A sewage intelligent management and control system and method based on a wireless IO module

Abstract

This invention discloses a smart wastewater management system and method based on a wireless I / O module, belonging to the field of intelligent wastewater treatment control. The system includes an existing PLC / DCS, an I / O acquisition terminal, data processing, AI analysis, priority arbitration, hardware interlocking units, and actuators. The I / O acquisition terminal supports high-impedance parallel external connection or native deployment, with opto-coupled isolation to avoid interference with the original system signals. The AI ​​analysis unit identifies impact loads based on the temporal coupling relationship between influent flow and water quality, outputting frequency conversion or switching commands to regulate the actuators and suppress impact loads. The priority arbitration unit incorporates hysteresis comparison and dead-time logic, switching only after a threshold is exceeded and a debouncing delay is applied to avoid system oscillation. The hardware interlocking unit achieves seamless fault switching based on a fault-oriented safety principle. This invention requires no modification to the PLC program, no production downtime, and is suitable for upgrading existing plants and deploying in new plants. It features lossless access, hardware interlocking, vibration resistance, and industrial safety compliance.

Description

Technical Field

[0001] This invention relates to the field of intelligent control technology for wastewater treatment, specifically to a wastewater intelligent management and control system and method based on a wireless I / O module that features uninterrupted operation, lossless access, hardware redundancy and interlocking, and fault-oriented safety. Background Technology

[0002] There are seven core defects in the intelligent transformation of existing sewage treatment plants: 1. The renovation requires modification of the existing PLC / DCS system, production shutdown and construction, which will affect production and is costly; 2. The plug-in system lacks hardware interlocking and redundant architecture, and the conflict between the two systems' instructions can easily lead to security incidents; 3. The AI ​​analysis logic is abstract and vague, lacking clear physical control binding; 4. System compatibility can be easily avoided by changing the communication method and adjusting the impedance value; 5. The power supply and signal power-taking logic is not clearly described, and the reliability of system data acquisition and control output is insufficient; 6. Outdated PLCs cannot be upgraded with new programs, making it difficult to implement lightweight smart systems. 7. The lack of dead zone and anti-jitter mechanism during dual-system command switching can easily lead to control oscillations and equipment damage.

[0003] To this end, the present invention provides a smart management and control solution with lossless access, hardware interlocking, command arbitration with hysteresis anti-jitter, strong binding of AI and physical control, and strong applicability. Summary of the Invention

[0004] Purpose of the invention Overcoming the shortcomings of existing technologies, this paper provides a wastewater intelligent management and control system and method based on wireless I / O modules, which requires no production downtime, no modification to the original program, features hardware redundancy and interlocking, fault-oriented safety, strong binding of AI analysis and physical execution, and priority arbitration with hysteresis dead zone. This enables lightweight and rapid upgrading of old wastewater treatment plants and native intelligent deployment of new wastewater treatment plants.

[0005] Technical solution 1. System Composition 1) Existing PLC / DCS System: The existing control core of the wastewater treatment plant; 2) IO Acquisition Terminal: Includes signal isolation circuit, microcontroller, communication interface unit, and power management circuit; can be connected in parallel with high impedance externally, or integrated as a native unit with minimal shunt and no interference to the original system; 3) Data Processing Unit: Filters, reduces noise, and normalizes to provide high-quality data; 4) AI Analysis Unit: Based on the flow-water quality coupling relationship, it determines the impact load through explicit mathematical calculations or time-series prediction models, directly outputs hardware control signals such as frequency converters and switching quantities, and adjusts actuators such as water pumps, valves, and dosing pumps to achieve physical suppression; 5) Priority Arbitration Unit: Built-in hysteresis comparison and switching dead zone, anti-jitter delay, and hardware relay physically disconnects the original PLC output circuit, switching only when conditions are met to avoid oscillation; 6) Hardware Interlock Unit: Relay interlock, switching back to the original system in milliseconds when the IO acquisition terminal malfunctions; 7) Actuators: Perform process actions such as aeration, dosing, flow regulation, and valve control.

[0006] 2. Core Innovation Points This invention is not simply a parallel signal acquisition, but a complete control architecture with dual-system parallelism, hardware priority arbitration with hysteresis dead zone, hardware interlock switching, and strong binding of AI computing and physical control, enabling the safe coexistence and lossless upgrade of the intelligent system and the original system.

[0007] 3. Power Supply Scheme The power management circuit is powered independently by an external DC24V industrial power supply to ensure stable operation of wireless / wired communication and control output; the signal acquisition end is a microampere-level shunt, used only for signal detection and does not bear the main power supply of the module, thus completely avoiding pulling down the sensor circuit voltage and causing false alarms in the original system.

[0008] 4. Impact Load Determination When the Pearson correlation coefficient |r| between the influent flow rate fluctuation rate and the COD concentration change rate is greater than 0.8, and the COD concentration change amplitude ΔCOD is greater than 20%, it is determined to be a shock load. Flow rate fluctuation rate = standard deviation of flow data over the past N sampling periods; COD change rate = difference between the COD value at the current moment and the previous moment; the determination result is directly converted into physical control commands such as frequency conversion control, valve opening, and dosing frequency to drive the actuators.

[0009] 5. Fault-oriented safety logic The hardware interlock unit uses relay hard interlocking: Normal operation: Under intelligent system control, normally open contacts are closed, and normally closed contacts are open. Abnormalities (power outage / connection failure / fault): Normally open switches open, normally closed switches close, and the system switches back to the original system without disturbance in milliseconds. The actuator does not suddenly open or close, and there is no fault alarm for disconnection.

[0010] 6. Priority arbitration debouncing logic The priority arbitration unit has a built-in hysteresis comparator, dead zone threshold, and anti-jitter delay. Hardware shielding and switching are only performed when the difference between the AI ​​instruction and the original PLC instruction exceeds the set threshold and the duration exceeds the anti-jitter delay, thus eliminating ping-pong oscillation.

[0011] Beneficial effects 1. Adaptable to various communication and impedance conditions: This system supports both wired and wireless communication, and can adapt to various impedance conditions, making it applicable to a wider range of working conditions; 2. The AI ​​algorithm matches the control link of the physical device and has a clear hardware execution carrier; the entire control process relies on physical circuits and equipment, and the solution boundaries are clear; 3. Stable operation without oscillation: Priority arbitration with hysteresis dead zone and anti-jitter delay completely eliminates ping-pong switching and system oscillation; 4. Strong adaptability to local deployment: External independent power supply + microampere-level signal acquisition, does not interfere with the original system; hardware shielding requires no program modification, perfectly compatible with old PLCs; 5. Industrial safety compliance: Dual hardware redundancy interlocks, fault-oriented safety, and compliance with industrial control safety standards; 6. Full-scenario adaptation: Supports wired / wireless communication and multiple process parameter configurations, suitable for the construction and renovation of various municipal / industrial / domestic wastewater treatment plants. Attached Figure Description

[0012] Figure 1 System overall structure diagram Figure 2 Method Flowchart Figure 3 Hardware interlock and signal shielding circuit diagram Among them: 100-existing PLC / DCS system; 200-IO acquisition terminal; 201-signal isolation circuit; 202-microcontroller; 203-communication interface unit; 204-power management circuit; 300-data processing unit; 400-AI analysis unit; 500-priority arbitration unit; 600-hardware interlock unit; 700-actuator. Detailed Implementation

[0013] Example 1: Upgrading an old wastewater treatment plant without shutting down production 1. Existing system: Siemens S7-300 PLC; 2. Deployment: The IO acquisition terminal is connected in parallel with high impedance to the liquid level, flow rate, and COD circuits, with independent DC24V power supply and hardware interlocking and arbitration configured; 3. Acquisition: Microampere-level signal splitting, opto-isolation, and data processing unit preprocessing; 4. AI Analysis: Based on |r|>0.8 and ΔCOD>20%, the impact load is determined, and the frequency control commands for the fan inverter and the dosing pump are directly generated; 5. Execution: After the priority arbitration unit detects that the difference between the detected instructions exceeds the dead zone threshold and continues to delay due to anti-jitter, it disconnects the original PLC output and forces the execution of the intelligent instruction; 6. Security: Hardware interlocks are monitored in real time, and intelligent management continues if no abnormalities are found.

[0014] Example 2: Fault-free handover IO acquisition terminal communication interruption → hardware interlock unit detection → relay action → disconnection of intelligent control → reconnection of original PLC circuit → seamless switching, no disconnection alarm, and smooth operation of actuator; intelligent control is automatically restored after fault repair.

[0015] Example 3: Multi-process adaptation For dyeing and printing wastewater: the AI ​​analysis unit is configured for color-oxidant dosage coupled analysis, directly outputting the dosing pump control signal. It can be adapted by adjusting the threshold without modifying the hardware.

[0016] Example 4: Native Integrated Deployment of New Wastewater Treatment Plant The new plant directly integrates IO acquisition terminals, AI analysis, priority arbitration with hysteresis and dead zone, and hardware interlocking units into a native design, replacing the traditional control architecture. It achieves intelligent management and control in one step without the need for external components, and is stable, reliable, and highly scalable.

Claims

1. A smart wastewater management system based on a wireless I / O module, characterized in that, include: The original PLC / DCS system (100), IO acquisition terminal (200), data processing unit (300), AI analysis unit (400), priority arbitration unit (500), hardware interlock unit (600) and actuator (700); The input terminal of the IO acquisition terminal (200) is connected to the sensor signal circuit of the original PLC / DCS system (100) in parallel with high input impedance. Its input impedance is configured so that the shunt current generated after connection is lower than a preset threshold, so as not to affect the normal signal acquisition of the original PLC / DCS system (100) and realize signal lossless multiplexing. The IO acquisition terminal (200) can be deployed externally or natively integrated. The IO acquisition terminal (200) contains a signal isolation circuit (201), a microcontroller (202), a communication interface unit (203) and a power management circuit (204). The signal isolation circuit (201) uses an optocoupler to achieve electrical isolation. The data processing unit (300) performs standardized preprocessing on the acquired signal to eliminate noise and error. The AI ​​analysis unit (400) is configured to: calculate the linear correlation coefficient, variance, and slope of change based on the coupling relationship between the influent flow time series data and the water quality parameter time series data, or perform analysis based on the machine learning time series prediction model; when the calculation results meet the preset physical condition judgment conditions, directly generate a frequency conversion control signal or switch action command for the actuator (700), and realize the physical suppression of sewage shock load by adjusting the pump speed, valve opening or dosing pump frequency; The priority arbitration unit (500) and the hardware interlock unit (600) constitute a dual-system hardware redundancy interlock architecture; The priority arbitration unit (500) has built-in hysteresis comparison logic, which is configured to: only when the difference between the control command generated by the AI ​​analysis unit (400) and the output command of the original PLC / DCS system (100) exceeds the preset dead zone threshold and the duration exceeds the anti-jitter delay, the output signal of the original PLC / DCS system (100) will be temporarily physically shielded in hardware to force the execution of the intelligent control command. The hardware interlock unit (600) adopts relay normally open / normally closed contact interlock logic to monitor the operating status of the IO acquisition terminal (200) in real time. When the IO acquisition terminal (200) is abnormal, it immediately cuts off its control output and switches the control right back to the original PLC / DCS system (100) without disturbance, so as to achieve fault-oriented safety. The actuator (700) receives and executes the equipment control instructions.

2. A method for intelligent wastewater management based on the system described in claim 1, characterized in that, Including the following steps: Step 1 System Deployment: Connect the IO acquisition terminal (200) to the sensor signal circuit in parallel with high input impedance, complete the wiring configuration of the priority arbitration unit (500) and the hardware interlock unit (600), the IO acquisition terminal can be deployed externally or natively integrated, without changing the underlying program of the original PLC / DCS system (100) and without interrupting production; Step 2: Signal Acquisition and Preprocessing: The IO acquisition terminal (200) synchronously acquires sensor signals, which are then isolated and sent to the data processing unit (300) for standardized preprocessing. Step 3 AI Intelligent Analysis: The AI ​​analysis unit (400) calculates the coupling relationship between the influent flow rate and water quality parameters. If the value exceeds the preset threshold, it is determined to be an impact load, and a frequency conversion control signal or switching command is directly generated to adjust the actuator to achieve physical suppression. Step 4: Command Anti-jitter Arbitration and Execution: The priority arbitration unit (500) performs hysteresis comparison. Only when the command difference exceeds the dead zone threshold and the anti-jitter delay continues, the hardware physically shields the original PLC signal and forces the execution of the intelligent control command. Step 5: Fault-safe switching: The hardware interlock unit (600) monitors the status of the IO acquisition terminal (200), and in case of an abnormality, it seamlessly switches back to the original system control in milliseconds; Step 6 Closed-loop optimization: The actuator (700) feeds back the operating data, the AI ​​analysis unit (400) updates the model parameters, and the data flows back to the signal acquisition stage to form a continuous optimization closed loop.

3. A computer-readable storage medium, characterized in that, It contains a computer program that, when executed by a processor, implements all the steps of the method described in claim 2.

4. The system according to claim 1, characterized in that, The input impedance of the IO acquisition terminal (200) is not less than 1MΩ, so that the shunt current is in the microampere range.

5. The system according to claim 1, characterized in that, The communication interface unit (203) supports wired communication (RS485, Ethernet, Modbus, Profibus, OPC UA) or wireless communication (LoRa, 4G).

6. The system according to claim 1, characterized in that, When the communication interface unit (203) transmits data and instructions, it uses AES or the national cryptographic SM4 industrial-grade symmetric encryption algorithm to encrypt the transmission. The data can only be executed after the decryption verification is passed.

7. The system according to claim 1, characterized in that, The power management circuit (204) is powered by an external DC24V independent power supply and supports circuit auxiliary power supply. It has overvoltage, overcurrent and overload protection.

8. The system according to claim 1, characterized in that, The actuator (700) includes at least one of a water pump, valve, dosing device, aeration blower, frequency converter, and electric gate.

9. The method according to claim 2, characterized in that, Preset thresholds can be adjusted remotely; activated sludge process is adapted to flow rate-DO coupling, chemical precipitation process is adapted to pH-dosing frequency coupling, denitrification and phosphorus removal process is adapted to ORP-internal reflux pump frequency coupling, and dyeing and printing wastewater is adapted to color-oxidant dosage coupling.

10. The system according to claim 1, characterized in that, The AI ​​analysis unit (400) supports extended multi-parameter coupled analysis of ammonia nitrogen, total phosphorus, total nitrogen, and ORP, adapting to different wastewater types.

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