Automatic assembly detection system based on CCD industrial camera

Abstract

The application relates to the technical field of automatic assembly, in particular to an automatic assembly detection system based on a CCD industrial camera, which is used for accurately assembling a first to-be-assembled part and a second to-be-assembled part, and comprises a mechanical arm and a CCD camera capable of moving along with the mechanical arm, the first to-be-assembled part is arranged in a jig on a rotary assembly table, the second to-be-assembled part is picked up by the mechanical arm and moved above the first to-be-assembled part, and the second to-be-assembled part, the CCD camera and the first to-be-assembled part are sequentially arranged in a top-to-bottom direction; the CCD camera is transversely slidably connected with the mechanical arm through an elastic connecting mechanism; and a telescopic part can be one-stage telescopic and two-stage telescopic. The CCD camera is turned over, so that the CCD camera can take pictures of the first to-be-assembled part and the second to-be-assembled part, thereby avoiding shooting errors caused by different cameras and improving the assembly precision.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic assembly, in particular to an automatic assembly detection system based on a CCD industrial camera. BACKGROUND

[0002] In the field of automatic assembly, CCD industrial cameras have become the core equipment for realizing automatic and intelligent production due to their high-precision imaging, low noise and wide dynamic range. For example, the Chinese utility model patent with the publication number CN202752805U discloses a micro part precision assembly detection device based on double CCD industrial cameras, which comprises a rack, an assembly workbench arranged on the top of the rack, and a mechanical arm installed on the assembly workbench. A positioning jig for positioning the workpiece to be assembled is arranged on the assembly workbench. At least one CCD industrial camera I is installed on the mechanical arm. At least one CCD industrial camera II is fixedly installed on the assembly workbench. A ring-shaped light source is fixedly installed at the front end of the lens of the CCD industrial camera I and the CCD industrial camera II. The CCD industrial camera I and the CCD industrial camera II are electrically connected with the mechanical arm controller.

[0003] The above technical solution has the characteristics of low cost, fast assembly speed and high assembly precision, but still has the following shortcomings in actual use:

[0004] The above technical solution adopts multiple CCD industrial cameras to respectively take samples of two different parts to be assembled, and then relies on corresponding algorithms to obtain the final movement data of the mechanical arm to realize the assembly of the two different parts to be assembled. Since there are slight differences in the picture accuracy of different CCD industrial cameras, or in other words, there are errors in the pictures taken by two CCD industrial cameras of the same type, the features extracted from the pictures will be biased, and finally the actual assembly precision will be adversely affected. SUMMARY

[0005] The present application aims to provide an automatic assembly detection system based on a CCD industrial camera to solve the problems raised in the background.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solution: an automatic assembly detection system based on a CCD industrial camera for precise assembly of a first part to be assembled and a second part to be assembled, comprising a mechanical arm and a CCD camera capable of moving with the mechanical arm. The first part to be assembled is arranged in a jig on a rotating assembly table. The second part to be assembled is picked up by the mechanical arm and moved above the first part to be assembled. The second part to be assembled, the CCD camera and the first part to be assembled are arranged in the order of top to bottom.

[0007] The CCD camera is connected with the mechanical arm through an elastic connecting mechanism in a transverse sliding mode;

[0008] The telescopic component is capable of one-stage telescoping and two-stage telescoping, wherein the two-stage telescoping of the telescopic component is used to push the CCD camera to move along a direction defined by the elastic connecting mechanism, so that the CCD camera can be switched between a shooting state located directly below the mechanical arm and an idle state located at one side of the mechanical arm;

[0009] The one-stage telescoping of the telescopic component can cooperate with a transmission mechanism to make the CCD camera flip up and down; when the lens of the CCD camera is upward, it is used to shoot the assembly surface of the second assembly part; when the lens of the CCD camera is downward, it is used to shoot the assembly surface of the first assembly part.

[0010] Preferably, the transmission mechanism comprises a shell, a synchronous belt and a connecting shaft;

[0011] The end of the one-stage telescoping rod of the telescopic component is fixedly connected with a lead screw, the outer side of the lead screw is sleeved with a ball nut, and the ball nut is rotationally connected in the interior of the shell;

[0012] One end of the connecting shaft is connected with the CCD camera, and the other end is rotationally connected in the interior of the shell;

[0013] The synchronous belt is arranged in the interior of the shell and is drivingly connected between the ball nut and the connecting shaft.

[0014] Preferably, the lead screw is a hollow tubular structure, the two-stage rod of the telescopic component penetrates through the lead screw, and the free end of the two-stage rod is flush with the free end of the one-stage telescoping rod.

[0015] Preferably, the free end of the two-stage rod is fixedly connected with a gasket, the gasket is in a circular plate shape, and the diameter of the gasket is greater than the diameter of the two-stage rod.

[0016] Preferably, one side of the CCD camera is fixedly connected with a cylindrical seat, the interior of the cylindrical seat is fixedly provided with a limiting ring coaxially arranged therein, and a limiting groove is arranged on the inner ring surface of the limiting ring;

[0017] One end of the connecting shaft is coaxially rotationally connected in the interior of the cylindrical seat, and one end of the connecting shaft is fixedly connected with a limiting protrusion;

[0018] The limiting protrusion is arranged in the interior of the limiting groove;

[0019] The CCD camera is directed upward or downward through a positioning mechanism.

[0020] Preferably, the positioning mechanism comprises an iron block, a first electromagnet and a second electromagnet;

[0021] The iron block is fixedly connected with the CCD camera;

[0022] The first electromagnet and the second electromagnet are both fixedly connected on the shell;

[0023] When the iron block is magnetically connected with the first electromagnet, the lens of the CCD camera is directed upward; when the iron block is magnetically connected with the second electromagnet, the lens of the CCD camera is directed downward.

[0024] Preferably, the telescopic component is fixedly connected with the transmission mechanism through a mounting bracket.

[0025] Preferably, the elastic connecting mechanism comprises two guide rods, two guide sleeves penetrating through the mechanical arm and a spring sleeved on the guide rods;

[0026] The guide sleeves are slidingly connected with the guide rods, one end of the two guide rods is fixed with a same first connecting block, the other end of the two guide rods is fixed with a same second connecting block, and the second connecting block is fixedly connected with the shell;

[0027] One end of the spring is abutted with the first connecting block, and the other end of the spring is abutted with the mechanical arm.

[0028] Preferably, the elastic connecting mechanism further comprises a protective cover, and the spring and the first connecting block are both arranged inside the protective cover.

[0029] Compared with the prior art, the present application has the following advantages:

[0030] The present application can avoid the shooting error caused by different cameras and improve the assembly precision by turning over a CCD camera to take samples of the first and second parts to be assembled; meanwhile, the telescopic component and the transmission mechanism are ingeniously matched, so that the telescopic component can switch the CCD camera between the shooting state and the idle state, and also can turn over the CCD camera, thereby reducing the investment cost of the whole system; furthermore, the cooperation between the limiting protrusion and the limiting groove is utilized first to enable the CCD camera to freely rotate within a small angle range when the CCD camera is turned over to direct the lens upward or downward, and then the magnetic attraction force between the iron block and the first or second electromagnet is utilized to accurately position the CCD camera, thereby avoiding the deviation of the CCD camera position caused by the error of the transmission mechanism and other structures during operation, ensuring that the CCD camera can shoot the parts to be assembled at the predetermined position, improving the actual shooting precision, and further improving the assembly precision. BRIEF DESCRIPTION OF DRAWINGS

[0031] Figure 1 is a schematic diagram of the overall planar structure of the present application;

[0032] Figure 2 is a schematic diagram of the three-dimensional structure of the mechanical arm of the present application;

[0033] Figure 3 is a schematic diagram of the front view structure of the present application; Figure 2

[0034] Figure 4 is a schematic diagram of the cross-sectional three-dimensional structure of the protective cover of the present application;

[0035] Figure 5 is a schematic diagram of the rear cross-sectional structure of the housing of the present application;

[0036] Figure 6 is a schematic diagram of the structure of the lead screw of the present application;

[0037] Figure 7 is a schematic diagram of the cross-sectional structure of the cylindrical seat of the present application;

[0038] Figure 8 is a schematic diagram of the side view structure of the limiting ring of the present application;

[0039] Figure 9 is a schematic diagram of the partial structure of the present application.

[0040] In the drawings: 101, support table; 102, rotating assembly table; 103, jig; 1, mechanical arm; 2, CCD camera; 21, cylindrical seat; 22, limiting ring; 23, limiting groove; 24, iron block; 3, telescopic component; 31, mounting frame; 32, lead screw; 33, ball nut; 34, secondary lever; 35, gasket; 4, transmission mechanism; 41, housing; 42, synchronous belt; 43, connecting shaft; 431, limiting protrusion; 44, first electromagnet; 45, second electromagnet; 5, elastic connecting mechanism; 51, protective cover; 52, guide rod; 53, spring; 54, guide sleeve; 55, first connecting block; 56, second connecting block. DETAILED DESCRIPTION

[0041] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0042] Please refer to Figures 1-9 , the present application provides a technical solution: ​

[0043] The application discloses an automatic assembly detection system based on a CCD industrial camera, which is used for precisely assembling a first part to be assembled and a second part to be assembled, wherein the first part to be assembled can be a single part or a combination of multiple parts assembled together, and the second part to be assembled is generally a single part.

[0044] The automatic assembly detection system comprises a mechanical arm 1 and a CCD camera 2 capable of moving together with the mechanical arm 1, wherein the CCD camera 2 is used for photographing and extracting features of the parts to be assembled; the first part to be assembled is arranged in a jig 103 on a rotating assembly table 102, the rotating assembly table 102 is rotatably arranged on the top of a support table 101, and the height of the rotating assembly table 102 is higher than the height of the support table 101; the second part to be assembled is picked up by the mechanical arm 1 and moved above the first part to be assembled, so that the second part to be assembled, the CCD camera 2 and the first part to be assembled are sequentially arranged in a top-down direction.

[0045] The basic working process of the above technical scheme is as follows: first, the first part to be assembled is placed into the jig 103, then the second part to be assembled is picked up by the mechanical arm 1 and moved above the first part to be assembled; then the CCD camera 2 is used for photographing and extracting the required assembly features of the first part to be assembled and the second part to be assembled, after that, the CCD camera 2 is moved away, and the positions of the first part to be assembled and the second part to be assembled are calculated and compared by using the algorithm inside the CCD camera 2, so as to obtain the deviation between the position of the second part to be assembled and the position of the first part to be assembled, then the mechanical arm 1 is controlled to move slightly according to the above deviation, so as to finely adjust the position of the second part to be assembled, and the first part to be assembled and the second part to be assembled can be precisely assembled.

[0046] The CCD camera 2 is transversely slidably connected with the mechanical arm 1 through an elastic connecting mechanism 5; the CCD camera 2 can be moved away from the position directly below the second part to be assembled, so as to prevent the CCD camera 2 from blocking the assembly of the first part to be assembled and the second part to be assembled; and since there is a height difference between the rotating assembly table 102 and the support table 101, the height difference can prevent the second part to be assembled from failing to be attached to the first part to be assembled when the mechanical arm 1 drives the second part to be assembled to move downwards to be close to the first part to be assembled after the CCD camera 2 is moved away from the first part to be assembled and the second part to be assembled.

[0047] The telescopic component 3 can be one of a two-stage telescopic electric cylinder and a two-stage telescopic oil cylinder, and the specific type is not limited; the telescopic component 3 is fixedly connected with the transmission mechanism 4 through the mounting frame 31; the working process of the telescopic component 3 is as follows: after the primary rod of the telescopic component 3 is extended to the maximum stroke, the secondary rod 34 is extended; wherein the two-stage telescoping of the telescopic component 3 is used to push the CCD camera 2 to move laterally along the direction defined by the elastic connecting mechanism 5, so that the CCD camera 2 can be switched between the shooting state located directly below the mechanical arm 1 and the idle state located at one side of the mechanical arm 1.

[0048] The primary telescoping of the telescopic component 3 can cooperate with the transmission mechanism 4 to flip the CCD camera 2 up and down, and this function is mainly used when the CCD camera 2 is in the shooting state; specifically, when the lens of the CCD camera 2 is upward, it is used to shoot the assembly surface of the second assembly part; when the lens of the CCD camera 2 is downward, it is used to shoot the assembly surface of the first assembly part.

[0049] The elastic connecting mechanism 5 includes two guide rods 52, two guide sleeves 54 penetrating the mechanical arm 1, and a spring 53 sleeved on the guide rod 52; the guide sleeve 54 is in sliding connection with the guide rod 52, and the end of the guide sleeve 54 close to the transmission mechanism 4 protrudes from the side surface of the mechanical arm 1; one end of the two guide rods 52 is fixed with a same first connecting block 55, and the other end of the two guide rods 52 is fixed with a same second connecting block 56, and the second connecting block 56 is fixedly connected with the shell 41; one end of the spring 53 abuts against the first connecting block 55, and the other end of the spring 53 abuts against the mechanical arm 1; the elastic connecting mechanism 5 further includes a protective cover 51, and the spring 53 and the first connecting block 55 are arranged in the interior of the protective cover 51; the protective cover 51 is used to protect the guide rod 52, the spring 53 and other structures, and prolong the service life thereof.

[0050] The basic working principle of the above technical solution is as follows: after the mechanical arm 1 moves the second assembly part and the CCD camera 2 above the first assembly part, the states of the mechanical arm 1 and the CCD camera 2 are as shown in FIG. 2, and the CCD camera 2 is in the idle state. Figures 2-5As shown, at this time, the CCD camera 2 is located directly below the second to-be-assembled part, the lens of the CCD camera 2 is upward, that is, the CCD camera 2 can be used to take a picture of the second to-be-assembled part, after the picture is taken, the telescopic component 3 is started to perform one-stage telescoping, driving the CCD camera 2 to flip 180°, so that the lens of the CCD camera 2 is downward, and then the first to-be-assembled part can be taken a picture; in this way, the position information of the first to-be-assembled part and the second to-be-assembled part can be obtained, then the CCD camera 2 extracts and analyzes the data of the taken picture, calculates the position deviation between the second to-be-assembled part and the first to-be-assembled part, and controls the mechanical arm 1 to move according to the deviation, so that the to-be-assembled surface of the second to-be-assembled part can be completely aligned with the to-be-assembled surface of the first to-be-assembled part in the vertical direction, and then the mechanical arm 1 is used to push the second to-be-assembled part to move to the first to-be-assembled part, until the two are assembled.

[0051] The transmission mechanism 4 comprises a housing 41, a synchronous belt 42 and a connecting shaft 43; further, the end of the one-stage telescoping rod of the telescopic component 3 is fixedly connected with a lead screw 32, the outer side of the lead screw 32 is sleeved with a ball nut 33, and the ball nut 33 is rotationally connected in the inside of the housing 41; the ball nut 33 and the connecting shaft 43 are respectively located at the upper and lower ends in the inside of the housing 41; one end of the connecting shaft 43 is connected with the CCD camera 2, and the other end is rotationally connected in the inside of the housing 41; the synchronous belt 42 is arranged in the inside of the housing 41 and is drivingly connected between the ball nut 33 and the connecting shaft 43. The lead screw 32 is a hollow tubular structure, the two-stage rod 34 of the telescopic component 3 penetrates through the lead screw 32, and the free end of the two-stage rod 34 is flush with the free end of the one-stage telescoping rod. The free end of the two-stage rod 34 is fixedly connected with a gasket 35, and the gasket 35 is a circular plate, and its diameter is larger than the diameter of the two-stage rod 34.

[0052] In actual use, the one-stage telescoping rod of the telescopic component 3 is extended to drive the lead screw 32 to move linearly, so that the ball nut 33 converts the linear motion of the lead screw 32 into rotary motion and transmits it to the connecting shaft 43 through the synchronous belt 42, driving the connecting shaft 43 and the CCD camera 2 connected thereto to rotate together, thereby realizing the flipping function of the CCD camera 2; when the CCD camera 2 rotates 180°, the gasket 35 abuts against the mechanical arm 1; at this time, the one-stage telescoping rod is fully extended, and then the two-stage rod 34 of the telescopic component 3 is extended, thereby driving the telescopic component 3 and the transmission mechanism 4 to gradually move away from the mechanical arm 1, so that the CCD camera 2 is switched from the shooting state to the idle state, facilitating the precise assembly of the first to-be-assembled part and the second to-be-assembled part; the whole process can be completed by only one CCD camera 2 and one telescopic component 3, the structure design is ingenious and reasonable, and the cost is saved, and at the same time, the shooting of two to-be-assembled parts by one CCD camera 2 can avoid the shooting error caused by different cameras, improving the assembly precision.

[0053] One side of the CCD camera 2 is fixedly connected with a cylindrical seat 21, the inside of the cylindrical seat 21 is fixedly connected with a limiting ring 22 coaxially arranged therein, a limiting groove 23 is formed on the inner ring surface of the limiting ring 22; one end of a connecting shaft 43 is coaxially rotatably connected to the inside of the cylindrical seat 21, and one end of the connecting shaft 43 is fixedly connected with a limiting protrusion 431; the limiting protrusion 431 is arranged in the inside of the limiting groove 23 and can move within the range defined by the limiting groove 23; the CCD camera 2 is made to have the lens face upward or downward by the positioning mechanism.

[0054] The positioning mechanism comprises an iron block 24, a first electromagnet 44 and a second electromagnet 45; the iron block 24 is fixedly connected with the CCD camera 2; the first electromagnet 44 and the second electromagnet 45 are both fixedly connected to the shell 41; when the iron block 24 is magnetically connected with the first electromagnet 44, the lens of the CCD camera 2 faces upward; when the iron block 24 is magnetically connected with the second electromagnet 45, the lens of the CCD camera 2 faces downward.

[0055] In the above technical solution, first, the cooperation between the limiting protrusion 431 and the limiting groove 23 is utilized to make the CCD camera 2 still freely rotate within a small angle range when the CCD camera 2 is flipped to have the lens face upward or downward, and then the magnetic attraction force between the iron block 24 and the first electromagnet 44 or the second electromagnet 45 is utilized to realize the accurate positioning of the CCD camera 2; specifically, when the lens of the CCD camera 2 faces upward, the first electromagnet 44 is connected with the power supply, at this time, the first electromagnet 44 will firmly attract the iron block 24, ensuring that the lens of the CCD camera 2 faces upward at this time; conversely, when the lens of the CCD camera 2 faces upward, the second electromagnet 45 is connected with the power supply, at this time, the second electromagnet 45 will firmly attract the iron block 24, ensuring that the lens of the CCD camera 2 faces downward at this time; the advantage of such arrangement is that it can avoid the deviation of the position of the CCD camera 2 caused by the error of the transmission mechanism 4 and other structures during operation, ensuring that the CCD camera 2 can take pictures of the part to be assembled at the predetermined position, and improving the actual shooting accuracy.

[0056] Although the embodiments of the present application have been shown and described, it is to be understood that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present application, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automated assembly and inspection system based on a CCD industrial camera, used to accurately assemble a first part to be assembled and a second part to be assembled, characterized in that, The assembly includes a robotic arm and a CCD camera that can move with the robotic arm. The first part to be assembled is placed in a fixture on a rotating assembly table. The second part to be assembled is picked up by the robotic arm and moved above the first part to be assembled, so that the second part to be assembled, the CCD camera and the first part to be assembled are arranged in a top-to-bottom direction. The CCD camera is laterally slidably connected to the robotic arm via an elastic connection mechanism; The telescopic component is capable of primary and secondary telescopic extension. The secondary telescopic extension of the telescopic component is used to push the CCD camera to move laterally along the direction defined by the elastic connection mechanism, so that the CCD camera can switch between a shooting state located directly below the robotic arm and an idle state located on one side directly below the robotic arm. The first-stage telescopic extension of the telescopic component can cooperate with the transmission mechanism to make the CCD camera flip up and down; when the lens of the CCD camera is facing upward, it is used to photograph the assembly surface of the second part to be assembled; when the lens of the CCD camera is facing downward, it is used to photograph the assembly surface of the first part to be assembled. The transmission mechanism includes a housing, a timing belt, and a connecting shaft; The end of the first-stage telescopic rod of the telescopic component is fixedly connected to a lead screw, and a ball nut is sleeved on the outside of the lead screw. The ball nut is rotatably connected inside the outer shell. One end of the connecting shaft is connected to the CCD camera, and the other end is rotatably connected to the inside of the housing; The timing belt is disposed inside the housing and is connected between the ball nut and the connecting shaft. The lead screw has a hollow tubular structure, and the secondary rod of the telescopic component passes through the lead screw, with the free end of the secondary rod flush with the free end of the primary telescopic rod. The elastic connection mechanism includes two guide rods, two guide sleeves passing through the robotic arm, and springs sleeved on the guide rods; The guide sleeve is slidably connected to the guide rod, one end of the two guide rods is fixed with the same first connecting block, and the other end of the two guide rods is fixed with the same second connecting block, which is fixedly connected to the outer shell; One end of the spring abuts against the first connecting block, and the other end abuts against the robotic arm.

2. The automatic assembly and inspection system based on a CCD industrial camera according to claim 1, characterized in that, A washer is fixedly connected to the free end of the secondary rod. The washer is circular and its diameter is larger than that of the secondary rod.

3. The automatic assembly and inspection system based on a CCD industrial camera according to claim 1, characterized in that, A cylindrical base is fixedly connected to one side of the CCD camera. A limiting ring is fixed inside the cylindrical base and is coaxially arranged with it. A limiting groove is formed on the inner ring surface of the limiting ring. One end of the connecting shaft is coaxially rotatably connected to the inside of the cylindrical seat, and a limit protrusion is fixedly connected to one end of the connecting shaft; The limiting protrusion is disposed inside the limiting groove; The CCD camera uses a positioning mechanism to orient the lens directly upwards or downwards.

4. The automatic assembly and inspection system based on a CCD industrial camera according to claim 3, characterized in that, The positioning mechanism includes an iron block, a first electromagnet, and a second electromagnet. The iron block is fixedly connected to the CCD camera; Both the first electromagnet and the second electromagnet are fixedly connected to the outer casing; When the iron block is magnetically connected to the first electromagnet, the lens of the CCD camera faces directly upward; when the iron block is magnetically connected to the second electromagnet, the lens of the CCD camera faces directly downward.

5. The automatic assembly and inspection system based on a CCD industrial camera according to claim 1, characterized in that, The telescopic component is fixedly connected to the transmission mechanism via a mounting bracket.

6. The automatic assembly and inspection system based on a CCD industrial camera according to claim 1, characterized in that, The elastic connection mechanism also includes a protective cover, and the spring and the first connecting block are both disposed inside the protective cover.

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