Tobacco foreign matter detection and removal time sequence synchronization method and removal control method

Abstract

The invention discloses a tobacco foreign matter detection and removal time sequence synchronization method and a removal control method, and the method comprises the steps: carrying out the real-time image collection of a conveyed material through a line scanning camera at a fixed line frequency and a fixed frame rate, and transmitting an image to an image processing unit for image detection processing after the image collection is completed; after image processing is completed, if sundries need to be removed, detection result data are sent to the time sequence and removal control unit, and then the corresponding removal electromagnetic valves are driven to act to remove foreign matter or unqualified materials in the materials. According to the invention, time sequence synchronous control among image acquisition, image processing and impurity removal is realized, all functional actions of the system in work are orderly carried out according to a fixed rhythm, the whole detection and removal system is not disordered in working time sequence and stable in operation, the accuracy of a target object needing to be removed in a material is improved, and the working efficiency is improved. And the rejection rate is improved through extension control of the rejection action.

Description

Technical Field

[0001] The present invention relates to a time-series synchronization method for detecting and removing tobacco foreign matter and a removal control method, and in particular to a time-series synchronization method and a removal control method for realizing image acquisition, processing and removal of tobacco foreign matter by using image detection and computer technology. Background Art

[0002] At present, automated control of production lines has been realized in the fields of tobacco and food processing. Computer vision is installed on the production line to monitor the raw materials or products on the production line in real time. Machine vision detection of foreign matter or unqualified materials mixed in the materials and their removal from the production line has been widely promoted in recent years. The method commonly used in the tobacco industry is to install a linear scan camera at the upper end of the material surface in the vertical direction of the conveyor line to collect real-time images of the materials. After the image is collected, the image is detected and processed. After the detection and processing, the results are sent to the multiple solenoid valves neatly arranged at the upper end of the material on the rear production line perpendicular to the conveyor line. When foreign matter is detected, the corresponding solenoid valve is opened to remove it.

[0003] As the requirements for production efficiency gradually increase, the requirements for the timeliness and accuracy of material detection and rejection also increase accordingly. Use a line scan camera to capture real-time images of the conveyed materials at a fixed line frequency and frame rate. After the image acquisition is completed, the image is sent to the image processing unit for image detection and processing. After the image processing is completed, if there are debris that need to be removed, the detection result data is sent to the timing and rejection control unit, and then the corresponding rejection solenoid valve is driven to operate to remove foreign matter or unqualified materials in the material. Since the above-mentioned work process is carried out on a running production line, the time for image acquisition, processing, and rejection is extremely short, and the action continuity and timeliness of the entire work process are extremely high. A method that can quickly and accurately synchronize the timing of image acquisition, processing, and rejection is required to ensure the orderly and stable operation of the entire detection and rejection process. Summary of the invention

[0004] The technical problem to be solved by the present invention is to improve the timeliness and accuracy of the detection and removal of debris and unqualified materials in tobacco processing, to ensure that the various execution actions of tobacco debris removal in the image acquisition, image processing, and debris removal workflow are carried out in an orderly manner, to achieve accurate removal of debris, and to stabilize the working state of the entire system.

[0005] The purpose of the present invention is achieved through the following technical solutions:

[0006] A timing synchronization method for detecting and rejecting foreign matter in tobacco and a rejection control party, the method uses a line scan camera to perform real-time image acquisition of the conveyed material at a fixed line frequency and frame rate, after the image acquisition is completed, the image is sent to an image processing unit for image detection and processing, after the image processing is completed, if there is any debris that needs to be rejected, the detection result data is sent to the timing and rejection control unit, and then the corresponding rejection solenoid valve is driven to operate to reject foreign matter or unqualified materials in the material.

[0007] Specifically, the timing synchronization method for detecting and removing tobacco foreign matter includes:

[0008] The conveying speed of the belt conveying the material is constant, and the line scan camera is set to continuously acquire images at a fixed line frequency and frame rate. The number of acquired lines and frame rate of each frame of the image are fixed, which ensures that the acquisition time of each frame of the image is fixed.

[0009] The time interval between each frame is t. The action rhythm of the three functions of image acquisition, processing and elimination is based on the image frame signal of the line scan camera.

[0010] The image acquisition unit starts to acquire images after receiving the frame signal of the 1-frame image, and the acquisition of the 1-frame image is completed after time t. After the image acquisition unit completes the acquisition of the 1-frame image, it will receive the frame signal of the 2-frame image, and the image acquisition unit continues to acquire the 2-frame image. At the same time, the image processing unit starts to process the acquired 1-frame image synchronously after receiving the frame signal of the 2-frame image, and the processing result of the 1-frame image needs to be completed within time t. After time t, the image acquisition unit starts to acquire the 3-frame image after receiving the frame signal of the 3-frame image, and at the same time, the image processing unit starts to process the 2-frame image synchronously after receiving the frame signal of the 3-frame image. At the same time, after receiving the frame signal of the 3-frame image, the rejection unit removes the debris according to the processing result of the 1-frame image. If the rejection unit has not received the processing result of the 1-frame image when receiving the frame signal of the 3-frame image (the processing time of the 1-frame image>t), the rejection unit does not perform the rejection process on the 1-frame image, and the processing unit immediately releases the various resources of the processing unit occupied by the 1-frame image synchronously to prepare for the processing of the 2-frame image. The subsequent timing control method for collecting, processing, and eliminating each frame of the image is repeated in the same way. This ensures that the action rhythm of the entire image collection, processing, and elimination is highly consistent, ensuring that the entire work process is stable and smooth.

[0011] Specifically, the tobacco foreign matter removal control method includes:

[0012] (1) Generate the elimination control matrix

[0013] Each frame of image is divided into the number of columns of the matrix at equal intervals according to the number of units of the culling device in the width direction of the conveying device, and the number of rows of the matrix is ​​divided into the number of pixels of the height of each frame of image at equal intervals according to the pixels collected during the culling control period, and a matrix is ​​constructed with the number of rows and columns to control the position and time of the culling unit action;

[0014] After the image is detected and processed, a rejection control matrix of the target object to be rejected is obtained according to the shape, contour and other characteristics of the target object.

[0015] (2) According to the rejection control matrix, the corresponding rejection information is sent to the rejection solenoid valve, and the rejection solenoid valve at the corresponding position is opened for a corresponding time according to the result of the rejection control matrix to accurately reject the target object in the material.

[0016] After the debris in the image is identified, the debris rejection solenoid valve A should be opened to remove the debris at the appropriate time. Since the movement trajectories of different debris are different, an extended solenoid valve (its adjacent solenoid valve A-1 and solenoid valve A+1) can be set to open the debris rejection solenoid valve A in the arrangement direction of the solenoid valves, or the opening time T of the debris rejection solenoid valve A can be extended to increase the possibility of the debris being hit, thereby further increasing the rejection accuracy of the entire rejection system.

[0017] The beneficial effects of the present invention include:

[0018] Ⅰ. The timing synchronization control between image acquisition, image processing and debris removal is realized, so that each functional action of the system can be carried out in an orderly manner according to a fixed beat, and the working timing of the entire detection and removal system is not chaotic and runs stably;

[0019] Ⅱ. Improved the accuracy of the target objects to be removed from the material;

[0020] III. The extended control of the rejection action is realized to improve the rejection rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 2 is a system composition diagram of the method of the present invention.

[0022] Figure 2 Schematic diagram of the timing synchronization method of the present invention.

[0023] Figure 3 The present invention is a method for removing the electromagnetic valve extension display intention.

[0024] Figure 4 A schematic diagram of time allocation. DETAILED DESCRIPTION

[0025] The technical solution of the present invention will be described in detail below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0026] Example 1

[0027] First, a 2048-pixel linear scan camera is used to continuously capture images of the material at a fixed scanning frequency and frame rate. After the image acquisition is completed, the image is sent to the image processing unit for processing. After the image processing is completed, if there is a target object that needs to be removed, the removal signal is sent to the removal solenoid valve. After the removal solenoid valve is actuated, foreign matter or unqualified materials in the material are removed. Since the above-mentioned work process is carried out on a running production line, the time for image acquisition, processing, and removal is extremely short, and the action continuity and timeliness of the entire work process are extremely high. A method that can quickly and accurately synchronize the image acquisition, processing, and removal timing is required to ensure the orderly and stable operation of the entire detection and removal process.

[0028] like Figure 1 As shown, the system consists of: conveyor belt, image data acquisition, image detection processing, timing and rejection control, and rejection valve.

[0029] like Figure 2 As shown, the image acquisition, processing, and debris removal actions are synchronized, and the time allocation method in the timing synchronization method is as follows Figure 4 The time allocation is divided as shown in the schematic diagram shown.

[0030] First, set: line scan camera resolution (horizontal resolution) - Rh; number of lines contained in a frame image (vertical resolution) - Rv; conveyor belt speed v; conveyor belt width W; frame image acquisition time T1; frame image processing time T2; rejection control element action time (i.e., execution time to complete the rejection action) T3; result transmission time T5; rejection preparation time T6;

[0031] Then, complete the following steps based on the above conditions:

[0032] S1 calculates the detection accuracy based on the width of the conveyor and the lateral resolution of the image:

[0033]

[0034] Where: R represents the detection accuracy, W represents the width of the conveyor belt, and Rh represents the lateral resolution of the collected image.

[0035] S2 calculates the longitudinal field of view detection size through the longitudinal resolution and detection accuracy of the line scan camera:

[0036] Fv=Rv*R

[0037] Where: Fv represents the longitudinal field of view detection size, Rv represents the longitudinal resolution of the image, and R represents the detection accuracy

[0038] S3 calculates the scanning frequency of the line scan camera based on the conveying speed and detection accuracy of the material conveyor belt:

[0039]

[0040] Where: S represents the scanning frequency of the line scan camera, v represents the conveyor belt conveying speed, and R represents the detection accuracy

[0041] S4 calculates the scanning period of the line scan camera through the scanning frequency of the line scan camera:

[0042]

[0043] Where: T' represents the scanning period of the line scan camera, S represents the scanning frequency of the line scan camera

[0044] S5 calculates the frame signal interval of the line scan camera through the scanning period of the line scan camera:

[0045] t=T′

[0046] Where: t represents the frame signal interval time, T′ represents the line scan camera scanning period

[0047] S6 calculates the distance from the line scan camera scanning line to the end of the conveyor belt through the line scan camera frame signal interval time and the conveyor belt conveying speed:

[0048] L1=t*2*v

[0049] Where: L1 represents the distance from the line scan camera to the end of the conveyor belt, t represents the frame signal interval time, and v represents the conveyor belt conveying speed.

[0050] S7 calculates the distance from the end of the conveyor to the rejection point through the rejection component action time and the conveyor speed:

[0051] L2=T3*v

[0052] Where: L2 represents the distance from the end of the conveying device to the rejection point, T3 represents the action time of the rejection control element, and v represents the conveying speed of the conveying device.

[0053] The timing synchronization method in the technical solution is further used to perform line scan camera image acquisition, image processing, and rejection time allocation setting. The material starts from the scanning line and completes frame image acquisition after T1 time, and then completes frame image processing and rejection data, rejection data transmission, rejection preparation and other tasks after T2 time. At this time, the material reaches the end of the conveyor belt, and the rejection solenoid valve completes the corresponding rejection action according to the frame signal and image processing results. T3 is used as the action time of the rejection control element. In the time allocation method, it must meet the following requirements: T1 = T2 = T4 + T5 + T6; T3 = rejection element action time; the running time of the image processing algorithm should be less than T4.

[0054] After calculating the above series of parameters, the image detection and rejection system designed according to these parameters can complete the synchronization relationship time requirements of each execution action between image detection, image processing and rejection.

[0055] Furthermore, an extended electromagnetic valve A-1 and an electromagnetic valve A+1 are provided in the arrangement direction of the electromagnetic valves to open the debris rejection electromagnetic valve A, so as to offset the uncertainty caused by the different movement trajectories of different debris (such as Figure 3 shown).

[0056] Furthermore, the possibility of the debris being hit is increased by extending the action time T3 of the rejection control element of the debris rejection solenoid valve A, so as to offset the uncertainty caused by the different movement trajectories of different debris.

[0057] Furthermore, according to the rejection control method in the technical solution, after the image is detected and identified, the rejection control matrix of the target object to be rejected can be obtained by converting the target debris image to the rejection control matrix. The corresponding rejection information is sent to the rejection solenoid valve according to the rejection control matrix. The rejection solenoid valve at the corresponding position is opened for the corresponding time according to the result of the timing calculation to accurately reject the target object in the material.

Claims

1. A method for synchronous detection and removal of tobacco foreign matter, characterized in that: include: Step (1), the conveying speed of the belt conveying the material is constant, and the line scan camera is set to continuously acquire images at a fixed line frequency and frame rate, the number of acquired lines and the frame rate of each frame of image are fixed, and the time interval between each frame of image is t; Step (2), the action rhythms of the three functions of image acquisition, processing and rejection are all based on the line scan camera image frame signal; When the image acquisition unit receives the frame signal of the 1-frame image, it starts to acquire the image. After the time t has passed, the acquisition of the 1-frame image is completed. After the image acquisition unit has acquired the 1-frame image, it will receive the frame signal of the 2-frame image, and the image acquisition unit continues to acquire the 2-frame image. At the same time, after the image processing unit receives the frame signal of the 2-frame image, it starts to process the acquired 1-frame image synchronously, and the processing result of the 1-frame image is completed within the time t. After the time t has passed, the image acquisition unit receives the frame signal of the 3-frame image and starts to acquire the 3-frame image. At the same time, after the image processing unit receives the frame signal of the 3-frame image, it starts to process the 2-frame image synchronously. At the same time, after the elimination unit receives the frame signal of the 3-frame image, it eliminates the debris according to the processing result of the 1-frame image. If the elimination unit has not received the processing result of the 1-frame image when receiving the frame signal of the 3-frame image, the elimination unit does not eliminate the 1-frame image, and the processing unit synchronously releases various resources of the processing unit occupied by the 1-frame image to prepare for the processing of the 2-frame image.

2. The method for detecting and removing foreign matter in tobacco according to claim 1, characterized in that: The subsequent timing control method for collecting, processing and eliminating each frame of image is repeated by analogy with step (2).

3. A method for synchronous detection and removal of tobacco foreign matter, characterized in that: The following steps are involved: S1, set the following parameters The horizontal resolution Rh of the line scan camera, the number of lines contained in one frame image Rv, the conveyor belt speed v, the conveyor belt width W, the frame image acquisition time T1, the frame image processing time T2, the rejection control element action time T3, the result transmission time T5, and the rejection preparation time T6; S2, respectively calculate the detection accuracy R, the longitudinal field of view detection size Fv, the line scan camera scanning frequency S, and the line scan camera scanning period T ′ , the frame signal interval time t of the line scan camera, the distance L1 from the line scan camera scanning line to the end of the conveyor belt, and the distance L2 from the end of the conveyor device to the rejection point: Fv=Rv*R t=T ′ L1=t*2*v L2 = T3 * v; S3, the material starts from the scanning line and completes frame image acquisition after T1 time, and then completes frame image processing and rejection data, rejection data transmission and rejection preparation after T2 time. At this time, the material reaches the end of the conveyor belt, and the rejection solenoid valve completes the corresponding rejection action according to the frame signal and image processing results. T3 is the action time of the rejection control element; in the time distribution method, it satisfies: T1=T2=T4+T5+T6, where T4 is defined as the maximum running time of the image processing algorithm.

4. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the timing synchronization method for detecting and removing tobacco foreign matter as described in any one of claims 1 to 3 are implemented.

5. A tobacco foreign matter removal control method of a tobacco foreign matter detection and removal timing synchronization method as claimed in any one of claims 1 to 3, characterized in that: include: (1) Generate the elimination control matrix Each frame of image is divided into the number of columns of the matrix at equal intervals according to the number of units of the culling device in the width direction of the conveying device, and the number of rows of the matrix is ​​divided into the number of pixels of the height of each frame of image at equal intervals according to the pixels collected during the culling control period, and a matrix is ​​constructed with the number of rows and columns to control the position and time of the culling unit action; After the image is detected and processed, a rejection control matrix of the target object to be rejected is obtained according to the shape and contour characteristics of the target object; (2) According to the rejection control matrix, the corresponding rejection information is sent to the rejection solenoid valve, and the rejection solenoid valve at the corresponding position is opened for a corresponding time according to the result of the rejection control matrix to accurately reject the target object in the material.

6. The tobacco foreign matter removal control method according to claim 5, characterized in that: After the debris in the image is identified, the debris removal solenoid valve A should be opened to remove the debris at an appropriate time.

7. The tobacco foreign matter removal control method according to claim 5, characterized in that: An extended solenoid valve for opening the debris rejection solenoid valve A is arranged in the arrangement direction of the solenoid valves to offset the uncertainty caused by the different movement trajectories of different debris. The extended solenoid valve is the adjacent solenoid valve A-1 and the solenoid valve A+1 of the debris rejection solenoid valve A.

8. The tobacco foreign matter removal control method according to claim 5, characterized in that: The action time T3 of the rejection control element of the debris rejection solenoid valve A is extended to increase the possibility of the debris being hit, so as to offset the uncertainty caused by the different movement trajectories of different debris.

9. The tobacco foreign matter removal control method according to any one of claims 5 to 8, characterized in that: According to the rejection control matrix, the corresponding rejection information is sent to the rejection solenoid valve, and the rejection solenoid valve at the corresponding position is opened for a corresponding time according to the result of the timing synchronization method to accurately reject the target object in the material.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the tobacco foreign matter removal control method according to any one of claims 5 to 9 are implemented.

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