CN-121977676-A - Flow pressure stabilizing calibration method and system based on liquid circulation loop

CN121977676ACN 121977676 ACN121977676 ACN 121977676ACN-121977676-A

Abstract

The invention discloses a flow pressure stabilizing calibration method and system based on a liquid circulation loop, which relates to the technical field of flow metering verification, and comprises the steps of obtaining a working condition characteristic vector to construct a window sample sequence, calculating a shortest distance matrix through Dijkstra algorithm, calculating original pressure deviation based on working condition characteristics, and screening manifold neighbors from the shortest distance matrix, calculating a weighting coefficient to reconstruct pressure deviation, constructing a stability index based on the reconstructed pressure deviation, judging a tuning state, and constructing a target execution flow control fluid infusion pump and a pressure relief valve by combining a global smoothness constraint index. And constructing a unified evaluation index to judge the calibration stability, and calculating a correction factor to carry out closed-loop correction. According to the invention, by constructing the multidimensional working condition feature vector and reconstructing the flow state manifold based on the geodesic distance, more real pressure deviation is generated, and the high precision, reliability and continuous stable convergence of pressure regulation and flow calibration under complex working conditions are improved by combining the self-adaptive pressure stabilization and calibration control of risk constraint.

Inventors

BI XIAOLONG
HE YANPING
GUAN HONGHUI
WANG XIAOSHUANG
CUI NAN
YIN SHUXIAN

Assignees

丹东贝特自动化工程仪表有限公司

Dates

Publication Date: 20260505
Application Date: 20260407

Claims (10)

1. The flow pressure stabilizing calibration method based on the liquid circulation loop is characterized by comprising the following steps of: Acquiring a working condition characteristic vector, constructing a window sample sequence, calculating a shortest path through a Dijkstra algorithm to obtain a shortest distance matrix, calculating an inner product matrix, carrying out symmetrical characteristic decomposition to obtain a characteristic component, and constructing a low-dimensional manifold coordinate vector; based on the working condition characteristic vector, calculating original pressure deviation, screening candidate manifold neighbors from the shortest distance matrix, screening effective manifold neighbors by combining with low-dimensional coordinates, calculating a weighting coefficient, reconstructing the pressure deviation to obtain reconstructed pressure deviation, calculating a local manifold abrupt change index, and extracting a maximum value as a global smooth constraint index; Based on the reconstructed pressure deviation, constructing a stability index, judging a tuning state, constructing a target execution flow by combining a global smoothness constraint index, and regulating and controlling a fluid supplementing pump and a pressure relief valve; and constructing a unified evaluation index, judging the calibration stability, and calculating a correction factor to carry out closed-loop correction.
2. The flow stabilizing calibration method based on the liquid circulation loop as set forth in claim 1, wherein the calculating the weighting coefficient and reconstructing the pressure deviation to obtain the reconstructed pressure deviation refers to calculating an original pressure deviation of the working condition characteristic vector based on the window sample sequence, constructing a manifold neighbor set of the working condition characteristic vector based on the shortest distance matrix, calculating an average shortest distance between the working condition characteristic vector and the manifold neighbor set, generating the weighting coefficient, and weighting and summing the original pressure deviation by using the weighting coefficient to obtain the reconstructed pressure deviation.
3. The method for calibrating flow stability based on a liquid circulation loop according to claim 2, wherein the calculating of local manifold steepness indexes, the extracting of the maximum value as the global smoothness constraint index means extracting the minimum value of all non-zero distances of the shortest distance matrix as the stable distance term, the calculating of the local manifold steepness indexes, the descending sorting of the local manifold steepness indexes, and the screening of the maximum value as the global smoothness constraint index.
4. The method for calibrating flow stability based on a fluid circulation loop according to claim 3, wherein said constructing a stability index based on a reconstructed pressure deviation, determining a tuning state refers to calculating a multidimensional index based on the reconstructed pressure deviation and constructing an execution sample, calculating a stability index, determining a reconstructed pressure deviation, and generating a tuning state.
5. The method for calibrating flow stabilization based on a liquid circulation loop according to claim 4, wherein the method is characterized in that the method comprises the steps of constructing a target execution flow index by combining a global smoothness constraint index, constructing a risk item, summing and averaging to obtain an original risk amount, judging a threshold value to obtain a risk indication loss, calculating a risk envelope index, constructing an execution performance index and an annealing safety index, generating an updated annealing gain, converting the updated annealing gain into an annealing inverse temperature, generating an annealing sharpening coefficient, multiplying the annealing sharpening coefficient by the risk envelope index to obtain a comprehensive execution coefficient, multiplying the comprehensive execution coefficient by a theoretical compensation flow, and generating the target execution flow.
6. The method for calibrating flow stability based on a liquid circulation loop according to claim 5, wherein the step of controlling the liquid replenishing pump and the pressure release valve means that if the control direction is a boost, the target execution flow is the target liquid replenishing flow, and if the control direction is a release, the target execution flow is the target release flow, and the liquid replenishing and the release are controlled respectively.
7. The method for calibrating flow stability based on a liquid circulation loop according to claim 6, wherein the step of constructing a unified evaluation index, the step of judging calibration stability refers to collecting test data after execution, the step of performing time alignment by using a sliding average method, the step of extracting a pressure error and a flow error, and the step of constructing a unified evaluation index, wherein if the unified evaluation index is smaller than or equal to an index threshold, the step of constructing the unified evaluation index is stable, otherwise, the step of indicating that adjustment is needed.
8. The method for calibrating flow regulation based on a liquid circulation loop according to claim 7, wherein calculating the correction factor for closed-loop correction means calculating the accumulated deviation when adjustment is required, multiplying the accumulated deviation by a negative value of a proportionality coefficient, generating the correction factor and correcting the accumulated deviation until the accumulated deviation is stabilized.
9. The method for calibrating flow stability based on a liquid circulation loop according to claim 8, wherein the calculating the inner product matrix and performing symmetric feature decomposition to obtain feature components, the constructing the low-dimensional manifold coordinate vector means constructing the working condition feature vector of a fixed sampling period and performing transverse arrangement according to time sequence to obtain a window sample sequence, constructing a distance matrix by using a Euclidean distance formula, screening a minimum distance to generate an adjacent matrix, constructing a shortest distance matrix by using a Dijkstra shortest path method, calculating the inner product matrix and performing decomposition by using a symmetric matrix feature value decomposition method to obtain the low-dimensional manifold coordinate vector.
10. The flow pressure stabilizing calibration system based on the liquid circulation loop is based on the flow pressure stabilizing calibration method based on the liquid circulation loop as claimed in any one of claims 1 to 9, and is characterized by comprising the following steps: The window sample module is used for normalizing the working condition characteristic vectors of the fixed sampling period, forming a window sample sequence according to time sequence, and sequentially generating a distance matrix, an adjacent matrix, a shortest distance matrix, an inner product matrix and a low-dimensional manifold coordinate vector; The pressure deviation module is used for calculating original pressure deviation based on the window sample sequence, the shortest distance matrix and the low-dimensional manifold coordinate vector, screening candidate manifold neighbor sets and manifold neighbor sets, and further obtaining a weighting coefficient, a reconstruction pressure deviation, a local manifold abrupt change index and a global smooth constraint index; The annealing gain module is used for generating a multidimensional index and a control direction based on the working condition characteristic vector, the reconstruction pressure deviation and the global smoothness constraint index, calculating a stability index, a risk envelope index and updating an annealing gain, and further generating an annealing reverse temperature, an annealing sharpening coefficient, a comprehensive execution coefficient and a target execution flow; The execution flow module is used for respectively executing the target fluid replacement flow or the target pressure release flow control based on the target execution flow and the control direction, and calculating residual error retention rate after execution so as to enter a new iteration; and the unified evaluation module is used for collecting the pressure of the front confluence channel, the standard flow and the detected flow after execution, constructing a unified evaluation index, and calculating accumulated deviation and correction factors to correct the original control quantity until the original control quantity is stable if the unified evaluation index does not meet an index threshold.

Description

Flow pressure stabilizing calibration method and system based on liquid circulation loop Technical Field The invention relates to the technical field of flow metering verification, in particular to a flow pressure stabilizing calibration method and system based on a liquid circulation loop. Background The flow pressure stabilizing calibration technology based on the liquid circulation loop is widely applied to a liquid flow standard device, an existing metering verification platform and a high-stability process control system, is mainly developed around paths such as pressure closed loop adjustment, valve pump cooperative control, liquid level compensation and temperature correction, and gradually develops from single variable control to multi-parameter coupling control, so that how to comprehensively utilize multi-source working condition information under continuous operation conditions, accurately identify the evolution trend of a flow state, and realize synchronous optimization of a calibration process on the basis of pressure stabilization becomes an important research direction in the technical field. However, the prior art is still deficient, the prior art lacks a state expression mechanism based on multi-sensor working condition fusion and manifold structure reconstruction, only relies on single-point pressure or simple multivariable combination to carry out deviation judgment, cannot accurately describe the real state migration relation of circulating loop liquid in the continuous operation process, causes pressure deviation characterization distortion under the condition of complex working conditions or local fluctuation, influences pressure stabilization and calibration precision, lacks a closed-loop control mechanism for executing risk constraint and self-adaptive regulation, adopts fixed parameters or experience rules to carry out fluid supplementing and pressure relief control, is difficult to realize stable convergence under the conditions of system disturbance, state mutation or multivariable coupling, and is easy to cause overshoot, oscillation or calibration deviation, so that the stability of the flow calibration process is insufficient. Disclosure of Invention The present invention has been made in view of the above-described problems occurring in the prior art. Therefore, the invention provides a flow pressure stabilizing calibration method and a flow pressure stabilizing calibration system based on a liquid circulation loop, which solve the problems that the prior art lacks a state expression mechanism based on multi-sensor working condition fusion and manifold structure reconstruction, only relies on single-point pressure or simple multi-variable combination to carry out deviation judgment, cannot accurately describe the real state migration relation of the liquid in the circulation loop in the continuous operation process, causes pressure deviation characterization distortion under the condition of complex working conditions or local fluctuation, influences pressure stabilizing and calibration precision, lacks a closed-loop control mechanism for executing risk constraint and self-adaptive regulation, adopts fixed parameters or experience rules to carry out fluid supplementing and pressure releasing control, is difficult to realize stable convergence under the conditions of system disturbance, state mutation or multi-variable coupling, and easily generates over-regulation, oscillation or calibration deviation, thereby leading to insufficient stability of the flow calibration process. In order to solve the technical problems, the invention provides the following technical scheme: in a first aspect, the present invention provides a flow regulation calibration method based on a liquid circulation loop, comprising: Acquiring a working condition characteristic vector, constructing a window sample sequence, calculating a shortest path through a Dijkstra algorithm to obtain a shortest distance matrix, calculating an inner product matrix, carrying out symmetrical characteristic decomposition to obtain a characteristic component, and constructing a low-dimensional manifold coordinate vector; based on the working condition characteristic vector, calculating original pressure deviation, screening candidate manifold neighbors from the shortest distance matrix, screening effective manifold neighbors by combining with low-dimensional coordinates, calculating a weighting coefficient, reconstructing the pressure deviation to obtain reconstructed pressure deviation, calculating a local manifold abrupt change index, and extracting a maximum value as a global smooth constraint index; Based on the reconstructed pressure deviation, constructing a stability index, judging a tuning state, constructing a target execution flow by combining a global smoothness constraint index, and regulating and controlling a fluid supplementing pump and a pressure relief valve; and constructing a unified evaluation index, ju