Device and method for automatically identifying completion of filter cake pressing of filter press

Abstract

The present invention discloses an automatic identification device and method for the completion of filter cake pressing of a filter press, which belongs to the technical field of filter presses. The device includes a water outlet pipe and a camera, the camera is used to sample the water flow image of the water outlet pipe, an LED light source and a photosensitive detection plate are relatively arranged below the water outlet pipe, the water outlet of the water outlet pipe is vertically downward, and the surface of the photosensitive detection plate is sequentially arranged with a first sensor group, a second sensor group and a third sensor group along the camera shooting direction, the first sensor group detects bright light and sends a first signal to the camera for the camera to sample the water flow image, the second sensor group detects bright light and sends a second signal to the camera for the camera to sample the water flow image, and the third sensor group detects bright light and sends a third signal to the camera for the camera to sample the water flow image; the device also includes an automatic identification unit for identifying the water flow state. The present invention uses an LED light source and photosensitive detection to roughly judge the water flow state, and then intermittently controls the camera to work, reduces the camera pressure, and reduces energy consumption.

Description

Technical Field

[0001] The invention relates to the technical field of filter presses, and in particular to an automatic identification device and method for completion of pressing of filter cakes of a filter press. Background Art

[0002] The filter press uses a special filter medium to apply a certain pressure to the object, so that the liquid can be dialyzed out. It is a commonly used solid-liquid separation equipment. It was used in chemical production in the early 18th century and is still widely used in chemical, pharmaceutical, metallurgical, dye, food, brewing, ceramics and environmental protection industries. During the operation of the filter press, it is an important link to ensure that the filtration has been completed, which is related to the filtration effect, equipment safety and the smooth progress of subsequent processing.

[0003] Whether the filtration is completed is determined by observing the drainage of the filter plate. If the amount of drainage is significantly reduced or even almost stopped, it also indicates that the material in the filter chamber has been basically compacted and most of the water and liquid have been discharged. The traditional observation of drainage is not necessarily entirely done manually. You can also use a camera to capture an image of the liquid outlet, and then use image processing technology to identify the size of the water flow at the liquid outlet. Using a camera to replace manual work is more intelligent. However, since the pressing time of the filter press varies significantly depending on the material or the degree of dryness or wetness of the material, the uncertainty of the pressing time causes the camera to take pictures all the time, which places high requirements on the quality of the camera. In addition, image processing involves the use of the processor. Processing a large number of images causes excessive pressure on the processor, and it is easy for the program to crash. Therefore, the traditional recognition of whether the pressing is completed requires not only the recognition equipment to have strong image processing capabilities but also a high-cost camera to complete, which greatly increases the cost of use and is not energy-saving and environmentally friendly. Summary of the invention

[0004] The present invention aims to solve the problem that the cost of judging whether the filtration is completed by the above-mentioned filter press is high and not energy-saving and environmentally friendly, and to provide an automatic identification device and method for the completion of filter cake pressing by a filter press. The device and method have the advantages of utilizing the water flow shading situation to judge the water flow size, intermittently controlling the camera to sample the water flow image, having high recognition accuracy, reducing the camera working time, reducing the workload of image processing, and putting less pressure on the camera and processor.

[0005] In the first aspect, in order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is:

[0006] An automatic recognition device for the completion of filter cake pressing of a filter press comprises a water outlet pipe and a camera, wherein the camera is used to sample a water flow image of the water outlet pipe, an LED light source and a photosensitive detection plate are relatively arranged below the water outlet pipe, the water outlet of the water outlet pipe is vertically downward, and the water flow passes between the LED light source and the photosensitive detection plate, a first sensor group, a second sensor group and a third sensor group are arranged in sequence on the surface of the photosensitive detection plate along the shooting direction of the camera, the first sensor group detects bright light and sends a first signal to the camera, which is used for the camera to sample a water flow image, the second sensor group detects bright light and sends a second signal to the camera, which is used for the camera to sample a water flow image, and the third sensor group detects bright light and sends a third signal to the camera, which is used for the camera to sample a water flow image;

[0007] The device also includes an automatic identification unit for receiving the water flow image and identifying the water flow state by processing the image.

[0008] Preferably, the distance between the first sensing group and the second sensing group is greater than the distance between the second sensing group and the third sensing group.

[0009] Preferably, the first sensor group, the second sensor group and the third sensor group are all composed of a plurality of vertically distributed photosensitive sensors, wherein the photosensitive sensors of the third sensor group are discretely distributed along a vertical line, and the photosensitive sensors of each group are connected in series.

[0010] Preferably, the LED light source includes a first light group, a second light group and a third light group, and the first light group, the second light group and the third light group are positioned opposite to the first sensor group, the second sensor group and the third sensor group in sequence.

[0011] Preferably, the LED light source is installed on a light box, and a delay control switch is installed in the light box. The delay control switch is used to receive a first signal and turn off the first light group after a preset delay time, receive a second signal and turn off the second light group after a preset delay time, and receive a third signal and turn off the third light group after a preset delay time.

[0012] Preferably, a background plate is also installed below the water outlet pipe, the background plate is arranged opposite to the camera, and the color of the background plate is blue or black.

[0013] Preferably, the camera is mounted on a sliding frame via a rotating shaft, the sliding frame is threadedly connected to a screw rod, and one end of the screw rod is connected to a displacement motor.

[0014] Preferably, the camera is an autofocus industrial camera.

[0015] Preferably, the automatic identification unit comprises:

[0016] An image processing module is used to perform Gaussian filtering and normalization processing on the water flow image to enhance the display of the water flow edge;

[0017] ROI area setting module, used to intercept a fixed ROI area on the processed image;

[0018] A gray value calculation module is used to calculate the gray value of the water flow pixel in the ROI area and the gray value of the background pixel in the image through binarization;

[0019] A threshold setting module, used to set the gray value threshold;

[0020] The comparison module is used to compare the average grayscale values ​​of all pixels in the ROI area, and output the compression completion result when the average grayscale value is lower than the grayscale value threshold.

[0021] In the second aspect, in order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is:

[0022] A method for automatically identifying that the pressing of filter cake of a filter press is completed, using the automatic identification device as described in the first aspect, the method comprising the following steps:

[0023] receiving a first signal, wherein the first signal is used for a camera to sample a water flow image;

[0024] receiving a second signal, wherein the second signal is used for a camera to sample a water flow image;

[0025] receiving a third signal, wherein the third signal is used for a camera to sample a water flow image;

[0026] Receive all sampled water flow images and identify the water flow status by processing the images.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] 1. The present invention symmetrically arranges photosensitive detection boards and LED light sources on both sides of the water flow of the outlet pipe. The bright light emitted by the LED light source is blocked by the water flow. Therefore, the size of the water flow can be judged by whether the photosensitive detection board detects the bright light. The three groups of sensor groups arranged on the photosensitive detection board just correspond to the three states of large, small and no water flow. When each state is detected, the camera is controlled to turn on to sample a group of water flow images. Finally, all the images are used to determine the state of the water flow. The state of the water flow in the image is used to realize the judgment of whether the filter press is completed. The image recognition result is more accurate and intelligent, and the camera does not need to work all the time, which reduces the pressure of image processing and image storage.

[0029] 2. The present invention sets the LED light source to a light group with a corresponding number of sensor groups, so that the brightness of the light irradiating each sensor group is more uniform, reducing the generation of errors, and the light group is also turned off according to the signal sent by the sensor group. After each sensor group sends a signal, wait for the camera sampling to be completed before turning off the corresponding light group, reducing the energy consumption of the LED light source, which is more energy-saving and environmentally friendly. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a schematic diagram of the overall structure of the automatic identification device of the present invention.

[0031] Figure 2 Schematic diagram of the distribution of sensor groups in the photosensitive detection board of the present invention.

[0032] Figure 3 It is a schematic diagram of the installation position of the water outlet pipe and the photosensitive detection plate of the present invention.

[0033] Figure 4 It is a schematic diagram of the shadow shielding range of the water outlet pipe of the present invention when there is a large water flow.

[0034] Figure 5 It is a schematic diagram of the shadow shielding range when the water outlet pipe of the present invention is a medium water flow.

[0035] Figure 6 It is a schematic diagram of the shadow shielding range when the water outlet pipe of the present invention is a small water flow.

[0036] Figure 7 It is a schematic diagram of the distribution of lamp groups in the LED light source of the present invention.

[0037] Figure 8 It is a schematic diagram of the camera installation structure of the present invention.

[0038] Fig. 9 It is a schematic diagram of the automatic identification unit component modules of the present invention.

[0039] Fig.10 It is a schematic diagram of the ROI area image selected under the medium water flow state of the present invention.

[0040] Fig.11 It is a schematic diagram of the ROI area image selected under the small water flow state of the present invention.

[0041] Fig.12 It is a schematic diagram of the ROI area image selected in the non-water flow state of the present invention.

[0042] In the figure: 1, filtrate end, 2, water outlet pipe, 3, fixed frame, 4, background plate, 5, light box, 6, LED light source, 7, photosensitive detection plate, 8, camera, 9, first light group, 10, second light group, 11, third light group, 12, sliding frame, 13, rotating shaft, 14, screw, 15, displacement motor, 16, first sensor group, 17, second sensor group, 18, third sensor group, 19, automatic identification unit. DETAILED DESCRIPTION

[0043] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0044] Example 1

[0045] like Figure 1 As shown, an automatic recognition device for the completion of filter cake squeezing of a filter press is disclosed, comprising a water outlet pipe 2 and a camera 8, wherein the camera 8 is used to sample a water flow image of the water outlet pipe 2, an LED light source 6 and a photosensitive detection plate 7 are relatively arranged below the water outlet pipe 2, and a water outlet of the water outlet pipe 2 is vertically downward, so that water flows through between the LED light source 6 and the photosensitive detection plate 7, and a first sensor group 16, a second sensor group 17 and a third sensor group 18 are sequentially arranged on the surface of the photosensitive detection plate 7 along the shooting direction of the camera 8, the first sensor group 16 detects bright light and sends a first signal to the camera 8 for the camera 8 to sample a water flow image, the second sensor group 17 detects bright light and sends a second signal to the camera 8 for the camera 8 to sample a water flow image, and the third sensor group 18 detects bright light and sends a third signal to the camera 8 for the camera 8 to sample a water flow image.

[0046] The water outlet pipe 2 is installed at the filtrate end 1 of the filter press. During the process of squeezing the material by the filter press, the filtrate flows along the filter plate into the filtrate end 1 and is finally discharged from the filter press through the water outlet pipe 2. The camera 8 is facing the water outlet pipe 2 and can take pictures of the water flow to sample the water flow image. The principle of judging whether the squeezing of the filter press is completed according to the water flow state is as follows: for example, if the water flow always exists in the sampled water flow image, it means that the filter press has not squeezed the material completely. When the water flow disappears, it means that the material can no longer be squeezed out of the liquid, indicating that the squeezing of the filter press is completed. Based on the above basic principles, in order to avoid excessive image processing pressure caused by the continuous sampling of images by the camera 8, or insufficient storage space of the camera 8, such as Figure 2As shown, an LED light source 6 and a photosensitive detection plate 7 are arranged on both sides of the water flow, and the light emitted by the LED light source 6 is projected onto the photosensitive detection plate 7. When water flows between the LED light source 6 and the photosensitive detection plate 7, because the water flow generated by the filter press is not pure and transparent, the water flow will block the light to form a shadow covering the surface of the photosensitive detection plate 7. Here, the water outlet of the water outlet pipe 2 is set to a vertical downward structure, so that the water flow can fall straight down, so that the shadow generated by the shading forms a regular rectangular shape, which is for better judging the shadow coverage area.

[0047] like Figure 3 As shown, the first sensor group 16, the second sensor group 17 and the third sensor group 18 are distributed from right to left on the surface of the photosensitive detection plate 7. When the water flow is large, the shadow area caused by the water flow shading is large, which can completely cover the first sensor group 16, the second sensor group 17 and the third sensor group 18. Figure 4 As shown in the figure, it means that the filter press is in the early stage of operation, and a large amount of liquid in the material is squeezed out. As the operation continues, the material is gradually squeezed and the internal liquid gradually decreases, so the water flow will also gradually decrease. Figure 5 As shown, at this time, the shadow caused by the water flow shading cannot cover the first sensor group 16, so the first sensor group 16 will generate an electrical signal as a first signal after detecting the light and send it to the camera 8. At this time, the camera 8 will take pictures after receiving the first signal and sample the water flow image in the current state. As the squeezing time becomes longer, the water flow continues to decrease, as shown in FIG. Figure 6 As shown, the shadow caused by the water flow shading cannot cover the second sensor group 17. Then, after the second sensor group 17 detects the light, it will generate an electrical signal as a second signal to send to the camera 8. At this time, the camera 8 will take pictures after receiving the second signal and sample the water flow image in the current state until no water flow is generated and the shadow disappears and returns to normal. Figure 3 In the state shown, the third sensor group 18 also detects light and generates a third signal to send to the camera 8. At this time, the camera 8 takes pictures after receiving the third signal and samples the water flow image of the current state. Using three sensor groups, the water flow is divided into four states: large water flow, medium water flow, small water flow and no water flow. In the medium water flow state, the camera 8 starts sampling, and each of the three states of medium water flow, small water flow and no water flow is sampled once. The camera 8 does not need to take images all the time, which reduces the memory usage and reduces the use cost.

[0048] like Figure 1As shown, the device also includes an automatic identification unit 19 for receiving water flow images and identifying the state of water flow by processing the images. The camera 8 sends the sampled water flow images to the automatic identification unit 19, and accurately determines the state of water flow through image processing and identification, which serves as a basis for determining whether the squeezing is completed. Although the water flow images sampled by the camera 8 are small, they include various states of water flow, which is not easy to produce judgment errors and reduces the workload of image processing. The device uses the cooperation of the LED light source 6 and the photosensitive sensor to roughly determine the various states of the water flow, and then uses the camera 8 to sample the water flow image in each state. Finally, based on the image processing and identification, it is determined whether the squeezing of the filter press is completed accurately, thereby ensuring accuracy, reducing the cost of use, and monitoring the working stage of the filter press.

[0049] like Figure 3 As shown, the spacing between the first sensor group 16 and the second sensor group 17 is greater than the spacing between the second sensor group 17 and the third sensor group 18. The spacing between the first sensor group 16 and the second sensor group 17 is A1, and the spacing between the second sensor group 17 and the third sensor group 18 is A2. Since the drainage water flow of the filter press is not uniformly reduced during the actual squeezing process, the transition time from medium water flow to small water flow is long, and the transition time from small water flow to no water flow is short, so if the method of A1=A2 is adopted, then when judging the state of the small water flow, it is not accurate enough, resulting in the sampled water flow image cannot be used as a reference for the water flow stage, thereby affecting the judgment of each working stage of the filter press. The first sensor group 16, the second sensor group 17 and the third sensor group 18 are all composed of a number of vertically distributed photosensitive sensors, among which the photosensitive sensors of the third sensor group 18 are discretely distributed along the vertical straight line, and each group of photosensitive sensors is connected in series. Since there are multiple photosensitive sensors in each group, they are connected in series. Only when all photosensitive sensors detect light will they output signals. This is to reduce the generation of signal output errors. In the above description, it can be seen that the third sensor group 18 is used to judge the state of the water flow from a small water flow to a no water flow stage. In the case of a large water flow, the water outlet is vertically downward, so the water column will approach a straight line, and in the case of a small water flow, the water column may shake or be intermittent. Here, the discretely distributed photosensitive sensors increase the spacing to increase the detection area, which also helps to reduce the occurrence of misjudgment. Of course, the solution to increase the detection area is not limited to discretely distributed photosensitive sensors. Technical means such as increasing the number of photosensitive sensors can also be used. According to the cost of use or actual installation considerations, choose a suitable solution. Other technical means will not be described in detail here.

[0050] In order to ensure that the light can be evenly directed to each sensor group, Figure 7As shown, the LED light source 6 includes a first light group 9, a second light group 10 and a third light group 11, and the first light group 9, the second light group 10 and the third light group 11 are located opposite to the first sensor group 16, the second sensor group 17 and the third sensor group 18 in sequence. Figure 1 The LED light source 6 is installed on the light box 5, and a delay control switch is installed in the light box 5. The delay control switch is used to receive a first signal and turn off the first light group 9 after reaching a preset delay time, receive a second signal and turn off the second light group 10 after reaching a preset delay time, and receive a third signal and turn off the third light group 11 after reaching a preset delay time. The light box 5 uses a delay control switch to control the closing of the light group so that when the water flow is small, redundant light groups can be turned off to reduce the energy consumption of the LED light source. For example, in a large water flow state, all light groups and sensor groups need to work normally. In the medium water flow state, the first sensor group 16 and the first light group 9 do not need to be used again after the cooperation is completed, so the first light group 9 can be turned off by the delay control switch to reduce energy consumption, and so on, until all the light groups are turned off, and the delay control switch also has the function of presetting the delay time, this is to avoid turning off the corresponding light group immediately after receiving the signal, so that the corresponding light group can work for a certain time, which is convenient for providing light to enhance the brightness of the water flow when the camera 8 is sampling, so that the sampled water flow image has clearer water flow, which is convenient for the processing of the automatic identification unit 19.

[0051] An independent switch can also be set on the sensor group. After the signal is sent, the corresponding sensor group is turned off. This also saves energy. This is because the water flow will not increase during the squeezing process of the filter press. Therefore, the sensor group does not need to be used again after the detection is completed, so it is turned off by an independent switch. Furthermore, a master control switch is added in the light box 5. When any signal is received, the closed light group is re-lit, and the light group is turned off again after the delay time preset by the delay control switch is reached, and the light group is restored to the previous off state. In this way, each time the camera 8 samples, the number of working light groups is fixed, and the lighting effect is also fixed. Then the water flow clarity in the sampled water flow image is also consistent, which is convenient for subsequent image processing.

[0052] In order to ensure that the water flow image sampled by camera 8 is clear and stable, Figure 1 As shown, a background plate 4 is also installed below the water outlet pipe 2. The background plate 4 is arranged opposite to the camera 8. The color of the background plate 4 is blue or black. The background plate 4 deepens the background color in the water flow image, so that the water flow can be clearly displayed in the water flow image. Figure 1 As shown, a fixing frame 3 is also installed below the water outlet pipe 2 , and a background plate 4 , an LED light source 6 and a photosensitive detection plate 7 are all installed on the fixing frame 3 .

[0053] like Figure 8 As shown, the camera 8 is mounted on the sliding frame 12 through the rotating shaft 13, and the sliding frame 12 is threadedly connected to the screw rod 14, and one end of the screw rod 14 is connected to the displacement motor 15. The camera 8 is an auto-focus industrial camera. The angle of the camera 8 can be adjusted by the rotating shaft 13 so that its shooting direction can face the water flow, and the displacement motor 15 controls the rotation of the screw rod 14 to drive the sliding frame 12 to move forward and backward. In this way, the position of the camera 8 can be adjusted by electric means to reduce the difficulty of operation.

[0054] This solution uses the automatic recognition unit 19 to process and recognize the water flow image to determine the working stage of the filter press and whether the pressing is completed. Fig. 9 As shown, the automatic identification unit 19 includes:

[0055] The image processing module is used to perform Gaussian filtering and normalization on the water flow image to enhance the display of the water flow edge. It uses Gaussian filtering image processing technology with a 5×5 convolution kernel to remove part of the noise and smooth the image, while retaining the edges and details in the image.

[0056] The ROI area setting module is used to intercept a fixed ROI area on the processed image. This module is used to select a specific imaging area, such as Fig.10 , Fig.11 and Fig.12 Shown are three water flow state diagrams of medium water flow, small water flow and no water flow. The left side is the water flow image, and the right side is the image of the selected ROI area.

[0057] The gray value calculation module is used to calculate the gray value of the water pixel in the ROI area and the gray value of the background pixel in the image through binarization. The threshold is set to 48. The gray value of the pixel greater than the threshold becomes 255, which is white; the gray value of the pixel less than the threshold becomes 0, which is black. For example Figure 10-12 In the figure, white is the water flow and black is the background.

[0058] The threshold setting module is used to set the gray value threshold, and the gray value threshold is used as a comparison reference object.

[0059] The comparison module is used to compare the average grayscale values ​​of all pixels in the ROI area, and output the compression completion result when the average grayscale value is lower than the grayscale value threshold.

[0060] Example 2

[0061] Disclosed is a method for automatically identifying that the pressing of a filter cake of a filter press is completed, using the automatic identification device as described in Example 1, the method comprising the following steps:

[0062] receiving a first signal, wherein the first signal is used for a camera to sample a water flow image;

[0063] receiving a second signal, wherein the second signal is used for a camera to sample a water flow image;

[0064] receiving a third signal, wherein the third signal is used for a camera to sample a water flow image;

[0065] Receive all sampled water flow images and identify the water flow status by processing the images.

[0066] Example 2 is essentially the same as Example 1, so the specific operating steps of the method are not repeated here.

[0067] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0068] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. An automatic recognition device for the completion of filter cake pressing of a filter press, comprising a water outlet pipe (2) and a camera (8), wherein the camera (8) is used to sample a water flow image of the water outlet pipe (2), and is characterized in that: An LED light source (6) and a photosensitive detection plate (7) are arranged opposite to each other below the water outlet pipe (2); the water outlet of the water outlet pipe (2) is directed vertically downward so that water flows through between the LED light source (6) and the photosensitive detection plate (7); a first sensor group (16), a second sensor group (17) and a third sensor group (18) are arranged in sequence on the surface of the photosensitive detection plate (7) along the shooting direction of the camera (8); the first sensor group (16) detects bright light and sends a first signal to the camera (8) for the camera (8) to sample a water flow image; the second sensor group (17) detects bright light and sends a second signal to the camera (8) for the camera (8) to sample a water flow image; and the third sensor group (18) detects bright light and sends a third signal to the camera (8) for the camera (8) to sample a water flow image; The LED light source (6) comprises a first light group (9), a second light group (10) and a third light group (11), the first light group (9), the second light group (10) and the third light group (11) being positioned opposite to the first sensor group (16), the second sensor group (17) and the third sensor group (18) in sequence, the LED light source (6) being mounted on a light box (5), a delay control switch being mounted in the light box (5), the delay control switch being used to turn off the first light group (9) after receiving a first signal and reaching a preset delay time, turn off the second light group (10) after receiving a second signal and reaching a preset delay time, and turn off the third light group (11) after receiving a third signal and reaching a preset delay time; The device also includes an automatic identification unit (19) for receiving the water flow image and identifying the water flow state by processing the image.

2. The automatic identification device for the completion of filter cake pressing of a filter press according to claim 1, characterized in that: The distance between the first sensing group (16) and the second sensing group (17) is greater than the distance between the second sensing group (17) and the third sensing group (18).

3. The automatic identification device for the completion of filter cake pressing of a filter press according to claim 1 or 2, characterized in that: The first sensor group (16), the second sensor group (17) and the third sensor group (18) are all composed of a plurality of vertically distributed photosensitive sensors, wherein the photosensitive sensors of the third sensor group (18) are discretely distributed along a vertical straight line, and the photosensitive sensors of each group are connected in series.

4. The automatic identification device for the completion of filter cake pressing of a filter press according to claim 1, characterized in that: A background plate (4) is also installed below the water outlet pipe (2). The background plate (4) is arranged opposite to the camera (8). The color of the background plate (4) is blue or black.

5. The automatic identification device for the completion of filter cake pressing of a filter press according to claim 1, characterized in that: The camera (8) is mounted on a sliding frame (12) via a rotating shaft (13); the sliding frame (12) is threadedly connected to a screw rod (14); one end of the screw rod (14) is connected to a displacement motor (15).

6. The automatic identification device for the completion of filter cake pressing of a filter press according to claim 1 or 5, characterized in that: The camera (8) is an autofocus industrial camera.

7. The automatic identification device for the completion of filter cake pressing of a filter press according to claim 1, characterized in that: The automatic identification unit (19) comprises: An image processing module is used to perform Gaussian filtering and normalization processing on the water flow image to enhance the display of the water flow edge; ROI area setting module, used to intercept a fixed ROI area on the processed image; A gray value calculation module is used to calculate the gray value of the water flow pixel in the ROI area and the gray value of the background pixel in the image through binarization; A threshold setting module, used to set the gray value threshold; The comparison module is used to compare the average grayscale values ​​of all pixels in the ROI area, and output the compression completion result when the average grayscale value is lower than the grayscale value threshold.

8. A method for automatically identifying the completion of filter cake pressing by a filter press, characterized in that: Using the automatic identification device according to any one of claims 1 to 7, the method comprises the following steps: receiving a first signal, wherein the first signal is used for a camera (8) to sample a water flow image; receiving a second signal, wherein the second signal is used for a camera (8) to sample a water flow image; receiving a third signal, wherein the third signal is used for a camera (8) to sample a water flow image; Receive all sampled water flow images and identify the water flow status by processing the images.

Images