Robotic automatic polishing method and system for frog castings

Abstract

The present invention discloses a robot-assisted automatic grinding method and system for frog castings. This method pre-builds a frog wing rail grinding database. Before actual grinding, the method only needs to scan and identify the type of frog casting to be ground. The corresponding grinding surface cross-section trajectory function can be automatically matched from the frog wing rail grinding database. Then, grinding is performed according to the corresponding trajectory function. The entire grinding process is automatic, requiring no human intervention, eliminating the need for manual teaching programming, greatly improving work efficiency, and being applicable to the grinding of frog castings of different types and sizes. At the same time, before formal grinding, the impurity thickness of several points on the grinding trajectory is obtained by scanning, and the minimum force for this grinding is calculated based on the maximum impurity thickness, thereby determining the compensatory grinding force. This can effectively avoid the situation where grinding is not in place, and each grinding trajectory uses a targeted grinding force, while improving grinding accuracy and efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of frog casting surface grinding, in particular to a robot automatic grinding method and system for frog castings. Background Art

[0002] Frogs, a crucial component of railroad tracks, are in high demand. However, cast frogs often have numerous burrs, bumps, marks, and flash on their surfaces, necessitating grinding. Manual grinding is labor-intensive, noisy, and produces significant dust, posing a significant health risk to operators. Furthermore, manual grinding suffers from low precision and efficiency, slowing frog production. To reduce the impact of the grinding environment on operators and increase production speed, robotic programming-based grinding has emerged. However, robotic programming-based grinding can introduce workpiece clamping errors. Three common methods for compensating for these errors are: 1. Clamp the workpiece to be ground in a standard position, which is determined by a vision system. During actual machining, the deviation between the workpiece clamping position and the standard position is determined by the vision system, and the standard grinding trajectory is offset based on this deviation. 2. During the grinding process, a force control system continuously compensates for the grinding force to ensure it remains within a certain range. 3. Combining visual position compensation with force control compensation further improves grinding accuracy.

[0003] However, the current robot teaching programming grinding method still has the following problems: 1. There are many types and sizes of frogs, and the manual teaching programming is large, the teaching time is long, and the teaching efficiency is low; 2. It is difficult to ensure the grinding accuracy even after compensation; 3. There are limitations in using force control devices to ensure that the grinding force is maintained within a certain range. Some firm impurities may not be ground in place, and some impurities that are easy to fall off may be over-ground and damaged the frog body. Summary of the Invention

[0004] The present invention provides a robot automatic grinding method and system for frog castings, so as to solve the technical problems of low teaching efficiency and difficulty in ensuring grinding accuracy and grinding force in the existing robot teaching programming grinding method.

[0005] According to one aspect of the present invention, a method for automatically polishing frog castings with a robot is provided, comprising the following steps:

[0006] Establishing a frog wing rail grinding database, wherein the frog wing rail grinding database stores trajectory functions of grinding surface cross sections of different types of frog wing rail models;

[0007] Identify the type of frog casting to be ground, and extract the corresponding trajectory function from the frog wing rail grinding database based on the identification result;

[0008] The robot is controlled to move the scanning device to the position directly above the starting point of the grinding process, and the grinding tool is driven to move according to the extracted trajectory function. During the movement, the scanning device is used to measure the thickness of impurities at several points on the grinding trajectory.

[0009] Calculate the minimum force of this grinding based on the maximum impurity thickness, and determine the compensating grinding force of the force control device according to the minimum force;

[0010] The robot is controlled to move the grinding rotation axis to the grinding starting point to start grinding.

[0011] Furthermore, the process of establishing the frog wing rail grinding database is specifically as follows:

[0012] Different types of frog wing rail models are established. For each frog wing rail model, a workpiece coordinate system is established with the cross-section bottom edge of the frog wing rail model as the Y-axis, the center of the cross-section bottom edge as the origin O, the direction perpendicular to the frog wing rail cross-section as the X-axis, and the vertical direction as the Z-axis. The polishing surface is set, and the trajectory function of the polishing surface cross-section in the workpiece coordinate system is calculated.

[0013] Furthermore, after extracting the corresponding trajectory function, the linear equation of the grinding rotation axis at each grinding point is calculated based on the trajectory function to ensure that the grinding tool is always tangent to the surface of the switch wing rail model during the grinding process, and in the process of measuring the impurity thickness and performing actual grinding, the robot is controlled to adjust the posture of the grinding rotation axis according to the corresponding linear equation at each grinding point.

[0014] Furthermore, after scanning and measuring the thickness of impurities at several points on the polishing track, the following contents are also included:

[0015] Clean the impurity thickness data of several points.

[0016] Furthermore, the process of cleaning the impurity thickness data of several points is specifically as follows:

[0017] Compare the impurity thickness of each point with the preset impurity thickness threshold. If the impurity thickness of a point is higher than the preset impurity thickness threshold, the impurity thickness data of the point will be discarded.

[0018] The maximum impurity thickness is screened out from the impurity thickness data of the remaining points, and the area ratio method is used to determine whether the point with the maximum impurity thickness is a burr. If it is determined to be a burr, the data of the point is removed and the judgment is continued until the point with the maximum impurity thickness is determined to be non-burr.

[0019] Furthermore, the process of using the area ratio method to determine whether the point with the maximum impurity thickness is a burr is specifically as follows:

[0020] Calculate the impurity area enclosed by all scanning points and the frog casting surface;

[0021] Use the maximum impurity thickness as the height and the total scan length as the base to form a rectangle, and calculate the area of ​​the rectangle;

[0022] The ratio of the impurity area to the rectangle area is calculated. If the area ratio does not exceed the preset threshold, the point where the maximum impurity thickness is located is determined to be a burr. If it exceeds the preset threshold, the point where the maximum impurity thickness is located is determined to be a non-burr.

[0023] Furthermore, during the grinding process, the impurity thickness of the next grinding track is measured by a scanning device and the minimum force and compensation grinding force of the next grinding are calculated. When the measured impurity thickness of all the next grinding tracks is less than zero, the grinding of the frog casting is determined to be completed after the next grinding is completed.

[0024] Furthermore, during the grinding process, a bow-shaped trajectory is used for grinding along the X-axis.

[0025] Furthermore, the distance between the grinding rotation axis and the scanning device is greater than the radius of the grinding tool and smaller than the diameter of the grinding tool.

[0026] In addition, the present invention also provides a robot automatic grinding system for frog castings, which adopts the robot automatic grinding method for frog castings as described above, comprising:

[0027] A database construction module is used to establish a frog wing rail grinding database, wherein the frog wing rail grinding database stores trajectory functions of grinding surface cross sections of different types of frog wing rail models;

[0028] A frog type recognition module is used to identify the type of frog casting to be ground and extract the corresponding trajectory function from the frog wing rail grinding database based on the recognition result;

[0029] The impurity thickness scanning module is used to control the robot to move the scanning device to the top of the grinding starting point, and drive the grinding tool to move according to the extracted trajectory function. During the movement, the scanning device measures the impurity thickness at several points on the grinding trajectory.

[0030] A force calculation module is used to calculate the minimum force of this grinding based on the maximum impurity thickness, and determine the compensating grinding force of the force control device according to the minimum force;

[0031] The grinding control module is used to control the robot to move the grinding rotation axis to the grinding starting point to start grinding.

[0032] The present invention has the following effects:

[0033] The present invention provides a robotic automatic grinding method for frog castings. By pre-building a frog wing rail grinding database, prior to actual grinding, the type of frog casting to be ground only needs to be scanned and identified. The corresponding grinding surface cross-section trajectory function can then be automatically matched from the frog wing rail grinding database. Subsequently, grinding can be performed according to the corresponding trajectory function. The fully automatic grinding process requires no human intervention, eliminating the need for manual teaching and programming, greatly improving work efficiency, and being applicable to the grinding of frog castings of different types and sizes. Furthermore, before actual grinding, the impurity thickness of several points on the grinding trajectory is obtained by scanning, and the minimum grinding force for this time is calculated based on the maximum impurity thickness, thereby determining the compensatory grinding force. This effectively avoids inadequate grinding, and each grinding trajectory uses a targeted grinding force, thereby improving grinding accuracy and efficiency.

[0034] In addition, the robot automatic grinding system for frog castings of the present invention also has the above advantages.

[0035] In addition to the above-described objects, features and advantages, the present invention has other objects, features and advantages. The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are intended to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0037] Figure 1 It is a schematic diagram of the main structure of the polishing robot adopted in the present invention.

[0038] Figure 2 It is a side structural schematic diagram of the polishing robot adopted in the present invention.

[0039] Figure 3 The figure is a schematic diagram of the posture of the grinding robot used in the present invention grinding a frog casting.

[0040] Figure 4 The figure is a flow chart of a robot automatic grinding method for frog castings according to a preferred embodiment of the present invention.

[0041] Figure 5 It is a schematic diagram of the ZY plane of the workpiece coordinate system established in the preferred embodiment of the present invention.

[0042] Figure 6 It is a schematic diagram of the ZX plane of the workpiece coordinate system established in the preferred embodiment of the present invention.

[0043] Figure 7It is a schematic diagram of a preferred embodiment of the present invention in which the scanning device is moved to a position just above the polishing starting point in preparation for scanning and measuring the thickness of impurities.

[0044] Figure 8 It is a schematic diagram of scanning and measuring the thickness of impurities on the surface of a frog casting in a preferred embodiment of the present invention.

[0045] Figure 9 The figure is a flow chart of a method for automatically polishing frog castings with a robot according to another embodiment of the present invention.

[0046] Figure 10 yes Figure 9 Schematic diagram of the sub-process of step S3a in FIG.

[0047] Figure 11 yes Figure 10 Schematic diagram of the sub-process of step S32a in FIG.

[0048] Figure 12 2 is a schematic diagram of using an area ratio method to determine whether an impurity is a burr in another embodiment of the present invention.

[0049] Figure 13 Schematic diagram of the grinding track spacing in a preferred embodiment of the present invention.

[0050] Figure 14 It is a schematic diagram of a grinding trajectory in which a bow-shaped trajectory is adopted for grinding along the X-axis in a preferred embodiment of the present invention.

[0051] Figure 15 It is a schematic diagram of the module structure of a robot automatic grinding system for frog castings according to another embodiment of the present invention.

[0052] Description of Reference Numerals

[0053] 1. Base; 2. Robot; 3. Force control device; 4. Spindle; 5. Grinding rotary axis; 6. Grinding tool; 7. Connecting mechanism; 8. Scanning device; 9. Frog casting. DETAILED DESCRIPTION

[0054] The embodiments of the present invention are described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered below.

[0055] It is understandable that Figures 1 to 3As shown, the polishing robot employed in the present invention specifically comprises a base 1, a robot 2, a force control device 3, a spindle 4, a polishing rotary axis 5, a polishing tool 6, a connecting mechanism 7, and a scanning device 8. The robot 2 is fixedly mounted on the base 1, and the force control device 3 is mounted on the driving end of the robot 2. The position of the driving end can be adjusted by controlling the movement posture of the robot 2. The force control device 3 can perform real-time and precise gravity compensation and force compensation, and can adaptively extend and retract in real time based on the contour characteristics of the contact surface of the frog casting 9. The spindle 4 is rotatably mounted on the force control device 3, and the scanning device 8 is connected to the spindle 4 via the connecting mechanism 7. The spacing between the scanning device 8 and the spindle 4 can be adjusted via the connecting mechanism 7. The grinding shaft 5 is mounted at the bottom end of the main shaft 4, and the grinding tool 6 is mounted at the bottom end of the grinding shaft 5. The main shaft 4, the grinding shaft 5, and the grinding tool 6 are coaxially arranged. The main shaft 4 is used to provide rotational power for the grinding shaft 5 and the grinding tool 6. The grinding tool 6 is used to grind the surface of the frog casting. The scanning device 8 is a laser scanning device, and the connecting mechanism 7 is a telescopic mechanism driven by electricity, hydraulics, or pneumatics.

[0056] It is understandable that Figure 4 As shown, a preferred embodiment of the present invention provides a robot automatic grinding method for frog castings, comprising the following contents:

[0057] Step S1: establishing a frog wing rail grinding database, wherein the frog wing rail grinding database stores trajectory functions of grinding surface cross sections of different types of frog wing rail models;

[0058] Step S2: Identify the type of frog casting to be ground, and extract the corresponding trajectory function from the frog wing rail grinding database according to the identification result;

[0059] Step S3: Control the robot to move the scanning device to the position directly above the grinding starting point, and drive the grinding tool to move according to the extracted trajectory function. During the movement, the scanning device is used to measure the thickness of impurities at several points on the grinding trajectory.

[0060] Step S4: Calculating the minimum force of this grinding based on the maximum impurity thickness, and determining the compensating grinding force of the force control device according to the minimum force;

[0061] Step S5: Control the robot to move the grinding rotation axis to the grinding starting point to start grinding.

[0062] It can be understood that the robotic automated grinding method for frog castings in this embodiment, by pre-building a frog wing rail grinding database, only needs to scan and identify the frog casting type to be ground before actual grinding. The corresponding grinding surface cross-section trajectory function can then be automatically matched from the frog wing rail grinding database. Subsequent grinding can be performed according to the corresponding trajectory function. This fully automated grinding process requires no human intervention, eliminating the manual teaching and programming process, greatly improving work efficiency, and being applicable to the grinding of frog castings of different types and sizes. Furthermore, before actual grinding, the impurity thickness at several points along the grinding trajectory is obtained by scanning. The minimum grinding force for this grinding is calculated based on the maximum impurity thickness, and then the compensatory grinding force is determined. This effectively avoids incomplete grinding, and each grinding trajectory is subjected to a targeted grinding force, thereby improving grinding accuracy and efficiency.

[0063] It can be understood that in step S1, the process of establishing the frog wing rail grinding database is specifically as follows:

[0064] Different types of frog wing rail models are established. For each frog wing rail model, a workpiece coordinate system is established with the cross-section bottom edge of the frog wing rail model as the Y-axis, the center of the cross-section bottom edge as the origin O, the direction perpendicular to the frog wing rail cross-section as the X-axis, and the vertical direction as the Z-axis. The grinding surface is set, and the trajectory function of the cross section of the grinding surface in the workpiece coordinate system is calculated, thereby constructing a frog wing rail grinding database.

[0065] Specifically, first, different types and sizes of frog wing rail models are established and the corresponding workpiece coordinate system is established. For each frog wing rail model, Figure 5 and Figure 6 As shown, a workpiece coordinate system is established with the cross-section bottom edge of the frog wing rail model as the Y-axis, the center of the cross-section bottom edge as the origin O, the direction perpendicular to the cross-section of the frog wing rail as the X-axis, and the vertical direction as the Z-axis. Then, a curved surface to be polished is set on the model, and the trajectory function z = f(y) of the cross section of the curved surface in the workpiece coordinate system is calculated.

[0066] It can be understood that in step S2, before starting grinding, the contour, size and other information of the frog casting to be ground are scanned by a scanning device, so as to identify the type of frog casting to be ground and its relative position information with respect to the grinding robot, and extract the workpiece coordinate system and the trajectory function z=f(y) of the cross section of the curved surface to be ground from the frog wing rail grinding database.

[0067] Optionally, in step S2, after extracting the corresponding trajectory function, the linear equation of the grinding rotation axis at each grinding point is calculated based on the trajectory function to ensure that the grinding tool is always tangent to the surface of the frog wing rail model during the grinding process, and in the subsequent measurement of impurity thickness and actual grinding process, the robot is controlled to adjust the posture of the grinding rotation axis according to the corresponding linear equation at each grinding point.

[0068] It is understood that in order to accurately calculate the surface impurity thickness of the frog casting and improve the scanning accuracy and grinding accuracy, it is necessary to ensure that the grinding rotation axis is always perpendicular to the surface of the frog casting, that is, the grinding tool is always tangent to the surface of the frog casting. Therefore, after the corresponding trajectory function is obtained in advance, the linear equation of the grinding rotation axis at each grinding point is calculated based on the trajectory function. Specifically, assuming that at A n (y 0n , z 0n ) point, the derivative of the function at that point is the slope of that point, that is, The slope of the line perpendicular to the point is Then in A n When the grinding rotation axis is at point, the equation of the straight line is z=K n y+b. And A n If the coordinates of the point are known, then b = z can be calculated. 0n -K n *y 0n Therefore, the equation of the straight line of the grinding rotation axis at this point is During the grinding process, as the position of the grinding point changes, the equation of the straight line on which the grinding rotation axis is located also changes continuously.

[0069] It can be understood that in step S3, Figure 7 As shown, the robot is controlled to move the scanning device 8 to directly above the grinding starting point. At this time, the grinding tool 6 and the surface to be ground of the frog casting 9 are on the same plane. The scanning laser emitted by the scanning device 8 is perpendicular to the frog casting 9. To ensure that the scanning device 8 can scan the surface of the frog casting 9, the distance l between the grinding rotation axis 5 and the laser emission hole of the scanning device 8 must be greater than the radius R of the grinding tool 6. During the scanning process, the grinding tool 6 moves along the trajectory corresponding to the trajectory function z = f(y). During this movement, the scanning device 8 continuously scans and measures the distance L between n points on the surface of the frog casting 9. n , and the theoretical distance between the scanning device 8 and the smooth surface of the frog wing rail is L, so the impurity thickness h at point n can be calculated n =LL n , n=1,2,3,…,p, such as Figure 8 shown.

[0070] It can be understood that in step S4, after scanning a polishing track, the surface impurity thickness data of p points can be obtained, from which the maximum value h is extracted. max , and then calculate the minimum force F for this grinding based on the maximum impurity thickness min The specific calculation formula is F min =c*h max , c represents the grinding force coefficient. Then, the force control device detects and compensates the grinding force F in real time N , (1-α)F min ≤F N ≤(1+α)F min α represents the compensation coefficient, which can be set according to actual conditions and is generally set to 0≤α≤0.5. By scanning the thickness of impurities on the frog casting surface and calculating the minimum grinding force and compensation grinding force based on the maximum impurity thickness, a targeted grinding force can be applied to each grinding track, achieving targeted and flexible grinding, ensuring that the thickest impurities on the frog casting surface are removed, while also improving grinding accuracy and efficiency.

[0071] It can be understood that the impurity thickness data of the p points scanned in step S3 may contain abnormal data. In order to further improve the grinding accuracy, optionally, as shown in FIG. Figure 9 As shown, the robot automatic grinding method for frog castings further includes the following steps after scanning and measuring the thickness of impurities at several points on the grinding track:

[0072] Step S3a: Cleaning the impurity thickness data of several points.

[0073] Specifically, if Figure 10 As shown, the process of cleaning the impurity thickness data of several points is specifically as follows:

[0074] Step S31a: Compare the impurity thickness of each point with a preset impurity thickness threshold. If the impurity thickness of a point is higher than the preset impurity thickness threshold, remove the impurity thickness data of the point.

[0075] Step S32a: Filter out the maximum impurity thickness from the impurity thickness data of the remaining points, and use the area ratio method to determine whether the point where the maximum impurity thickness is located is a burr. If it is determined to be a burr, remove the point data and continue to determine until it is determined that the point where the maximum impurity thickness is located is not a burr.

[0076] Specifically, first exclude abnormal impurity thickness data, pre-set the impurity thickness threshold Δh, and scan the impurity thickness data (h n =LL n , n=1,2,3,…,p) and compare with Δh, if h nIf the value is ≥Δh, the point is considered abnormal and is removed. Furthermore, since burrs are thin, high impurities that are easily polished, if the thickness of the burr point is equal to the maximum impurity thickness, the calculated minimum polishing force will be too high, potentially leading to over-polishing. Therefore, further burr analysis is required for the remaining impurity thickness data.

[0077] Among them, Figure 11 As shown, the process of using the area ratio method to determine whether the point with the maximum impurity thickness is a burr is specifically as follows:

[0078] Step S321a: Calculating the impurity area enclosed by all scanning points and the frog casting surface;

[0079] Step S322a: forming a rectangle with the maximum impurity thickness as the height and the total scan length as the base, and calculating the area of ​​the rectangle;

[0080] Step S323a: Calculate the ratio of the impurity area to the rectangle area. If the area ratio does not exceed the preset threshold, the point where the maximum impurity thickness is located is determined to be a burr. If it exceeds the preset threshold, the point where the maximum impurity thickness is located is determined to be a non-burr.

[0081] Specifically, after removing the abnormal impurity thickness data, calculate the impurity area enclosed by all normal impurities and the frog casting surface, such as Figure 12 As shown, the distance between each two adjacent scanning points is a, and the figure formed by the two adjacent scanning points and the frog casting surface is a trapezoid. Taking points 1 and 2 as an example, the area of ​​the trapezoidal area enclosed is Assuming that there are m scanning points left after removing the abnormal impurity thickness data, the total impurity area is Right now Figure 12 Then, the maximum impurity thickness h max (Take the impurity thickness h8 of point 8 as the maximum impurity thickness as an example) as the height and the total scanning length (m-1)a as the base, calculate the area of ​​the enclosed rectangle S8 = h8*(m-1)a, that is Figure 12 Then calculate Q% = S sum / S8, if Q% is less than or equal to the preset threshold, the current maximum impurity thickness h8 is determined to be a burr, and the minimum grinding force F is not calculated based on the impurity thickness at this point min If Q% is greater than the preset threshold, it is determined that the current maximum impurity thickness h8 is non-burr, and the minimum grinding force F is calculated based on the maximum impurity thickness h8. minIt can be understood that if the current maximum impurity thickness h8 is determined to be a burr, the second highest point h7 is selected to perform the area ratio calculation, and the calculation is iterated continuously until the calculated area ratio Q% is greater than the preset threshold. The preset threshold of the area ratio can be set according to actual conditions and is generally set to 50% or 60%, which is not specifically limited here.

[0082] In addition, after cleaning the impurity thickness data, when calculating the minimum grinding force based on the maximum impurity thickness, the grinding force coefficient c is related to the area ratio Q%. The larger the Q%, the closer the surface impurity thickness is to h. max , the larger the value of c; on the contrary, if Q% is smaller, it means that the thickness of surface impurities is generally thin, and the value of c is smaller.

[0083] It can be understood that in step S5, the robot is controlled to move the grinding rotation axis to the grinding starting point to start grinding. During the grinding process, the force control device detects and compensates the grinding force in real time.

[0084] Optionally, during the grinding process, the impurity thickness of the next grinding track is measured by a scanning device and the minimum force and compensation grinding force of the next grinding are calculated. When the measured impurity thickness of all the next grinding tracks is less than zero, the grinding of the frog casting is determined to be completed after the next grinding is completed.

[0085] Specifically, during the robot's grinding process, the scanning device scans at the same time to obtain the impurity thickness data of the next grinding track, and then calculates the minimum grinding force and the compensation grinding force. Figure 13 As shown, the grinding track spacing is the distance l between the grinding axis and the scanning device. To ensure that the grinding tool can completely cover the impurities between the two grinding tracks, l must be less than 2R. Therefore, the distance l between the grinding axis and the scanning device is greater than the grinding tool radius R and less than the grinding tool diameter 2R. Therefore, before starting grinding, the distance between the spindle and the scanning device must be adjusted using the connection mechanism.

[0086] Optionally, during the grinding process, a bow-shaped trajectory is used to grind along the X axis, such as Figure 14 As shown, it is helpful to further improve the grinding efficiency. When the thickness of all impurities in the next grinding track is measured to be less than zero, that is, the actual distance L between the scanning device and the surface of the frog casting nIf both are greater than the theoretical distance L, it means that the scanning device has not scanned the surface of the frog casting. At this time, the distance between the grinding rotation axis and the end of the frog casting is less than l, and no scanning is performed during the next grinding task. After the next grinding task is completed, the frog casting is judged to have been polished. This can automatically determine whether the grinding is complete. For frog castings of different lengths, there is no need to manually set the grinding length, which improves the grinding efficiency. Among them, since the impurity thickness data cannot be scanned in advance during the last grinding, the minimum force and compensation grinding force during the last grinding cannot be calculated. Therefore, the grinding force for the last grinding is based on the previous grinding.

[0087] In addition, if Figure 15 As shown, the present invention also provides a robot automatic grinding system for frog castings, preferably using the robot automatic grinding method for frog castings as described above, comprising:

[0088] A database construction module is used to establish a frog wing rail grinding database, wherein the frog wing rail grinding database stores trajectory functions of grinding surface cross sections of different types of frog wing rail models;

[0089] A frog type recognition module is used to identify the type of frog casting to be ground and extract the corresponding trajectory function from the frog wing rail grinding database based on the recognition result;

[0090] The impurity thickness scanning module is used to control the robot to move the scanning device to the top of the grinding starting point, and drive the grinding tool to move according to the extracted trajectory function. During the movement, the scanning device measures the impurity thickness at several points on the grinding trajectory.

[0091] A force calculation module is used to calculate the minimum force of this grinding based on the maximum impurity thickness, and determine the compensating grinding force of the force control device according to the minimum force;

[0092] The grinding control module is used to control the robot to move the grinding rotation axis to the grinding starting point to start grinding.

[0093] It can be understood that the robotic automatic grinding system for frog castings in this embodiment, by pre-building a frog wing rail grinding database, only needs to scan and identify the type of frog casting to be ground before actual grinding. The corresponding grinding surface cross-section trajectory function can be automatically matched from the frog wing rail grinding database. Subsequent grinding is performed according to the corresponding trajectory function. This fully automatic grinding process requires no human intervention, eliminating the manual teaching and programming process, greatly improving work efficiency, and being applicable to the grinding of frog castings of different types and sizes. Furthermore, before actual grinding, the impurity thickness at several points along the grinding trajectory is scanned and the minimum grinding force for this grinding is calculated based on the maximum impurity thickness, thereby determining the compensatory grinding force. This effectively avoids incomplete grinding, and each grinding trajectory is subjected to a targeted grinding force, thereby improving grinding accuracy and efficiency.

[0094] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

[0095] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code. The scheme in the embodiment of the present application can be implemented in various computer languages, for example, object-oriented programming language Java and literal translation scripting language JavaScript, etc.

[0096] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0097] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0098] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0099] Although the preferred embodiments of the present application have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present application.

[0100] Obviously, those skilled in the art may make various changes and modifications to this application without departing from the spirit and scope of this application. Thus, if these modifications and variations of this application fall within the scope of the claims of this application and their equivalents, this application is intended to include these modifications and variations.

Claims

1. A robot automatic grinding method for frog castings, characterized in that: Includes the following: Establishing a frog wing rail grinding database, wherein the frog wing rail grinding database stores trajectory functions of grinding surface cross sections of different types of frog wing rail models; Identify the type of frog casting to be ground, and extract the corresponding trajectory function from the frog wing rail grinding database based on the identification result; The robot is controlled to move the scanning device to the position directly above the starting point of the grinding process, and the grinding tool is driven to move according to the extracted trajectory function. During the movement, the scanning device is used to measure the thickness of impurities at several points on the grinding trajectory. Calculate the minimum force of this grinding based on the maximum impurity thickness, and determine the compensating grinding force of the force control device according to the minimum force; Control the robot to move the grinding rotation axis to the grinding starting point to start grinding; After scanning and measuring the thickness of impurities at several points on the polishing track, the following contents are also included: Clean the impurity thickness data of several points; The process of cleaning the impurity thickness data of several points is specifically as follows: Compare the impurity thickness of each point with the preset impurity thickness threshold. If the impurity thickness of a point is higher than the preset impurity thickness threshold, the impurity thickness data of the point will be discarded. The maximum impurity thickness is screened out from the impurity thickness data of the remaining points, and the area ratio method is used to determine whether the point with the maximum impurity thickness is a burr. If it is determined to be a burr, the data of the point is removed and the judgment is continued until the point with the maximum impurity thickness is determined to be non-burr.

2. The robot automatic grinding method for frog castings according to claim 1, characterized in that: The process of establishing the frog wing rail grinding database is specifically as follows: Different types of frog wing rail models are established. For each frog wing rail model, a workpiece coordinate system is established with the cross-section bottom edge of the frog wing rail model as the Y-axis, the center of the cross-section bottom edge as the origin O, the direction perpendicular to the frog wing rail cross-section as the X-axis, and the vertical direction as the Z-axis. The polishing surface is set, and the trajectory function of the polishing surface cross-section in the workpiece coordinate system is calculated.

3. The robot automatic grinding method for frog castings according to claim 1, characterized in that: After extracting the corresponding trajectory function, the linear equation of the grinding rotation axis at each grinding point is calculated based on the trajectory function to ensure that the grinding tool is always tangent to the surface of the switch wing rail model during the grinding process, and in the process of measuring the impurity thickness and performing actual grinding, the robot is controlled to adjust the posture of the grinding rotation axis according to the corresponding linear equation at each grinding point.

4. The robot automatic grinding method for frog castings according to claim 1, characterized in that: The specific process of using the area ratio method to determine whether the point with the maximum impurity thickness is a burr is as follows: Calculate the impurity area enclosed by all scanning points and the frog casting surface; Use the maximum impurity thickness as the height and the total scan length as the base to form a rectangle, and calculate the area of ​​the rectangle; The ratio of the impurity area to the rectangle area is calculated. If the area ratio does not exceed the preset threshold, the point where the maximum impurity thickness is located is determined to be a burr. If it exceeds the preset threshold, the point where the maximum impurity thickness is located is determined to be a non-burr.

5. The robot automatic grinding method for frog castings according to claim 1, characterized in that: During the grinding process, the impurity thickness of the next grinding track is measured by the scanning device and the minimum force and compensation grinding force of the next grinding are calculated. When the measured impurity thickness of all the next grinding tracks is less than zero, the grinding of the frog casting is determined to be completed after the next grinding is completed.

6. The robot automatic grinding method for frog castings according to claim 2, characterized in that: During the grinding process, a bow-shaped trajectory is used to grind along the X axis.

7. The robot automatic grinding method for frog castings according to claim 5, characterized in that: The distance between the grinding rotation axis and the scanning device is greater than the radius of the grinding tool and smaller than the diameter of the grinding tool.

8. A robot automatic grinding system for frog castings, using the robot automatic grinding method for frog castings according to any one of claims 1 to 7, characterized in that: include: A database construction module is used to establish a frog wing rail grinding database, wherein the frog wing rail grinding database stores trajectory functions of grinding surface cross sections of different types of frog wing rail models; A frog type recognition module is used to identify the type of frog casting to be ground and extract the corresponding trajectory function from the frog wing rail grinding database based on the recognition result; The impurity thickness scanning module is used to control the robot to move the scanning device to the top of the grinding starting point, and drive the grinding tool to move according to the extracted trajectory function. During the movement, the scanning device measures the impurity thickness at several points on the grinding trajectory. A force calculation module is used to calculate the minimum force of this grinding based on the maximum impurity thickness, and determine the compensating grinding force of the force control device according to the minimum force; The grinding control module is used to control the robot to move the grinding rotation axis to the grinding starting point to start grinding.

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