracy of reading height, and minimize the error, the height data needs to be filtered. T test points are selected on the current additive surface, and the host computer performs median filtering and Gaussian smoothing filtering on each test point.

[0161] Median filtering: For any test point, a (2k+1)×(2k+1) template window is established with it as the center. The height data of each grid center is recorded as h[i][j]. Figure 3 When the laser sensor measures a grid height value greater than μ times the sum of the heights in the template, it is considered a noise grid, and the height value of the noise grid is replaced by the mean of the remaining grids:

[0162]

[0163] In order to smooth the height data and further suppress noise interference, the host computer performs Gaussian smoothing filtering:

[0164]

[0165] The larger σ is, the larger the neighborhood range for Gaussian filtering is; the smaller G is, the smoother the filtering is.

[0166] Then the average height of each grid in the window is:

[0167]

[0168] According to the above method, measure the height of all test points in turn:

[0169] Then the actual height of the current additive surface is:

[0170]

[0171] Step 6: Subsequent multi-layer online planning and simultaneous material addition.

[0172] The host computer sets the next slice height to h ii =h i +d, slicing software in h ii The height is sliced ​​in layers, and the trajectory planning and additive forming are completed according to the method in step 4. The height is read in real time and the slicing is synchronized to eliminate the cumulative error. The trajectory file is transferred to the robot control system to complete the additive forming of the next layer; return to step 5 until h ii >Total model height, stop printing.

[0173] After each layer of material is added, the laser distance sensor reads the current layer height and sends it to the synchronous trajectory planning system. The next layer height is sliced ​​and the trajectory is planned, and then sent to the robot to add the next layer until the part is printed.

[0174] The subsequent multi-layer online planning of synchronous additive is automatically and continuously executed without human intervention. The synchronous online trajectory planning system serves as the control and dispatching center of the entire system, with the total height of the additive parts to be processed as the main control loop. The completion of each layer of trajectory planning and the completion of robot additive processing drive the next action through the message queue.

[0175] The present invention provides a synchronous ranging online trajectory planning robot arc additive method, which can read the height in real time, synchronously slice, and eliminate the cumulative error to obtain a better additive manufacturing effect.

[0176] The beneficial effects of the present invention are as follows: after each layer of additive material is completed, the height data is fed back to the host computer through the laser sensor, and the layered slicing trajectory planning is performed for the current height of the three-dimensional model, and then transmitted to the arc welding robot for additive trajectory movement, thereby minimizing the multi-layer cumulative error as much as possible, ensuring the accuracy of the parameters and the quality of the formed workpiece. The present invention solves the shortcomings of traditional one-time slicing by introducing real-time ranging slicing. On the basis of the existing arc welding robot, a laser ranging sensor is added. Through the real-time monitoring of the additive layer height by the sensor and the online planning of the host computer, the refined control of the WAAM process is realized, a more stable forming process is obtained, and the amount of formed parts is improved, the accuracy of the product is better improved, and the superiority of laser ranging online planning is reflected.

[0177] like Figure 7 As shown, the present invention also provides an electronic device 700. The electronic device 700 includes a processor 701, a memory 702 and a display 703. Figure 7 Only some components of the electronic device 700 are shown, but it should be understood that it is not required to implement all of the components shown, and more or fewer components may be implemented instead.

[0178] In some embodiments, the processor 701 can be a central processing unit (CPU), a microprocessor or other data processing chip, which is used to run the program code or process data stored in the memory 702, such as the synchronous ranging online trajectory planning robot arc additive method in the present invention.

[0179] In some embodiments, the processor 701 may be a single server or a server group. The server group may be centralized or distributed. In some embodiments, the processor 701 may be local or remote. In some embodiments, the processor 701 may be implemented in a cloud platform. In some embodiments, the cloud platform may include a private cloud, a public cloud, a hybrid cloud, a community cloud, a distributed cloud, an internal cloud, a multi-cloud, etc., or any combination thereof.

[0180] In some embodiments, the memory 702 may be an internal storage unit of the electronic device 700, such as a hard disk or memory of the electronic device 700. In other embodiments, the memory 702 may also be an external storage device of the electronic device 700, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), etc. equipped on the electronic device 700.

[0181] Furthermore, the memory 702 may include both an internal storage unit of the electronic device 700 and an external storage device. The memory 702 is used to store application software installed in the electronic device 700 and various data.

[0182] In some embodiments, the display 703 may be an LED display, a liquid crystal display, a touch-sensitive liquid crystal display, an organic light-emitting diode (OLED) touch device, etc. The display 703 is used to display information on the electronic device 700 and to display a visual user interface. The components 701-703 of the electronic device 700 communicate with each other via a system bus.

[0183] In one embodiment, when the processor 701 executes the synchronous ranging online trajectory planning robot arc additive program in the memory 702, the following steps may be implemented:

[0184] After the current layer of arc additive is completed, based on the first height of the current layer of additive and the preset layer thickness, a second height corresponding to the next layer of slices is determined; the next layer of slices is obtained by performing layered slicing processing on the three-dimensional model of the component to be additively manufactured;

[0185] When the second height is less than a preset threshold, performing trajectory planning at the second height to obtain an additive path;

[0186] Based on the additive path, arc additive is performed on the next layer.

[0187] It should be understood that: when the processor 701 executes the synchronous ranging online trajectory planning robot arc additive program in the memory 702, in addition to the above functions, other functions can also be realized. For details, please refer to the description of the corresponding method embodiment above.

[0188] Furthermore, the embodiment of the present invention does not specifically limit the type of the electronic device 700 mentioned, and the electronic device 700 may be a portable electronic device such as a mobile phone, a tablet computer, a personal digital assistant (PDA), a wearable device, a laptop computer, etc. Exemplary embodiments of portable electronic devices include but are not limited to portable electronic devices equipped with IOS, Android, Microsoft or other operating systems. The above-mentioned portable electronic devices may also be other portable electronic devices, such as a laptop computer with a touch-sensitive surface (e.g., a touch panel). It should also be understood that in some other embodiments of the present invention, the electronic device 700 may not be a portable electronic device, but a desktop computer with a touch-sensitive surface (e.g., a touch panel).

[0189] Accordingly, an embodiment of the present application also provides a computer-readable storage medium, which is used to store computer-readable programs or instructions. When the program or instructions are executed by a processor, it can implement the steps or functions of the synchronous ranging online trajectory planning robot arc additive method provided in the above-mentioned method embodiments.

[0190] Those skilled in the art will appreciate that all or part of the processes of the above-mentioned embodiments can be implemented by instructing related hardware (such as a processor, a controller, etc.) through a computer program, and the computer program can be stored in a computer-readable storage medium, wherein the computer-readable storage medium is a disk, an optical disk, a read-only storage memory, or a random access memory, etc.

[0191] The above is a detailed introduction to the synchronous ranging, online trajectory planning, robot arc additive method, device and medium provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea; at the same time, for technical personnel in this field, according to the idea of ​​the present invention, there will be changes in the specific implementation method and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. A synchronous ranging online trajectory planning robot arc material addition method, characterized in that: include: After the arc addition of the current layer is completed, based on the first height of the current layer of addition and the preset layer thickness, a second height corresponding to the next layer of slicing is determined; The next layer of slices is obtained by performing layered slicing processing on the three-dimensional model of the component to be added; When the second height is less than a preset threshold, performing trajectory planning at the second height to obtain an additive path; Based on the additive path, performing arc additive on the next layer; The expression of the second height is as follows: h ii =h i +d in, h ii Indicates the second height, h i Indicates the first height, d Indicates the preset layer thickness; The first height of the current layer of additive material is determined by: Determine a plurality of test points on the additive surface of the current layer; Perform median filtering and Gaussian smoothing filtering on the height data corresponding to each test point to obtain processed height data; Based on the processed height data, the first height is determined.

2. The synchronous ranging online trajectory planning robot arc material addition method according to claim 1 is characterized in that: When the second height is less than a preset threshold, performing trajectory planning at the second height to obtain an additive path includes: Slicing the three-dimensional model of the component to be added with material in layers according to the second height to determine a cross-sectional contour line; Based on a preset number of offsets, adjacent outer contour lines in the cross-sectional contour line are offset inwardly by a target distance to determine a first intersection point after the offset, and adjacent inner contour lines in the cross-sectional contour line are offset outwardly by a target distance to determine a second intersection point after the offset; Determine a curve sequence set based on the first intersection point and the second intersection point; Based on the set of curve sequences, an additive path is determined.

3. The synchronous ranging online trajectory planning robot arc material addition method according to claim 1, characterized in that: The first height of the first layer of additive material is equal to the preset layer thickness.

4. The synchronous ranging online trajectory planning robot arc material addition method according to claim 1, characterized in that: Before performing median filtering and Gaussian smoothing filtering on the height data corresponding to each test point to obtain the processed height data, the method further includes: A template window of a preset size is established with each test point as the center; the template window includes a plurality of grids; The height data corresponding to the center of each grid is used as the height data corresponding to each test point.

5. The synchronous ranging online trajectory planning robot arc material addition method according to claim 1, characterized in that: The expression of the first height is as follows: in, Indicates the first height, t Indicates the number of test points. Indicates the processed i Height data of each test point, Represents the minimum value in the processed height data, Indicates the maximum value in the processed height data.

6. A synchronous ranging online trajectory planning robot arc material adding device, characterized in that: include: Arc welding robot, welding gun, laser distance sensor, host computer, work platform, additive substrate, control cabinet and laser distance measurement execution robot; The welding gun is arranged at the end of the arc welding robot; The laser distance sensor is arranged at the end of the laser distance measurement execution robot; The laser ranging execution robot is arranged on the working platform; The laser beam emitted by the laser distance sensor is perpendicular to the additive substrate; The control cabinet is connected to the host computer; The host computer is wirelessly connected to the arc welding robot and the laser ranging execution robot respectively; The laser distance sensor is used to obtain a first height of the current layer of additive material; The host computer is used to determine the second height corresponding to the next layer of slices based on the first height of the current layer of additive and the preset layer thickness, and to perform trajectory planning at the second height to obtain an additive path when the second height is less than a preset threshold; The arc welding robot is used to perform arc addition on the next layer based on the addition path; The expression of the second height is as follows: h ii =h i +d in, h ii Indicates the second height, h i Indicates the first height, d Indicates the preset layer thickness; The first height of the current layer of additive material is determined by: Determine a plurality of test points on the additive surface of the current layer; Perform median filtering and Gaussian smoothing filtering on the height data corresponding to each test point to obtain processed height data; Based on the processed height data, the first height is determined.

7. The synchronous ranging online trajectory planning robot arc material adding device according to claim 6, characterized in that: The laser distance sensor is a direct line laser distance sensor; The laser ranging execution robot is a six-axis industrial robot.

8. An electronic device, characterized in that: comprising a memory and a processor, wherein: The memory is used to store programs; The processor is coupled to the memory and is used to execute the program stored in the memory to implement the synchronous ranging online trajectory planning robot arc additive method as described in any one of claims 1 to 5.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the synchronous ranging and online trajectory planning robot arc additive method as described in any one of claims 1 to 5 is implemented.

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