Manipulator polishing and grinding switching system based on machine vision

Abstract

The invention relates to the technical field of grinding and polishing, in particular to a mechanical arm polishing and grinding switching system based on machine vision. A lateral movement unit; a longitudinal moving unit; a transfer manipulator unit; the polishing unit and the grinding unit are symmetrically arranged on the two sides of the rack; the data acquisition module is used for acquiring texture information of each sub-region and a curvature value of the surface of each sub-region; the secondary judgment module is used for carrying out secondary judgment on a surface curvature change value obtained according to a curvature value under the condition that the condition that the grinding of the workpiece does not meet a preset standard is judged according to a texture direction characterization value obtained according to the data texture direction and the texture number; and the control module is used for determining the reason that the polishing of the workpiece does not conform to the preset standard according to the surface peak valley value obtained according to the height value and determining the polishing duration or the polishing pressure according to the gray characteristic value under the condition that the polishing of the workpiece does not conform to the preset standard according to the glossiness of the workpiece. The polishing effect is improved.

Description

Technical Field

[0001] The invention relates to the technical field of grinding and polishing, and in particular to a robot polishing and grinding switching system based on machine vision. Background Art

[0002] The polishing and grinding robot is an automated robot specially used for surface treatment. It has a high degree of autonomy and precision. It can polish and grind the surfaces of various materials. It can improve surface treatment efficiency, reduce labor intensity, improve the working environment, and achieve higher precision and consistency in surface treatment effects.

[0003] Grinding and polishing are very important processing technologies in industrial processing. Grinding refers to the process of using machinery to increase the roughness of the workpiece surface to obtain patterns or remove burrs on the workpiece surface, and polishing refers to the process of using machinery to reduce the roughness of the workpiece surface to obtain a bright and flat surface. The equipment for grinding and polishing is basically the same, the difference is that grinding is to contact the workpiece surface with a grinding wheel, and polishing is to contact the workpiece surface with a polishing wheel. They both use a high-speed rotating grinding wheel or polishing wheel to press against the workpiece, and the abrasive on the surface of the grinding wheel or polishing wheel rolls and slightly cuts the workpiece surface, thereby obtaining a carved, deburred or bright processed surface.

[0004] However, existing robotic polishing and grinding systems still have some technical bottlenecks. For example, most systems lack accurate workpiece identification and positioning capabilities, resulting in insufficient polishing and grinding accuracy, making it difficult to meet high-quality product requirements. In addition, some systems lack sufficient flexibility and adaptability when processing workpieces of complex shapes and materials, limiting their scope of application.

[0005] Chinese patent publication number: CN114029818A, discloses an industrial robot flexible grinding equipment based on machine vision, relates to the technical field of grinding equipment, comprises a mechanical arm, a slide is fixed on the bottom surface of the mechanical arm, a slide is arranged on the bottom surface of the slide, the slide is movably connected with the slide, a power device at one end of the mechanical arm is provided with a joint replacement device, the joint replacement device comprises an outer shell, an inner shell is arranged inside the outer shell, a motor is fixed with a bolt on the top surface of the outer shell, a bevel gear is respectively fixed on the rotating end of the motor a and the surface of the inner shell, a connecting rod is arranged inside the mounting column of the inner wall of the inner shell, a polishing head, a burr removal head and a scanning head are respectively arranged at one end of the three groups of connecting rods, a limit plate head end of the top surface of the connecting rod is welded with the top surface of the connecting rod, a cylinder is fixed on the top surface of the outer shell, a pressing plate is fixed on the telescopic end of the cylinder, a grinding, polishing and burr removal device are integrated, a variety of joints are automatically replaced according to the user's usage, and standard parts are used as a comparison, thereby improving the processing accuracy of the workpiece and improving the processing qualification rate.

[0006] It can be seen that the above technical solution does not consider the influence of the shape of the workpiece surface on the polishing accuracy and does not consider the influence of the grinding rate, polishing pressure and polishing time on the workpiece processing quality, which leads to the problem of poor grinding and polishing effect. Summary of the invention

[0007] To this end, the present invention provides a robot polishing and grinding conversion system based on machine vision to overcome the problem that the prior art does not consider the influence of the shape of the workpiece surface on the polishing and grinding accuracy and does not consider the influence of the grinding rate, polishing pressure and polishing time on the workpiece processing quality, thereby resulting in poor grinding and polishing effects.

[0008] To achieve the above object, the present invention provides a robot polishing and grinding transfer system based on machine vision, comprising:

[0009] The machine frame includes a horizontal moving unit, a vertical moving unit, a transfer robot unit, a polishing unit, a grinding unit, a data acquisition module and a control module, wherein:

[0010] The lateral moving unit is arranged on one side of the top of the frame, and is used to drive the longitudinal moving unit to move lateraly;

[0011] A longitudinal moving unit connected to the transverse moving unit, used to drive the transfer robot unit to move longitudinally and to fix the visual sensor;

[0012] A transfer robot unit, which is connected to the longitudinal moving unit and is used for transfer and transportation of workpieces;

[0013] The polishing unit and the grinding unit are symmetrically arranged on both sides of the frame, wherein the grinding unit is provided with a grinding wheel, and the polishing unit is provided with a polishing wheel;

[0014] A data acquisition module is connected to the visual sensor and is used to divide the workpiece surface image obtained by the visual sensor into several sub-areas, and obtain the texture information and curvature value of each sub-area. The texture information includes texture direction, texture quantity, gray value and height value of surface contour;

[0015] A control module is respectively connected to the data acquisition module, the lateral moving unit, the longitudinal moving unit, the transfer robot unit, the polishing unit and the grinding unit, and is used to determine whether the grinding of the workpiece does not meet the preset standard according to the texture direction characterization value obtained by the data texture direction and the texture quantity, and to make a secondary judgment according to the surface curvature change value obtained according to the curvature value, or to determine the reason why the grinding of the workpiece does not meet the preset standard according to the surface peak-valley value obtained by the height value, and to determine to increase the polishing time or increase the grinding pressure according to the grayscale characteristic value under the condition that the polishing of the workpiece does not meet the preset standard according to the glossiness of the workpiece.

[0016] Furthermore, the lateral moving unit includes a first guide rail, a moving block sleeved on the first guide rail, and a mounting plate vertically arranged on the side of the moving block, and guide constraint grooves are evenly arranged on both sides of the edge of the mounting plate.

[0017] Furthermore, the longitudinal moving unit is slidably connected to the mounting plate through a guide constraint groove, and the longitudinal moving unit includes a second guide rail, a mounting seat, a hollow rotating table, a visual sensor, a connecting arm, a rotating shaft, and a mounting frame, wherein a side of the second guide rail away from the guide constraint groove is connected to the mounting seat, a hollow rotating table is arranged above the mounting seat, a visual sensor is installed in the hollow rotating table, one end of the connecting arm is connected to the side wall of the hollow rotating table, and the other end of the connecting arm is connected to the rotating shaft, and a mounting frame is arranged above the rotating shaft, and the longitudinal moving direction of the second guide rail and the lateral moving direction of the first guide rail are perpendicular to each other.

[0018] Further, the transfer robot unit is connected to the mounting frame by bolts, and includes a first robot arm assembly, a second robot arm assembly, and a third robot arm assembly;

[0019] The first mechanical arm assembly includes a first groove seat, a lead screw, a lead screw nut, a first motor for driving the lead screw, a guide sliding groove, a guide rail, a connecting block, and a bearing seat, wherein the bearing seats are symmetrically installed at both ends of the bottom of the first groove, the two ends of the lead screw are respectively connected to the bearing seats, the lead screw drives the connecting block to move through the rotation of the lead screw nut, the guide rail is arranged at both ends of the bearing seat, and the guide sliding grooves are symmetrically arranged on both sides of the inner wall of the first groove seat;

[0020] The second robotic arm assembly includes a synchronous belt, a second groove seat, a linear guide rail, and a limiting sliding groove, wherein the side wall of the second groove seat slides into the guide sliding groove, the bottom of the second groove seat is connected to the screw nut, the bottom of the second groove seat is symmetrically provided with linear guide rails, and a synchronous belt is provided between the linear guide rails.

[0021] Furthermore, the third robotic arm assembly includes a belt, a second motor for driving the belt to rotate, a one-way bearing, an adapter suction cup, a locking block, a driving block, and a third groove seat, wherein the locking block is arranged at the bottom of the third groove seat, the synchronous belt drives the third groove seat to move through the locking block, the driving block is symmetrically arranged at the bottom of the third groove seat, and a belt is arranged in the third groove seat, one end of the belt is connected to the second motor, and the other end of the belt is connected to the adapter suction cup through the one-way bearing.

[0022] Further, the control module determines that the grinding of the workpiece does not meet the preset standard under the condition that the texture direction characterization value is less than the second preset texture direction characterization value,

[0023] and determining the reason why the grinding of the workpiece does not meet the preset standard according to the surface peak-to-valley value under the condition that the texture direction characterization value is less than the first preset texture direction characterization value,

[0024] and secondarily determining whether the grinding of the workpiece meets the preset standard according to the surface curvature change value under the condition that the texture direction characterization value is greater than or equal to the first preset texture direction characterization value and less than the second preset texture direction characterization value;

[0025] The texture direction characterization value is determined by the texture direction and the texture quantity collected by the data collection module.

[0026] Further, the control module determines, based on the surface peak-to-valley values, that the reason why the grinding of the workpiece does not meet the preset standard is that the grinding rate of the grinding wheel is too high and reduces the grinding rate of the grinding wheel, or that the grinding wheel is worn and issues an early warning;

[0027] The surface peak-to-valley value is determined by the vertical distance between the maximum contour peak and the maximum contour valley in the sub-area.

[0028] Further, the control module reduces the feed rate of the grinding wheel under the condition that the grinding of the workpiece does not meet the preset standard according to the comparison result that the surface curvature change value is greater than or equal to the preset surface curvature change value;

[0029] The surface curvature change value is the maximum value of the surface curvature differences between adjacent sub-areas after grinding.

[0030] Furthermore, the control module determines whether the polishing of the workpiece meets the preset standard according to the glossiness of the workpiece, wherein:

[0031] If the glossiness is less than the first preset glossiness, it is determined that the polishing of the workpiece does not meet the preset standard, and the polishing pressure of the polishing wheel is increased according to the difference between the first preset glossiness and the glossiness;

[0032] If the glossiness is greater than or equal to the first preset glossiness and less than the second preset glossiness, it is determined that the polishing of the workpiece does not meet the preset standard, and an adjustment strategy is determined under the condition that the polishing of the workpiece does not meet the preset standard according to the grayscale feature value;

[0033] If the glossiness is greater than or equal to the second preset glossiness, it is determined that the polishing of the workpiece meets the preset standard;

[0034] The glossiness is determined by the grayscale value of the surface of the sub-region.

[0035] Further, the control module determines, based on the grayscale characteristic value, an adjustment strategy under the condition that the polishing of the workpiece does not meet the preset standard, including: increasing the polishing time, or increasing the grinding pressure;

[0036] The grayscale characteristic value is the ratio between the number of sub-areas whose grayscale mean is less than or equal to the preset grayscale mean and the total number of sub-areas.

[0037] Compared with the prior art, the beneficial effects of the present invention lie in that, through the coordinated control of the lateral moving unit and the longitudinal moving unit, the present invention combines the design of the screw drive, synchronous belt transmission and belt transmission of the first robot arm, the second robot arm and the third robot arm, so as to realize the precise positioning and rapid transmission of the workpiece; the grinding unit and the polishing unit are symmetrically arranged, and cooperate with the multi-degree-of-freedom movement of the transfer robot to adapt to the grinding and polishing of different workpiece surfaces, thereby enhancing the adaptability of the system; the nested design of the first robot arm, the second robot arm and the third robot arm improves the stability of the system; a visual sensor is arranged in the hollow rotating table to collect the texture direction, peak-to-valley values ​​and surface curvature changes of the workpiece surface in real time, thereby improving the level of intelligent processing; the grinding effect of the workpiece is tested according to the texture direction characterization value and the surface curvature change value; the polishing effect of the workpiece is tested according to the glossiness and grayscale characteristic values, thereby improving the grinding and polishing effect of the transfer system.

[0038] Furthermore, the present invention makes a secondary judgment or determines the reason why the grinding of the workpiece does not meet the preset standard when it is judged that the grinding of the workpiece does not meet the standard through the texture direction characterization value, so as to avoid the accidental error of a single detection, thereby improving the credibility of the evaluation result.

[0039] Furthermore, the present invention determines through the surface peak-to-valley values ​​that the reasons why the grinding of the workpiece does not meet the preset standard include excessive grinding rate of the grinding wheel or wear of the grinding wheel, thereby improving the grinding efficiency.

[0040] Furthermore, the present invention reduces the grinding pressure of the grinding wheel by the difference between the surface curvature change value and the preset surface curvature change value, thereby achieving precise control of the reduction range of the grinding pressure.

[0041] Furthermore, the present invention determines whether the polishing of the workpiece meets the preset standard by the glossiness of the workpiece, and sets the glossiness of the workpiece as an evaluation index of whether the polishing of the workpiece meets the preset standard, thereby improving the accuracy of evaluating the polishing quality.

[0042] Furthermore, the present invention determines the adjustment strategy under the condition that the polishing of the workpiece does not meet the preset standard through the grayscale characteristic value, including increasing the polishing time or increasing the polishing pressure, thereby optimizing the process parameters of the grinding and polishing. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 It is a structural schematic diagram of a robot polishing and grinding switching system based on machine vision according to an embodiment of the present invention;

[0044] Figure 2It is a schematic structural diagram of a lateral moving unit of a robot polishing and grinding transfer system based on machine vision according to an embodiment of the present invention;

[0045] Figure 3 It is a schematic structural diagram of a longitudinal moving unit of a robot polishing and grinding transfer system based on machine vision according to an embodiment of the present invention;

[0046] Figure 4 It is a schematic diagram of the exploded structure of the first mechanical arm assembly of the mechanical arm polishing and grinding switching system based on machine vision according to an embodiment of the present invention;

[0047] Figure 5 It is a schematic diagram of the exploded structure of the second mechanical arm assembly of the mechanical arm polishing and grinding transfer system based on machine vision according to an embodiment of the present invention;

[0048] Figure 6 It is a schematic diagram of the exploded structure of the third robot arm assembly of the robot polishing and grinding switching system based on machine vision according to an embodiment of the present invention;

[0049] Figure 7 It is a schematic diagram of the exploded structure of a transfer robot unit of a robot polishing and grinding transfer system based on machine vision according to an embodiment of the present invention;

[0050] Figure 8 This is a schematic diagram of module connections of a robot polishing and grinding switching system based on machine vision according to an embodiment of the present invention;

[0051] Fig. 9 This is a flow chart of an embodiment of the present invention for determining whether the grinding of a workpiece meets a preset standard according to a texture direction characterization value;

[0052] In the figure, 1, frame; 2, lateral moving unit; 3, longitudinal moving unit; 4, transfer robot unit; 5, grinding unit; 6, polishing unit; 51, grinding wheel; 61, polishing wheel; 21, first guide rail; 22, moving block; 23, mounting plate; 24, guide constraint groove; 31, second guide rail; 32, mounting seat; 33, hollow rotating table; 34, visual sensor; 35, connecting arm; 36, rotating shaft; 37, mounting frame; 41, first robot arm assembly; 42, second robot arm Assembly; 43, third robot arm assembly; 411, first groove seat; 412, lead screw; 413, lead screw nut; 414, first motor; 415, guide sliding groove; 416, guide rail; 417, connecting block; 418, bearing seat; 421, synchronous belt; 422, second groove seat; 423, linear guide; 424, limit sliding groove; 431, belt; 432, second motor; 434, transfer suction cup; 435, locking block; 436, driving block; 437, third groove seat. DETAILED DESCRIPTION

[0053] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0054] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0055] It should be pointed out that the data in this embodiment are obtained by comprehensive analysis and evaluation of the historical test data of the present invention in the three months before this test and the corresponding historical test results. It can be understood by those skilled in the art that the present invention can determine the above parameters for a single item by selecting the highest proportion of values ​​as the preset standard parameters according to the data distribution, using weighted summation to use the obtained values ​​as the preset standard parameters, substituting each historical data into a specific formula and using the values ​​obtained by the formula as the preset standard parameters or other selection methods, as long as the method of the present invention can clearly define the different specific situations in the single determination process through the obtained values.

[0056] See also Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 as well as Fig. 9 As shown, they are respectively a schematic diagram of the structure of a robot polishing and grinding transfer system based on machine vision in an embodiment of the present invention; a schematic diagram of the structure of a lateral moving unit of a robot polishing and grinding transfer system based on machine vision in an embodiment of the present invention; a schematic diagram of the structure of a longitudinal moving unit of a robot polishing and grinding transfer system based on machine vision in an embodiment of the present invention; a schematic diagram of the exploded structure of the first robot arm assembly of a robot polishing and grinding transfer system based on machine vision in an embodiment of the present invention; a schematic diagram of the exploded structure of the second robot arm assembly of a robot polishing and grinding transfer system based on machine vision in an embodiment of the present invention; a schematic diagram of the exploded structure of the third robot arm assembly of a robot polishing and grinding transfer system based on machine vision in an embodiment of the present invention; a schematic diagram of the exploded structure of a transfer robot unit of a robot polishing and grinding transfer system based on machine vision in an embodiment of the present invention; a schematic diagram of the module connection of a robot polishing and grinding transfer system based on machine vision in an embodiment of the present invention; a flowchart of determining whether the grinding of a workpiece meets a preset standard according to a texture direction characterization value in an embodiment of the present invention.

[0057] The embodiment of the present invention provides a robot polishing and grinding switching system based on machine vision, comprising:

[0058] See also Figure 1 As shown, the frame 1, the lateral moving unit 2, the longitudinal moving unit 3, the transfer robot unit 4, the polishing unit 6, the grinding unit 5, the data acquisition module and the control module, wherein:

[0059] The lateral moving unit 2 is arranged on one side of the top of the frame 1, and is used to drive the longitudinal moving unit 3 to move lateraly;

[0060] A longitudinal moving unit 3, which is connected to the transverse moving unit 2, and is used to drive the transfer robot unit 4 to move longitudinally and to fix the visual sensor 34;

[0061] A transfer robot unit 4, which is connected to the longitudinal moving unit 3 and is used for transfer and transportation of workpieces;

[0062] The polishing unit 6 and the grinding unit 5 are symmetrically arranged on both sides of the frame 1, the grinding unit 5 is provided with a grinding wheel 51, and the polishing unit 6 is provided with a polishing wheel 61;

[0063] A data acquisition module, which is connected to the visual sensor 34, and is used to divide the workpiece surface image obtained by the visual sensor 34 into a number of sub-areas, and obtain texture information of each sub-area and the curvature value of the surface of each sub-area, wherein the texture information includes texture direction, texture quantity, gray value and height value of surface contour;

[0064] A control module is respectively connected to the data acquisition module, the lateral moving unit 2, the longitudinal moving unit 3, the transfer robot unit 4, the polishing unit 6 and the grinding unit 5, and is used to determine whether the grinding of the workpiece does not meet the preset standard according to the texture direction characterization value obtained by the data texture direction and the texture quantity, and to make a secondary judgment according to the surface curvature change value obtained according to the curvature value, or to determine the reason why the grinding of the workpiece does not meet the preset standard according to the surface peak-valley value obtained by the height value, and to determine to increase the polishing time or increase the grinding pressure according to the grayscale characteristic value under the condition that the polishing of the workpiece does not meet the preset standard according to the glossiness of the workpiece.

[0065] See also Figure 2 As shown, specifically, the lateral moving unit 2 includes a first guide rail 21, a moving block 22 mounted on the first guide rail 21, and a mounting plate 23 vertically arranged on the side of the moving block 22. The mounting plate 23 moves along the length direction of the first guide rail 21 through the moving block 22, and guide constraint grooves 24 are evenly arranged on both sides of the edge of the mounting plate 23.

[0066] See also Figure 3As shown, specifically, the longitudinal moving unit 3 is slidably connected to the mounting plate 23 through the guide constraint groove 24, and the longitudinal moving unit 3 includes a second guide rail 31, a mounting seat 32, a hollow rotating table 33, a visual sensor 34, a connecting arm 35, a rotating shaft 36, and a mounting frame 37, wherein the second guide rail 31 is connected to the mounting seat 32 at one side away from the guide constraint groove 24, a hollow rotating table 33 is arranged above the mounting seat 32, a visual sensor 34 is installed in the hollow rotating table 33, one end of the connecting arm 35 is connected to the side wall of the hollow rotating table 33, and the other end of the connecting arm 35 is connected to the rotating shaft 36, a mounting frame 37 is arranged above the rotating shaft 36, and the longitudinal moving direction of the second guide rail 31 and the lateral moving direction of the first guide rail 21 are perpendicular to each other.

[0067] The visual sensor 34 in this embodiment is selected as a 3D visual sensor 34, which is not specifically limited and only needs to meet the requirements of obtaining two-dimensional images and three-dimensional images of the workpiece.

[0068] See also Figure 7 As shown, specifically, the transfer robot unit 4 is connected to the mounting frame 37 by bolts, and includes a first robot arm assembly 41, a second robot arm assembly 42, and a third robot arm assembly 43;

[0069] See also Figure 4 As shown, the first mechanical arm assembly 41 includes a first groove seat 411, a lead screw 412, a lead screw 412 nut, a first motor 414 for driving the lead screw 412, a guide sliding groove 415, a guide rail 416, a connecting block 417, and a bearing seat 418, wherein the bearing seats 418 are symmetrically installed at both ends of the bottom of the first groove, and the two ends of the lead screw 412 are respectively connected to the bearing seats 418, and the lead screw 412 drives the connecting block 417 to move through the rotation of the lead screw 412 nut, and the connecting block 417 slides along the length direction of the guide rail 416, and the guide rail 416 is arranged at both ends of the bearing seat 418, and the guide sliding grooves 415 are symmetrically arranged on both sides of the inner wall of the first groove seat 411;

[0070] See also Figure 5 As shown, the second mechanical arm assembly 42 includes a synchronous belt 421, a second groove seat 422, a linear guide rail 423, and a limiting sliding groove 424, wherein:

[0071] The side wall of the second groove seat 422 slides into the guide sliding groove 415 , the bottom of the second groove seat 422 is connected to the nut of the lead screw 412 , and linear guide rails 423 are symmetrically arranged at the bottom of the second groove seat 422 , and synchronous belts 421 are arranged between the linear guide rails 423 .

[0072] See also Figure 6As shown, specifically, the third robotic arm assembly 43 includes a belt 431, a second motor 432 for driving the belt 431 to rotate, a one-way bearing, a transfer suction cup 434, a locking block 435, a driving block 436, and a third groove seat 437, wherein the locking block 435 is arranged at the bottom of the third groove seat 437, the synchronous belt 421 drives the third groove seat 437 to move through the locking block 435, the driving block 436 is symmetrically arranged at the bottom of the third groove seat 437, the driving block 436 slides along the length direction of the linear guide 423, and the third groove seat 437 is provided with a belt 431, one end of the belt 431 is connected to the second motor 432, and the other end of the belt 431 is connected to the transfer suction cup 434 through a one-way bearing.

[0073] See also Fig. 9 Specifically, the control module determines whether the grinding of the workpiece meets the preset standard according to the texture direction characterization value, wherein:

[0074] If the texture direction characterization value is less than the first preset texture direction characterization value 0.35, it is determined that the grinding of the workpiece meets the preset standard, and the workpiece is transferred to the polishing unit 6;

[0075] If the texture direction characterization value is greater than or equal to the first preset texture direction characterization value and less than the second preset texture direction characterization value 0.67, it is determined that the grinding of the workpiece does not meet the preset standard, and a second determination is made based on the surface curvature change value whether the grinding of the workpiece meets the preset standard;

[0076] If the texture direction characterization value is greater than or equal to the second preset texture direction characterization value, it is determined that the grinding of the workpiece does not meet the preset standard, and the reason why the grinding of the workpiece does not meet the preset standard is determined according to the surface peak-to-valley value.

[0077] In this embodiment, the first preset texture direction characterization value is selected as 0.35 and the second preset texture direction characterization value is selected as 0.67, which are obtained based on the average value of historical detection data, but the above values ​​are not limited to this. Technical personnel in this field can also adjust the values ​​according to actual needs.

[0078] The process of obtaining the texture direction representation value includes:

[0079] Obtain a two-dimensional image of the workpiece after grinding; process the two-dimensional image through a directional filter to quantify the texture direction into a number of directional intervals; count the number of textures in each directional interval to form a histogram in which the horizontal axis represents the texture direction and the vertical axis represents the number of textures in the corresponding direction;

[0080] The texture direction representation value is calculated using the following formula:

[0081]

[0082] Where P represents the texture direction representation value; x i represents the midpoint direction value of the i-th direction interval in the histogram; μ represents the weighted average of the middle values ​​of the direction interval; y i It represents the ratio between the number of textures in the i-th direction interval and the total number of textures; n represents the total number of direction intervals; i=1, 2, 3, ..., n.

[0083] The weighted average of the middle values ​​of the directional intervals is calculated using the following formula:

[0084]

[0085] Where μ represents the weighted average of the middle values ​​of the direction interval; x i Indicates the midpoint direction value of the i-th direction interval in the histogram, f i It represents the number of textures corresponding to the midpoint direction value of the i-th direction interval in the histogram, and n represents the total number of direction intervals.

[0086] Specifically, the control module determines the reason why the grinding of the workpiece does not meet the preset standard based on the surface peak-to-valley value, wherein:

[0087] If the surface peak-to-valley value is less than the preset surface peak-to-valley value, it is determined that the grinding rate of the grinding wheel 51 is too large, and the grinding rate of the grinding wheel 51 is reduced according to the difference between the preset surface peak-to-valley value and the surface peak-to-valley value;

[0088] If the surface peak-to-valley value is greater than or equal to the preset surface peak-to-valley value, it is determined that the grinding wheel 51 is worn and an early warning is issued.

[0089] Specifically, the control module determines whether the grinding of the workpiece meets the preset standard based on the surface curvature change value.

[0090] If the surface curvature change value is less than the preset surface curvature change value 3mm -1 , it is determined that the grinding of the workpiece meets the preset standard, and the workpiece is transferred to the polishing unit 6;

[0091] If the surface curvature change value is greater than or equal to the preset surface curvature change value, it is determined that the grinding of the workpiece does not meet the preset standard, and the feed rate of the grinding wheel 51 is reduced according to the difference between the surface curvature change value and the preset surface curvature change value;

[0092] The surface curvature change value is the maximum value of the surface curvature differences between adjacent sub-areas after grinding.

[0093] The 3D vision sensor 34 acquires an image of the surface of the workpiece after grinding, and the surface curvature of the sub-area after grinding is acquired through image processing software, such as ImageJ or Mountainsmap, which is not specifically limited and only needs to meet the curvature acquisition requirements.

[0094] In this embodiment, the range of the preset surface curvature change value (2mm -1 , 5mm -1 ), preferably, the preset surface curvature change value is 3mm -1 , but the above values ​​are not limited to this, as long as they meet the detection requirements.

[0095] Specifically, the control module determines whether the polishing of the workpiece meets the preset standard according to the glossiness of the workpiece, wherein:

[0096] If the glossiness is less than the first preset glossiness 60GU, it is determined that the polishing of the workpiece does not meet the preset standard, and the polishing pressure of the polishing wheel 61 is increased according to the difference between the first preset glossiness and the glossiness;

[0097] If the glossiness is greater than or equal to the first preset glossiness and less than the second preset glossiness 80GU, it is determined that the polishing of the workpiece does not meet the preset standard, and an adjustment strategy is determined under the condition that the polishing of the workpiece does not meet the preset standard according to the grayscale feature value;

[0098] If the glossiness is greater than or equal to the second preset glossiness, it is determined that the polishing of the workpiece meets the preset standard;

[0099] The glossiness is the average grayscale value of all sub-area surfaces. The grayscale value is obtained by image processing software such as ImageJ. The specific type of image processing software is not limited, and it only needs to meet the grayscale value acquisition requirements.

[0100] The increase in the polishing pressure of the polishing wheel 61 is positively correlated with the gloss difference, wherein the positive correlation is, for example, a linear positive correlation or a nonlinear positive correlation, and the linear slope of the linear positive correlation is not specifically limited. It can be understood that the greater the gloss difference, the greater the increase in the polishing pressure of the polishing wheel 61; the gloss difference is the difference between the first preset gloss and the gloss.

[0101] Specifically, the control module determines the adjustment strategy under the condition that the polishing of the workpiece does not meet the preset standard according to the grayscale feature value, wherein:

[0102] If the grayscale characteristic value is less than the preset grayscale threshold value of 0.45, the polishing time is increased according to the difference between the preset grayscale threshold value and the grayscale characteristic value;

[0103] If the grayscale characteristic value is greater than or equal to the preset grayscale threshold, the polishing pressure is increased according to the difference between the grayscale characteristic value and the preset grayscale threshold;

[0104] The grayscale characteristic value is the ratio between the number of sub-areas whose grayscale mean is less than or equal to the preset grayscale mean 135 and the total number of sub-areas.

[0105] The increase in the polishing time of the polishing wheel 61 is positively correlated with the difference between the preset grayscale threshold and the grayscale characteristic value, wherein the positive correlation is, for example, a linear positive correlation or a nonlinear positive correlation, and the linear slope of the linear positive correlation is not specifically limited. It can be understood that the greater the difference between the preset grayscale threshold and the grayscale characteristic value, the greater the increase in the polishing pressure of the polishing wheel 61.

[0106] The increase in the grinding pressure of the grinding wheel 51 is positively correlated with the difference between the grayscale characteristic value and the preset grayscale threshold, wherein the positive correlation is, for example, a linear positive correlation or a nonlinear positive correlation, and the linear slope of the linear positive correlation is not specifically limited. It can be understood that the greater the difference between the grayscale characteristic value and the preset grayscale threshold, the greater the increase in the grinding pressure of the grinding wheel 51.

[0107] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

[0108] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A robot polishing and grinding transfer system based on machine vision, characterized in that: include: The machine frame includes a horizontal moving unit, a vertical moving unit, a transfer robot unit, a polishing unit, a grinding unit, a data acquisition module and a control module, wherein: The transverse moving unit is arranged on one side of the top of the frame, and is used to drive the longitudinal moving unit to move transversely; A longitudinal moving unit, connected to the transverse moving unit, for driving the transfer robot unit to move longitudinally and for fixing the visual sensor; A transfer robot unit, which is connected to the longitudinal moving unit and is used for transfer and transportation of workpieces; The polishing unit and the grinding unit are symmetrically arranged on both sides of the frame, wherein the grinding unit is provided with a grinding wheel, and the polishing unit is provided with a polishing wheel; A data acquisition module is connected to the visual sensor and is used to divide the workpiece surface image obtained by the visual sensor into several sub-areas, and obtain the texture information of each sub-area and the curvature value of the surface of each sub-area. The texture information includes texture direction, texture quantity, gray value and height value of surface contour; A control module is respectively connected to the data acquisition module, the lateral moving unit, the longitudinal moving unit, the transfer robot unit, the polishing unit and the grinding unit, and is used to determine whether the grinding of the workpiece does not meet the preset standard according to the texture direction characterization value obtained by the data texture direction and the texture quantity, and to make a secondary judgment according to the surface curvature change value obtained according to the curvature value, or to determine the reason why the grinding of the workpiece does not meet the preset standard according to the surface peak-valley value obtained by the height value, and to determine to increase the polishing time or increase the grinding pressure according to the grayscale characteristic value under the condition that the polishing of the workpiece does not meet the preset standard according to the glossiness of the workpiece.

2. The machine vision-based robot polishing and grinding transfer system according to claim 1 is characterized in that: The lateral moving unit comprises a first guide rail, a moving block sleeved on the first guide rail, and a mounting plate vertically arranged on the side of the moving block, and guide constraint grooves are evenly arranged on both sides of the edge of the mounting plate.

3. The machine vision-based robot polishing and grinding transfer system according to claim 2 is characterized in that: The longitudinal moving unit is slidably connected to the mounting plate through a guide constraint groove, and the longitudinal moving unit includes a second guide rail, a mounting seat, a hollow rotating table, a visual sensor, a connecting arm, a rotating shaft, and a mounting frame, wherein a side of the second guide rail away from the guide constraint groove is connected to the mounting seat, a hollow rotating table is arranged above the mounting seat, a visual sensor is installed in the hollow rotating table, one end of the connecting arm is connected to the side wall of the hollow rotating table, and the other end of the connecting arm is connected to the rotating shaft, and a mounting frame is arranged above the rotating shaft, and the longitudinal moving direction of the second guide rail and the lateral moving direction of the first guide rail are perpendicular to each other.

4. The machine vision-based robot polishing and grinding transfer system according to claim 3 is characterized in that: The transfer robot unit is connected to the mounting frame by bolts, and includes a first robot arm assembly, a second robot arm assembly, and a third robot arm assembly; The first mechanical arm assembly includes a first groove seat, a lead screw, a lead screw nut, a first motor for driving the lead screw, a guide sliding groove, a guide rail, a connecting block, and a bearing seat, wherein the bearing seats are symmetrically installed at both ends of the bottom of the first groove, the two ends of the lead screw are respectively connected to the bearing seats, the lead screw drives the connecting block to move through the rotation of the lead screw nut, the guide rail is arranged at both ends of the bearing seat, and the guide sliding grooves are symmetrically arranged on both sides of the inner wall of the first groove seat; The second robotic arm assembly includes a synchronous belt, a second groove seat, a linear guide rail, and a limiting sliding groove, wherein the side wall of the second groove seat slides into the guide sliding groove, the bottom of the second groove seat is connected to the screw nut, the bottom of the second groove seat is symmetrically provided with linear guide rails, and a synchronous belt is provided between the linear guide rails.

5. The machine vision-based robot polishing and grinding transfer system according to claim 4 is characterized in that: The third robotic arm assembly includes a belt, a second motor for driving the belt to rotate, a one-way bearing, a transfer suction cup, a locking block, a driving block, and a third groove seat, wherein the locking block is arranged at the bottom of the third groove seat, the synchronous belt drives the third groove seat to move through the locking block, the driving block is symmetrically arranged at the bottom of the third groove seat, and a belt is arranged in the third groove seat, one end of the belt is connected to the second motor, and the other end of the belt is connected to the transfer suction cup through the one-way bearing.

6. The machine vision-based robot polishing and grinding transfer system according to claim 5 is characterized in that: The control module determines that the grinding of the workpiece does not meet the preset standard under the condition that the texture direction characterization value is less than the second preset texture direction characterization value, and determining the reason why the grinding of the workpiece does not meet the preset standard according to the surface peak-to-valley value under the condition that the texture direction characterization value is less than the first preset texture direction characterization value, and secondarily determining whether the grinding of the workpiece meets the preset standard according to the surface curvature change value under the condition that the texture direction characterization value is greater than or equal to the first preset texture direction characterization value and less than the second preset texture direction characterization value; The texture direction characterization value is determined by the texture direction and the texture quantity collected by the data collection module.

7. The machine vision-based robot polishing and grinding transfer system according to claim 6 is characterized in that: The control module determines, based on the surface peak-to-valley values, that the reason why the grinding of the workpiece does not meet the preset standard is that the grinding rate of the grinding wheel is too high and reduces the grinding rate of the grinding wheel, or the grinding wheel is worn and issues an early warning; The surface peak-to-valley value is determined by the vertical distance between the maximum contour peak and the maximum contour valley in the sub-area.

8. The machine vision-based robot polishing and grinding transfer system according to claim 6, characterized in that: The control module reduces the feed rate of the grinding wheel under the condition that the grinding of the workpiece does not meet the preset standard according to the comparison result that the surface curvature change value is greater than or equal to the preset surface curvature change value; The surface curvature change value is the maximum value of the surface curvature differences between adjacent sub-areas after grinding.

9. The machine vision-based robot polishing and grinding transfer system according to claim 8, characterized in that: The control module determines whether the polishing of the workpiece meets the preset standard according to the glossiness of the workpiece, wherein: If the glossiness is less than the first preset glossiness, it is determined that the polishing of the workpiece does not meet the preset standard, and the polishing pressure of the polishing wheel is increased according to the difference between the first preset glossiness and the glossiness; If the glossiness is greater than or equal to the first preset glossiness and less than the second preset glossiness, it is determined that the polishing of the workpiece does not meet the preset standard, and an adjustment strategy is determined under the condition that the polishing of the workpiece does not meet the preset standard according to the grayscale feature value; If the glossiness is greater than or equal to the second preset glossiness, it is determined that the polishing of the workpiece meets the preset standard; The glossiness is determined by the grayscale value of the surface of the sub-region.

10. The machine vision-based robot polishing and grinding transfer system according to claim 9, characterized in that: The control module determines, based on the grayscale characteristic value, an adjustment strategy under the condition that the polishing of the workpiece does not meet the preset standard, including: increasing the polishing time, or increasing the grinding pressure; The grayscale characteristic value is the ratio between the number of sub-areas whose grayscale mean is less than or equal to the preset grayscale mean and the total number of sub-areas.

Images