Control system for non-interference switching between APC system and DCS system

Abstract

The invention belongs to the technical field of industrial control, and discloses a control system for non-interference switching between an APC system and a DCS system. According to the control system, an operator can control a switch of the APC system and the upper and lower limit ranges of operating variables and control variables, daily operation of the APC system in the DCS system is achieved, and daily operation of the APC system is simplified; meanwhile, an instruction issued by the APC system and the communication link state of the APC system and the DCS system can be identified and judged, it is guaranteed that the working state of an execution mechanism of the DCS is not changed when the APC system and the DCS system are switched, interference-free switching is achieved, and the safety of the APC system when the APC system is applied to the DCS system is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of industrial control, and particularly to a control system for non-interference switching between an APC system and a DCS system. Background Art

[0002] Advanced Process Control (APC) is a multi-variable predictive control technology based on process models. With the development and changes in recent years, APC has been extended from the petrochemical industry to other chemical industry fields such as coal chemical industry. Implementing advanced control can improve the operation level and economic benefits of the device. Generally, APC communicates directly with the DCS through the OPC service, and conveys each control instruction to the DCS through the OPC, and finally realizes the control of the DCS actuators.

[0003] Generally, the APC server is stored in the engineer station. In daily use, if simple control index changes are required, technicians need to go there alone for modification, which is not conducive to daily operation; and using APC to control the DCS instead of operators, the core issue is to ensure the safe operation of the system. If operation problems such as communication failures occur, how to control and coordinate so as not to affect normal production.

[0004] Therefore, there is an urgent need for a control system at present. Through this system, operators can perform daily operations on the APC (such as switching on and off the APC, setting the upper and lower limits of operation variables and control variables), and at the same time monitor the communication status between the APC server and the DCS system. It is of great significance to be able to perform non-disturbing switching in a timely manner when a failure occurs to avoid process fluctuations. Summary of the Invention

[0005] In order to solve the problems in the background art, the present invention provides a control system for non-interference switching between an APC system and a DCS system.

[0006] To achieve the above object, the technical solution adopted by the present invention is as follows: A control system for non-interference switching between an APC system and a DCS system, comprising: A main switch module, used to control the use or shutdown of the control system, linked with the APC system switch, and judging whether to shut down the main switch according to the communication connection status between the APC system and the DCS system; An operation variable control and parameter setting module, including a first switch and an operation variable setting unit. The first switch is used to control the use or shutdown of this module, and the main switch module is master-slave controlled with the first switch; the operation variable setting unit is used to set the upper and lower limit ranges of the operable operation variables, and shares the same link with the corresponding operation variable setting unit of the APC system; The control variable parameter setting module includes a control variable setting unit for setting the upper and lower limit ranges of the APC system's control of the target control variable, sharing the same link with the control variable upper and lower limit setting unit corresponding to the APC system.

[0007] Preferably, the main switch module includes a timing unit and a communication signal detection unit. The communication signal detection unit determines whether the communication between the APC system and the DCS system is normal through signal detection. The timing unit monitors the communication status and triggers the protection mechanism through timing and timeout judgment.

[0008] Preferably, if the communication between the APC system and the DCS system is disconnected, the main switch is turned off, and the control of the APC system over the DCS ends.

[0009] Preferably, the manipulated variable control and parameter setting module further includes: a first display unit for displaying the current value of the manipulated variable of the DCS system; A second display unit for displaying the output value of the manipulated variable calculated based on the current time of the APC system.

[0010] Preferably, when the current value of the manipulated variable of the DCS system is within the set upper and lower limit ranges of the operable manipulated variable, the first switch is turned on, that is, the manipulated variable control and parameter setting module is put into use; when the absolute value of the change rate of the manipulated variable value calculated by the APC system in the current cycle compared to the previous cycle is greater than the preset change rate threshold, the first switch is turned off, that is, the manipulated variable control and parameter setting module is turned off.

[0011] Preferably, the control variable parameter setting module further includes a third display unit for displaying the current value of the control variable of the DCS system.

[0012] Preferably, the control variable parameter setting module further includes a second switch for controlling the use or shutdown of this module.

[0013] Compared with the prior art, the present invention has the following beneficial effects: (1) Through the control system of the present invention, operators can more intuitively observe the calculation results of the APC system for the manipulated variable and the feedback results of the manipulated variable of the DCS system. At the same time, the switch of the APC system and the upper and lower limit ranges of the manipulated variable and the control variable can be controlled, realizing the daily operation of the APC system in the DCS system, and simplifying the daily operation of the APC system.

[0014] (2) The control system of the present invention can also identify and judge the instructions issued by the APC system and the communication link status between the APC system and the DCS system, ensuring that the working state of the DCS's own actuators does not change during the switching between the APC system and the DCS system, achieving interference-free switching and improving the safety of the APC system when applied to the DCS system. Description of the Drawings

[0015] Figure 1 This is a schematic structural diagram of a control system for the interference - free switching between an APC system and a DCS control system provided by an embodiment of the present invention. Detailed Embodiment

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part rather than all of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0017] The objective of the present invention is to provide a control system for the interference - free switching between an APC system and a DCS control system. By configuring the DCS system, setting new working logics, and adding them to the DCS system, the instructions issued by the APC system are judged to ensure that the working state of the actuators of the DCS system itself does not change during the switching between the APC system and the DCS system, achieving interference - free switching. Its core safety mechanism is that when the following situations occur, the APC system will automatically and without disturbance withdraw and fully hand over to the DCS system operator for control to ensure that it does not affect the normal production and control of the DCS system.

[0018] 1) Communication anomaly (communication failure between the APC system and the DCS system); 2) The adjustment step of the manipulated variable exceeds the limit range set by the artificial intelligence control system.

[0019] The embodiment of the present invention provides a control system for the interference - free switching between an APC system and a DCS system. Figure 1 For the schematic diagram of the control system 10 for the interference - free switching between the APC system and the DCS system, refer to Figure 1 , the control system 10 for the interference - free switching between the APC system and the DCS system includes: The main switch module 100 is used to control the use or shutdown of the control system, is linked with the APC system switch, and judges whether to close the main switch according to the communication connection status between the APC system and the DCS system; The manipulated variable control and parameter setting module 200 includes a first switch 201 and a manipulated variable setting unit 202. The first switch is used to control the use or shutdown of this module, and the main switch module is master - slave controlled with the first switch; the manipulated variable setting unit is used to set the upper and lower limit ranges within which the manipulated variable can be operated and shares the same link with the corresponding manipulated variable setting unit of the APC system; The control variable parameter setting module 300 includes a control variable setting unit 301 for setting the upper and lower limit ranges for the APC system to control the target control variable, sharing the same link with the control variable upper and lower limit setting unit corresponding to the APC system.

[0020] Regarding the above main switch module 100, which is linked with the APC system switch, that is, the switching on and off of the APC system can be controlled in the control system provided by the embodiment of the present invention. When the main switch module is put into use, the APC system is put into use; when the main switch module exits, the APC system exits.

[0021] In some preferred embodiments, to ensure that when there is an abnormal communication between the APC system and the DCS system, the APC system can automatically exit and be controlled by the DCS system. The main switch module includes a timing unit and a communication signal detection unit. The communication signal detection unit determines whether the communication between the APC system and the DCS system is normal through signal detection. The timing unit monitors the communication status and triggers a protection mechanism through timing and timeout judgment.

[0022] For the working processes of the timing unit and the communication signal detection unit, the example is as follows: The timer unit starts timing from 0 (this value can be set by itself), increasing by 1 per second (this value can be set by itself). The APC system sends a signal to the timing unit every 1 minute (taking 1 minute as a cycle, this value can be set by itself) through the OPC server. When the timing unit receives the signal, the value returns to 0 and starts timing again, continuously cycling. If there is a communication failure in the APC system, the reset signal cannot be sent to the timing unit through the OPC, then the timing continues. After 0.5 cycles, the main switch control module determines that the communication between the APC system and the DCS system fails through the signal of the timing unit, and automatically closes the main switch, and the control of the APC system over the DCS ends.

[0023] The operation variable setting unit shares the same link with the operation variable setting unit corresponding to the APC system. Specifically, the operation variable setting unit is used to set the upper and lower limit ranges within which the operation variable can be operated, endowing a writable function, and setting the same link as the upper and lower limit range of the APC system, with the same function (set as a readable and writable function. When setting in the APC system, its set value can be directly read or directly written, and it takes effect in the APC system). After completing the upper and lower limit settings, the APC system can only adjust the operation variable within this range.

[0024] In the operation variable control and parameter setting module, the main switch module is connected to the first switch in a master-slave control manner, that is, the main switch module is a necessary condition for the operation of the control system of this application. If the main switch is put into use, the first switch of the operation variable control and parameter setting module will take effect; if the main switch is closed, regardless of the state of the first switch system, the operation variable control and parameter setting module will be forcibly closed.

[0025] For the first switch, based on the master-slave control relationship with the main switch module, when the current value of the operating variable of the DCS system is within the upper and lower limits of the operable range of the set operating variable, the first switch is turned on, that is, the operating variable control and parameter setting module is put into use; when the absolute value of the change rate of the operating variable value calculated by the APC system in the current cycle and the previous cycle is greater than the preset change rate threshold, the first switch is turned off, that is, the operating variable control and parameter setting module is closed. That is to say, the operation variable control and parameter setting module needs to meet two conditions simultaneously to be put into use: (1) The actual current value of the operation variable is within the upper limit setting of the operation variable and the lower limit setting of the operation variable; (2) The main switch module is in the put-into-use state; after this module is put into use, the control authority of the operation variable in the DCS system will be automatically changed, and the operation variable will be bound to the set value of the APC system. After binding, the operator will no longer be able to directly control and set the operation variable in the DCS system.

[0026] When the following conditions are met, the first switch automatically exits. During the normal operation of the APC system, when the absolute value of the change rate of the set value of the APC system in the current cycle and the previous cycle is greater than the preset change rate threshold, the first switch exits. After exiting, the operation variable control mode remains unchanged, and the adjustment control authority is returned to the DCS system. At the moment when this switch is completed, the control mode and value of the operation variable will not change, ensuring the safety of the switching process.

[0027] In some preferred embodiments, the operation variable control and parameter setting module further includes: a first display unit for displaying the current value of the operation variable of the DCS system; a second display unit for displaying the output value of the operation variable calculated by the APC system at the current time. Specifically, the set value given by the APC system to the operation variable is connected to the output value of the operation variable calculated by the APC system at the current time (set to read-only function), and the output value of the operation variable calculated by the APC system at the current time is read and displayed; the current value of the operation variable of the DCS system, that is, it is connected to the operation variable corresponding to the DCS system (set to read-only function), and the value of the current operation variable of the current DCS system is read and displayed.

[0028] For the control variable setting unit in the control variable parameter setting module, it shares the same link with the upper and lower limit setting unit of the control variable corresponding to the APC system. Specifically, the control variable setting module is used to set the upper and lower limit ranges of the target control variable of the APC system, and is set to the same link as the upper and lower limit ranges of the control variable corresponding to the APC system, with the same function (set to read-write function. When writing settings in the APC system, the set value can be directly read or written, and it takes effect in the APC system).

[0029] In some preferred embodiments, the control variable parameter setting module further includes a third display unit for displaying the current value of the DCS system control variable, which is connected to the control variable corresponding to the DCS system (set to read-only function), reads the value of the current control variable of the current DCS system and displays it.

[0030] In some preferred embodiments, the control variable parameter setting module further includes a second switch for controlling the use or shutdown of the module.

[0031] The embodiment of the present invention is based on the DCS system, uses the function blocks of the DCS system for design configuration, sets new working logic, and adds it to the DCS system. The APC system is linked to the tag number of the corresponding function point through the OPC server, and partial function intercommunication between the two can be realized. Operators can operate on the switch function, parameter upper and lower limit setting, etc. of the APC system through the DCS interface of this system. At the same time, the instructions issued by the APC system and the communication link status between the APC system and the DCS system are identified and judged to ensure that the working state of the DCS own actuator does not change during the switching between the APC system and the DCS system, achieving interference-free switching and improving the safety of the APC system when applied to the DCS system.

[0032] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of 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. The above embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A control system for non-interference switching between an APC system and a DCS system, characterized in that: Include: The main switch module is used to control the use or shutdown of the control system, and is linked with the APC system switch to determine whether to turn off the main switch according to the communication connection status between the APC system and the DCS system; The operating variable control and parameter setting module includes a first switch and an operating variable setting unit. The first switch is used to control the use or shutdown of the module. The main switch module is connected to the first switch in a master-slave control manner. The operating variable setting unit is used to set the upper and lower limit ranges of the operating variables. The operating variable setting unit shares the same link with the operating variable setting unit corresponding to the APC system. The control variable parameter setting module includes a control variable setting unit, which is used to set the upper and lower limits of the target control variable controlled by the APC system, and shares the same link with the control variable upper and lower limit setting units corresponding to the APC system.

2. The control system according to claim 1, characterized in that: The main switch module includes a timing unit and a communication signal detection unit. The communication signal detection unit determines whether the communication between the APC system and the DCS system is normal through signal detection. The timing unit monitors the communication status and triggers the protection mechanism through timing and timeout judgment.

3. The control system according to claim 2, characterized in that: If the communication between the APC system and the DCS system is disconnected, the main switch is turned off and the APC system's control over the DCS ends.

4. The control system according to claim 1, characterized in that: The operating variable control and parameter setting module further comprises: a first display unit for displaying the current value of the operating variable of the DCS system; The second display unit is used to display the output value of the operating variable calculated by the APC system at the current time.

5. The control system according to claim 4, characterized in that: When the current value of the DCS system operating variable is within the set upper and lower limits of the operating variable, the first switch is turned on, that is, the operating variable control and parameter setting module is put into use; when the absolute value of the change rate of the operating variable value calculated by the APC system between the current cycle and the previous cycle is greater than the preset change rate threshold, the first switch is turned off, that is, the operating variable control and parameter setting module is turned off.

6. The control system according to claim 1, characterized in that: The control variable parameter setting module also includes a third display unit for displaying the current value of the DCS system control variable.

7. The control system according to claim 1 or 6, characterized in that: The control variable parameter setting module also includes a second switch for controlling the use or shutdown of the module.

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