Flour particle detector using a combination of laser and CCD camera

Abstract

The present invention provides a flour particle detector combining a laser and a CCD camera. The detector comprises a sampling screw conveyor, an air compressor, a Venturi tube, a CCD industrial camera, a laser, a laser signal collector, a parallel light source, and a return pipe hopper. The discharge port of the sampling screw conveyor is connected to the feed port of the Venturi tube, and the air compressor supplies air to the Venturi tube. The discharge port of the Venturi tube is suspended from top to bottom, directing the flour particles downward vertically. The return pipe hopper is connected to the discharge port of the Venturi tube. The parallel light source and the CCD industrial camera are arranged horizontally on either side of the detection area, opposite each other. The laser and the laser signal collector are arranged opposite each other on either side of the detection area, with the laser being arranged horizontally below the CCD industrial camera. This device has the advantages of improving the detection accuracy of the device, compensating for the laser's inability to derive images, and compensating for the insufficient detection accuracy of the CCD camera.

Description

Technical Field

[0001] The present invention relates to a flour particle detection device, in particular to a flour particle detector combining a laser and a CCD camera. Background Art

[0002] During flour production, the flour produced during the milling process needs to be tested for particle size to determine whether the milling process parameters are set correctly. The main parameters tested are the flour particle size and the proportion of flour particles of different sizes. This online testing process can quickly feedback data, making it easier to adjust the milling process parameters. It is an important parameter for the advancement of flour production automation.

[0003] Currently commonly used high-precision methods include CCD camera method and laser method.

[0004] The CCD camera method is to take photos continuously and use computer software algorithms to read the number of particles of the same size in the photos for classification and statistics. Its disadvantage is that the camera method has extremely high requirements on the performance of the camera and the capabilities of the computer software. Due to cost factors, the recognition ability is limited and the detection accuracy is not as high as the laser method.

[0005] The laser method projects a laser into the flour flow. When the laser hits large particles, the diffraction angle is small, and when it hits small particles, the diffraction angle is large. By arranging a laser signal collector on the diffraction light path, the size of the particles is judged by light signals at different angles. This method belongs to the category of collection statistics. Its disadvantage is that the laser cannot export an image for optical viewing, which is not intuitive enough.

[0006] In order to solve the above problems, people have been seeking an ideal technical solution. Summary of the Invention

[0007] The purpose of the present invention is to address the deficiencies of the existing technology and thus provide a flour particle detector that combines a laser and a CCD camera to improve the detection accuracy of the equipment, compensate for the defect that the laser cannot derive images, and compensate for the defect that the CCD camera has insufficient detection accuracy.

[0008] In order to achieve the above object, the technical solution adopted by the present invention is: a flour particle detector combined with a laser and a CCD camera, comprising a sampling screw conveyor, an air compressor, a venturi tube, a CCD industrial camera, a laser, a laser signal collector, a parallel light source and a return pipe hopper;

[0009] The discharge port of the sampling screw conveyor is sealed and connected to the feed port of the venturi tube. The air compressor provides pressurized air to the venturi tube. The discharge port of the venturi tube is suspended from top to bottom so that the flour particles flow vertically downward. The return pipe hopper is connected to the bottom of the discharge port of the venturi tube. A detection area is formed between the discharge port of the venturi tube and the return pipe hopper.

[0010] The parallel light source is opposite to the CCD industrial camera and is horizontally arranged on both sides of the detection area;

[0011] The laser and the laser signal collector are relatively arranged on both sides of the detection area, and the laser is arranged horizontally and located below the CCD industrial camera;

[0012] The CCD industrial camera and the laser signal collector are both connected to a processor so that the flour particles photographed by the CCD industrial camera match the flour particles collected by the laser signal collector based on the flour flow rate at the outlet of the venturi tube and the installation positions of the CCD industrial camera, the laser, and the laser signal collector.

[0013] Based on the above, a high-speed camera for speed measurement is provided at the outlet of the venturi tube.

[0014] Based on the above, it also includes a detection box, which is a closed box. The Venturi tube, CCD industrial camera, laser, laser signal collector, parallel light source and return pipe hopper are all arranged in the detection box.

[0015] Based on the above, the venturi tube is arranged horizontally, the outlet end of the venturi tube is connected through a section of curved pipe, and the complete discharge port serves as the discharge port of the venturi tube.

[0016] Based on the above, a purge mechanism is provided for the lens of the CCD industrial camera and the lens of the parallel light source.

[0017] Based on the above, the CCD industrial camera is equipped with a telecentric lens.

[0018] Based on the above, the laser signal collector includes several color receivers.

[0019] The present invention has outstanding substantial features and significant progress compared to the prior art. Specifically, the present invention has the following advantages:

[0020] 1. The combination of laser and CCD camera can make up for the defects of laser inability to export images for intuitive observation, and the limited detection accuracy of CCD industrial cameras that cannot detect fine particles. The advantages of both are complemented by computer algorithms. It can not only observe the image information of particles in flour, but also combine with laser to obtain the distribution of flour particles at the corresponding moment, taking advantage of each other's strengths to provide basic sensor data for the automatic processing and advancement of flour processing equipment.

[0021] 2. To avoid calculation errors, a high-speed camera for speed measurement is installed at the outlet of the Venturi tube so that the initial speed value can be provided for the subsequent computer calculation process.

[0022] 3. Seal the detection box to prevent ambient light, wind interference, environmental dust and other substances from affecting the detection process.

[0023] 4. The Venturi tube is designed horizontally, and a bend is added at the outlet to give full play to the characteristics of the Venturi tube.

[0024] 5. In order to prevent dust from interfering with the detection of CCD industrial cameras and light sources, a purge mechanism is set up to clean the lens.

[0025] 6. Equipped with telecentric lens to improve the shooting performance of CCD industrial camera. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The figure is a schematic diagram of the structure of the flour particle detector of the present invention which is a combination of laser and CCD camera.

[0027] Figure 1: 1. Sampling screw conveyor; 2. Mill discharge pipe; 3. Venturi tube; 4. Air compressor; 5. Bend pipe; 6. Flour particle flow; 7. Return pipe hopper; 8. Parallel light source; 9. CCD industrial camera; 10. Laser; 11. Laser signal collector; 12. Detection box; 13. Telecentric lens; 14. Valve group. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described in detail below through specific implementation methods.

[0029] like Figure 1As shown, taking the flour discharged from the grinding device as an example, the sampling screw conveyor 1 is connected to the discharge pipe 2 of the grinding mill, and the discharge port of the sampling screw conveyor 1 is sealed and connected to the feed port of the venturi tube 3. The air compressor 4 provides pressurized air to the venturi tube 3 through the valve group 14. The venturi tube is horizontally arranged, and its discharge end is connected to a curved pipe 5, so that the discharge port is suspended from top to bottom and the flour particles flow 6 vertically downward. The return pipe hopper 7 is connected to the bottom of the discharge port of the venturi tube 3, and a detection area is formed between the discharge port of the venturi tube 3 and the return pipe hopper 7.

[0030] The parallel light source 8 and the CCD industrial camera 9 are arranged horizontally on both sides of the detection area opposite to each other, providing instantaneous images of the flour flow at high speed, and providing flour distribution while classifying and counting flour particles.

[0031] The laser 10 and the laser signal collector 11 are arranged on both sides of the detection area relative to each other. The laser 10 is arranged horizontally and located below the CCD industrial camera 9. In this embodiment, the laser signal collector 11 includes, from top to bottom, the following: a red light receiver for receiving 500-1000 micron light signals, a yellow light receiver for receiving 300-500 micron light signals, a green light receiver for receiving 100-300 micron light signals, a cyan light receiver for receiving 50-100 micron light signals, and a pink light receiver for receiving 20-50 micron light signals, which basically covers the range where the flour particles are located.

[0032] The CCD industrial camera 9 and the laser signal collector 11 are both connected to a processor, which respectively integrates a computer algorithm for counting the size of particles based on the images taken by the CCD industrial camera, a computer algorithm for classifying and counting the size of particles based on the laser signal collector, and an algorithm for matching the flour particles photographed by the CCD industrial camera with the flour particles collected by the laser signal collector based on the flour flow rate at the outlet of the venturi tube and the installation position of the CCD industrial camera, laser and laser signal collector.

[0033] Among them, the algorithm for counting particle size by CCD industrial cameras and laser signal collectors themselves is the traditional algorithm used in the industry.

[0034] The flour flow rate at the outlet of the Venturi tube can be calculated based on the parameters of the Venturi tube and the airflow parameters. The installation positions of the CCD industrial camera and the laser are specific values. Combined with the time tags they carry, the flour at the same stage can be easily calculated. The particles photographed by the CCD industrial camera and the particles collected by the laser signal collector belong to the same group of particles, and then the particle statistics and image information of the same group of particles are obtained, which can not only accurately obtain the particle distribution, but also intuitively see the image distribution of the particles.

[0035] In order to provide a more reference basis for the further optimization of flour process equipment, the above data can also be continuously counted and amplified, combined with computer big data algorithms and final product grade confirmation to obtain the optimal flour particle size ratio value, providing an important reference basis for future flour equipment automation upgrades.

[0036] Workflow:

[0037] The flour produced by the grinding mill is fed into the venturi tube 3 through the sampling screw conveyor 1. Under the acceleration characteristics of the venturi tube 3, the flour particle flow is discharged from the discharge port at high speed and passes through the detection area from top to bottom.

[0038] First, the CCD industrial camera 9 captures images of the flour particle flow, and combines computer algorithms to count the size and number of particles in the flour particle flow.

[0039] Then the laser 10 and the laser signal collector 11 detect the flour particle flow, and in combination with the computer algorithm, directly collect and count flour particles of different particle sizes.

[0040] Finally, the flow rate of the flour particle flow, that is, the initial speed of the discharge port, and the travel distance are combined and matched through an algorithm to eliminate the time error of the particles detected by the two sets of detection methods and classify them as the same batch of particles. Finally, the image distribution and particle size statistics of the same batch of particles are obtained.

[0041] In other embodiments, in order to make the detected flour flow rate more accurate, a high-speed camera for speed measurement is provided at the outlet of the venturi tube.

[0042] In a preferred embodiment, a detection box 12 is further included. The detection box is a closed box, and the venturi tube, CCD industrial camera, laser, laser signal collector, parallel light source and return pipe hopper are all arranged in the detection box.

[0043] In a preferred embodiment, a purge mechanism is provided for the lens of the CCD industrial camera and the lens of the parallel light source to prevent dust contamination that affects detection accuracy.

[0044] In a preferred embodiment, the CCD industrial camera is equipped with a telecentric lens 13 to improve detection accuracy.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention and not to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention. They should all be included in the scope of the technical solution for protection of the present invention.

Claims

1. A flour particle detector using a combination of laser and CCD camera, characterized by: Including sampling screw conveyor, air compressor, venturi tube, CCD industrial camera, laser, laser signal collector, parallel light source and return pipe hopper; The discharge port of the sampling screw conveyor is sealed and connected to the feed port of the venturi tube. The venturi tube is arranged horizontally, and the outlet end of the venturi tube is connected through a curved pipe. The discharge port of the curved pipe serves as the discharge port of the venturi tube. A high-speed camera for speed measurement is provided at the outlet of the venturi tube. The air compressor provides pressurized air to the venturi tube. The discharge port of the venturi tube is suspended from top to bottom and causes the flour particles to flow vertically downward. The return pipe hopper is connected to the bottom of the discharge port of the venturi tube. A detection area is formed between the discharge port of the venturi tube and the return pipe hopper. The parallel light source is opposite to the CCD industrial camera and is horizontally arranged on both sides of the detection area; The laser and the laser signal collector are relatively arranged on both sides of the detection area, and the laser is arranged horizontally and located below the CCD industrial camera; The CCD industrial camera and the laser signal collector are both connected to a processor so that the flour particles photographed by the CCD industrial camera match the flour particles collected by the laser signal collector based on the flour flow rate at the outlet of the venturi tube and the installation positions of the CCD industrial camera, the laser, and the laser signal collector. The particles photographed by the CCD industrial camera and the particles collected by the laser signal collector belong to the same group of particles.

2. The flour particle detector using a laser and CCD camera combination according to claim 1, characterized in that: It also includes a detection box, which is a closed box. The venturi tube, CCD industrial camera, laser, laser signal collector, parallel light source and return pipe hopper are all arranged in the detection box.

3. The flour particle detector using a laser and CCD camera combination according to claim 2, characterized in that: A purge mechanism is provided for the lens of the CCD industrial camera and the lens of the parallel light source.

4. The flour particle detector using a laser and CCD camera combination according to claim 3, characterized in that: The CCD industrial camera is equipped with a telecentric lens.

5. The flour particle detector using a laser and CCD camera combination according to claim 4, characterized in that: The laser signal collector includes several color receivers.

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