CN-121978999-A - Valve positioner control algorithm switching method, system, equipment and storage medium based on self-tuning

CN121978999ACN 121978999 ACN121978999 ACN 121978999ACN-121978999-A

Abstract

The invention relates to the technical field of industrial automation control, in particular to a valve positioner control algorithm switching method, a system, equipment and a storage medium based on self-tuning, which comprises the following steps that S1, a self-tuning calibration process is carried out on a valve, and motion parameters including the whole-course motion time, the position deviation and the minimum effective control quantity of the valve are obtained; and S2, calculating a discrimination factor representing the valve resistance characteristic through a preset weighted calculation formula according to the motion parameter, and S3, comparing the discrimination factor with a preset critical value, automatically selecting a target control algorithm from a plurality of pre-stored control algorithms according to a comparison result, and performing closed-loop control on the valve by adopting the algorithm. The invention realizes the automatic and accurate matching of the control algorithm and the valve resistance characteristic, effectively improves the adaptability, stability and control quality of the valve control, and simultaneously obviously reduces the debugging and maintenance cost.

Inventors

ZHANG LEI
SHEN YIPENG
YU LIMING
XUE BIN
HU MENGJIE

Assignees

中控技术股份有限公司
浙江中控自动化仪表有限公司

Dates

Publication Date: 20260505
Application Date: 20251222

Claims (10)

1. The valve positioner control algorithm switching method based on self-tuning is characterized by comprising the following steps of: s1, executing a self-tuning calibration process on a valve, and acquiring a plurality of motion parameters of the valve, wherein the motion parameters at least comprise the whole-course motion time of the valve, the position deviation between valve position feedback and instructions and the minimum effective control quantity; S2, calculating a judgment factor used for representing the control characteristic of the valve according to the motion parameter and a preset judgment factor calculation formula; And S3, comparing the discrimination factor with a preset critical value to obtain a comparison result, screening a target control algorithm adapting to the valve control characteristic from a plurality of prestored control algorithms according to the comparison result, and performing valve position closed-loop control on the valve by adopting the target control algorithm.
2. The method according to claim 1, wherein in step S1, the self-tuning calibration process is performed on the valve to obtain a number of motion parameters of the valve, and further comprising: S11, defining a first position, a second position and an intermediate position of the valve; S12, a full-stroke control instruction is sent by adopting a Bang-Bang control mode, a valve is driven to run from the first position to the second position, the first full-stroke movement time T1 of the valve for completing the stroke is recorded in real time, the valve is driven to reversely run from the second position to the first position, the second full-stroke movement time T2 of the valve for completing the reverse stroke is recorded, and the first full-stroke movement time T1 and the second full-stroke movement time are the valve full-stroke movement time; S13, adopting the Bang-Bang control mode, driving a valve to run from the first position to the middle position, immediately stopping control, collecting an actual valve position value after the valve position is stable, calculating a difference value between the actual valve position value and the middle position as a first position deviation X1, immediately stopping control after the valve is controlled to run from the second position to the middle position, collecting the actual valve position value after the valve position is stable, calculating a difference value between the actual valve position value and the middle position as a second position deviation X2, and calculating the first position deviation X1 and the second position deviation X2 as the position deviations; S14, through the Bang-Bang control mode, the valve is operated from the first position and the second position to the middle position, then control is stopped, the valve is switched to a pulse control mode, a control signal is sent to the valve in a mode of starting with an initial duty ratio and increasing the pulse duty ratio by a preset step length until effective displacement of the valve is detected, and the control quantity corresponding to the duty ratio at the moment is recorded as a first minimum control quantity W1 and a second minimum control quantity W2.
3. The method according to claim 2, wherein in step S1, the first position is a fully closed position corresponding to 0% valve position, the second position is a fully open position corresponding to 100% valve position, and the intermediate position is a 50% position corresponding to 50% valve position of the valve stroke.
4. A valve positioner control algorithm switching method based on self-tuning as in claim 2 or 3, wherein the pulse control mode parameter setting comprises: The initial duty ratio of the pulse control mode is 10%, and the increment mode is to increment the preset duty ratio step length every preset time step length; The actual displacement of the valve is acquired in real time through a valve position feedback module of the valve, and when the actual displacement is detected to exceed a preset minimum displacement threshold value, the duty cycle increment is stopped immediately; and records the current duty ratio as the first minimum control amount W1 or the second minimum control amount W2.
5. The method according to claim 2, wherein in step S2, the determining factor for characterizing the valve control characteristic is calculated by a preset determining factor calculation formula, and further comprising: Calculating the discrimination factor k according to the first full-motion time T1, the second full-motion time T2, the first position deviation X1, the second position deviation X2, the first minimum control amount W1 and the second minimum control amount W2, as follows: k=A*(T1+T2)+B*(C-X1-X2)+D*(W1+W2) Wherein A, B, C, D is the weighting coefficient.
6. The method of claim 5, wherein the weight factor a is 0.01, the weight factor B is 0.8, the weight factor C is 1, and the weight factor D is 0.33.
7. The switching method of valve positioner control algorithm based on self-tuning of claim 1, wherein in step S3, a target control algorithm that is adapted to the valve control characteristic is selected from a plurality of control algorithms that are prestored according to the comparison result, further comprising: Setting a preset critical value Kth, if the discrimination factor is smaller than or equal to the preset critical value Kth, judging that the valve is a low-resistance valve, and selecting a first control algorithm as the target control algorithm, wherein the first control algorithm is a classical PID control algorithm; And if the discrimination factor k is larger than the preset critical value Kth, judging that the valve is a high-resistance valve, and selecting a second control algorithm as the target control algorithm, wherein the second control algorithm is a fuzzy PID control algorithm.
8. A valve positioner control algorithm switching system based on self-tuning, comprising: the self-tuning execution module executes a self-tuning calibration process on the valve to acquire a plurality of motion parameters of the valve, wherein the motion parameters at least comprise the whole-course motion time of the valve, the position deviation between valve position feedback and instructions and the minimum effective control quantity; The characteristic discrimination factor calculation module calculates discrimination factors used for representing the control characteristics of the valve according to the motion parameters through a preset discrimination factor calculation formula; And the algorithm decision and switching module is used for comparing the discrimination factor with a preset critical value to obtain a comparison result, screening a target control algorithm adapting to the valve control characteristic from a plurality of prestored control algorithms according to the comparison result, and performing valve position closed-loop control on the valve by adopting the target control algorithm.
9. A computer device comprising a memory and a processor, the memory having stored therein computer readable instructions which, when executed by the processor, cause the processor to perform the steps of the self-tuning based valve positioner control algorithm switching method of any of claims 1 to 7.
10. A storage medium storing computer readable instructions which, when executed by one or more processors, cause the one or more processors to perform the steps of the self-tuning based valve positioner control algorithm switching method of any of claims 1 to 7.

Description

Valve positioner control algorithm switching method, system, equipment and storage medium based on self-tuning Technical Field The invention relates to the technical field of industrial automation control, in particular to a valve positioner control algorithm switching method, system, equipment and storage medium based on self-tuning. Background The valve positioner is a key execution unit device in the field of industrial process control and is widely applied to industries such as petroleum, chemical industry, electric power and the like. The core function of the valve is to accurately receive a control signal from a controller (such as DCS or PLC) and drive a pneumatic or electric actuating mechanism to accurately position the valve core of the valve at a required opening degree, thereby realizing accurate adjustment of technological parameters such as fluid flow, pressure and the like. A typical valve control system generally includes a valve body, a pneumatic actuator, a valve positioner, and a gas source. The valve positioner serves as a control center and controls the opening and closing actions of the valve by adjusting the flow or pressure of gas into or out of the actuator. In this process, the valve resistance characteristics inherent in the valve system itself become key factors affecting the quality of control. The characteristic is determined by various factors such as valve rod friction force, stuffing box sealing force, acting force of fluid on a valve core, air chamber design and the like, and directly influences the travel time, response speed, control precision and stability of the valve. In order to ensure control accuracy, modern intelligent valve positioners all need to perform a self-tuning process before being put into operation. The process aims to automatically acquire dynamic characteristic parameters (such as travel time, gain, dead zone and the like) of the valve system and parameter setting is carried out on a built-in control algorithm (such as PID and variant algorithms thereof) based on the parameters. Currently, the closest prior art implementation within the industry can be summarized as a single self-tuning + single control algorithm mode. That is, the positioner performs a self-tuning to generate a set of optimal parameters and provides them to a fixed, preset control algorithm (e.g., an optimized PID algorithm) for use. However, the above prior art solutions have significant limitations and drawbacks: the control algorithm is not well matched with the valve characteristics, namely, the resistance characteristics of the industrial field valves are quite different, the valves have small resistance and flexible actions (such as certain butterfly valves), the valves have large resistance and slow actions (such as stop valves under high pressure difference working conditions), and a set of fixed control algorithm is difficult to show optimal control performance on all valves with resistance characteristics. For a valve with the initially unmatched resistance characteristics and algorithm design, even if the self-tuning parameters are accurate, the problems of overlong adjustment time, overlarge overshoot, even valve position continuous oscillation and the like with poor control quality are very easy to occur; The application range of the positioner with the single control algorithm is limited, the applicable valve type range of the positioner is narrow, manufacturers often need to provide different series of positioner products aiming at different application scenes, the complexity of product lines is increased, and difficulty is brought to the type selection of users. Once the user selects the shape improperly, the ideal control-control effect cannot be obtained; The maintenance cost is high, the usability is poor, and when the control quality is poor, in order to solve the problem of overshoot or oscillation, professional staff with abundant experience is usually sent to the site for manual debugging. The debugger may need to try to switch different control modes or fine-tune a large number of algorithm parameters, which is time-consuming and laborious, greatly increases the later maintenance cost of the system, and puts an excessive demand on the technical level of the operator, reducing the overall usability of the device. Therefore, there is an urgent need in the art for an intelligent valve positioner control method that can automatically adapt to different valve resistance characteristics, fundamentally improve control quality, widen application range, and reduce use and maintenance costs. Disclosure of Invention The invention aims to solve the defects in the prior art, and provides a valve positioner control algorithm switching method based on self-tuning, which comprises the following steps: s1, executing a self-tuning calibration process on a valve, and acquiring a plurality of motion parameters of the valve, wherein the motion parameters at least comprise the whole