Flexible feeding method and system

Abstract

The invention discloses a flexible feeding method and system, the feeding system comprises a vibration disc, a visual mechanism and a manipulator, and the vibration disc adjusts the posture of a product through vibration; the visual mechanism is arranged on the upper side of the vibration disc in a lifting mode and used for obtaining pictures of products in the vibration disc and extracting position information of the products; the mechanical arm is arranged on the side face of the vibration disc, receives the position information, extracted by the visual mechanism, of the products and picks up the products meeting the requirements from the vibration disc to the designated position. Wherein the position information of the product comprises horizontal coordinates, angle information and height information. By arranging the liftable visual mechanism, the product images of different heights can be obtained, whether the products are stacked or not can be judged according to the focusing values of the products, the mechanical arm can adjust the picking height according to whether the products are stacked or not, and the products are prevented from being crushed or scratched.

Description

Technical Field

[0001] The present invention relates to the technical field of flexible feeding, and in particular to a flexible feeding method and system. Background Art

[0002] Flexible feeding refers to a feeding method that uses a flexible feeding system to screen, position, and place products on a plate before providing them to assembly production. When feeding, the product is first placed in a flexible vibration plate, and the product on the vibration plate is adjusted through different vibration modes. The product is identified and screened using a visual system, and finally the product is picked up by a robot and placed on a plate for the next assembly operation. Compared with conventional manual feeding methods, flexible feeding greatly improves production efficiency.

[0003] However, the existing manipulators pick up products at a fixed height. When sheet products are stacked in the vibration plate, the pressing height of the picking mechanism of the manipulator remains unchanged, which can easily cause scratches or crushing of the products and also affect the service life of the picking mechanism and the vibration plate.

[0004] Based on the above technical problems, the present application proposes a flexible feeding method and system. Summary of the invention

[0005] The purpose of the present invention is to provide a flexible feeding method and system to solve the technical problems mentioned in the background technology. The purpose of the present invention is achieved through the following technical solutions: A flexible feeding method comprises the following steps: Step S1, using a vibration plate to adjust the posture of the product; Step S2, moving the visual mechanism to a first height to obtain a first image of the product in the vibration plate; Step S3, extracting the location information of the product with the highest definition and meeting the requirements in the first image; Step S4, moving the visual mechanism upward to a second height to obtain a second image of the product in the vibration plate; Step S5, extracting the location information of the product with the highest definition and meeting the requirements in the second image; Step S6: Use a robot arm to sequentially pick up products that meet the requirements in the second image and the first image.

[0006] Furthermore, the first height and the second height are both the distances between the visual mechanism and the surface of the vibration disk, the first height is the sum of the minimum working distance of the visual mechanism and the thickness of a single product, and the second height is the sum of the first height and the thickness of a single product.

[0007] Furthermore, the method for obtaining the position with the highest definition in the first image and the second image is: Step S11, using a focus evaluation algorithm to evaluate the focus values ​​of pixels in the first image and the second image; Step S12, traverse all pixel points to obtain the position with the highest focus value in the first image and the second image.

[0008] Furthermore, the focus evaluation algorithm includes an evaluation algorithm based on a gradient edge, a discrete cosine transform algorithm, a Fourier transform algorithm or an information entropy algorithm.

[0009] A flexible feeding system includes a vibration plate, a visual mechanism and a manipulator, wherein the vibration plate adjusts the posture of a product by vibration; the visual mechanism is arranged on the upper side of the vibration plate in a liftable manner, and the visual mechanism is used to obtain a picture of the product in the vibration plate and extract the position information of the product; the manipulator is arranged on the side of the vibration plate, and the manipulator receives the position information of the product extracted by the visual mechanism, and picks up the product that meets the requirements from the vibration plate to the designated position; wherein the position information of the product includes horizontal coordinates, angle information and height information.

[0010] Furthermore, the vibration tray includes a vibration table and a material tray. The material tray is made of a transparent material, and a backlight panel is provided at the bottom of the material tray.

[0011] Furthermore, the visual mechanism includes a column, a linear screw module, a camera and a light source, the column is installed on one side of the vibration plate, the linear screw module is vertically installed on the side of the column, a lifting seat is installed on the linear screw module, a camera bracket is installed on the lifting seat, the free end of the camera bracket extends to the upper side of the vibration plate, the camera is fixed at the free end of the camera bracket, and the camera lens is vertically downward; the light source is a ring-shaped light source, and the light source is fixed on the lower side of the camera.

[0012] Furthermore, the manipulator includes a base, a main swing arm, a secondary swing arm, a guide column and a material picking head. The base is installed on one side of the vibration plate, one end of the main swing arm is pivoted to the top of the base, one end of the secondary swing arm is pivoted to the end of the main swing arm away from the base, the guide column is vertically installed at the end of the secondary swing arm away from the main swing arm, and the material picking head is installed at the lower end of the guide column through an angle adjustment mechanism.

[0013] Furthermore, the material taking head is a suction nozzle or a clamping claw.

[0014] Furthermore, a feeding mechanism is installed on one side of the vibration plate. The feeding mechanism includes a base, a hopper and a vibrator. The hopper is installed on the base through the vibrator. An opening is opened at one end of the hopper, and the opening extends to the upper side of the vibration plate.

[0015] The technical solution provided in the embodiments of the present application has at least the following technical effects or advantages: 1. By setting up a liftable visual mechanism, it is possible to obtain product images at different heights, and then determine whether the products are stacked according to the focus value of the products, so that the robot can adjust the picking height according to whether the products are stacked, avoiding crushing or scratching the products; 2. By adjusting the picking height of the manipulator, the impact of the picking head on the vibration plate can be reduced, extending the service life of the picking head and the vibration plate; 3. By identifying the product pile, the number of times the vibration plate adjusts the product posture can be reduced, thereby improving the feeding efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings in the specification, which constitute a part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention.

[0017] Figure 1 This is a schematic diagram of the structure of the feeding system of the embodiment of the present application; Figure 2 This is a schematic diagram of the structure of the vibration plate of the embodiment of the present application; Figure 3 This is a schematic diagram of the structure of the feeding mechanism of the embodiment of the present application; Figure 4 This is a schematic diagram of the visual mechanism structure of an embodiment of the present application; Figure 5 This is a schematic diagram of the structure of the robot according to an embodiment of the present application.

[0018] Markings in the attached figure: 1. Vibrating plate; 11. Vibrating table; 12. Material tray; 2. Feeding mechanism; 21. Base; 22. Vibrator; 23. Hopper; 231. Opening; 3. Visual mechanism; 31. Column; 32. Linear screw module; 33. Camera; 34. Light source; 35. Lifting seat; 36. Camera bracket; 37. Reinforcement block; 4. Manipulator; 41. Base; 42. Main swing arm; 43. Auxiliary swing arm; 44. Guide column; 45. Angle adjustment mechanism; 46. Material picking head. DETAILED DESCRIPTION

[0019] In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the drawings and specific implementation methods of the specification. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1 like Figure 1-5 A flexible feeding system shown includes a vibration plate 1, a feeding mechanism 2, a visual mechanism 3 and a manipulator 4. The vibration plate 1 adjusts the posture of the product by vibration. The feeding mechanism 2 is installed on one side of the vibration plate 1, and is used to intermittently convey the product into the vibration plate 1. The visual mechanism 3 can be installed on the upper side of the vibration plate 1 in a liftable manner. The visual mechanism 3 is used to obtain the image of the product in the vibration plate 1 and extract the position information of the product; the manipulator 4 is set on the side of the vibration plate 1, and the manipulator 4 receives the position information of the product extracted by the visual mechanism 3, and picks up the product that meets the requirements from the vibration plate 1 to the specified position; wherein the position information of the product includes horizontal coordinates, angle information and height information.

[0021] like Figure 2 As shown, the vibration plate 1 includes a vibration table 11 and a material tray 12. The four corners of the material tray 12 are connected to the vibration table 11 through four voice coil motors. By controlling the different vibration frequencies and vibration phases of the four voice coil motors, the dispersion, aggregation, and flipping of the product in the material tray 12 are realized. Among them, the material tray 12 is made of transparent plastic material, and a backlight panel is installed at the bottom of the material tray 12. The plastic material of the material tray 12 can reduce the impact and friction between the material tray 12 and the product, thereby reducing scratches and scratches on the product. The backlight panel at the bottom of the material tray 12 can improve the recognition of the edge of the product and facilitate the recognition of the visual mechanism 3.

[0022] like Figure 1 , Figure 3 As shown, the feeding mechanism 2 includes a base 21, a vibrator 22 and a hopper 23. The hopper 23 is mounted on the base 21 through the vibrator 22. An opening 231 is provided at one end of the hopper 23, and the opening 231 extends to the upper side of the vibrating plate 1 and the material tray 12. The opening 231 of the hopper 23 is slightly inclined downward. When the vibrator 22 vibrates, the product in the hopper 23 slides down along the bottom to the material tray 12; when the vibrator 22 stops working, the product stays still in the hopper 23 due to friction.

[0023] like Figure 1 , Figure 4As shown, the visual mechanism 3 includes a column 31, a linear screw module 32, a camera 33 and a light source 34. The column 31 is vertically mounted on one side of the vibration plate 1, and a reinforcement block 37 is installed at the bottom of the column 31 to improve the stability of the column 31. The linear screw module 32 is vertically mounted on the side of the column 31 close to the vibration plate 1. A lifting seat 35 is installed on the slider of the linear screw module 32, and a camera bracket 36 is horizontally installed on the lifting seat 35. The free end of the camera bracket 36 extends to the upper side of the center of the vibration plate 1. The camera 33 is fixed at the free end of the camera bracket 36. The lens of the camera 33 is vertically downward, which is used to obtain the image of the product in the vibration plate 1. The light source 34 is a ring light source, which is fixed to the lower side of the camera 33 through a light source bracket (not shown), and the light source 34 is used to illuminate the product from top to bottom. The linear screw module 32 is driven by a servo motor, so that the vertical height of the camera 33 can be precisely adjusted.

[0024] like Figure 1 , Figure 5 As shown, the manipulator 4 includes a base 41, a main swing arm 42, a secondary swing arm 43, a guide column 44, an angle adjustment mechanism 45 and a material taking head 46. The base 41 is installed on one side of the vibration plate 1. One end of the main swing arm 42 is pivoted to the top of the base 41. A first driving member (not shown) is installed in the base 41. The first driving member drives the main swing arm 42 to rotate around the base 41. One end of the secondary swing arm 43 is pivoted to the end of the main swing arm 42 away from the base 41. A second driving member (not shown) is installed in the main swing arm 42. The second driving member drives the secondary swing arm 43 to rotate. The guide column 44 is vertically installed at the end of the secondary swing arm 43 away from the main swing arm 42. A third driving member (not shown) is installed in the secondary swing arm 43. The third driving member drives the guide column 44 to reciprocate up and down. The material taking head 46 is installed at the lower end of the guide column 44 through the angle adjustment mechanism 45, and the angle adjustment mechanism 45 can rotate the material taking head 46, so as to adjust the angle picked up by the material taking head 46 according to the angle information of the product. Among them, the material taking head 46 is a suction nozzle or a clamping claw.

[0025] When in use, the position of the material taking head 46 is adjusted by the swing angle of the main swing arm 42 and the auxiliary swing arm 43; the height of the material taking head 46 is adjusted by the lifting and lowering of the guide rod 44; and the material taking angle of the material taking head 46 is adjusted by the angle adjustment mechanism 45. The specific structure and principle of the manipulator 4 are all existing technologies and will not be described here.

[0026] Example 2 A flexible feeding method using the above-mentioned flexible feeding system comprises the following steps: Step S1, using a vibration plate to adjust the posture of the product.

[0027] Through the different vibration modes of the vibration plate, the product in the vibration plate can be dispersed as much as possible.

[0028] Step S2, moving the visual mechanism to a first height to obtain a first image of the product in the vibration plate.

[0029] The first height refers to the distance between the camera lens of the visual mechanism and the surface of the vibration plate. The first height is the sum of the minimum working distance of the visual mechanism and the thickness of a single product. The minimum working distance is the minimum distance at which the camera lens can focus clearly. When the camera is at the first height, the image clarity of a single-layer product in the camera is the highest.

[0030] Step S3: extracting the location information of the product with the highest definition and meeting the requirements in the first image.

[0031] The method for obtaining the position with the highest definition in the first image is as follows: Step S11, evaluating the focus value of the pixel point in the first image by using a focus evaluation algorithm; Step S12, traverse all pixel points to obtain the position with the highest focus value, the position with the highest focus value and the position with the highest clarity in the first image.

[0032] Among them, the focus evaluation algorithm selects one of the evaluation algorithms based on gradient edge, discrete cosine transform, Fourier transform or information entropy. Discrete cosine transform algorithm and Fourier transform algorithm belong to frequency domain evaluation algorithm, which transforms the image from spatial domain to frequency domain, and then calculates the transformed two-dimensional coefficients to obtain the clarity evaluation function of the image after frequency domain transformation. This type of method has high sensitivity, can still obtain excellent evaluation results in low-contrast images, and has strong robustness. Information entropy describes the richness of information. When the clarity of the image changes, the grayscale value and interval distribution of its pixels will also change accordingly. The information entropy in the focused and clear image is large, and the information entropy in the out-of-focus and blurred image is small. The above-mentioned focus evaluation algorithms are all existing technologies and will not be described here.

[0033] Step S4, move the visual mechanism upward by the thickness of one product to a second height, and obtain a second image of the products in the vibration plate. When the camera is at the second height, the image clarity of the stacked products on the upper layer in the camera is the highest.

[0034] Step S5: extracting the location information of the product with the highest definition and meeting the requirements in the second image.

[0035] The method for obtaining the position with the highest definition in the second image is the same as the method for obtaining the position with the highest definition in the first image, which will not be described in detail here. The position information in the first image and the second image includes horizontal coordinates, angle information and height information.

[0036] Step S6, using the robot to pick up the products that meet the requirements in the second image and the first image in sequence. When picking up the product in the second image, the pressing height of the robot's material head is higher than the height of the product in the first image by the thickness of one product. The products that meet the requirements are the products that meet the predetermined angle or sequence.

[0037] The technical solution provided in the embodiments of the present application has at least the following technical effects or advantages: 1. By setting up a liftable visual mechanism, it is possible to obtain product images at different heights, and then determine whether the products are stacked according to the focus value of the products, so that the robot can adjust the picking height according to whether the products are stacked, avoiding crushing or scratching the products; 2. By adjusting the picking height of the manipulator, the impact of the picking head on the vibration plate can be reduced, extending the service life of the picking head and the vibration plate; 3. By identifying the product pile, the number of times the vibration plate adjusts the product posture can be reduced, thereby improving the feeding efficiency.

[0038] 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 flexible feeding method, characterized in that: The following steps are involved: Step S1, using a vibration plate to adjust the posture of the product; Step S2, moving the visual mechanism to a first height to obtain a first image of the product in the vibration plate; Step S3, extracting the location information of the product with the highest definition and meeting the requirements in the first image; Step S4, moving the visual mechanism upward to a second height to obtain a second image of the product in the vibration plate; Step S5, extracting the location information of the product with the highest definition and meeting the requirements in the second image; Step S6: Use a robot arm to sequentially pick up products that meet the requirements in the second image and the first image.

2. A flexible feeding method according to claim 1, characterized in that: The first height and the second height are both the distances between the visual mechanism and the surface of the vibration disk. The first height is the sum of the minimum working distance of the visual mechanism and the thickness of a single product, and the second height is the sum of the first height and the thickness of a single product.

3. A flexible feeding method according to claim 1, characterized in that: The method for obtaining the position with the highest definition in the first image and the second image is as follows: Step S11, using a focus evaluation algorithm to evaluate the focus values ​​of pixels in the first image and the second image; Step S12, traverse all pixel points to obtain the position with the highest focus value in the first image and the second image.

4. A flexible feeding method according to claim 3, characterized in that: The focus evaluation algorithm includes an evaluation algorithm based on gradient edge, a discrete cosine transform algorithm, a Fourier transform algorithm or an information entropy algorithm.

5. A flexible feeding system based on any feeding method of claims 1-4, characterized in that: It includes a vibration plate, a visual mechanism and a manipulator, wherein the vibration plate adjusts the posture of the product by vibration; the visual mechanism is arranged on the upper side of the vibration plate in a liftable manner, and the visual mechanism is used to obtain the image of the product in the vibration plate and extract the position information of the product; the manipulator is arranged on the side of the vibration plate, and the manipulator receives the position information of the product extracted by the visual mechanism, and picks up the product that meets the requirements from the vibration plate to the designated position; wherein the position information of the product includes horizontal coordinates, angle information and height information.

6. A flexible feeding system according to claim 5, characterized in that: The vibration tray comprises a vibration table and a material tray. The material tray is made of a transparent material, and a backlight panel is arranged at the bottom of the material tray.

7. A flexible feeding system according to claim 5, characterized in that: The visual mechanism includes a column, a linear screw module, a camera and a light source, the column is installed on one side of the vibration plate, the linear screw module is vertically installed on the side of the column, a lifting seat is installed on the linear screw module, a camera bracket is installed on the lifting seat, the free end of the camera bracket extends to the upper side of the vibration plate, the camera is fixed at the free end of the camera bracket, and the lens of the camera is vertically downward; the light source is a ring light source, and the light source is fixed on the lower side of the camera.

8. A flexible feeding system according to claim 5, characterized in that: The manipulator includes a base, a main swing arm, an auxiliary swing arm, a guide column and a material picking head. The base is installed on one side of the vibration plate, one end of the main swing arm is pivoted to the top of the base, one end of the auxiliary swing arm is pivoted to the end of the main swing arm away from the base, the guide column is vertically installed at the end of the auxiliary swing arm away from the main swing arm, and the material picking head is installed at the lower end of the guide column through an angle adjustment mechanism.

9. A flexible feeding system according to claim 8, characterized in that: The material taking head is a suction nozzle or a clamping claw.

10. A flexible feeding system according to claim 5, characterized in that: A feeding mechanism is also installed on one side of the vibration plate. The feeding mechanism includes a base, a hopper and a vibrator. The hopper is installed on the base through the vibrator. An opening is opened at one end of the hopper, and the opening extends to the upper side of the vibration plate.

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