Multi-PID (Proportion Integration Differentiation) parallel regulation system and method and programmable controller program product

Abstract

The invention discloses a multi-PID (proportion integration differentiation) parallel regulation system and method and a programmable controller program product, comprising a plurality of PID controllers working in parallel, each PID controller independently calculating according to an input signal and outputting a result value, calculating a minimum output value from the result values output by the plurality of PID controllers as a control signal, and controlling the PID controllers to work according to the minimum output value. According to the method and the system, the PID controllers are used as control signals, the preset deviation value is added to the control signals to serve as the maximum output value limiting reference of each PID controller, then the control signals are output to the actuator to achieve multi-PID parallel adjustment, and compared with traditional PID control, the stability and robustness of the system are enhanced, the control precision is improved, the self-adaptive adjustment capacity is improved, and the service life of the system is prolonged. And meanwhile, the risk and the failure rate are reduced, and high-precision control over a single actuator in a multivariable control scene is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of automatic control systems, and in particular relates to a multiple PID parallel adjustment system, method and programmable controller program product. Background Art

[0002] Traditional PID controllers perform well in a single control loop, but when faced with multi-variable or multi-target control, a single controller often cannot meet the requirements of fast response, stability, and control accuracy at the same time. When there are multiple complex and variable interference factors in the system, or when the state of a single measuring point changes, it will affect the changes of several other measuring points. If only PID controls a single measuring point, it will affect other measuring points. At this time, the system will not be able to achieve PID linkage adjustment, and whenever an alarm occurs, the operation of the equipment is more likely to become unstable. In severe cases, it may cause abnormal shutdown of the equipment or accidents. Therefore, modern automation control requires a method of multiple PID parallel adjustment control and a control system for linked parallel PID closed-loop loops. Summary of the invention

[0003] In order to solve the above-mentioned problems existing in the prior art, the present application provides a multiple PID parallel adjustment system, method and programmable controller program product, which can cope with high-precision control of a single actuator in a complex control environment and effectively integrate multiple control objectives to overcome the above-mentioned shortcomings of the prior art.

[0004] According to a first aspect of the present invention, a multiple PID parallel control system is proposed, comprising:

[0005] Multiple PID controllers: Multiple PID controllers work in parallel, and each PID controller performs independent calculations based on the input signal and outputs the result value. That is, each PID controller is responsible for independently calculating the result value based on a specific control target or parameter. By distributing the control tasks, the system can maintain a high degree of stability in a complex and changing environment, reduce the impact of external interference on a single control loop, and avoid overall system failure caused by a single fault by intelligently allocating control responsibilities to each PID loop, thereby improving operational safety, enhancing the robustness of the system, and optimizing the ability to handle multi-variable control tasks.

[0006] Minimum output value calculation module: Calculate the minimum output value from the result values ​​output by multiple PID controllers as a control signal. This effectively avoids excessive action of the actuator caused by an overexcited single PID controller, and improves the safety and smoothness of control.

[0007] Control signal output module: outputs the control signal to the actuator to realize multiple PID parallel regulation.

[0008] Preferably, it also includes a maximum output value calculation module: the control signal plus a preset deviation value is used as the maximum output value limit reference of each PID controller. By inputting the maximum output value limit reference into each PID controller as feedback, the adaptive adjustment of the control strategy during the regulation process is realized, the flexibility and efficiency of the control are increased, and the ability to respond quickly to emergency or abnormal conditions is increased.

[0009] Preferably, each of the PID controllers includes a feedback value and a set value, wherein the feedback value enters the PID controller after being processed by a low-pass filter, and the set value enters the PID controller after being processed by a set value ramp filter. The signal entering the PID controller can be smoothed to improve accuracy and optimize the dynamic performance of the system.

[0010] Preferably, the output signal of each PID controller is processed by the minimum output value calculation module to obtain the minimum value, and then processed by the output value ramp filter and output to the actuator, so as to further smooth the control signal and reduce the sudden change and oscillation in the actuator response, thereby improving the dynamic performance of the system while maintaining the control accuracy.

[0011] Preferably, each PID controller is equipped with a switch, and the working state of the single PID controller is controlled by the switch. According to the actual process, the PID controller that needs to be put into the process in the process control system is selected, which improves the flexibility of the system and expands the application range of the system.

[0012] Preferably, an alarm interlock protection module is also included. When the device alarms, the alarm signal is connected to the PID controller to force the actuator to output a 0% output value. By setting the alarm interlock protection, the system equipment safety is improved and the rapid response capability to emergency or abnormal working conditions is enhanced.

[0013] According to a second aspect of the present invention, a multiple PID parallel adjustment method is proposed, comprising:

[0014] Multiple PID controllers in parallel: Multiple PID controllers work in parallel, and each PID controller performs independent calculations based on the input signal and outputs the result value. That is, each PID controller is responsible for independently calculating the result value based on a specific control target or parameter. By distributing the control tasks, the system can maintain a high degree of stability in a complex and changing environment, reduce the impact of external interference on a single control loop, and avoid overall system failure caused by a single fault by intelligently allocating control responsibilities to each PID loop, thereby improving operational safety, enhancing the robustness of the system, and optimizing the ability to handle multi-variable control tasks.

[0015] Minimum output value calculation: The minimum output value is calculated from the result values ​​output by the multiple PID controllers as a control signal. This effectively avoids excessive action of the actuator caused by an overexcited single PID controller, and improves the safety and smoothness of the control.

[0016] Control signal output: The control signal is output to the actuator to realize multiple PID parallel regulation.

[0017] Preferably, it also includes maximum output value calculation: the control signal plus the preset deviation value is used as the maximum output value limit benchmark of each PID controller. The adaptive adjustment of the control strategy during the regulation process is realized, the flexibility and efficiency of the control are increased, and the ability to respond quickly to emergency or abnormal conditions is increased.

[0018] Preferably, each of the PID controllers includes a feedback value and a set value, wherein the feedback value enters the PID controller after being processed by a low-pass filter, and the set value enters the PID controller after being processed by a set value ramp filter. The signal entering the PID controller can be smoothed to improve accuracy and optimize the dynamic performance of the system.

[0019] Preferably, the output signal of each PID controller is processed by the minimum output value calculation and then processed by the output value ramp filter before being output to the actuator. By exponential smoothing of the control signal, high-frequency noise can be removed, long-term signal trends can be retained, accuracy can be improved, and mutations and oscillations in the actuator response can be reduced, thereby optimizing the dynamic performance of the system while maintaining control accuracy.

[0020] Preferably, each PID controller is equipped with a switch, and the working state of the single PID controller is controlled by the switch. According to the actual process, the PID controller that needs to be put into the process in the process control system is selected, which improves the flexibility of the system and expands the application range of the system.

[0021] Preferably, it also includes alarm interlock protection. When the equipment alarms, the alarm signal is connected to the PID controller to force the actuator to output a 0% output value. By setting the alarm interlock protection, the safety of the system equipment is improved and the ability to respond quickly to emergency or abnormal conditions is enhanced.

[0022] According to a third aspect of the present invention, a programmable controller program product is provided, on which a computer program is stored, and the computer program implements the above method when executed by a processor.

[0023] Compared with the prior art, the beneficial results of the present invention are:

[0024] (1) Enhance system stability and robustness: The multiple PID parallel adjustment mechanism enables the actuators or components to intelligently respond to changes in multiple influencing factors by distributing control tasks, and to perform PID adjustment in a timely and automatic manner. It can maintain high stability in a complex and changing environment and reduce the impact of external interference on a single control loop.

[0025] (2) Improve control accuracy: The combination of multiple PID minimum output value selection strategy and filtering technology greatly reduces the overshoot and oscillation of the actuator response, and achieves high-precision control of a single actuator, especially in multi-variable control scenarios.

[0026] (3) Improve adaptive regulation capability: The dynamic maximum output value limiting strategy adaptively adjusts the control strategy according to the current state of the system to prevent abnormal changes in the system and enhance the ability to respond quickly to emergency or abnormal conditions.

[0027] (4) Reduce operational risks and failure rates: By intelligently allocating control responsibilities to each PID loop, each PID adjustment loop can switch efficiently with each other, and timely adjust the measurement point that is about to appear abnormal or most likely to exceed the specified range of operating conditions, avoiding overall system failure caused by a single fault and improving operational safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and together with the description are used to explain the principles of the present invention. Other embodiments and many expected advantages of the embodiments will be readily appreciated as they become better understood by reference to the following detailed description. Other features, objects and advantages of the present application will become more apparent by reading the detailed description of the non-limiting embodiments made with reference to the following drawings:

[0029] Figure 1 is a flow chart of a multiple PID parallel adjustment method according to a specific embodiment of the present invention;

[0030] Figure 2 is a principle block diagram of a multiple PID parallel regulation system according to a specific embodiment of the present invention;

[0031] Figure 3 is a principle block diagram of a minimum output value calculation module according to a specific embodiment of the present invention;

[0032] Figure 4 is a principle block diagram of a maximum output value calculation module according to a specific embodiment of the present invention;

[0033] Figure 5 is a block diagram of the principle of ramp filtering processing according to a specific embodiment of the present invention;

[0034] Figure 6 It is a block diagram of the low-pass filtering processing principle according to a specific embodiment of the present invention.

[0035] The meaning of the numbers in the figure are: 1-1, first PID controller; 1-2, second PID controller; 2-1 set value ramp filter; 2-2, output value ramp filter; 3, low-pass filter; 4, switch; 5, minimum output value calculation module; 6, maximum output value calculation module; 7, alarm interlock protection module; 8, actuator. DETAILED DESCRIPTION

[0036] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0037] In the description of the present invention, it should be noted that the terms "comprises", "includes" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. The terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly stipulated and limited, the terms "installed", "provided with", "mounted / connected", "connected", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be a direct connection or an indirect connection through an intermediate medium. It can be the internal connection of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] To facilitate understanding by those skilled in the art, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0040] Figure 1 FIG. 4 is a flow chart showing a multiple PID parallel adjustment method according to a specific embodiment of the present invention. Figure 1 As shown, including:

[0041] Multiple PID controllers in parallel: Multiple PID (Multiple-Proportional-Integral-Derivative) controllers work in parallel, and each PID controller performs independent calculations based on the input signal and outputs the result value. That is, each PID controller is responsible for independently calculating the result value based on a specific control target or parameter. By distributing the control tasks, the system can maintain a high degree of stability in a complex and changing environment, reduce the impact of external interference on a single control loop, and avoid overall system failure caused by a single fault by intelligently allocating control responsibilities to each PID loop, thereby improving operational safety, enhancing the robustness of the system, and optimizing the ability to handle multi-variable control tasks.

[0042] Minimum output value calculation: The minimum output value is calculated from the result values ​​output by the multiple PID controllers as a control signal, which effectively avoids excessive action of the actuator 8 caused by overexcitation of a single PID controller, thereby improving the safety and smoothness of the control.

[0043] Maximum output value calculation: The control signal plus the preset deviation value is used as the maximum output value limit benchmark of each PID controller. This realizes the adaptive adjustment of the control strategy during the regulation process, increases the flexibility and efficiency of the control, and the ability to respond quickly to emergency or abnormal conditions.

[0044] Control signal output: The control signal is output to the actuator 8 to realize multiple PID parallel regulation.

[0045] In a specific embodiment, multiple PID controllers work in parallel. After each PID controller independently calculates and outputs its own result value, the output values ​​of all PID controllers are calculated by the GetMin minimum output value calculation module 5 to obtain the minimum output value as the control signal. The control signal is processed by the output value ramp filter 2-2 and output to the actuator 8. At the same time, the control signal output from the GetMin minimum output value calculation module 5 is processed by the Set PID Max LimitValue maximum output value calculation module 6 and then fed back to each PID controller. The processing of the Set PID Max Limit Value maximum output value calculation module 6 is specifically to add the control signal to the preset deviation value and output it to the PID controller as the maximum output value limit benchmark of each PID controller.

[0046] In a specific embodiment, each of the PID controllers includes a feedback value and a set value. The feedback value enters the PID controller after being processed by a low-pass filter 3, and the set value enters the PID controller after being processed by a set value ramp filter 2-1.

[0047] Optionally, the feedback value is an instrument that needs to be controlled in the process system, such as actual temperature or pressure, and the set value is a process target value that needs to be controlled in the process system.

[0048] In a specific embodiment, the output signal of each PID controller is processed by the minimum output value calculation and then processed by the output value ramp filter 2-2 before being output to the actuator, thereby further smoothing the control signal and reducing the sudden change and oscillation in the response of the actuator 8, thereby improving the dynamic performance of the system while maintaining the control accuracy.

[0049] It should be noted that the set value ramp filter 2-1 in this application refers to the ramp filter that the set value passes through before entering the PID controller, and the output value ramp filter 2-2 refers to the ramp filter that the output signal of the PID controller passes through after being processed by taking the minimum value.

[0050] In a specific embodiment, each of the PID controllers is equipped with a switch 4, which controls the working state of a single PID controller. Optionally, the switch is an on-off switch. According to the actual process, the PID controller that needs to be put into the process in the process control system is selected, thereby improving the flexibility of the system and expanding the application scope of the system.

[0051] In a specific embodiment, when the equipment alarms, the alarm signal is connected to the PID controller, and the actuator 8 is forced to output a 0% output value. By setting the alarm interlock protection, the safety of the system equipment is improved, and the ability to respond quickly to emergency or abnormal conditions is enhanced.

[0052] Figure 2 FIG. 4 shows a schematic block diagram of a multiple PID parallel control system according to a specific embodiment of the present invention. Figure 2 As shown, a multiple PID parallel control system includes:

[0053] Multiple PID controllers: Multiple PID controllers work in parallel, each of which performs independent calculations based on the input signal and outputs the result value;

[0054] Minimum output value calculation module 5: calculates the minimum output value from the result values ​​output by the plurality of PID controllers as a control signal;

[0055] Control signal output module: outputs the control signal to the actuator 8 to realize multiple PID parallel regulation.

[0056] In a specific embodiment, it also includes:

[0057] Maximum output value calculation module 6: adds a preset deviation value to the control signal as a maximum output value limit reference of each PID controller.

[0058] In a specific embodiment, each of the PID controllers includes a feedback value and a set value, wherein the feedback value enters the PID controller after being processed by a low-pass filter 3, and the set value enters the PID controller after being processed by a set value ramp filter 2-1. The signal entering the PID controller can be smoothed, the accuracy can be improved, and the dynamic performance of the system can be optimized.

[0059] Optionally, the output signal of each PID controller is processed by the minimum output value calculation module 5 to obtain the minimum value, and then processed by the output value ramp filter 2-2 and output to the actuator 8. The control signal is further smoothed to reduce the sudden change and oscillation in the response of the actuator 8, thereby improving the dynamic performance of the system while maintaining the control accuracy.

[0060] Optionally, each of the PID controllers is equipped with a switch 4, and the switch 4 is used to control the working state of the single PID controller.

[0061] Optionally, an alarm interlock protection module 7 is further included. When the device alarms, the alarm signal is connected to the PID controller to force the actuator 8 to output a 0% output value.

[0062] In a specific embodiment, multiple PID controllers work in parallel, such as Figure 2 As shown, multiple PID controllers including PID1, PID2, PID3~PIDn work in parallel, and each of the PID controllers performs independent calculations according to the input signal and outputs the result value; that is, each PID controller is responsible for independently calculating the result value according to a specific control target or parameter. By dispersing the control tasks, the system can maintain a high degree of stability in a complex and changeable environment, reduce the impact of external interference on a single control loop, and avoid the overall system failure caused by a single fault by intelligently allocating control responsibilities to each PID loop, thereby improving operational safety, enhancing the robustness of the system, and optimizing the ability to handle multi-variable control tasks.

[0063] The specific working principle is described below by taking the first PID controller and the second PID controller 1-2 in the parallel adjustment of multiple PID controllers as an example. In other embodiments, multiple PID controllers working in parallel can be set according to the actual process.

[0064] Optionally, the first PID controller 1-1 performs PID adjustment according to the feedback value PV1 and the set value SP1, and the second PID controller 1-2 performs PID adjustment according to the feedback value PV2 and the set value SP2. The feedback value PV1 of the first PID controller 1-1 and the feedback value PV2 of the second PID controller 1-2 are processed by the low-pass filter LP Filter and then input into the first PID controller 1-1 and the second PID controller 1-2 for calculation respectively. The set value SP1 of the first PID controller 1-1 and the set value SP2 of the second PID controller 1-2 are processed by the ramp filter Ramp Filter and then input into the first PID controller 1-1 and the second PID controller 1-2 for calculation respectively. Other PID controller loops can be added for parallel adjustment according to the actual process, such as adding Figure 2 The PID controllers such as PID3~PIDn shown in the figure add corresponding filters to the feedback value and set value corresponding to each PID controller for preprocessing. Through the exponential smoothing of the control signal, high-frequency noise can be removed, the long-term trend of the signal can be retained, the accuracy can be improved, and the dynamic performance of the system can be optimized.

[0065] Optionally, the feedback values ​​PV1 and PV2 may specifically be instruments that need to be controlled in the process system, such as actual temperature or pressure, etc., which are set according to the actual process, and the feedback values ​​of other PID controllers are set similarly.

[0066] Optionally, the set values ​​SP1 and SP2 may specifically be process target values ​​that need to be controlled in the process system, and the set values ​​of other PID controllers are similar.

[0067] The following explanation takes the output value of valve opening as an example. It should be noted that the opening in this application refers to the degree or proportion of valve opening, which is used to indicate the degree of valve opening. It can be a specific value, such as a percentage or an angle. For example, if a valve is completely closed, its opening is 0%; if the valve is fully open, its opening is 100%. In different application scenarios, the valve opening will affect the flow rate, pressure and other parameters of the fluid.

[0068] In a specific embodiment, the output result adjusted by each PID controller is calculated by selecting the minimum opening function GetMin to calculate the minimum opening of all PID controllers, and the output Output of each PID controller is connected to the Value of the minimum output value calculation module 5, such as Figure 2As shown, the Output of the first PID controller 1-1 is connected to Value1 of the minimum output value calculation module 5, and the Output of the second PID controller 1-2 is connected to Value2 of the minimum output value calculation module 5. The minimum output value is calculated from the result values ​​output by the multiple PID controllers as a control signal, that is, the minimum opening value MinCV, and then output to the actuator 8 through the output value ramp filter 2-2. The output opening range of the actuator 8 is 0% to 100%, which effectively avoids excessive action of the actuator 8 caused by overexcitation of a single PID controller, thereby improving the safety and smoothness of the control.

[0069] In a specific embodiment, the control signal plus a preset deviation value is used as the maximum output value limit benchmark of each PID controller; through the SetPID MaxLimitvalue calculation block, the minimum opening value MinCV selected by all PIDs plus the preset deviation value is used as the maximum opening limit benchmark of each PID controller.

[0070] Optionally, the preset deviation value may be 0.75. In other embodiments, the preset deviation value may be set between 0.5 and 3 to prevent a large change in the output opening of the actuator 8 during the switching process of the PID controller.

[0071] In a specific embodiment, the limit reference of the maximum output value is assigned to the MaxLimit of the first PID controller 1-1 and the MaxLimit of the second PID controller 1-2. Adaptive adjustment of the control strategy during the regulation process is achieved, the flexibility and efficiency of the control are increased, and the ability to respond quickly to emergency or abnormal conditions is increased. The control signal is then output to the actuator 8 to achieve multiple PID parallel regulation.

[0072] In a specific embodiment, the control signal is processed by the output value ramp filter 2-2 and then output to the actuator 8, which further smoothes the control signal and reduces the sudden changes and oscillations in the response of the actuator 8, thereby improving the dynamic performance of the system while maintaining the control accuracy.

[0073] Optionally, each of the PID controllers is equipped with a switch 4. In a specific embodiment, Figure 2 The option switch 4 shown controls the working state of a single PID controller through the switch 4. According to the actual process, the PID controller that needs to be put into the process in the process control system is selected, which improves the flexibility of the system and expands the application scope of the system.

[0074] In a specific embodiment, it is possible to choose whether to connect the alarm signal to the protection interface of the PID controller according to the process. When the equipment alarms, the actuator 8 is forced to output a 0% output value. By setting the alarm interlock protection Alarm, the safety of the system equipment is improved, and the ability to respond quickly to emergency or abnormal conditions is enhanced.

[0075] Figure 3 FIG. 5 shows a block diagram of a minimum output value calculation module 5 according to a specific embodiment of the present invention. Figure 3 As shown, the minimum output value calculation module 5 calculates the minimum opening of all PID controller outputs by selecting the minimum opening function GetMin, and the output Output of each PID controller is connected to the Value of the minimum output value calculation module 5, and the minimum opening value MinCV is calculated through the input Value1, Value2 and Value3.

[0076] Figure 4 FIG. 6 shows a principle block diagram of a maximum output value calculation module 6 according to a specific embodiment of the present invention. Figure 4 As shown, the maximum opening limit calculation method is shown. Through the SetPID MaxLimitvalue calculation module, the minimum opening value MinCV selected by all PID controllers plus the preset deviation value are used as the maximum opening limit benchmark of each PID controller, and the output MaxLimit is connected to the MaxLimit of each PID controller. The specific formula of the maximum output value calculation module 6 is:

[0077] Limit(0.0,MinCV+x,100.0)

[0078] Among them, MinCV represents the minimum opening value, x represents the deviation value, in the specific embodiment, the default value of x is 0.75, and the specific function of Limit is described as follows: it is used to limit the output of the value of the input variable. No matter how the input variable changes, only the value between 0.0 and 100.0 is output. In this embodiment, 0.0 is defined as the minimum value of the function block, and 100.0 is defined as the maximum value of the function block. MinCV+x represents the original data of the function block. When the value of the original data is between 0.0 and 100.0, the output is equal to the value of MinCV+x. When the value of the original data is less than or equal to the minimum value, the minimum value is output. When the value of the original data is greater than the maximum value, the maximum value is output. This module realizes the adaptive adjustment of the control strategy during the regulation process, which increases the flexibility and efficiency of the control.

[0079] Optionally, the default value of the preset deviation value x is 0.75. In other embodiments, the preset deviation value may be set between 0.5 and 3 to prevent a large change in the output opening of the actuator 8 during the switching process of the PID controller.

[0080] Figure 5 FIG. 4 shows a schematic diagram of a slope filtering process according to a specific embodiment of the present invention. Figure 5 As shown, upRamp in the set value ramp filter 2-1RampFilter and the output value ramp filter 2-2RampFilter can set the maximum rising rate per unit cycle time according to the actual control process; dnRamp can set the maximum falling rate per unit cycle time according to the actual control process; loopTime can set the unit cycle time according to the actual control process, such as the mode of 0.1 second, which improves the safety and smoothness of control.

[0081] Figure 6 FIG. 4 shows a low-pass filtering processing principle block diagram of a specific embodiment of the present invention. Figure 6 The low-pass filter 3LP Filter and its principle are shown in the figure. The specific formula is:

[0082] ExpRate = EXP (-0.1 / Ftau)

[0083] Ftau = 0.1

[0084] FVLast=FVLast*ExpRate+(x*(1-ExpRate))

[0085] y=FVLast

[0086] Among them, x represents the input signal, that is, the original data at the current moment, y represents the output signal, that is, the data after passing through the low-pass filter 3, ExpRate represents the smoothing factor, which is used to control the response speed of the filter. The value of the smoothing factor is between 0 and 1. The closer to 0, the stronger the filter's suppression of high-frequency noise, but the slower the response speed; the closer to 1, the faster the filter's response speed, but the weaker the suppression effect on high-frequency noise. Ftau is a time constant in seconds. Ftau determines the size of the smoothing factor. In this embodiment, Ftau = 0.1; FVLast represents the last value after filtering, that is, the filtering result at the last sampling moment. By controlling the exponential smoothing of the signal, high-frequency noise can be removed and the long-term trend of the signal can be retained.

[0087] This application adopts the innovative design of multiple PID parallel architecture, the strategy of selecting the minimum opening value from the output of all PID controllers as the direct control signal of actuator 8, and the adaptive algorithm of dynamic maximum opening limit. The stability and robustness of the control system are enhanced through the collaborative operation of multiple PID controllers, especially when dealing with control objects with multiple interferences and complex dynamic characteristics, which can achieve more refined control effects and higher system adaptability.

[0088] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above invention concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

Claims

1. A multiple PID parallel control system, characterized in that: include: Multiple PID controllers: Multiple PID controllers work in parallel, each of which performs independent calculations based on the input signal and outputs the result value; Minimum output value calculation module: calculates the minimum output value from the result values ​​output by the multiple PID controllers as a control signal; Control signal output module: outputs the control signal to the actuator to realize multiple PID parallel regulation.

2. A multiple PID parallel control system according to claim 1, characterized in that: Also includes: Maximum output value calculation module: adds the control signal to the preset deviation value as the maximum output value limit benchmark of each PID controller.

3. The multiple PID parallel control system according to claim 1 is characterized in that: Each of the PID controllers includes a feedback value and a set value. The feedback value enters the PID controller after being processed by a low-pass filter, and the set value enters the PID controller after being processed by a set value ramp filter.

4. The multiple PID parallel control system according to claim 1 is characterized in that: The output signal of each PID controller is processed by the minimum output value calculation module to obtain the minimum value, and then processed by the output value ramp filter before being output to the actuator.

5. The multiple PID parallel control system according to claim 1, characterized in that: Each of the PID controllers is equipped with a switch, and the working state of the single PID controller is controlled by the switch.

6. The multiple PID parallel control system according to claim 1, characterized in that: It also includes an alarm interlock protection module. When the device alarms, the alarm signal is connected to the PID controller to force the actuator to output a 0% output value.

7. A multiple PID parallel adjustment method, characterized in that: include: Multiple PID controllers in parallel: multiple PID controllers work in parallel, each of which performs independent calculations based on the input signal and outputs the result value; Minimum output value calculation: Calculate the minimum output value from the result values ​​output by the multiple PID controllers as a control signal; Control signal output: The control signal is output to the actuator to realize multiple PID parallel regulation.

8. The multiple PID parallel adjustment method according to claim 7 is characterized in that: Also includes: Maximum output value calculation: the control signal plus a preset deviation value is used as the maximum output value limit benchmark of each PID controller.

9. The multiple PID parallel adjustment method according to claim 7, characterized in that: Each of the PID controllers includes a feedback value and a set value. The feedback value enters the PID controller after being processed by a low-pass filter, and the set value enters the PID controller after being processed by a set value ramp filter.

10. The multiple PID parallel adjustment method according to claim 7, characterized in that: The output signal of each PID controller is processed by the minimum output value calculation and then processed by the output value ramp filter before being output to the actuator.

11. The multiple PID parallel adjustment method according to claim 7, characterized in that: Each of the PID controllers is equipped with a switch, and the working state of the single PID controller is controlled by the switch.

12. The multiple PID parallel adjustment method according to claim 7, characterized in that: It also includes alarm interlock protection. When the device alarms, the alarm signal is connected to the PID controller to force the actuator to output a 0% output value.

13. A programmable controller program product, characterized in that: The program is stored in a programmable controller, and when the programmable controller program is executed by a processor, the method according to any one of claims 7 to 12 is implemented.

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