Cloth paving and cutting device and control method thereof

Abstract

The present application relates to a cloth cutting device and a control method thereof. The cloth cutting device comprises a workbench, a cloth conveying mechanism for conveying cloth onto the workbench, and a cutting mechanism for cutting the cloth on the workbench; an image acquisition module for acquiring cloth images at a predetermined frequency during the process of conveying the cloth onto the workbench; a controller for obtaining a cloth conveying speed according to the cloth images, obtaining a cloth inertial movement length according to a mapping relationship between a predetermined cloth type, the cloth conveying speed and the cloth inertial movement length, determining a cloth conveying stop time according to a difference between a predetermined cloth cutting length and the cloth inertial movement length and the cloth conveying speed, and determining a cloth movement stop time according to the cloth images. The present application aims to solve the problem that the existing cloth cutting device cannot obtain an accurate cloth length according to actual needs due to the influence of inertia.

Description

Technical Field

[0001] This invention belongs to the field of garment manufacturing technology, and more specifically, relates to a fabric laying and cutting device and its control method. Background Technology

[0002] Fabric cutting devices are used in garment manufacturing to cut fabric. Fabric is laid out onto a worktable from a feeding device and then cut to the required length. Modern fabric cutting devices have automated length monitoring. The required length value is set in the device's control system, the feeding device starts feeding the fabric, and when the fabric reaches the specified length, the feeding stops, completing the cutting process.

[0003] However, the fabric length calculated in this way is not accurate enough. The control system calculates the feeding length based on the product of the fabric conveying speed and time. However, due to the inertia of the fabric, after the conveying device stops feeding, the fabric will still move forward a certain distance under the action of inertia, resulting in the actual length of the fabric being greater than the predetermined length. Summary of the Invention

[0004] The purpose of this invention is to solve the problem that existing fabric cutting devices cannot obtain the accurate fabric length according to actual needs due to the influence of inertia on the fabric.

[0005] To achieve the above objectives, the present invention provides a fabric laying and cutting device and its control method.

[0006] According to a first aspect of the present invention, a fabric laying and cutting apparatus is provided, comprising a worktable, a fabric conveying mechanism for conveying fabric to the worktable, and a cutting mechanism for cutting the fabric on the worktable;

[0007] The fabric laying and cutting device also includes:

[0008] The image acquisition module is used to acquire images of the fabric at a predetermined frequency during the process of the fabric being conveyed to the worktable;

[0009] The controller is configured to obtain the fabric conveying speed based on the fabric image, obtain the fabric inertial movement length based on a predetermined fabric type, the mapping relationship between the fabric conveying speed and the fabric inertial movement length, determine the fabric stop conveying time based on the difference between the predetermined fabric cutting length and the fabric inertial movement length and the fabric conveying speed, and determine the fabric stop movement time based on the fabric image.

[0010] Optionally, the cutting mechanism includes a first motor, a support arm, and a pressing rod. The first motor is connected to the pressing rod through the support arm. The pressing rod is located at one end of the worktable near the fabric conveying mechanism and is used to press the fabric on the worktable. A slide rail is formed on the pressing rod, and both ends of the slide rail extend beyond the side edge of the fabric. A slider is provided in the slide rail, and a cutting blade is provided at the bottom of the slider. The slider drives the cutting blade to slide along the slide rail and cut the fabric in the width direction.

[0011] Alternatively, the cutting blade extends downwards from the bottom of the pressure bar within the slide.

[0012] Optionally, the image acquisition module includes a camera, which is positioned at one end of the worktable near the fabric conveying mechanism.

[0013] According to a second aspect of the present invention, a control method for any of the above-described fabric laying and cutting devices is provided, applied to the controller;

[0014] Used to obtain the fabric conveying speed based on the fabric image;

[0015] The fabric inertial movement length is obtained based on the mapping relationship between the predetermined fabric type, fabric conveying speed and fabric inertial movement length.

[0016] The fabric stopping time is determined based on the difference between the predetermined fabric cutting length and the fabric inertial movement length, as well as the fabric conveying speed, and the fabric conveying mechanism is shut down at the fabric stopping time.

[0017] The moment when the fabric stops moving is determined based on the fabric image, and the cutting mechanism is started at the moment when the fabric stops moving.

[0018] Optionally, the process of obtaining the fabric conveying speed based on the fabric image includes:

[0019] Edge detection is performed on the fabric image acquired by the image acquisition module, and the results are subtracted to obtain the gradient difference;

[0020] Color difference calculation is performed on the fabric image acquired by the image acquisition module;

[0021] Perform an OR operation on the gradient difference and color difference;

[0022] The result of the OR operation is binarized and filtered to identify the target fabric in the fabric image;

[0023] For the target fabric, the fabric conveying speed is obtained based on the frame difference between the number of image frames entering the first preset position and the number of image frames entering the second preset position, the frame rate of the image acquisition module, and the distance between the first preset position and the second preset position.

[0024] Alternatively, the edge detection is implemented based on the following formula:

[0025] F x =F(x, y) - F(x+1, y+1);

[0026] F y =F(x+1, y) - F(x, y+1);

[0027] In the formula, F(x, y) is the pixel value at point (x, y), F x and F y The convolution operator is:

[0028]

[0029] Alternatively, the gradient difference is implemented based on the following formula:

[0030] Grad F(x，y) =|F x |+|F y |;

[0031] Select amplitude A, if Grad F(x，y) If the value is greater than A, then the point (x, y) is considered an edge point;

[0032] D Grad (x, y) = |Grad F(x，y) -Grad B(x，y) |

[0033] Alternatively, the color difference is implemented based on the following formula:

[0034] D t (x, y) = |F t (x, y)-R t (x, y)|;

[0035] Among them, F t (x, y) is the cloth image in frame t, B t (x, y) is the background image of the t-th frame.

[0036] Optionally, for the target fabric, the fabric conveying speed is obtained based on the frame difference between the number of image frames entering the first preset position and the number of image frames entering the second preset position, the frame rate of the image acquisition module, and the distance between the first preset position and the second preset position, using the following formula:

[0037]

[0038] Where l is the distance between the two first preset positions and the second preset position, N is the frame rate of the image acquisition module, Z1 is the number of image frames when the target fabric enters the first preset position, and Z2 is the number of image frames when the target fabric enters the second preset position.

[0039] The beneficial effects of this invention are as follows: the image acquisition module acquires a fabric image; the controller obtains the fabric conveying speed based on the fabric image, obtains the fabric inertial movement length based on the predetermined fabric type, the mapping relationship between the fabric conveying speed and the fabric inertial movement length, determines the fabric stopping time based on the difference between the predetermined fabric cutting length and the fabric inertial movement length and the fabric conveying speed, and determines the fabric stopping time based on the fabric image, thus obtaining an accurate fabric length.

[0040] The remaining beneficial effects of the present invention are described in the specific embodiments. Attached Figure Description

[0041] The present invention can be better understood by referring to the following description taken in conjunction with the accompanying drawings, in which the same or similar reference numerals are used throughout the drawings to denote the same or similar parts.

[0042] Figure 1 A schematic diagram of the fabric laying and cutting device according to an embodiment of the present invention is shown;

[0043] Figure 2 A schematic diagram of the fabric pressing rod according to an embodiment of the present invention is shown;

[0044] In the diagram: 1. Support; 2. Workbench; 3. Side block; 4. Fabric feeding roller; 5. Fabric pressing rod; 501. Slide rail; 502. Slider; 503. Cutting blade; 6. Support arm; 7. First motor; 8. Bracket; 9. Camera. Detailed Implementation

[0045] To enable those skilled in the art to more fully understand the technical solutions of the present invention, exemplary embodiments of the present invention will be described more comprehensively and in detail below with reference to the accompanying drawings. Obviously, the one or more embodiments of the present invention described below are merely one or more specific ways to implement the technical solutions of the present invention, and are not exhaustive. It should be understood that other ways belonging to a general inventive concept can be used to implement the technical solutions of the present invention, and should not be limited to the embodiments described exemplary. Based on one or more embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0046] Example: Figure 1 and Figure 2 As shown, this embodiment provides a fabric laying and cutting device, including a worktable, a fabric conveying mechanism for conveying fabric to the worktable, and a cutting mechanism for cutting the fabric on the worktable.

[0047] The fabric cutting device also includes:

[0048] An image acquisition module is used to acquire images of the fabric at a predetermined frequency during the process of the fabric being conveyed to the worktable.

[0049] The controller is used to obtain the fabric conveying speed based on the fabric image, obtain the fabric inertial movement length based on the predetermined fabric type, the mapping relationship between the fabric conveying speed and the fabric inertial movement length, determine the fabric stop conveying time based on the difference between the predetermined fabric cutting length and the fabric inertial movement length and the fabric conveying speed, and determine the fabric stop movement time based on the fabric image.

[0050] Furthermore, the cutting mechanism includes a first motor, a support arm, and a pressing rod. The first motor is connected to the pressing rod through the support arm. The pressing rod is located at one end of the worktable near the fabric conveying mechanism and is used to press the fabric on the worktable. A slide is formed on the pressing rod, and the beginning and end of the slide extend beyond the side edge of the fabric. A slider is provided in the slide, and a cutting blade is provided at the bottom of the slider. The slider drives the cutting blade to slide along the slide and cut the fabric in the width direction.

[0051] Furthermore, the image acquisition module includes a camera, which is positioned at one end of the worktable near the fabric conveying mechanism.

[0052] Specifically, the device has a support at the bottom that supports a worktable. Side blocks are located on both sides of one end of the worktable, with a fabric conveying roller and a fabric pressing rod positioned between the two side blocks. A bracket is located next to one of the side blocks, and a camera is mounted on top of the bracket. A second motor drives the fabric conveying roller to rotate, transporting the fabric to the worktable. The fabric pressing rod has a slide rail containing a slider. A cutting blade is located at the bottom of the slider. A first motor is connected to the fabric pressing rod via a support arm. The first motor drives the support arm to rotate, thus pressing the fabric pressing rod firmly onto the fabric. Once the pressing rod is firmly pressed onto the fabric, the slider slides along the slide rail, and the cutting blade cuts the fabric.

[0053] Furthermore, the cutting blade extends downwards from the bottom of the pressure bar within the slide.

[0054] Specifically, when the pressure bar presses the fabric down, the cutting blade contacts the fabric, and the slider slides from one end of the slide to the other, thus cutting the fabric.

[0055] Based on the above-mentioned fabric laying and cutting device, this embodiment provides a control method applied to a controller;

[0056] Used to determine the fabric conveying speed based on a fabric image;

[0057] The fabric inertial movement length is obtained based on the mapping relationship between the predetermined fabric type, fabric conveying speed and fabric inertial movement length.

[0058] The fabric stopping time is determined based on the difference between the predetermined fabric cutting length and the fabric inertial movement length, as well as the fabric conveying speed, and the fabric conveying mechanism is shut down at the time the fabric stops conveying.

[0059] The moment when the fabric stops moving is determined based on the fabric image, and the cutting mechanism is started at the moment when the fabric stops moving.

[0060] Furthermore, the method for obtaining the fabric conveying speed based on the fabric image includes:

[0061] Edge detection is performed on the fabric image acquired by the image acquisition module, and the results are subtracted to obtain the gradient difference;

[0062] Color difference calculation is performed on the fabric image acquired by the image acquisition module;

[0063] Perform an OR operation on the gradient difference and color difference;

[0064] The result of the OR operation is binarized and filtered to identify the target fabric in the fabric image;

[0065] For the target fabric, the fabric conveying speed is obtained based on the frame difference between the number of image frames entering the first preset position and the number of image frames entering the second preset position, the frame rate of the image acquisition module, and the distance between the first preset position and the second preset position.

[0066] Furthermore, edge detection is implemented based on the following formula:

[0067] F x =F(x, y) - F(x+1, y+1);

[0068] F y =F(x+1, y) - F(x, y+1);

[0069] In the formula, F(x, y) is the pixel value at point (x, y), F x and F y The convolution operator is:

[0070]

[0071] Furthermore, gradient differencing is implemented based on the following formula:

[0072] Grad F(x，y) =|F x |+|F y |;

[0073] Select amplitude A, if Grad F(x，y If (x, y) > A, then the point (x, y) is considered an edge point;

[0074] D Grad (x, y) = |Grad F(x，y) -Grad B(x，y) |

[0075] Furthermore, color difference is achieved based on the following formula:

[0076] D t (x, y) = |F t (x, y)-b t (x, y)|;

[0077] Among them, F t (x, y) is the cloth image in frame t, B t (x, y) is the background image of the t-th frame.

[0078] Furthermore, for the target fabric, the fabric conveying speed is obtained based on the frame difference between the number of image frames entering the first preset position and the number of image frames entering the second preset position, the frame rate of the image acquisition module, and the distance between the first preset position and the second preset position, using the following formula:

[0079]

[0080] Where l is the distance between the two first preset positions and the second preset position, N is the frame rate of the image acquisition module, Z1 is the number of image frames when the target fabric enters the first preset position, and Z2 is the number of image frames when the target fabric enters the second preset position.

[0081] Specifically, the principle of this invention is as follows:

[0082] An image acquisition module is set up to acquire fabric images. The controller processes each frame of the fabric image to obtain the fabric conveying speed. The conveying time is obtained based on the distance between the first and second preset positions, the difference in the number of frames of the fabric images at the two preset positions, and the frame rate of the image acquisition module. The fabric length at the corresponding moment is obtained by combining the conveying time and the conveying speed. The inertial movement length of the fabric is determined based on the obtained fabric conveying speed and fabric type. Finally, the moment when the fabric stops conveying is determined.

[0083] While one or more embodiments of the present invention have been described above, those skilled in the art will recognize that the present invention can be implemented in any other form without departing from its spirit and scope. Therefore, the embodiments described above are illustrative and not restrictive, and many modifications and substitutions will be apparent to those skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A control method for a fabric laying and cutting device, characterized in that, The fabric cutting device includes: Workbench; A fabric conveying mechanism for transporting fabric to the workbench; A cutting mechanism for cutting the fabric on the workbench; The image acquisition module is used to acquire images of the fabric at a predetermined frequency during the process of the fabric being conveyed to the worktable; The controller is used to obtain the fabric conveying speed based on the fabric image, obtain the fabric inertial movement length based on the predetermined fabric type, the mapping relationship between the fabric conveying speed and the fabric inertial movement length, determine the fabric stop conveying time based on the difference between the predetermined fabric cutting length and the fabric inertial movement length and the fabric conveying speed, and determine the fabric stop movement time based on the fabric image. The control method is applied to the controller and includes the following steps: The fabric conveying speed is obtained from the fabric image; The fabric inertial movement length is obtained based on the mapping relationship between the predetermined fabric type, fabric conveying speed and fabric inertial movement length. The fabric stopping time is determined based on the difference between the predetermined fabric cutting length and the fabric inertial movement length, as well as the fabric conveying speed, and the fabric conveying mechanism is shut down at the fabric stopping time. The moment when the fabric stops moving is determined based on the fabric image, and the cutting mechanism is started at the moment when the fabric stops moving.

2. The control method according to claim 1, characterized in that, The method for obtaining the fabric conveying speed based on the fabric image includes: Edge detection is performed on the fabric image acquired by the image acquisition module, and the results are subtracted to obtain the gradient difference; Color difference calculation is performed on the fabric image acquired by the image acquisition module; Perform an OR operation on the gradient difference and color difference; The result of the OR operation is binarized and filtered to identify the target fabric in the fabric image; For the target fabric, the fabric conveying speed is obtained based on the frame difference between the number of image frames entering the first preset position and the number of image frames entering the second preset position, the frame rate of the image acquisition module, and the distance between the first preset position and the second preset position.

3. The control method according to claim 2, characterized in that, The edge detection is achieved based on the following formula: ； ； In the formula, Let be the pixel value at point (x, y). and The convolution operator is: 。 4. The control method according to claim 3, characterized in that, The gradient difference is implemented based on the following formula: ； If amplitude A is selected, if If A >, then the point (x, y) is considered an edge point; 5. The control method according to claim 4, characterized in that, The color difference is achieved based on the following formula: ； in, Let t be the cloth image of the t-th frame. Let t be the background image of the t-th frame.

6. The control method according to claim 5, characterized in that, For the target fabric, the fabric conveying speed is obtained based on the frame difference between the number of image frames entering the first preset position and the number of image frames entering the second preset position, the frame rate of the image acquisition module, and the distance between the first preset position and the second preset position, using the following formula: ； Where l is the distance between the two first preset positions and the second preset position, N is the frame rate of the image acquisition module, Z1 is the number of image frames when the target fabric enters the first preset position, and Z2 is the number of image frames when the target fabric enters the second preset position.

Images