Sewage treatment process control method and system based on safety logic controller

Abstract

The invention discloses a sewage treatment process control method and system based on a safety logic controller, and the method comprises the steps: deploying a water quality sensor and an external environment sensor, and collecting and obtaining sewage index data and external environment parameters; an I / O communication module is configured on the safety logic controller, establishes communication with a water quality sensor and an external environment sensor, communicates with an upper computer through an industrial Ethernet, and sends sewage index data and external environment parameters to the upper computer; the upper computer processes sewage index data and external environment parameters, inputs the sewage index data and the external environment parameters into a three-layer feedforward neural network model, obtains sewage treatment control parameters, generates a sewage treatment control instruction, and transmits the sewage treatment control instruction back to the safety logic controller through the industrial Ethernet, so that regulation and control of sewage treatment equipment are realized. And meanwhile, the safety interlocking logic is deployed, so that automatic process control on the sewage treatment process is realized, and the deployed safety interlocking logic can quickly respond to dangerous working conditions.

Description

Technical Field

[0001] The present invention relates to the field of sewage treatment process control, and particularly to a sewage treatment process control method and system based on a safety logic controller. Background Art

[0003] Currently, the control of the sewage treatment process is mainly carried out manually for detection, setting and implementation, without achieving full automation. At the same time, there are still some defects in the safety guarantee mechanism of the sewage treatment process, resulting in problems in terms of safety and reliability in the sewage treatment process. Summary of the Invention

[0004] The object of the present invention is to provide a sewage treatment process control method and system based on a safety logic controller, aiming to solve the problems that the current control of the sewage treatment process is mainly carried out manually for detection, setting and implementation, without achieving full automation, and there are still some defects in the safety guarantee mechanism of the sewage treatment process, resulting in problems in terms of safety and reliability in the sewage treatment process.

[0005] In view of the above problems, the present application provides a sewage treatment process control method and system based on a safety logic controller.

[0006] In the first aspect disclosed by the present application, a sewage treatment process control method based on a safety logic controller is provided. The method includes: Deploy water quality sensors to collect sewage index data, and at the same time deploy external environment sensors to collect external environment parameters; Configure an I / O communication module on the safety logic controller to establish communication with the water quality sensors and external environment sensors, and obtain sewage index data and external environment parameters; The safety logic controller communicates with the host computer through the industrial Ethernet, and sends the sewage index data and external environment parameters to the host computer; The host computer processes the sewage index data and external environment parameters, combines them to generate a sewage feature vector, and inputs the sewage feature vector into a three-layer feedforward neural network model to obtain sewage treatment control parameters; The host computer compiles the sewage treatment control parameters to generate sewage treatment control instructions; The host computer sends the sewage treatment control instructions back to the safety logic controller through the industrial Ethernet. The safety logic controller regulates and controls the sewage treatment equipment according to the sewage treatment control instructions. At the same time, the safety logic controller deploys a safety interlock logic for parameter overrun protection.

[0007] Preferably, the sewage index data includes biochemical oxygen demand, total organic carbon, ammonia nitrogen, total nitrogen, total phosphorus, pH value, and the content of insoluble particulate matter. The external environmental parameters include temperature and humidity. The sewage treatment control parameters include dissolved oxygen concentration, nitrate nitrogen concentration, mixed liquor suspended solids concentration, reflux ratio, sludge retention time, and aeration volume.

[0008] Preferably, an I / O communication module is configured on the safety logic controller to establish communication with the water quality sensor and the external environment sensor, specifically including: Configure an I / O communication module that supports mixed signal input on the safety logic controller, connect it to the water quality sensor and the external environment sensor using a twisted pair shielded cable, and install an optoelectronic coupler to cut off the conduction interference path, and establish communication with the water quality sensor and the external environment sensor through a differential signal protocol.

[0009] Preferably, the safety logic controller communicates with the host computer through industrial Ethernet, specifically including: The host computer obtains the IP address and port number of the safety logic controller, and establishes a communication link according to the serial port type supported by the safety logic controller; The host computer installs the driver program of the safety logic controller, performs data alignment processing, and at the same time establishes a virtual local area network to isolate the current communication link. During the data sending and receiving process, the CRC check algorithm is used for data integrity check.

[0010] Preferably, the host computer processes the sewage index data and the external environmental parameters, combines them to generate a sewage characteristic vector, and inputs the sewage characteristic vector into a three-layer feedforward neural network model to obtain the sewage treatment control parameters, specifically including: The host computer corrects the outliers of the sewage index data and the external environmental parameters using a sliding window algorithm, performs normalization processing, and then performs spatial dimension splicing through a feature fusion unit to generate a sewage characteristic vector; Construct a three-layer feedforward neural network model including an input layer, a hidden layer, and an output layer. Input the sewage characteristic vector into the three-layer feedforward neural network model to obtain the sewage treatment control parameters. Among them, the number of nodes in the input layer is the same as the dimension of the sewage characteristic vector, the number of nodes in the output layer is the same as the number of sewage treatment control parameters, and the number of nodes in the hidden layer is the average value between the number of nodes in the input layer and the number of nodes in the output layer.

[0011] Preferably, the host computer compiles the sewage treatment control parameters to generate sewage treatment control instructions, specifically including: Based on the programming format of the safety logic controller, the host computer converts the sewage treatment control parameters into programming logic statements; Check the syntax errors and logical conflicts of the programming logic statements. If there are syntax errors and logical conflicts, an exception is thrown. If there are no syntax errors and logical conflicts, the programming logic statements are converted into sewage treatment control instructions recognizable by the safety logic controller composed of machine codes.

[0012] Preferably, the safety logic controller deploys safety interlock logic for parameter overrun protection, specifically including: When the safety logic controller detects that the sewage treatment control parameters in the sewage treatment control instruction exceed the preset threshold range, or the operation sequence of the equipment is incorrect when the sewage treatment control instruction regulates the sewage treatment equipment, the emergency shutdown mechanism of the sewage treatment equipment is triggered.

[0013] In the second aspect disclosed in this application, a sewage treatment process control system based on a safety logic controller is provided. The system is used for the above-mentioned sewage treatment process control method based on a safety logic controller. The system includes: A sensor module, which is used to deploy water quality sensors to collect and obtain sewage index data, and at the same time deploy external environment sensors to collect and obtain external environment parameters; A first communication module, which is used to configure an I / O communication module on the safety logic controller to establish communication with the water quality sensor and the external environment sensor, and obtain sewage index data and external environment parameters; A second communication module, which is used for the safety logic controller to communicate with the upper computer through the industrial Ethernet, and send the sewage index data and external environment parameters to the upper computer; A calculation module, which is used for the upper computer to process the sewage index data and external environment parameters, merge and generate a sewage feature vector, input the sewage feature vector into a three-layer feedforward neural network model, and obtain sewage treatment control parameters; A compilation module, which is used for the upper computer to compile the sewage treatment control parameters to generate sewage treatment control instructions; A process control module, which is used for the upper computer to send the sewage treatment control instructions back to the safety logic controller through the industrial Ethernet. The safety logic controller regulates the sewage treatment equipment according to the sewage treatment control instructions. At the same time, the safety logic controller deploys safety interlock logic for parameter overrun protection.

[0014] The beneficial effects of the present invention are as follows: (1) Realize the automatic process control of the whole process of the sewage treatment process, and solve the problem that the current control of the sewage treatment process is mainly carried out manually; (2) Build a safety interlock logic based on the safety logic controller to ensure that even in the case of a host computer or communication failure, it can still quickly respond to dangerous working conditions, avoid equipment damage or environmental pollution, and improve the safety and reliability of sewage treatment. Description of the Drawings

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0016] Figure 1 It is the overall flowchart of the sewage treatment process control method based on the safety logic controller.

[0017] Figure 2 It is the overall structure diagram of the sewage treatment process control system based on the safety logic controller. Detailed Embodiments

[0018] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0019] Embodiment 1: As Figure 1 shown, the embodiment of the present application provides a sewage treatment process control method based on a safety logic controller, and the method includes: Step 1: Deploy water quality sensors to collect and obtain sewage index data, and at the same time deploy external environment sensors to collect and obtain external environment parameters. Among them, the sewage index data includes biochemical oxygen demand, total organic carbon, ammonia nitrogen, total nitrogen, total phosphorus, pH value, and insoluble particulate matter content, and the external environment parameters include temperature and humidity.

[0020] Step 2: Configure an I / O communication module on the safety logic controller to establish communication with the water quality sensors and external environment sensors, and obtain sewage index data and external environment parameters; Specifically, configure an I / O communication module that supports mixed-signal input on the safety logic controller, connect it to the water quality sensor and the external environment sensor using a shielded twisted pair cable, and ground the shield at one end to avoid ground loops. Additionally, install an optocoupler TLP521 to cut off the conduction interference path, and establish communication with the water quality sensor and the external environment sensor through the differential signal protocol RS-485, which has better anti-interference ability than single-ended signals.

[0021] Step 3: The safety logic controller communicates with the host computer through the industrial Ethernet, and sends the sewage index data and external environment parameters to the host computer. Specifically, it includes: The host computer obtains the IP address and port number of the safety logic controller, and establishes a communication link according to the serial port type supported by the safety logic controller. The host computer installs the driver program of the safety logic controller, performs data alignment processing, and simultaneously establishes a virtual local area network to isolate the current communication link. During the data sending and receiving process, the CRC check algorithm is used to perform data integrity verification. On this basis, the safety logic controller sends the sewage index data and external environment parameters to the host computer.

[0022] Step 4: The host computer first corrects the outliers of the sewage index data and external environment parameters using the sliding window algorithm, performs normalization processing, and then performs spatial dimension splicing through the feature fusion unit to generate a sewage feature vector. Secondly, the host computer constructs a three-layer feedforward neural network model including an input layer, a hidden layer, and an output layer, inputs the sewage feature vector into the three-layer feedforward neural network model, and obtains the sewage treatment control parameters. Among them, the number of nodes in the input layer is the same as the dimension of the sewage feature vector, the number of nodes in the output layer is the same as the number of sewage treatment control parameters, and the number of nodes in the hidden layer is the average value between the number of nodes in the input layer and the output layer.

[0023] Specifically, the three-layer feedforward neural network model needs to be trained, and the training process includes: (1) Collect a large amount of historical sewage index data and external environment parameters, correct the outliers and perform normalization operations, and then construct a sewage feature dataset composed of sewage feature vectors. (2) Label the sewage feature vectors in the sewage feature dataset to construct a supervised sewage feature dataset, and divide the supervised sewage feature dataset into a training set and a test set according to a ratio of 9:1. (3) Randomly initialize the weights and biases of the three-layer feedforward neural network model. Use the mean squared error loss function to measure the gap between the predicted values and the labeled data. Calculate the gradients through the gradient descent algorithm, and update the weights and biases. Iteratively train the three-layer feedforward neural network model using the training set, and use the Dropout mechanism to randomly discard 20% of the nodes in the hidden layer to prevent overfitting. Repeat the iteration until the mean squared error loss function converges; (4) Evaluate the performance of the three-layer feedforward neural network model on the test set. Turn off the Dropout mechanism during testing.

[0024] Step Five: The host computer compiles the sewage treatment control parameters to generate sewage treatment control instructions; Specifically, it includes: Based on the programming format of the safety logic controller, the host computer converts the sewage treatment control parameters into programming logic statements; Check for syntax errors and logical conflicts in the programming logic statements. If there are syntax errors and logical conflicts, an exception is thrown. If there are no syntax errors and logical conflicts, the programming logic statements are converted into sewage treatment control instructions recognizable by the safety logic controller composed of machine codes.

[0025] Step Six: The host computer transmits the sewage treatment control instructions back to the safety logic controller through the industrial Ethernet. The safety logic controller regulates the sewage treatment equipment according to the sewage treatment control instructions. At the same time, the safety logic controller deploys safety interlock logic for parameter overrun protection. Among them, the safety interlock logic is specifically: when the safety logic controller detects that the sewage treatment control parameters in the sewage treatment control instructions exceed the preset threshold range, or the operation sequence of the equipment is incorrect when the sewage treatment control instructions regulate the sewage treatment equipment, the emergency shutdown mechanism of the sewage treatment equipment is triggered.

[0026] In summary, the sewage treatment process control method based on the safety logic controller provided by the embodiments of the present application has the following technical effects: (1) It realizes the automatic process control of the entire sewage treatment process, and solves the problem that the current control of the sewage treatment process is mainly carried out manually; (2) Build safety interlock logic based on the safety logic controller to ensure that even in the case of host computer or communication failures, it can still quickly respond to dangerous working conditions, avoid equipment damage or environmental pollution, and improve the safety and reliability of sewage treatment.

[0027] Embodiment Two: Based on the same inventive concept as the sewage treatment process control method based on the safety logic controller in Embodiment One, as Figure 2As shown in the figure, the present application provides a sewage treatment process control system based on a safety logic controller. The system includes: A sensor module, which is used to deploy water quality sensors to collect sewage index data, and at the same time deploy external environment sensors to collect external environment parameters; A first communication module, which is used to configure an I / O communication module on the safety logic controller, establish communication with the water quality sensors and external environment sensors, and obtain sewage index data and external environment parameters; A second communication module, which is used for the safety logic controller to communicate with the upper computer through industrial Ethernet, and send the sewage index data and external environment parameters to the upper computer; A calculation module, which is used for the upper computer to process the sewage index data and external environment parameters, merge and generate a sewage feature vector, input the sewage feature vector into a three-layer feedforward neural network model, and obtain sewage treatment control parameters; A compilation module, which is used for the upper computer to compile the sewage treatment control parameters to generate sewage treatment control instructions; A process control module, which is used for the upper computer to send the sewage treatment control instructions back to the safety logic controller through industrial Ethernet. The safety logic controller regulates the sewage treatment equipment according to the sewage treatment control instructions. At the same time, the safety logic controller deploys safety interlock logic for parameter overrun protection.

[0028] Through the foregoing detailed description of the sewage treatment process control method based on a safety logic controller in this specification, those skilled in the art can clearly know the sewage treatment process control system based on a safety logic controller in this embodiment. Since it corresponds to the method disclosed in the embodiment, the description is relatively simple. For related parts, reference can be made to the description in the method part.

[0029] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0030] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present application. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A sewage treatment process control method based on a safety logic controller, characterized in that, The method includes: Deploy water quality sensors to collect sewage index data, and at the same time deploy external environment sensors to collect external environment parameters; Configure an I / O communication module on the safety logic controller to establish communication with the water quality sensors and external environment sensors, and obtain sewage index data and external environment parameters; The safety logic controller communicates with the host computer through the industrial Ethernet, and sends the sewage index data and external environment parameters to the host computer; The host computer processes the sewage index data and external environment parameters, combines them to generate a sewage feature vector, and inputs the sewage feature vector into a three-layer feedforward neural network model to obtain sewage treatment control parameters; The host computer compiles the sewage treatment control parameters to generate sewage treatment control instructions; The host computer sends the sewage treatment control instructions back to the safety logic controller through the industrial Ethernet. The safety logic controller regulates the sewage treatment equipment according to the sewage treatment control instructions. At the same time, the safety logic controller deploys a safety interlock logic to perform parameter overrun protection.

2. The sewage treatment process control method based on a safety logic controller according to claim 1, characterized in that The sewage index data includes biochemical oxygen demand, total organic carbon, ammonia nitrogen, total nitrogen, total phosphorus, pH value, and insoluble particulate matter content. The external environment parameters include temperature and humidity. The sewage treatment control parameters include dissolved oxygen concentration, nitrate nitrogen concentration, mixed liquor suspended solid concentration, reflux ratio, sludge retention time, and aeration volume.

3. The sewage treatment process control method based on a safety logic controller according to claim 1, wherein, The configuration of the I / O communication module on the safety logic controller to establish communication with the water quality sensors and external environment sensors specifically includes: Configure an I / O communication module that supports mixed signal input on the safety logic controller, connect it to the water quality sensors and external environment sensors using a double-shielded twisted pair cable, and install an optocoupler to cut off the conduction interference path, and establish communication with the water quality sensors and external environment sensors through a differential signal protocol.

4. The sewage treatment process control method based on a safety logic controller according to claim 1, characterized in that, The communication between the safety logic controller and the host computer through the industrial Ethernet specifically includes: The host computer obtains the IP address and port number of the safety logic controller, and establishes a communication link according to the serial port type supported by the safety logic controller; The host computer installs the driver program of the safety logic controller and performs data alignment processing. At the same time, a virtual local area network is established to isolate the current communication link. During the data sending and receiving process, the CRC check algorithm is used to perform data integrity check.

5. The sewage treatment process control method based on a safety logic controller according to claim 1, characterized in that, The processing of the sewage index data and external environment parameters by the host computer, combining them to generate a sewage feature vector, and inputting the sewage feature vector into a three-layer feedforward neural network model to obtain sewage treatment control parameters specifically includes: The host computer corrects outliers in the sewage index data and external environment parameters using a sliding window algorithm, performs normalization processing, and then performs spatial dimension splicing through a feature fusion unit to generate a sewage feature vector; Construct a three-layer feedforward neural network model including an input layer, a hidden layer, and an output layer. Input the sewage feature vector into the three-layer feedforward neural network model to obtain sewage treatment control parameters. Among them, the number of nodes in the input layer is the same as the dimension of the sewage feature vector, the number of nodes in the output layer is the same as the number of sewage treatment control parameters, and the number of nodes in the hidden layer is the average value between the number of nodes in the input layer and the output layer.

6. The sewage treatment process control method based on a safety logic controller according to claim 1, wherein, The host computer compiles the sewage treatment control parameters to generate sewage treatment control instructions, specifically including: Based on the programming format of the safety logic controller, the host computer converts the sewage treatment control parameters into programming logic statements; Check the syntax errors and logical conflicts of the programming logic statements. If there are syntax errors and logical conflicts, an exception is thrown. If there are no syntax errors and logical conflicts, the programming logic statements are converted into sewage treatment control instructions recognizable by the safety logic controller composed of machine codes.

7. The sewage treatment process control method based on a safety logic controller according to claim 1, characterized in that, The safety logic controller deploys safety interlock logic for parameter overrun protection, specifically including: When the safety logic controller detects that the sewage treatment control parameters in the sewage treatment control instructions exceed the preset threshold range, or the operation sequence of the equipment is incorrect when the sewage treatment control instructions regulate the sewage treatment equipment, the emergency shutdown mechanism of the sewage treatment equipment is triggered.

8. A sewage treatment process control system based on a safety logic controller, the system includes: A sensor module, which is used to deploy water quality sensors to collect and obtain sewage index data, and at the same time deploy external environment sensors to collect and obtain external environment parameters; A first communication module, which is used to configure an I / O communication module on the safety logic controller to establish communication with the water quality sensors and external environment sensors to obtain sewage index data and external environment parameters; A second communication module, which is used for the safety logic controller to communicate with the host computer through an industrial Ethernet, and send the sewage index data and external environment parameters to the host computer; A calculation module, which is used for the host computer to process the sewage index data and external environment parameters, merge them to generate a sewage feature vector, input the sewage feature vector into a three-layer feedforward neural network model, and obtain sewage treatment control parameters; A compilation module, which is used for the host computer to compile the sewage treatment control parameters to generate sewage treatment control instructions; A process control module, which is used for the host computer to send the sewage treatment control instructions back to the safety logic controller through an industrial Ethernet. The safety logic controller regulates the sewage treatment equipment according to the sewage treatment control instructions. At the same time, the safety logic controller deploys safety interlock logic for parameter overrun protection.

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