PID (Proportion Integration Differentiation) parameter setting method, system and equipment based on phase analysis and medium

Abstract

The invention relates to a PID (Proportion Integration Differentiation) parameter setting method, system and device based on phase analysis and a medium. The method comprises the following steps: acquiring historical trend values and PID initial parameters of PV parameters, SV parameters and MV parameters in a control loop; performing phase analysis processing on each parameter according to a trend chart constructed by historical trend values to obtain a phase feature point corresponding to each parameter and step change information of the SV parameter; when the SV parameter has step change, adjusting the proportionality and integral time of the PID initial parameter according to overshoot and rise time obtained by phase feature points of the PV parameter and the SV parameter; and when the step change does not exist in the SV parameter, adjusting the proportion degree and the integration time of the PID initial parameter according to an integral judgment index and a proportion judgment index obtained by the phase feature points of the PV parameter and the MV parameter. According to the method, the PID parameter setting speed and accuracy are improved, and the application range of PID setting software is widened.

Description

Technical Field

[0001] The present invention relates to the field of industrial control technology, and in particular to a PID parameter setting method, system, equipment and medium based on phase analysis. Background Art

[0002] In today's industrial production field, PID control is still the most widely used regulator control law. Since the advent of PID controller, it has become one of the main technologies of industrial control with its advantages of simple structure, high stability, reliable operation and convenient adjustment. According to statistics, more than 90% of controllers in industrial production use PID controllers. However, although it shows different adjustment requirements under different control objects and process flows, accurate setting of PID parameters is still the key to ensure that the controller performs at its best.

[0003] Existing PID parameter tuning methods include model tuning method and empirical method. Model-based tuning methods often rely on a large amount of control loop operation data and step test calculations. However, in the actual use of PID tuning software in engineering, problems such as insufficient loop excitation and insufficient data source length often occur, making it impossible for the model tuning method to accurately tune the results. If the model-based tuning method is still used, it will definitely consume more time and energy. Therefore, the accuracy of PID parameter tuning is also limited by the accuracy of the model, and it is often not suitable for large-scale PID parameter tuning. Empirical tuning is suitable for process industries, but the technical requirements for operators are too high. Many companies lack experienced technicians. Inexperienced operators cannot guarantee the estimated effect of control parameters, nor can they guarantee the stable state of process industry production. Its operation is not suitable for most users.

[0004] Therefore, how to achieve high-precision PID parameter tuning in a control loop with insufficient data source is an urgent problem to be solved by those skilled in the art. Summary of the invention

[0005] 1. Technical issues to be resolved In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a PID parameter tuning method, system, device and medium based on phase analysis, which solves the technical problem of low accuracy of PID parameter tuning in a control loop with insufficient data source.

[0006] (II) Technical solution In order to achieve the above object, the main technical solutions adopted by the present invention include: In a first aspect, an embodiment of the present invention provides a PID parameter tuning method based on phase analysis, comprising: Preprocess the operating data of the control loop to obtain the historical trend value and PID initial parameters within a set time period, the historical trend value includes PV parameters, SV parameters and MV parameters; Constructing a trend graph of the historical trend value according to the time sequence, and performing phase analysis processing on each parameter of the historical trend value in the trend graph to obtain the phase characteristic point corresponding to each parameter and the step change information of the SV parameter; When there is a step change in the SV parameters, the proportionality and integral time in the PID initial parameters are adjusted according to the overshoot and rise time obtained from the phase characteristic points of the PV parameters and SV parameters to obtain the PID parameters; When there is no step change in the SV parameters, the proportionality and integral time in the PID initial parameters are adjusted according to the integral judgment index and proportional judgment index obtained from the phase characteristic points of the PV parameters and the MV parameters to obtain the PID parameters.

[0007] Optionally, the phase characteristic points include: SV parameter change starting point, the SV parameter change starting point is the position point where the SV parameter undergoes a step change in the trend graph; PV parameter peak, the PV parameter peak is the peak point of each fluctuation of the PV parameter curve in the trend graph; PV parameter zero point, the PV parameter zero point is the first position point where the PV parameter curve and the SV parameter curve have the same value when the SV parameter has no step change in the trend graph, or the PV parameter zero point is the first position point where the PV parameter and the SV parameter are equal after the SV parameter has a step change in the trend graph; MV parameter trough, the MV parameter trough is the trough point of each fluctuation of the MV parameter curve in the trend graph.

[0008] Optionally, when there is a step change in the SV parameter, the proportionality and integral time in the PID initial parameters are adjusted according to the overshoot and rise time obtained from the phase characteristic points of the PV parameter and the SV parameter, and the PID parameters obtained include: When there is a step change in the SV parameter, the overshoot and rise time are obtained based on the phase characteristic points of the PV parameter and the SV parameter; Determine whether the rise time meets a set first threshold range; If the rise time is greater than 0.9 times the target rise time and less than 1.1 times the target rise time, the proportionality in the PID initial parameters is maintained; If the rise time is less than 0.9 times of the target rise time or the rise time is greater than 1.1 times of the target rise time, the proportionality in the PID initial parameters is adjusted according to the rise time, and it is determined whether the overshoot meets the set second threshold range; If the overshoot is greater than 0.8 and less than 1.1, the integral time in the PID initial parameters is maintained; If the overshoot is greater than 1.1 and the rise time is less than 0.9 times the target rise time, or the overshoot is in the range of 0 to 0.8 and the rise time is greater than 1.1 times the target rise time, the integral time in the PID initial parameters is adjusted according to the overshoot.

[0009] Optionally, the overshoot is obtained by: (1) In formula (1), Overshoot represents the overshoot, PV max Represents the peak value of the first PV parameter after the SV parameter undergoes a step change. new represents the parameter value after the SV parameter undergoes a step change, and △SV represents the amplitude of the step change of the SV parameter; The formula for obtaining the rise time is: (2) In formula (2), RiseTime represents the rise time, T1 represents the first moment when the PV parameter reaches the peak after the SV parameter undergoes a step change, and T2 represents the starting moment when the SV parameter undergoes a step change; The adjustment formula for adjusting the proportionality in the PID initial parameters according to the rise time is: (3) In formula (3), PB′ represents the adjusted proportionality, Ks represents the iteration coefficient, Tss represents the steady-state time, which is equal to the time interval between two adjacent peaks in the PV parameters, and PB represents the proportionality in the PID initial parameters; The adjustment formula for adjusting the integral time in the PID initial parameters according to the overshoot is: (4) In formula (4), Ti′ represents the adjusted integral time, and Ti represents the integral time in the PID initial parameters.

[0010] Optionally, when there is no step change in the SV parameter, the proportionality and integral time in the PID initial parameters are adjusted according to the integral judgment index and the proportional judgment index obtained from the phase characteristic points of the PV parameter and the MV parameter, and the PID parameters obtained include: When there is no step change in the SV parameter, the integral judgment index and the proportional judgment index are obtained according to the phase characteristic points of the PV parameter and the MV parameter; Determine whether the integral judgment index meets the set third threshold range; If the integral judgment index is less than 0.4 and the integral judgment index is greater than 0.1, the integral time in the PID initial parameters is maintained; If the integral judgment index is greater than 0.4 or the integral judgment index is less than 0.1, the integral time in the PID initial parameters is adjusted according to the integral judgment index, and it is determined whether the proportional judgment index meets the set fourth threshold range; If the proportional judgment index is greater than 0.225 times the steady-state time and the proportional judgment index is less than 0.275 times the steady-state time, the proportionality in the PID initial parameters is maintained; If the proportional judgment index is less than 0.225 times of the steady-state time and the integral judgment index is less than 0.1, or the proportional judgment index is greater than 0.275 times of the steady-state time and the integral judgment index is greater than 0.4, the proportionality in the PID initial parameters is adjusted according to the proportional judgment index.

[0011] Optionally, the formula for obtaining the integral judgment index is: (5) In formula (5), Ki represents the integral judgment index, T1 ′ represents the first moment when the PV parameter reaches the peak within the set time period, T2′ represents the first moment when the PV parameter curve is equal to the SV parameter curve within the set time period, and T3′ represents the first moment when the MV parameter reaches the trough within the set time period; The formula for obtaining the ratio judgment index is: (6) In formula (6), Kp represents the integral judgment index; The adjustment formula for adjusting the integral time in the PID initial parameters according to the integral judgment index is: (7) In formula (7), Ti′ represents the adjusted integral time, Ti represents the integral time in the PID initial parameters, Tss represents the steady-state time, and the steady-state time is equal to the time interval between two adjacent peaks in the PV parameters; The adjustment formula for adjusting the proportionality in the PID initial parameters according to the proportional judgment index is: (8) In formula (8), PB′ represents the proportionality after adjustment, and PB represents the proportionality in the PID initial parameters.

[0012] Optionally, it also includes: Writing the PID parameters into the control loop, and determining whether the deviation between the PV parameters and the SV parameters of the control loop is greater than a set deviation threshold; If the deviation between the PV parameter and the SV parameter of the control loop is greater than the set deviation threshold, it is determined that the PID parameter needs secondary tuning; If the deviation between the PV parameter and the SV parameter of the control loop is not greater than the set deviation threshold, it is determined that the PID parameter tuning is completed.

[0013] In a second aspect, an embodiment of the present invention further provides a PID parameter tuning system based on phase analysis, comprising: A preprocessing module is used to preprocess the operation data of the control loop to obtain the historical trend value and PID initial parameters within a set time period. The historical trend value includes PV parameters, SV parameters and MV parameters; A phase analysis module, used to construct a trend graph of the historical trend value according to the time sequence, and perform phase analysis processing on each parameter of the historical trend value in the trend graph to obtain the phase characteristic point corresponding to each parameter and the step change information of the SV parameter; The first PID parameter tuning module is used to adjust the proportionality and integral time in the PID initial parameters according to the overshoot and rise time obtained from the phase characteristic points of the PV parameters and the SV parameters when there is a step change in the SV parameters to obtain the PID parameters; The second PID parameter tuning module is used to adjust the proportionality and integral time in the PID initial parameters to obtain the PID parameters based on the integral judgment index and proportional judgment index obtained from the phase characteristic points of the PV parameters and the MV parameters when there is no step change in the SV parameters.

[0014] In a third aspect, an embodiment of the present invention further provides an electronic device, including: processor; A memory storing the steps of the PID parameter setting method based on phase analysis described above for the processor to control In a fourth aspect, an embodiment of the present invention further provides a computer-readable medium having computer executable instructions stored thereon, and when the executable instructions are executed by a processor, the above-mentioned method steps for PID parameter tuning based on phase analysis are implemented.

[0015] (III) Beneficial effects The beneficial effect of the present invention is as follows: the present invention proposes a PID parameter tuning method based on phase analysis, which firstly judges and analyzes the operating data such as PV parameters, SV parameters and MV parameters in the control loop, constructs a historical trend graph of each parameter, and then uses the phase characteristic points in the historical trend graph to analyze the loop characteristics of the overshoot and rise time of the step response of the PID control system, thereby providing a suitable PID parameter adjustment strategy. Compared with the prior art, it speeds up the tuning speed of PID parameters and improves the applicable scope and tuning accuracy of the PID tuning software.

[0016] At the same time, the present invention determines the phase difference caused by the integral time and proportion of the control loop based on the phase characteristic points of each operating parameter in the control loop, and then determines the adjustment direction of the control loop. Compared with the prior art, it improves the applicability of the PID parameter tuning method in the process industry and improves the flexibility of the PID parameter tuning method. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A flow chart of a PID parameter tuning method based on phase analysis provided by one embodiment of the present invention; Figure 2 A trend diagram of phase characteristic points when the SV parameter in the PID control loop provided by one embodiment of the present invention has a step change; Figure 3 A trend diagram of phase characteristic points when the SV parameter in a PID control loop has no step change provided by an embodiment of the present invention; Figure 4 A schematic flow chart of step S3 in a PID parameter tuning method based on phase analysis provided in one embodiment of the present invention; Figure 5 A flow chart of step S4 in a PID parameter setting method based on phase analysis provided in one embodiment of the present invention Figure 6 A schematic diagram of the composition of a PID parameter tuning system based on phase analysis provided by one embodiment of the present invention; Figure 7 A schematic diagram of the structure of a computer system of an electronic device provided by an embodiment of the present invention; Figure 8 An algorithm flow chart of a PID parameter tuning method based on phase analysis is provided in one embodiment of the present invention.

[0018] [Description of Reference Numerals] 300: PID parameter setting system; 301: preprocessing module; 302: phase analysis module; 303: first PID parameter adjustment module; 304: second PID parameter adjustment module; 400: computer system; 401: CPU; 402: ROM; 403: RAM; 404: bus; 405: I / O interface; 406: input part; 407: output part; 408: storage part; 409: communication part; 410: drive; 411: removable medium. DETAILED DESCRIPTION

[0019] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation modes in conjunction with the accompanying drawings.

[0020] refer to Figure 1-Figure 8 As shown, an embodiment of the present invention proposes a PID parameter tuning method, system, device and medium based on phase analysis, and the PID parameter tuning method includes: preprocessing the operation data of the control loop to obtain the historical trend value and the PID initial parameter within a set time period, and the historical trend value includes the PV parameter, the SV parameter and the MV parameter; constructing a trend graph of the historical trend value according to the time sequence, and performing phase analysis processing on each parameter of the historical trend value in the trend graph to obtain the phase characteristic point corresponding to each parameter and the step change information of the SV parameter; when there is a step change in the SV parameter, the proportionality and the integral time in the PID initial parameter are adjusted according to the overshoot and rise time obtained from the phase characteristic points of the PV parameter and the SV parameter to obtain the PID parameter; when there is no step change in the SV parameter, the proportionality and the integral time in the PID initial parameter are adjusted according to the integral judgment index and the proportional judgment index obtained from the phase characteristic points of the PV parameter and the MV parameter to obtain the PID parameter.

[0021] The present embodiment proposes a PID parameter tuning method based on phase analysis. First, the operating data such as PV parameters, SV parameters and MV parameters in the control loop are judged and analyzed, and a historical trend graph of each parameter is constructed. Then, the phase characteristic points in the historical trend graph are used to analyze the loop characteristics of the overshoot and rise time of the step response of the PID control system, and then a suitable PID parameter adjustment strategy is given. Compared with the prior art, it speeds up the tuning speed of the PID parameters and improves the applicable scope and tuning accuracy of the PID tuning software.

[0022] At the same time, this embodiment, based on the phase characteristic points of each operating parameter in the control loop, determines the phase difference caused by the integral time and proportion of the control loop, and then determines the adjustment direction of the control loop. Compared with the prior art, it improves the applicability of the PID parameter tuning method in the process industry and improves the flexibility of the PID parameter tuning method.

[0023] In order to better understand the above technical solution, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. On the contrary, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0024] Specifically, refer to Figure 1 As shown, an embodiment of the present invention proposes a PID parameter tuning method based on phase analysis, which includes: S1. Preprocess the operation data of the control loop to obtain the historical trend value and PID initial parameters within a set time period. The historical trend value includes PV parameters, SV parameters and MV parameters.

[0025] In this embodiment, the type of the control loop to be adjusted is obtained by preprocessing the operating data of the control loop to be adjusted, and the control loop includes: temperature control loop (TIC), pressure control loop (PIC), liquid level control loop (LIC), flow control loop (FIC) and other analyzer control loops (AIC). Then, according to the type of the control loop to be adjusted, combined with the preprocessed operating data, the historical trend value and PID initial parameters of the control loop to be adjusted within a set time period are obtained, and the historical trend value includes: PV parameter (measured value), SV parameter (set value) and MV parameter (output value).

[0026] S2. Construct a trend graph of the historical trend value according to the time sequence, and perform phase analysis on each parameter of the historical trend value in the trend graph to obtain the phase characteristic point corresponding to each parameter and the step change information of the SV parameter.

[0027] To further explain, the phase characteristic points include: the starting point of SV parameter change, the peak of PV parameter, the zero point of PV parameter and the trough of MV parameter. The starting point of SV parameter change is the position point where the SV parameter undergoes a step change in the trend graph; the peak of PV parameter is the peak point of each fluctuation of the PV parameter curve in the trend graph; the zero point of PV parameter is the first position point where the PV parameter curve and the SV parameter curve have the same value when the SV parameter has no step change in the trend graph, or the zero point of PV parameter is the first position point where the PV parameter and the SV parameter are equal after the SV parameter undergoes a step change in the trend graph; the trough of MV parameter is the trough point of each fluctuation of the MV parameter curve in the trend graph.

[0028] In a specific embodiment, the operation data in a certain flow control loop is preprocessed to obtain the PV parameters, SV parameters and MV parameters within a period of time, and then the trend graphs of the PV parameters, SV parameters and MV parameters are constructed based on the time sequence. When the SV parameter in the flow control loop has a step change, the trend graph of its phase characteristic point is as follows: Figure 2 As shown; when there is no step change in the SV parameter in the flow control loop, the trend diagram of its phase characteristic point is as follows Figure 3 Based on Figure 2 or Figure 3 As shown in the trend chart, users can set the corresponding phase characteristic points according to the trend chart, or automatically determine and display the phase characteristic points of each parameter according to the phase characteristic point search rules, so that users can clearly understand the phase characteristic points of each parameter, thereby accumulating users' experience in PID parameter tuning. The specific process of automatically finding the phase characteristic points of each parameter is as follows: (1) Filter the curves of each parameter in the constructed trend chart to remove useless noise.

[0029] (2) Fit the trend data through the fitting algorithm and fit the curve of the trend graph into a smooth curve.

[0030] (3) Identify whether a step change occurs in the SV parameter in the control loop. If a step change occurs in the SV parameter, determine the location where the step change occurs as the starting point of the SV parameter change; if no step change occurs in the SV parameter, the control program executes the next step.

[0031] (4) The first position point where the PV parameter curve and the SV parameter curve have the same value after the SV parameter undergoes a step change is determined as the PV parameter zero point; or, the first position point where the PV parameter curve and the SV parameter curve have the same value when the SV parameter does not undergo a step change is determined as the PV parameter zero point.

[0032] (5) In the PV parameter curve after the PV parameter zero point, the point where the SV parameter is equal to the PV parameter is used as the dividing point to divide the PV parameter curve into several segments, and the point with the maximum difference between the PV parameter curve and the SV parameter in each segment is used as the peak or trough, where the PV parameter value at the peak is greater than the SV parameter value, and the PV parameter value at the trough is less than the SV parameter value.

[0033] (6) In the MV parameter curve, a reference value line is set that runs through each fluctuation curve of the MV parameter. The reference value line is a straight line with the same value. Then, the point where the MV parameter and the reference value line have the same value is used as the dividing point to divide the MV parameter curve into several segments. The point with the maximum difference between the values ​​of the MV parameter curve and the reference value line in each segment is used as the peak or trough. The MV parameter value at the peak is greater than the value of the reference value line, and the MV parameter value at the trough is less than the value of the reference value line.

[0034] S3. When there is a step change in the SV parameter, the proportionality and integration time in the PID initial parameters are adjusted according to the overshoot and rise time obtained from the phase characteristic points of the PV parameter and the SV parameter to obtain the PID parameters.

[0035] For example, refer to Figure 4 As shown, step S3 in this embodiment may include the following sub-steps S31 to S34: S31. When there is a step change in the SV parameter, the overshoot and rise time are obtained according to the phase characteristic points of the PV parameter and the SV parameter.

[0036] The formula for obtaining the overshoot is: (1) In formula (1), Overshoot represents the overshoot, PV max Represents the peak value of the first PV parameter after the SV parameter undergoes a step change. new It represents the parameter value after the SV parameter undergoes a step change, and △SV represents the amplitude of the step change of the SV parameter.

[0037] The formula for obtaining the rise time is: (2) In formula (2), RiseTime represents the rise time, T1 represents the first moment when the PV parameter reaches the peak after the SV parameter undergoes a step change, and T2 represents the starting moment when the SV parameter undergoes a step change.

[0038] S32: Determine whether the rise time satisfies a set first threshold range.

[0039] S33a. If the rise time is greater than 0.9 times the target rise time and less than 1.1 times the target rise time, the proportionality in the PID initial parameters is maintained.

[0040] S33b. If the rise time is less than 0.9 times of the target rise time or the rise time is greater than 1.1 times of the target rise time, the proportionality in the PID initial parameters is adjusted according to the rise time, and it is determined whether the overshoot meets the set second threshold range.

[0041] The adjustment formula for adjusting the proportionality in the PID initial parameters according to the rise time is: (3) In formula (3), PB′ represents the adjusted proportionality, Ks represents the iteration coefficient, Tss represents the steady-state time, which is equal to the time interval between two adjacent peaks in the PV parameters, and PB represents the proportionality in the PID initial parameters.

[0042] S34a, if the overshoot is greater than 0.8 and less than 1.1, the integral time in the PID initial parameters is maintained.

[0043] S34b. If the overshoot is greater than 1.1 and the rise time is less than 0.9 times the target rise time, or the overshoot is in the range of 0 to 0.8 and the rise time is greater than 1.1 times the target rise time, the integral time in the PID initial parameters is adjusted according to the overshoot.

[0044] Further explanation: When the overshoot is greater than 1.1 and the rise time is less than 0.9 times the target rise time, the integral time in the PID initial parameters is adjusted by the overshoot to reduce the integral effect. When the overshoot is in the range of 0 to 0.8 and the rise time is greater than 1.1 times the target rise time, the integral time in the PID initial parameters is adjusted by the overshoot to increase the integral effect.

[0045] The adjustment formula for adjusting the integral time in the PID initial parameters according to the overshoot is: (4) In formula (4), Ti′ represents the adjusted integral time, and Ti represents the integral time in the PID initial parameters.

[0046] S4. When there is no step change in the SV parameter, the proportionality and integral time in the PID initial parameters are adjusted according to the integral judgment index and proportional judgment index obtained from the phase characteristic points of the PV parameter and the MV parameter to obtain the PID parameters.

[0047] For example, refer to Figure 5 As shown, step S4 in this embodiment may include the following sub-steps S41 to S44: S41. When there is no step change in the SV parameter, an integral judgment index and a proportional judgment index are obtained according to the phase characteristic points of the PV parameter and the MV parameter.

[0048] The formula for obtaining the integral judgment index is: (5) In formula (5), Ki represents the integral judgment index, T1′ represents the first moment when the PV parameter reaches the peak within the set time period, T2′ represents the first moment when the PV parameter curve is equal to the SV parameter curve within the set time period, and T3′ represents the first moment when the MV parameter reaches the trough within the set time period.

[0049] The formula for obtaining the ratio judgment index is: (6) In formula (6), Kp represents the integral judgment index S42: Determine whether the integral judgment index satisfies a set third threshold range.

[0050] S43a: If the integral judgment index is less than 0.4 and the integral judgment index is greater than 0.1, the integral time in the PID initial parameters is maintained.

[0051] S43b. If the integral judgment index is greater than 0.4 or less than 0.1, the integral time in the PID initial parameters is adjusted according to the integral judgment index, and it is determined whether the proportional judgment index satisfies the set fourth threshold range.

[0052] Further explanation: when the integral judgment index is greater than 0.4, the integral time in the PID initial parameters is adjusted by the integral judgment index to reduce the integral effect. When the integral judgment index is less than 0.1, the integral time in the PID initial parameters is adjusted by the integral judgment index to increase the integral effect.

[0053] The adjustment formula for adjusting the integral time in the PID initial parameters according to the integral judgment index is: (7) In formula (7), Ti′ represents the adjusted integral time, Ti represents the integral time in the PID initial parameters, and Tss represents the steady-state time, which is equal to the time interval between two adjacent peaks in the PV parameters.

[0054] S44a. If the proportionality judgment index is greater than 0.225 times the steady-state time and the proportionality judgment index is less than 0.275 times the steady-state time, the proportionality in the PID initial parameters is maintained.

[0055] S44b. If the proportional judgment index is less than 0.225 times of the steady-state time and the integral judgment index is less than 0.1, or the proportional judgment index is greater than 0.275 times of the steady-state time and the integral judgment index is greater than 0.4, the proportionality in the PID initial parameters is adjusted according to the proportional judgment index.

[0056] Further explanation: when the proportional judgment index is less than 0.225 times of the steady-state time and the integral judgment index is less than 0.1, the proportionality in the PID initial parameters is adjusted by the proportional judgment index to reduce the proportional action. When the proportional judgment index is greater than 0.275 times of the steady-state time and the integral judgment index is greater than 0.4, the proportionality in the PID initial parameters is adjusted by the proportional judgment index to increase the proportional action.

[0057] The adjustment formula for adjusting the proportionality in the PID initial parameters based on the proportional judgment index is: (8) In formula (8), PB′ represents the proportionality after adjustment, and PB represents the proportionality in the PID initial parameters.

[0058] Furthermore, the PID parameter tuning method based on phase analysis proposed in this embodiment further includes: S5, writing the PID parameters into the control loop and verifying the tuning results of the PID parameters. Step S5 is specifically as follows: S51. Write the PID parameters into the control loop, and determine whether the deviation between the PV parameter and the SV parameter of the control loop is greater than the set deviation threshold.

[0059] S52a: If the deviation between the PV parameter and the SV parameter of the control loop is greater than the set deviation threshold, it is determined that the PID parameters need secondary tuning.

[0060] S52b: If the deviation between the PV parameter and the SV parameter of the control loop is not greater than the set deviation threshold, it is determined that the PID parameter tuning is completed.

[0061] In this embodiment, after the adjusted PID parameters are written into the control loop, when the control loop is put into automatic use, the deviation value between the PV parameter and the SV parameter is obtained by the following formula (9). When the deviation value is less than the set deviation threshold, the fluctuation range of the PV parameter is small, and it is determined that the PID parameter tuning is completed. When the deviation value is greater than the set deviation threshold, the fluctuation range of the PV parameter is large, and it is determined that the PID parameter needs secondary tuning. Among them, the deviation threshold is 1% of the PV parameter range value.

[0062] (9) In formula (9), △MVn represents the change value of MV parameter, En represents the deviation value between PV parameter and SV parameter, △En represents the change value of deviation value, PB represents proportionality, Ti represents integration time, and △Un represents differential term.

[0063] also, Figure 6 A schematic diagram of the composition of a PID parameter tuning system based on phase analysis provided by the present invention is shown in FIG. Figure 6 As shown, the present invention also provides a PID parameter tuning system 300 based on phase analysis, which includes: The preprocessing module 301 is used to preprocess the operation data of the control loop to obtain the historical trend value and PID initial parameters within a set time period. The historical trend value includes PV parameters, SV parameters and MV parameters.

[0064] The phase analysis module 302 is used to construct a trend graph of the historical trend value according to the time sequence, and perform phase analysis processing on each parameter of the historical trend value in the trend graph to obtain the phase feature point corresponding to each parameter and the step change information of the SV parameter.

[0065] The first PID parameter adjustment module 303 is used to adjust the proportionality and integration time in the PID initial parameters according to the overshoot and rise time obtained from the phase characteristic points of the PV parameters and the SV parameters to obtain the PID parameters when there is a step change in the SV parameters.

[0066] The second PID parameter adjustment module 304 is used to adjust the proportionality and integration time in the PID initial parameters according to the integral judgment index and the proportional judgment index obtained from the phase characteristic points of the PV parameters and the MV parameters to obtain the PID parameters when there is no step change in the SV parameters.

[0067] The functions of each module in the system refer to the relevant description in the above method embodiment, which will not be repeated here.

[0068] On the other hand, the present invention also provides an electronic device, including a processor and a memory, wherein the memory stores steps of a PID parameter setting method based on phase analysis for the processor to control the above-mentioned process.

[0069] Reference below Figure 7 , which shows a schematic diagram of the structure of a computer system 400 suitable for implementing an electronic device of an embodiment of the present application. Figure 7 The electronic device shown is merely an example and should not bring any limitation to the functions and scope of use of the embodiments of the present application.

[0070] like Figure 7As shown, the computer system 400 includes a central processing unit (CPU) 401, which can perform various appropriate actions and processes according to a program stored in a read-only memory (ROM) 402 or a program loaded from a storage part 408 into a random access memory (RAM) 403. In the RAM 403, various programs and data required for the operation of the computer system 400 are also stored. The CPU 401, the ROM 402, and the RAM 403 are connected to each other through a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0071] The following components are connected to the I / O interface 405: an input section 406 including a keyboard, a mouse, etc.; an output section 407 including a cathode ray tube (CRT), a liquid crystal display (LCD), etc., and a speaker, etc.; a storage section 408 including a hard disk, etc.; and a communication section 409 including a network interface card such as a LAN card, a modem, etc. The communication section 409 performs communication processing via a network such as the Internet. A drive 410 is also connected to the I / O interface 405 as needed. A removable medium 411, such as a magnetic disk, an optical disk, a magneto-optical disk, a semiconductor memory, etc., is installed on the drive 410 as needed, so that a computer program read therefrom is installed into the storage section 408 as needed.

[0072] In particular, according to an embodiment of the present invention, the process described above with reference to the flowchart can be implemented as a computer software program. For example, an embodiment of the present invention includes a computer program product, which includes a computer program carried on a computer-readable medium, and the computer program contains program code for executing the method shown in the flowchart. In such an embodiment, the computer program can be downloaded and installed from a network through the communication part 409, and / or installed from a removable medium 411. When the computer program is executed by the central processing unit (CPU) 401, the above-mentioned functions defined in the system of the present application are executed.

[0073] It should be noted that the computer-readable medium shown in the present application may be a computer-readable signal medium or a computer-readable medium or any combination of the above two. The computer-readable medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or device, or any combination of the above. More specific examples of computer-readable media may include, but are not limited to: an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present application, a computer-readable medium may be any tangible medium containing or storing a program that can be used by or in combination with an instruction execution system, device or device. In the present application, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, which carries a computer-readable program code. This propagated data signal may take a variety of forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. The computer-readable signal medium may also be any computer-readable medium other than a computer-readable medium that can send, propagate or transmit a program for use by or in conjunction with an instruction execution system, apparatus or device. The program code contained on the computer-readable medium may be transmitted using any appropriate medium, including but not limited to: wireless, wire, optical cable, RF, etc., or any suitable combination of the above.

[0074] The flow chart and block diagram in the accompanying drawings illustrate the possible architecture, function and operation of the system, method and computer program product according to various embodiments of the present application. In this regard, each box in the flow chart or block diagram can represent a module, a program segment or a part of a code, and the above-mentioned module, program segment or a part of a code contains one or more executable instructions for realizing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two boxes represented in succession can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram or flow chart, and the combination of the boxes in the block diagram or flow chart can be implemented with a dedicated hardware-based system that performs a specified function or operation, or can be implemented with a combination of dedicated hardware and computer instructions.

[0075] The units involved in the embodiments described in this application may be implemented by software or hardware. The units described may also be arranged in a processor, wherein the names of these units do not constitute limitations on the units themselves in certain circumstances.

[0076] On the other hand, the present invention also provides a computer-readable medium, which may be included in the device described in the above embodiment; or may exist independently without being assembled into the device. The above computer-readable medium carries one or more programs, and when the above one or more programs are executed by a device, the device includes the following method steps: S1. Preprocess the operation data of the control loop to obtain the historical trend value and PID initial parameters within a set time period. The historical trend value includes PV parameters, SV parameters and MV parameters.

[0077] S2. Construct a trend graph of the historical trend value according to the time sequence, and perform phase analysis on each parameter of the historical trend value in the trend graph to obtain the phase characteristic point corresponding to each parameter and the step change information of the SV parameter.

[0078] S3. When there is a step change in the SV parameter, the proportionality and integration time in the PID initial parameters are adjusted according to the overshoot and rise time obtained from the phase characteristic points of the PV parameter and the SV parameter to obtain the PID parameters.

[0079] S4. When there is no step change in the SV parameter, the proportionality and integral time in the PID initial parameters are adjusted according to the integral judgment index and proportional judgment index obtained from the phase characteristic points of the PV parameter and the MV parameter to obtain the PID parameters.

[0080] S5. Write the PID parameters into the control loop and verify the tuning results of the PID parameters.

[0081] In summary, the embodiment of the present invention proposes a PID parameter tuning method, system, device and medium based on phase analysis. The method performs tuning by simulating experienced engineers to analyze the control loop characteristics, judges and analyzes the current control loop characteristics, and then uses the peaks, troughs and zero points of the control loop parameter curve to analyze the overshoot and rise time of the step response of the PID control system, and then obtains the adjustment strategy of the PID parameters based on the overshoot and rise time. In the embodiment of the present invention, the user can obtain reasonable PID parameters after several short adjustment processes, which speeds up the tuning speed of the PID parameters. The PID parameter tuning process is also applicable to control loops with insufficient data sources, and because it simulates experienced engineers to analyze the control loop characteristics for tuning, it is more suitable for PID parameter tuning of control loops in process industries.

[0082] Since the system / device described in the above embodiments of the present invention is a system / device used to implement the method of the above embodiments of the present invention, a person skilled in the art can understand the specific structure and deformation of the system / device based on the method described in the above embodiments of the present invention, and thus will not be described in detail here. All systems / devices used in the method of the above embodiments of the present invention belong to the scope of protection of the present invention.

[0083] It should be understood by those skilled in the art that embodiments of the present invention may be provided as methods, systems or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0084] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems) and computer program products according to embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions.

[0085] It should be noted that in the description of the present invention, the word "a" or "an" preceding a component does not exclude the presence of a plurality of such components. The present invention can be implemented by means of hardware comprising several different components and by means of a suitably programmed computer. The use of the words first, second, third, etc., is only for convenience of expression and does not indicate any order. These words may be understood as part of the name of the component.

[0086] In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, unless they are contradictory.

[0087] Although preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments after obtaining the basic inventive concepts.

[0088] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the invention.

Claims

1. A PID parameter tuning method based on phase analysis, characterized in that: include: Preprocess the operating data of the control loop to obtain the historical trend value and PID initial parameters within a set time period, the historical trend value includes PV parameters, SV parameters and MV parameters; Constructing a trend graph of the historical trend value according to the time sequence, and performing phase analysis processing on each parameter of the historical trend value in the trend graph to obtain the phase characteristic point corresponding to each parameter and the step change information of the SV parameter; When there is a step change in the SV parameters, the proportionality and integral time in the PID initial parameters are adjusted according to the overshoot and rise time obtained from the phase characteristic points of the PV parameters and SV parameters to obtain the PID parameters; When there is no step change in the SV parameters, the proportionality and integral time in the PID initial parameters are adjusted according to the integral judgment index and proportional judgment index obtained from the phase characteristic points of the PV parameters and the MV parameters to obtain the PID parameters.

2. The method according to claim 1, characterized in that The phase characteristic points include: SV parameter change starting point, the SV parameter change starting point is the position point where the SV parameter undergoes a step change in the trend graph; PV parameter peak, the PV parameter peak is the peak point of each fluctuation of the PV parameter curve in the trend graph; PV parameter zero point, the PV parameter zero point is the first position point where the PV parameter curve and the SV parameter curve have the same value when the SV parameter has no step change in the trend graph, or the PV parameter zero point is the first position point where the PV parameter and the SV parameter are equal after the SV parameter has a step change in the trend graph; MV parameter trough, the MV parameter trough is the trough point of each fluctuation of the MV parameter curve in the trend graph.

3. The method according to claim 1, characterized in that When there is a step change in the SV parameter, the proportionality and integral time in the PID initial parameters are adjusted according to the overshoot and rise time obtained from the phase characteristic points of the PV parameter and the SV parameter, and the PID parameters obtained include: When there is a step change in the SV parameter, the overshoot and rise time are obtained based on the phase characteristic points of the PV parameter and the SV parameter; Determine whether the rise time meets a set first threshold range; If the rise time is greater than 0.9 times the target rise time and less than 1.1 times the target rise time, the proportionality in the PID initial parameters is maintained; If the rise time is less than 0.9 times of the target rise time or the rise time is greater than 1.1 times of the target rise time, the proportionality in the PID initial parameters is adjusted according to the rise time, and it is determined whether the overshoot meets the set second threshold range; If the overshoot is greater than 0.8 and less than 1.1, the integral time in the PID initial parameters is maintained; If the overshoot is greater than 1.1 and the rise time is less than 0.9 times the target rise time, or the overshoot is in the range of 0 to 0.8 and the rise time is greater than 1.1 times the target rise time, the integral time in the PID initial parameters is adjusted according to the overshoot.

4. The method according to claim 3, characterized in that The formula for obtaining the overshoot is: （1） In formula (1), Overshoot represents the overshoot, PV max Represents the peak value of the first PV parameter after the SV parameter undergoes a step change. new represents the parameter value after the SV parameter undergoes a step change, and △SV represents the amplitude of the step change of the SV parameter; The formula for obtaining the rise time is: （2） In formula (2), RiseTime represents the rise time, T1 represents the first moment when the PV parameter reaches the peak after the SV parameter undergoes a step change, and T2 represents the starting moment when the SV parameter undergoes a step change; The adjustment formula for adjusting the proportionality in the PID initial parameters according to the rise time is: （3） In formula (3), PB′ represents the adjusted proportionality, Ks represents the iteration coefficient, Tss represents the steady-state time, which is equal to the time interval between two adjacent peaks in the PV parameters, and PB represents the proportionality in the PID initial parameters; The adjustment formula for adjusting the integral time in the PID initial parameters according to the overshoot is: （4） In formula (4), Ti′ represents the adjusted integral time, and Ti represents the integral time in the PID initial parameters.

5. The method according to claim 1, characterized in that When there is no step change in the SV parameter, the proportionality and integral time in the PID initial parameters are adjusted according to the integral judgment index and proportional judgment index obtained from the phase characteristic points of the PV parameter and the MV parameter, and the PID parameters obtained include: When there is no step change in the SV parameter, the integral judgment index and the proportional judgment index are obtained according to the phase characteristic points of the PV parameter and the MV parameter; Determine whether the integral judgment index meets the set third threshold range; If the integral judgment index is less than 0.4 and the integral judgment index is greater than 0.1, the integral time in the PID initial parameters is maintained; If the integral judgment index is greater than 0.4 or the integral judgment index is less than 0.1, the integral time in the PID initial parameters is adjusted according to the integral judgment index, and it is determined whether the proportional judgment index meets the set fourth threshold range; If the proportional judgment index is greater than 0.225 times the steady-state time and the proportional judgment index is less than 0.275 times the steady-state time, the proportionality in the PID initial parameters is maintained; If the proportional judgment index is less than 0.225 times of the steady-state time and the integral judgment index is less than 0.1, or the proportional judgment index is greater than 0.275 times of the steady-state time and the integral judgment index is greater than 0.4, the proportionality in the PID initial parameters is adjusted according to the proportional judgment index.

6. The method according to claim 5, characterized in that The formula for obtaining the integral judgment index is: （5） In formula (5), Ki represents the integral judgment index, T1′ represents the first moment when the PV parameter reaches the peak within the set time period, T2′ represents the first moment when the PV parameter curve is equal to the SV parameter curve within the set time period, and T3′ represents the first moment when the MV parameter reaches the trough within the set time period; The formula for obtaining the ratio judgment index is: （6） In formula (6), Kp represents the integral judgment index; The adjustment formula for adjusting the integral time in the PID initial parameters according to the integral judgment index is: （7） In formula (7), Ti′ represents the adjusted integral time, Ti represents the integral time in the PID initial parameters, Tss represents the steady-state time, and the steady-state time is equal to the time interval between two adjacent peaks in the PV parameters; The adjustment formula for adjusting the proportionality in the PID initial parameters according to the proportional judgment index is: （8） In formula (8), PB′ represents the proportionality after adjustment, and PB represents the proportionality in the PID initial parameters.

7. The method according to claim 1, characterized in that Also includes: Writing the PID parameters into the control loop, and determining whether the deviation between the PV parameters and the SV parameters of the control loop is greater than a set deviation threshold; If the deviation between the PV parameter and the SV parameter of the control loop is greater than the set deviation threshold, it is determined that the PID parameter needs secondary tuning; If the deviation between the PV parameter and the SV parameter of the control loop is not greater than the set deviation threshold, it is determined that the PID parameter tuning is completed.

8. A PID parameter tuning system based on phase analysis, characterized in that: include: A preprocessing module is used to preprocess the operation data of the control loop to obtain the historical trend value and PID initial parameters within a set time period. The historical trend value includes PV parameters, SV parameters and MV parameters; A phase analysis module, used to construct a trend graph of the historical trend value according to the time sequence, and perform phase analysis processing on each parameter of the historical trend value in the trend graph to obtain the phase characteristic point corresponding to each parameter and the step change information of the SV parameter; The first PID parameter tuning module is used to adjust the proportionality and integral time in the PID initial parameters according to the overshoot and rise time obtained from the phase characteristic points of the PV parameters and the SV parameters when there is a step change in the SV parameters to obtain the PID parameters; The second PID parameter tuning module is used to adjust the proportionality and integral time in the PID initial parameters to obtain the PID parameters based on the integral judgment index and proportional judgment index obtained from the phase characteristic points of the PV parameters and the MV parameters when there is no step change in the SV parameters.

9. An electronic device, characterized in that: include: processor; A memory storing steps of a PID parameter tuning method based on phase analysis as described in any one of claims 1-7 for the processor to control.

10. A computer-readable medium having computer-executable instructions stored thereon, characterized in that: When the executable instructions are executed by the processor, the steps of a PID parameter tuning method based on phase analysis as described in any one of claims 1 to 7 are implemented.

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