Control method, control device, control system, storage medium, and program product

Abstract

The invention provides a control method, a control device, a control system, a storage medium and a program product, and relates to the field of industrial control. The digital base judges at least one of whether the first waterway opening number and the second waterway opening number are consistent or not and whether the frame loss rate of communication between the PLC and the gateway is larger than a set value or not, the first waterway opening number is the waterway opening number, calculated in real time when the PLC works normally, of the air conditioning system, and the second waterway opening number is the waterway opening number of the air conditioning system; the second waterway opening number is the waterway opening number, calculated by the digital base in real time, of the air conditioning system, and the first waterway opening number and the second waterway opening number are the same in calculation logic; and under the condition of inconsistency or the frame loss rate is greater than the set value, the digital base judges that the PLC fails and takes over the control of the air conditioning system. The state of the PLC is comprehensively and accurately judged on the basis of the consistency of the opening number of the waterways and the double dimensions of the frame loss rate, and when the PLC breaks down, the digital base takes over control over the air conditioning system in time, so that the operation stability of the air conditioning system is improved.

Description

Technical Field

[0001] This disclosure relates to the field of industrial control, and in particular to a control method, control device, control system, storage medium, and program product. Background Technology

[0002] In industrial automation group control systems, a master-slave architecture is mainly adopted. The programmable logic controller (PLC) serves as the scheduling center of the group control system, undertaking core functions such as equipment collaborative control, dynamic load balancing, and interaction with the host computer.

[0003] However, this master-slave architecture has a fatal single point of failure risk; that is, when the PLC fails, the group control system will completely lose its data interaction capability. For example, the subordinate gateways will be unable to receive coordination instructions from the PLC, causing equipment to malfunction; the human-machine interface system will be unable to obtain equipment status and control instructions. Summary of the Invention

[0004] In this embodiment, based on the consistency of the number of open water channels and the frame drop rate, the state of the programmable logic controller (PLC) is comprehensively and accurately determined. When the PLC fails, the digital base promptly takes over the control of the air conditioning system, improving the stability of the air conditioning system and preventing the entire air conditioning system from going out of control due to a PLC failure.

[0005] This disclosure provides a control method in some embodiments, including:

[0006] The digital base determines at least one of the following: whether the number of water circuits open is consistent with the number of water circuits open, and whether the frame loss rate of communication between the programmable logic controller and the gateway is greater than a set value. The number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time when the programmable logic controller is working normally. The number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time by the digital base. The calculation logic of the number of water circuits open is the same as that of the number of water circuits open.

[0007] If the number of open water channels is inconsistent with the number of open water channels, or if the frame drop rate is greater than a set value, the digital base determines that the programmable logic controller is faulty and takes over the control of the air conditioning system.

[0008] In some embodiments, the calculation logic for the number of water circuits opened and the number of water circuits opened is as follows: the number of water circuits opened in the air conditioning system is calculated based on fixed value parameters and real-time monitoring parameters. The fixed value parameters include the density of water and the specific heat capacity of water. The real-time monitoring parameters include the total cooling load of the building, the unit load rate, the unit flow rate, and the temperature difference between the unit's supply water and return water.

[0009] In some embodiments, calculating the number of water circuits to be opened in the air conditioning system based on fixed-value parameters and real-time monitoring parameters includes:

[0010] Calculate the first product of the building's total cooling load and the unit's load rate;

[0011] Calculate the density of water, the specific heat capacity of water, the unit flow rate, and the second product of the temperature difference between the unit's supply and return water;

[0012] The ratio of the first product to the second product is used as the number of water circuits to be opened in the air conditioning system.

[0013] In some embodiments, the total building cooling load is determined based on the building structure, heat source, and weather conditions; and / or the unit load rate is determined based on the ratio of the unit's actual load to its rated load.

[0014] In some embodiments, the situations where the number of first waterway openings differs from the number of second waterway openings include:

[0015] The first number of water circuits open is calculated by the programmable logic controller (PLC) based on fixed parameters and real-time monitoring parameters, using the latest first monitoring value when the PLC was working normally before the fault.

[0016] The second waterway opening count is calculated by the digital base based on the fixed parameter and the current second monitoring value of the real-time monitoring parameter;

[0017] When the second monitoring value of the real-time monitoring parameter changes relative to the first monitoring value, the number of the first waterway openings is inconsistent with the number of the second waterway openings.

[0018] In some embodiments, the method for calculating the frame loss rate during communication between the programmable logic controller and the gateway includes:

[0019] Calculate the difference between the number of frames sent by the programmable logic controller and the number of frames received by the gateway;

[0020] The ratio of the difference to the number of frames sent by the programmable logic controller is used as the frame loss rate for communication between the programmable logic controller and the gateway.

[0021] In some embodiments, the system further includes: after the digital base takes over the control of the air conditioning system, if the number of first water circuit openings is the same as the number of second water circuit openings, the digital base determines that the programmable logic controller has recovered from the fault and switches to the programmable logic controller to take over the control of the air conditioning system.

[0022] In some embodiments, the control method further includes:

[0023] The digital base is preloaded with a first control program;

[0024] In response to a first program update request sent by the programmable logic controller (PLC), the digital dock takes over the control of the air conditioning system based on the first control program and synchronizes the first control program to the PLC, switching the control of the air conditioning system to the PLC. The first program update request is sent when the versions of the second control program of the PLC and the first control program of the digital dock are inconsistent.

[0025] In some embodiments, the control method further includes:

[0026] The digital base is preloaded with a first control program;

[0027] In response to a second program update request sent by the programmable logic controller (PLC), the digital base station synchronizes the first control program to the PLC. The second program update request is sent when the versions of the PLC's second control program and the digital base station's first control program are inconsistent and no unit is running.

[0028] This disclosure provides a control device in some embodiments, including:

[0029] The fault judgment module is configured to judge at least one of the following: whether the number of water circuits open is consistent with the number of water circuits open, and whether the frame loss rate of communication between the programmable logic controller and the gateway is greater than a set value. The number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time when the programmable logic controller is working normally, and the number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time by the digital base. The calculation logic of the number of water circuits open is the same as that of the number of water circuits open.

[0030] The takeover control module is configured to determine that the programmable logic controller is faulty when the number of the first water channel openings is inconsistent with the number of the second water channel openings or the frame drop rate is greater than a set value, and to control the digital base to take over the control of the air conditioning system.

[0031] In some embodiments, the control device further includes: a program synchronization module configured to control the digital dock, preload a first control program, respond to a first program update request sent by the programmable logic controller, take over the control of the air conditioning system based on the first control program, synchronize the first control program to the programmable logic controller, and switch the programmable logic controller to take over the control of the air conditioning system, wherein the first program update request is sent when the version of the second control program of the programmable logic controller is inconsistent with the version of the first control program of the digital dock.

[0032] Some embodiments of this disclosure provide a control device including: a memory; and a processor coupled to the memory, the processor being configured to execute control methods of various embodiments based on instructions stored in the memory.

[0033] This disclosure provides a control system in some embodiments, including:

[0034] The programmable logic controller (PLC) is configured to control the air conditioning system during normal operation and to calculate the number of opening water channels in the air conditioning system in real time; and

[0035] The digital base is configured to execute the control methods of various embodiments.

[0036] Some embodiments of this disclosure provide a computer-readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the control methods of various embodiments.

[0037] This disclosure provides, in some embodiments, a computer program product including computer instructions that, when executed by a processor, implement the control methods of various embodiments. Attached Figure Description

[0038] The accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. This disclosure can be more clearly understood from the following detailed description with reference to the accompanying drawings.

[0039] Obviously, the accompanying drawings described below are merely some embodiments of this disclosure. Those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0040] Figure 1 A schematic diagram of an air conditioning system with a master-slave architecture based on related technologies is shown.

[0041] Figure 2 A schematic diagram of an air conditioning system with a redundant backup architecture according to some embodiments of the present disclosure is shown.

[0042] Figure 3 A schematic diagram illustrating a control method according to some embodiments of the present disclosure is shown.

[0043] Figure 4 A schematic diagram illustrating a control method according to some embodiments of the present disclosure is shown.

[0044] Figure 5 A schematic diagram illustrating a control method according to some embodiments of the present disclosure is shown.

[0045] Figure 6 A schematic diagram illustrating a control method according to some embodiments of the present disclosure is shown.

[0046] Figure 7 A schematic diagram of a control device according to some embodiments of the present disclosure is shown.

[0047] Figure 8 A schematic diagram of a control device according to some embodiments of the present disclosure is shown.

[0048] Figure 9 A schematic diagram of a control system according to some embodiments of the present disclosure is shown. Detailed Implementation

[0049] It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of this disclosure.

[0050] Those skilled in the art will understand that the terms "first," "second," etc., in the embodiments of this disclosure are only used to distinguish different steps, devices, or modules, and do not represent any specific technical meaning, nor do they indicate a necessary logical order between them.

[0051] It should also be understood that in the embodiments disclosed herein, "a plurality of" may refer to two or more, and "at least one" may refer to one, two or more.

[0052] It should also be understood that any component, data or structure mentioned in the embodiments of this disclosure can generally be understood as one or more unless expressly defined or given to the contrary in the context.

[0053] Furthermore, the term "and / or" in this disclosure is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this disclosure generally indicates that the preceding and following related objects have an "or" relationship.

[0054] It should also be understood that the description of the various embodiments in this disclosure emphasizes the differences between the various embodiments, and the similarities or similarities can be referred to each other. For the sake of brevity, they will not be described in detail.

[0055] At the same time, it should be understood that, for ease of description, the dimensions of the various parts shown in the accompanying drawings are not drawn according to actual scale.

[0056] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit this disclosure or its application or use.

[0057] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0058] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0059] Furthermore, in order to avoid obscuring this disclosure with unnecessary details, only processing steps and / or device structures closely related to the scheme at least according to this disclosure are shown in the accompanying drawings, while other details that are not closely related to this disclosure are omitted.

[0060] Figure 1 A schematic diagram of an air conditioning system with a master-slave architecture based on related technologies is shown.

[0061] like Figure 1 As shown, the PLC and HMI system are connected to the switch and can communicate using Modbus TCP (Transmission Control Protocol). Each gateway is connected to the switch and to various devices in the air conditioning system, such as: chilled water pumps, chilled water pump meters, cooling water pump meters, cooling towers, cooling tower meters, cooling tower valves, temperature sensors, pressure sensors, flow sensors, etc., but not limited to the examples given. The PLC and HMI system can communicate with these devices through the switch and gateways, for example, by sending control commands and uploading sensor data, but not limited to the examples given.

[0062] This master-slave architecture air conditioning system has a fatal single point of failure risk, that is, when the PLC fails, the air conditioning system will completely lose its data interaction capability.

[0063] Figure 2 A schematic diagram of an air conditioning system with a redundant backup architecture according to some embodiments of the present disclosure is shown.

[0064] like Figure 2As shown, the PLC, digital docking station, and human-machine interface system are connected to the switch. The programmable logic controller (PLC) and the digital docking station serve as backups for each other. The PLC and the HMC can communicate using Modbus TCP, while the digital docking station can communicate using MQTT (Message Queuing Telemetry Transport). Each gateway is connected to the switch, and each gateway connects to various devices in the air conditioning system, such as: units, unit meters, unit valves; chilled water pumps, water pump meters; cooling water pumps, water pump meters; cooling towers, cooling tower meters, cooling tower valves; temperature sensors, pressure sensors, flow sensors, etc., but not limited to the examples given. The PLC, digital docking station, and HMC can communicate with various devices in the air conditioning system through the switch and various gateways, for example, by sending control commands and uploading sensor data, but not limited to the examples given.

[0065] PLC: As the main control unit, it is responsible for executing core control logic under normal operating conditions. It communicates with various gateways via the Modbus TCP protocol, sends control commands to the controlled equipment (such as units, water pumps, cooling tower fans, valves, etc.) in real time, and collects equipment operating status data through various sensors. The hardware of the PLC is an industrial-grade PLC, also known as a hardware PLC, which has high real-time performance and strong anti-interference capabilities.

[0066] Digital base station: Deployed on an industrial server and built on a microservice architecture, it can monitor the Modbus TCP communication data stream between the PLC and each gateway in real time, and has a built-in control program that is completely consistent with the PLC. It can immediately take over the control of the air conditioning system after switching, and communicate with each gateway via the MQTT protocol.

[0067] Compared to hardware PLCs, digital docking stations can be built directly using conventional computers or servers, and can be deployed on the same server as the host computer software, enabling control logic, human-machine interaction, and database to be deployed on the same platform.

[0068] Gateway: For example, an IoT (Internet of Things) gateway, which acts as a physical layer communication hub, connecting all lower-level controlled devices with the upper-level control system. It has multi-protocol conversion capabilities, can receive instructions from PLCs and digital docks, and forward the instructions to the corresponding devices.

[0069] When the control program is deployed for the first time, it can be deployed to the digital base first. After verification, the control program can be synchronized to the PLC. When the digital base detects that the control program of the PLC is consistent with the control program of the digital base, the synchronization process of the control program is completed and the redundancy configuration of the control program is completed.

[0070] This deployment method reduces the deployment risk of control programs. If the control program is deployed directly to the PLC, syntax errors or logical vulnerabilities in the program may cause the PLC to shut down abnormally and production to be interrupted. However, by first deploying it to the digital dock, offline simulation, logic verification, and conflict detection can be completed on the digital dock before synchronization to the PLC. This pre-screening prevents unqualified control programs from entering the production process.

[0071] Furthermore, the digital base can remotely and in batches synchronize verified and qualified control programs to multiple PLCs, making it suitable for control program deployment scenarios in PLC clusters, improving the deployment efficiency of control programs, and is especially suitable for large-scale deployment at the production line and factory levels.

[0072] After deploying consistent control programs on the digital base station and the PLC, the digital base station and the PLC can act as backups for each other in controlling the air conditioning system. That is, when the PLC fails, the digital base station can take over the control of the air conditioning system; conversely, when the digital base station malfunctions, the PLC can take over the control of the air conditioning system. Furthermore, before or during the switch of control between the digital base station and the PLC, the two systems need to synchronize the current operating status of the air conditioning system (such as fan speed, valve opening, etc.) to avoid parameter gaps after the switch and improve the stability of continuous control. For example, if the fan frequency is 50Hz when the PLC fails, the digital base station will not control the fan based on its initial frequency of 0Hz, but will instead operate based on the fan frequency of 50Hz.

[0073] Because industrial-grade PLCs possess high real-time performance and strong anti-interference capabilities, in some embodiments, the air conditioning system is preferentially controlled by the PLC. When the PLC fails, the digital docking station can temporarily take over the control of the air conditioning system. When the PLC recovers, the control of the air conditioning system is switched back to the PLC. This achieves a "PLC-centric, digital docking station-assisted" control mode, which retains the advantages of the PLC's high real-time performance and strong anti-interference capabilities in industrial scenarios, while the digital docking station provides low-cost, easily expandable, redundant backup control, effectively mitigating the risk of single-point failure in the air conditioning system.

[0074] The following describes various methods for controlling air conditioning systems based on digital docking stations and PLCs.

[0075] Figure 3 The diagram illustrates a control method according to some embodiments of the present disclosure. In this embodiment, when the programmable logic controller fails, the digital dock actively takes over the control of the air conditioning system.

[0076] Step 310: The digital base obtains the number of the first waterway open and the number of the second waterway open in real time.

[0077] The first water circuit opening count is the real-time calculation of the air conditioning system's water circuit opening count when the programmable logic controller (PLC) is operating normally. The second water circuit opening count is the real-time calculation of the air conditioning system's water circuit opening count by the digital base station. The calculation logic for the first and second water circuit opening counts is the same. The digital base station obtains the first water circuit opening count, calculated in real-time by the PLC during normal operation, and calculates the second water circuit opening count in real time. Thus, the digital base station obtains both the first and second water circuit opening counts in real time.

[0078] The calculation logic for the number of water circuits opened and the number of water circuits opened is as follows: the number of water circuits opened in the air conditioning system is calculated based on fixed parameters and real-time monitoring parameters. Fixed parameters include physical property parameters such as water density and specific heat capacity. Real-time monitoring parameters include actual operating condition parameters such as total building cooling load, unit load rate, unit flow rate, and temperature difference between unit supply and return water, which can cover multiple dimensions of load, equipment, and medium.

[0079] The calculation logic for the number of water circuits to be opened clearly includes fixed parameters (density of water, specific heat capacity) and real-time monitoring parameters (total building cooling load, unit load rate, unit flow rate, temperature difference between unit supply and return water). This ensures that the calculation of the number of water circuits to be opened is based on physical characteristics and actual operating conditions, and can accurately calculate the number of water circuits to be opened to meet the current cooling load, providing strong data support for subsequent fault diagnosis.

[0080] The calculation of the number of water circuits to be opened in the air conditioning system based on fixed parameters and real-time monitoring parameters includes: calculating the first product of the total building cooling load and the unit load rate, which represents the "actual cooling load required by the building"; calculating the second product of the water density, water specific heat capacity, unit flow rate, and the temperature difference between the unit supply and return water, which represents the "actual cooling load supplied by a single water circuit"; and taking the ratio of the first product to the second product as the number of water circuits to be opened in the air conditioning system, that is, the minimum number of water circuits required to meet the cooling load.

[0081] This calculation method can be expressed by the formula: Where N represents the number of water channels open, Q represents the total building cooling load, and L represents the unit load rate. C represents the density of water, C represents the specific heat capacity of water, and V represents the unit flow rate. This indicates the temperature difference between the unit's supply water and return water.

[0082] This calculation method transforms abstract load requirements into specific equipment start-up and shutdown quantities. The formula logic is concise and quantifiable, facilitating program implementation by PLC and digital base station, ensuring complete consistency of calculation logic between the two systems, and providing a reliable mathematical basis for subsequent fault diagnosis.

[0083] Each water line is a "cooling capacity transport unit" of the air conditioning system, corresponding to an independent "cooling production + cooling transmission" sub-system. Activating different numbers of water lines can match different total cooling load requirements of a building. A water line typically includes: the unit, water pump, valves, and other supporting equipment, as well as pipes.

[0084] The total cooling load of a building is affected by factors such as building structure, heat sources, and weather conditions. Therefore, the total cooling load can be determined based on these factors. By comprehensively considering multiple influencing factors, the accuracy of the total cooling load can be improved, thereby optimizing the calculation accuracy of the number of water channels open.

[0085] The total cooling load of a building is equal to the sum of its individual components, such as the building structure heat transfer load, indoor heat source load, and fresh air load. The building structure heat transfer load refers to the amount of cooling transferred through the building envelope (exterior walls, roof, windows, etc.) due to the temperature difference between indoors and outdoors. It can be calculated using factors such as the thermal conductivity of building materials, area, and temperature difference. For example, building structure heat transfer load = (material thermal conductivity × area × indoor-outdoor temperature difference ÷ envelope thickness). Different parts, such as exterior walls, roof, and windows, can be calculated separately and then summed. Indoor heat source load includes heat dissipation from equipment (e.g., computers, lighting fixtures) and heat dissipation from occupants (heat generated by human metabolism). For example, equipment heat dissipation = equipment power × percentage of operating time × heat dissipation coefficient; occupant heat dissipation = heat dissipation per person × number of people indoors. The fresh air load is the amount of cooling required to process outdoor air to meet indoor fresh air demand. It can be calculated using factors such as fresh air volume and the temperature difference between outdoor and indoor air. For example, fresh air load = fresh air volume × air density × specific heat capacity of air × (outdoor temperature - indoor temperature).

[0086] The total cooling load of a building can be calculated using simulation software such as EnergyPlus and DeST. Based on input information such as building structure, equipment / personnel parameters, and meteorological data, the simulation software calculates the current total cooling load of the building hourly using the methods described above.

[0087] The unit load factor is determined by the ratio of the actual load to the rated load, representing the unit's load status. The digital base and programmable logic controller (PLC) can read the current unit load factor in real time from the unit's operating data. The actual / rated load directly reflects the unit's operating efficiency and output capacity, avoiding calculation errors caused by ambiguity in the definition of the unit load factor, thereby optimizing the calculation accuracy of the number of water circuit openings.

[0088] In addition, the density of water is a fixed value, for example, 1000 kg / m³ at room temperature; the specific heat capacity of water is a fixed value, for example, 4.186 kJ / (kg·℃); the unit flow rate can be detected in real time using a flow sensor; the temperature difference between the unit's supply water and return water can be detected using a temperature sensor to measure the supply water temperature and return water temperature, and the difference between the two can be calculated.

[0089] Step 320: The digital base station monitors the data flow between the programmable logic controller and the gateway in real time and calculates the frame loss rate of the communication between the programmable logic controller and the gateway.

[0090] The method for calculating the frame loss rate in communication between the programmable logic controller (PLC) and the gateway includes: calculating the difference between the number of frames sent by the PLC and the number of frames received by the gateway; and using the ratio of the difference to the number of frames sent by the PLC as the frame loss rate in communication between the PLC and the gateway.

[0091] This calculation method can be expressed by the formula: Where a represents the frame loss rate, n1 represents the number of frames sent by the programmable logic controller, and n2 represents the number of frames received by the gateway.

[0092] This calculation method can accurately calculate the frame loss rate. The formula is simple, quantifiable, and easy to implement in the PLC and digital base programs. It ensures that the calculation logic of the two systems is completely consistent, providing a reliable mathematical basis for subsequent fault diagnosis.

[0093] Step 330: The digital base determines at least one of the following: whether the number of open water channels is consistent with the number of open water channels, and whether the frame loss rate of communication between the programmable logic controller and the gateway is greater than a set value, in order to determine the current status of the programmable logic controller (such as fault, normal, etc.).

[0094] The situations in which the number of open water channels is the same as the number of open water channels include: the programmable logic controller is normal, and the number of open water channels is calculated by the programmable logic controller based on the current monitoring value of fixed parameters and real-time monitoring parameters; the number of open water channels is calculated by the digital base based on the current monitoring value of fixed parameters and real-time monitoring parameters; the situations in which the number of open water channels is different from the number of open water channels.

[0095] The inconsistency between the first and second waterway opening counts includes: a programmable logic controller (PLC) malfunction, where the first waterway opening count is calculated based on the latest first monitoring value of the PLC when it was operating normally before the malfunction, using fixed parameters and real-time monitoring parameters; and the second waterway opening count is calculated based on the current second monitoring value of the digital base station using fixed parameters and real-time monitoring parameters. When the second monitoring value of the real-time monitoring parameter changes relative to the first monitoring value, the first and second waterway opening counts will be inconsistent.

[0096] The control programs for the PLC and the digital base station are the same. Under normal circumstances, the PLC and the digital base station independently execute the calculation logic for the number of water circuit openings, and the parameter values ​​and calculation logic are identical. Therefore, the calculated number of water circuit openings is consistent. When the PLC malfunctions, it cannot continue calculating the number of water circuit openings and will remain at the calculated value of the water circuit openings just before the malfunction. Meanwhile, the digital base station continues to calculate the number of water circuit openings in real time. The value of the real-time monitoring parameter for calculating the number of water circuit openings changes in real time. At this time, the second number of water circuit openings calculated by the digital base station will be inconsistent with the first number of water circuit openings calculated by the PLC. This indicates that the PLC has malfunctioned.

[0097] For example, the building's total cooling load Q is 400KW, and the unit load rate L is 100%. The calculated power is 400KW. Under normal circumstances, both the PLC and the digital control unit calculate the number of water circuits to be open (N) as 1, meaning one water circuit needs to be opened (e.g., 1 unit, 1 water pump, 1 valve). Due to an increase in the number of people in the building, the total cooling load Q increases to 800KW. At this time, the number of water circuits to be open (N) should be 2. If the PLC malfunctions at this point, it will still maintain the original calculated value of 1 for the number of water circuits to be open, while the digital control unit has already calculated the number of water circuits to be open (N) as 2. The two values ​​are not equal, indicating that the PLC is malfunctioning and is not performing logical operations.

[0098] Under normal communication conditions, the frame loss rate between the programmable logic controller (PLC) and the gateway should not exceed the set value. If the frame loss rate exceeds the set value, it indicates that the PLC may be malfunctioning.

[0099] The combination of consistency in the number of open water channels and frame loss rate enables comprehensive monitoring of the entire PLC calculation and communication link status, ensuring accurate PLC status determination results.

[0100] Step 340: If the number of open water channels is inconsistent with the number of open water channels, or if the frame drop rate is greater than the set value, the digital base determines that the programmable logic controller is faulty and takes over the control of the air conditioning system.

[0101] Before or during the switch of control between the digital base station and the PLC, the digital base station and the PLC also need to synchronize the current operating status of the air conditioning system (such as fan speed, valve opening, etc.) to avoid parameter gaps after the switchover and improve the stability of the continuous control.

[0102] Step 350: If the number of first water channels open is the same as the number of second water channels open and the frame drop rate is not greater than the set value, the digital base determines that the programmable logic controller is normal and maintains the programmable logic controller's control over the air conditioning system.

[0103] The digital docking station determines whether the number of water circuits open in the air conditioning system calculated in real time by itself and the programmable logic controller (PLC) is consistent, and whether the frame loss rate between the PLC and the gateway exceeds a set value. If the number of water circuits open is inconsistent or the frame loss rate exceeds the set value, the PLC is deemed to be faulty, and the digital docking station takes over the control of the air conditioning system. Thus, based on the consistency of the number of water circuits open and the frame loss rate, the system comprehensively and accurately judges the state of the PLC. In the event of a PLC failure, the digital docking station promptly takes over the control of the air conditioning system, improving the stability of the air conditioning system and preventing the entire air conditioning system from going out of control due to a PLC failure.

[0104] Figure 4 The diagram illustrates a control method according to some embodiments of the present disclosure. In this embodiment, after the programmable logic controller (PLC) recovers from a fault, the digital dock actively switches control back to the PLC.

[0105] Step 410: After the digital base takes over the control of the air conditioning system, it obtains the number of the first water channel opening and the number of the second water channel opening in real time.

[0106] The digital base station obtains the first waterway opening count, calculated in real time by the programmable logic controller (PLC) during normal operation, and also calculates the second waterway opening count in real time. The calculation logic for the first and second waterway opening counts is the same, as described in the preceding embodiments. Thus, the digital base station obtains the first and second waterway opening counts in real time.

[0107] Step 420: The digital base determines whether the number of the first water circuit open and the number of the second water circuit open are consistent in order to determine the current state of the programmable logic controller (such as fault, normal, etc.).

[0108] The situations where the number of open water channels and the number of open water channels are the same include: after the programmable logic controller (PLC) recovers from a fault, the number of open water channels is calculated by the PLC based on the current monitoring values ​​obtained in real time after the PLC recovers from the fault, according to the fixed-value parameters and real-time monitoring parameters; the number of open water channels is calculated by the digital base based on the current monitoring values ​​of the fixed-value parameters and real-time monitoring parameters; since the parameter values ​​and calculation logic are the same, the number of open water channels and the number of open water channels are the same.

[0109] The inconsistency between the first and second waterway opening counts includes the following situations: the programmable logic controller (PLC) has not yet recovered from a fault; the first waterway opening count is calculated by the PLC based on the latest first monitoring value when the PLC was working normally before the fault, using fixed-value parameters and real-time monitoring parameters; the second waterway opening count is calculated by the digital base based on the current second monitoring value of the fixed-value parameters and real-time monitoring parameters; when the second monitoring value of the real-time monitoring parameters changes relative to the first monitoring value, the first and second waterway opening counts will be inconsistent.

[0110] Step 430: If the number of the first water circuits opened is the same as the number of the second water circuits opened, the digital base determines that the programmable logic controller (PLC) has recovered from the fault and switches to the PLC to take over the control of the air conditioning system.

[0111] Before or during the switch of control between the digital base station and the PLC, the digital base station and the PLC also need to synchronize the current operating status of the air conditioning system (such as fan speed, valve opening, etc.) to avoid parameter gaps after the switchover and improve the stability of the continuous control.

[0112] Step 440: If the number of the first water circuits opened is inconsistent with the number of the second water circuits opened, the digital base determines that the programmable logic controller fault has not been recovered and maintains the digital base's control over the air conditioning system.

[0113] After the digital base takes over the control of the air conditioning system, it automatically identifies the fault recovery status of the programmable logic controller (PLC) based on the condition that the number of water circuits open is consistent with the number of water circuits open. It then completes the switch of control authority, ensuring the accuracy of the switchback timing. Furthermore, the "number of water circuits open" directly anchors to the actual operating status of the air conditioning system, ensuring that the PLC's control logic does not conflict with the current system status during the switchback. This avoids problems such as sudden opening / closing of water circuits and drastic temperature fluctuations during the switchback, thus ensuring the continuity of the air conditioning system's operation.

[0114] Figure 5 The diagram illustrates a control method according to some embodiments of the present disclosure. In this embodiment, the control program can be updated without shutting down the air conditioning system.

[0115] Step 510: The digital dock preloads the first control program (updated control program).

[0116] The control program is pre-loaded and updated on the digital docking station, reducing the risk of control program updates. If the control program is directly updated to the PLC, syntax errors or logical vulnerabilities in the control program may cause the PLC to shut down abnormally and production to be interrupted. However, updating to the digital docking station first allows for offline simulation, logic verification, conflict detection, and other verification work to be completed on the digital docking station. Only after successful verification is the program synchronized to the PLC. This pre-emptive safety check prevents unqualified control programs from entering the production process.

[0117] Furthermore, the digital base can remotely and in batches synchronize new control programs that have passed verification to multiple PLCs, making it suitable for control program deployment scenarios in PLC clusters, improving the efficiency of control program updates, and is especially suitable for large-scale deployment at the production line and factory levels.

[0118] In step 520, the digital base responds to the first program update request sent by the programmable logic controller and takes over control of the air conditioning system based on the first control program. After taking over control, step 530 is then executed.

[0119] Specifically, the first program update request is sent when the versions of the second control program of the programmable logic controller (PLC) and the first control program of the digital base are inconsistent. This allows the PLC to automatically detect program version differences and trigger the update process, reducing manual intervention, improving the system's intelligence and operational efficiency, and ensuring that the control program versions of the PLC and the digital base are consistent, thus avoiding inconsistencies in calculation logic or control conflicts caused by version differences.

[0120] In step 530, the digital base station synchronizes the first control program to the programmable logic controller. After the first control program is synchronized, step 540 is executed.

[0121] Step 540: The digital base switches to a programmable logic controller (PLC) to take over the control of the air conditioning system.

[0122] The digital base is preloaded with the latest control program. When the PLC control program version is inconsistent, it takes over the control first and then synchronizes the program to achieve "non-stop update". This ensures the continuous operation of the air conditioning system and avoids control abnormalities caused by incomplete programs during the PLC update process, thus ensuring control continuity and system stability.

[0123] Figure 6 The diagram illustrates a control method according to some embodiments of the present disclosure. In this embodiment, no digital docking station is required to take over control and update the control program.

[0124] Step 610: The digital base preloads the first control program (updated control program).

[0125] Step 620: In response to the second program update request sent by the programmable logic controller, the digital base synchronizes the first control program to the programmable logic controller. The second program update request is sent when the versions of the second control program of the programmable logic controller and the first control program of the digital base are inconsistent and no unit is running.

[0126] Thus, the programmable logic controller automatically detects program version differences and triggers the update process when the unit is not in operation, reducing manual intervention, improving the system's intelligence level and operation and maintenance efficiency, while ensuring that the control program versions of the PLC and the digital base are consistent, avoiding inconsistencies in calculation logic or control conflicts caused by version differences.

[0127] The program update logic is designed for the "no unit operation" scenario. When the PLC program version is inconsistent and no unit is running, the latest program of the digital base is directly synchronized, without the need for the digital base to take over the control, simplifying the update process and shortening the update time.

[0128] Figure 5 and Figure 6 The implementation plan meets the differentiated needs of control program updates under load and without load, complementing each other to cover program update requirements under all operating conditions, ensuring that the PLC control program is always up-to-date, while also taking into account the safety and efficiency of program updates.

[0129] Figure 7 A schematic diagram of a control device according to some embodiments of the present disclosure is shown.

[0130] The control device includes one or more modules that execute the control method. For example... Figure 7 As shown, the control device 700 includes modules 710-730, but is not limited to this division example. Other division methods can be used, such as merging multiple modules into one module, or splitting one module into multiple sub-modules.

[0131] The fault judgment module 710 is configured to judge at least one of the following: whether the number of water circuits open is consistent with the number of water circuits open, and whether the frame loss rate of communication between the programmable logic controller and the gateway is greater than a set value. The number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time when the programmable logic controller is working normally, and the number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time by the digital base. The calculation logic of the number of water circuits open is the same as that of the number of water circuits open.

[0132] The takeover control module 720 is configured to determine that the programmable logic controller is faulty when the number of the first water channel openings is inconsistent with the number of the second water channel openings or the frame drop rate is greater than a set value, and to control the digital base to take over the control of the air conditioning system.

[0133] The takeover control module 720 is configured to, after the digital base takes over the control of the air conditioning system, determine that the programmable logic controller has recovered from a fault and switch to the programmable logic controller to take over the control of the air conditioning system if the number of first water circuit openings is the same as the number of second water circuit openings.

[0134] The program synchronization module 730 is configured to control the digital dock, preload a first control program, respond to a first program update request sent by the programmable logic controller, take over the control of the air conditioning system based on the first control program, synchronize the first control program to the programmable logic controller, and switch the programmable logic controller to take over the control of the air conditioning system. The first program update request is sent when the version of the second control program of the programmable logic controller is inconsistent with the version of the first control program of the digital dock.

[0135] The program synchronization module 730 is configured to control the digital base station, preload a first control program, and synchronize the first control program to the programmable logic controller in response to a second program update request sent by the programmable logic controller. The second program update request is sent when the versions of the second control program of the programmable logic controller and the first control program of the digital base station are inconsistent and no unit is running.

[0136] Figure 8 A schematic diagram of a control device according to some embodiments of the present disclosure is shown.

[0137] like Figure 8 As shown, the control device 800 of this embodiment includes a memory 810 and a processor 820 coupled to the memory 810. The processor 820 is configured to execute the control methods of any of the foregoing embodiments based on instructions stored in the memory 810. See the preceding description for details, which will not be repeated here.

[0138] The control device 800 may also include an input / output interface 830, a network interface 840, a storage interface 850, etc. These interfaces 830, 840, 850, as well as the memory 810 and the processor 820, can be connected, for example, via a bus 860.

[0139] The memory 810 may include, for example, system memory, fixed non-volatile storage media, etc. The system memory may store, for example, the operating system, application programs, boot loader, and other programs.

[0140] The processor 820 can be implemented using a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gates, or transistors, or other discrete hardware components.

[0141] The input / output interface 830 provides a connection interface for input / output devices such as monitors, mice, keyboards, and touchscreens. The network interface 840 provides a connection interface for various networked devices. The storage interface 850 provides a connection interface for external storage devices such as SD cards and USB flash drives. The bus 860 can use any bus architecture from a variety of bus structures. For example, bus architectures include, but are not limited to, Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, and Peripheral Component Interconnect (PCI) bus.

[0142] Figure 9 A schematic diagram of a control system according to some embodiments of the present disclosure is shown.

[0143] like Figure 9 As shown, the control system 900 includes a programmable logic controller 910 and a digital base 920.

[0144] The programmable logic controller 910 is configured to control the air conditioning system and calculate the number of first water channels opened in the air conditioning system in real time during normal operation.

[0145] The digital docking station 920 is configured to determine at least one of the following: whether the number of water circuits open is consistent with the number of water circuits open, and whether the frame loss rate of communication between the programmable logic controller (PLC) and the gateway is greater than a set value. The first number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time when the PLC is operating normally. The second number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time by the digital docking station. The calculation logic for the first and second water circuits open is the same. If the first and second water circuits open are inconsistent or the frame loss rate is greater than the set value, the PLC is determined to be faulty, and the control of the air conditioning system is taken over.

[0146] The digital dock 920 is configured to, after the digital dock takes over the control of the air conditioning system, determine that the programmable logic controller has recovered from a fault when the number of the first water circuit openings is the same as the number of the second water circuit openings, and then switch to the programmable logic controller to take over the control of the air conditioning system.

[0147] The digital dock 920 is configured to preload a first control program; in response to a first program update request sent by the programmable logic controller, it takes over the control of the air conditioning system based on the first control program, and synchronizes the first control program to the programmable logic controller, switching to the programmable logic controller taking over the control of the air conditioning system, wherein the first program update request is sent when the version of the second control program of the programmable logic controller is inconsistent with the version of the first control program of the digital dock.

[0148] The digital dock 920 is configured to preload a first control program and, in response to a second program update request sent by the programmable logic controller, synchronize the first control program to the programmable logic controller, wherein the second program update request is sent when the versions of the second control program of the programmable logic controller and the first control program of the digital dock are inconsistent and no unit is running.

[0149] Some embodiments of this disclosure also propose a computer-readable storage medium storing computer instructions that, when executed by a processor, implement the control methods of the various embodiments. See the foregoing description for details, which will not be repeated here.

[0150] This disclosure also proposes a computer program product, including computer instructions that, when executed by a processor, implement the control methods of the various embodiments. See the foregoing description for details, which will not be repeated here.

[0151] Those skilled in the art will understand that embodiments of this disclosure can be provided as methods, systems, or computer program products. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more (non-transitory) computer-readable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, cloud storage, etc.) containing computer program code. A computer program product should be understood as a software product that primarily implements its solution through a computer program.

[0152] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this disclosure. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0153] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0154] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

Claims

1. A control method, characterized in that, include: The digital base determines at least one of the following: whether the number of water circuits open is consistent with the number of water circuits open, and whether the frame loss rate of communication between the programmable logic controller and the gateway is greater than a set value. The number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time when the programmable logic controller is working normally. The number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time by the digital base. The calculation logic of the number of water circuits open is the same as that of the number of water circuits open. If the number of open water channels is inconsistent with the number of open water channels, or if the frame drop rate is greater than a set value, the digital base determines that the programmable logic controller is faulty and takes over the control of the air conditioning system.

2. The control method according to claim 1, characterized in that, The calculation logic for the number of water circuits opened in the first water circuit and the number of water circuits opened in the second water circuit is as follows: the number of water circuits opened in the air conditioning system is calculated based on fixed value parameters and real-time monitoring parameters. The fixed value parameters include the density of water and the specific heat capacity of water. The real-time monitoring parameters include the total cooling load of the building, the unit load rate, the unit flow rate, and the temperature difference between the unit's supply water and return water.

3. The control method according to claim 2, characterized in that, The number of water circuits to be opened in the air conditioning system is calculated based on fixed parameters and real-time monitoring parameters, including: Calculate the first product of the building's total cooling load and the unit's load rate; Calculate the density of water, the specific heat capacity of water, the unit flow rate, and the second product of the temperature difference between the unit's supply and return water; The ratio of the first product to the second product is used as the number of water circuits to be opened in the air conditioning system.

4. The control method according to claim 2, characterized in that, The total building cooling load is determined based on the building structure, heat sources, and weather conditions; and / or The unit load rate is determined based on the ratio of the unit's actual load to its rated load.

5. The control method according to claim 2, characterized in that, The situations where the number of waterways opened differs from the number of waterways opened include: The first number of water circuits open is calculated by the programmable logic controller (PLC) based on fixed parameters and real-time monitoring parameters, using the latest first monitoring value when the PLC was working normally before the fault. The second waterway opening count is calculated by the digital base based on the fixed parameter and the current second monitoring value of the real-time monitoring parameter; When the second monitoring value of the real-time monitoring parameter changes relative to the first monitoring value, the number of the first waterway openings is inconsistent with the number of the second waterway openings.

6. The control method according to claim 1, characterized in that, The method for calculating the frame loss rate in communication between the programmable logic controller and the gateway includes: Calculate the difference between the number of frames sent by the programmable logic controller and the number of frames received by the gateway; The ratio of the difference to the number of frames sent by the programmable logic controller is used as the frame loss rate for communication between the programmable logic controller and the gateway.

7. The control method according to any one of claims 1-6, characterized in that, Also includes: After the digital base takes over the control of the air conditioning system, if the number of the first water circuit opening is the same as the number of the second water circuit opening, the digital base determines that the programmable logic controller has recovered from the fault and switches to the programmable logic controller to take over the control of the air conditioning system.

8. The control method according to any one of claims 1-6, characterized in that, Also includes: The digital base is preloaded with a first control program; In response to a first program update request sent by the programmable logic controller (PLC), the digital dock takes over the control of the air conditioning system based on the first control program and synchronizes the first control program to the PLC, switching the control of the air conditioning system to the PLC. The first program update request is sent when the versions of the second control program of the PLC and the first control program of the digital dock are inconsistent.

9. The control method according to any one of claims 1-6, characterized in that, Also includes: The digital base is preloaded with a first control program; In response to a second program update request sent by the programmable logic controller (PLC), the digital base station synchronizes the first control program to the PLC. The second program update request is sent when the versions of the PLC's second control program and the digital base station's first control program are inconsistent and no unit is running.

10. A control device, characterized in that, include: The fault judgment module is configured to judge at least one of the following: whether the number of water circuits open is consistent with the number of water circuits open, and whether the frame loss rate of communication between the programmable logic controller and the gateway is greater than a set value. The number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time when the programmable logic controller is working normally, and the number of water circuits open is the number of water circuits open in the air conditioning system calculated in real time by the digital base. The calculation logic of the number of water circuits open is the same as that of the number of water circuits open. The takeover control module is configured to determine that the programmable logic controller is faulty when the number of the first water channel openings is inconsistent with the number of the second water channel openings or the frame drop rate is greater than a set value, and to control the digital base to take over the control of the air conditioning system.

11. The control device according to claim 10, characterized in that, Also includes: The program synchronization module is configured to control the digital dock, preload a first control program, respond to a first program update request sent by the programmable logic controller, take over the control of the air conditioning system based on the first control program, synchronize the first control program to the programmable logic controller, and switch the programmable logic controller to take over the control of the air conditioning system. The first program update request is sent when the version of the second control program of the programmable logic controller is inconsistent with the version of the first control program of the digital dock.

12. A control device, comprising: Memory; And a processor coupled to the memory, characterized in that the processor is configured to execute the control method of any one of claims 1-10 based on instructions stored in the memory.

13. A control system, characterized in that, include: The programmable logic controller is configured to control the air conditioning system and calculate the number of first water circuits to be opened in real time when the system is operating normally. as well as The digital dock is configured to perform the control method according to any one of claims 1-10.

14. A computer-readable storage medium storing computer instructions thereon, characterized in that, When the computer instructions are executed by the processor, they implement the control method according to any one of claims 1-10.

15. A computer program product comprising computer instructions, characterized in that, When the computer instructions are executed by the processor, they implement the control method according to any one of claims 1-10.

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