A waveform tracking and active inverse compensation gas supplementing system for volume pump outlet pulsation suppression and a control method thereof

Abstract

The application discloses a kind of based on waveform tracking and active reverse phase air supplementing volumetric pump outlet pulsation suppression system and control method thereof, it is related to pulsation suppression technical field, for solving the problem that volumetric pump outlet pressure pulsation causes fluid delivery instability and affects system operating state during operation, by the real-time acquisition and phase analysis of the outlet pressure waveform of the volumetric pump to be measured, pressure fluctuation trend is constructed, based on phase reverse matching generation air supplementing regulation instruction realizes the reverse phase synchronization of air chamber regulation action and pressure change, and dynamic evaluation and compensation correction are carried out to gas-liquid coupling characteristics in combination with liquid level response, while introducing hysteresis control mechanism to closed-loop judge regulation termination and pulsation return state, to realize the adaptive suppression of pressure pulsation under different operating rhythm, improve outlet pressure stability, reduce pulsation residual amplitude, enhance system dynamic response consistency and operating reliability.

Description

Technical Field

[0001] This invention relates to the field of pulsation suppression technology, and more specifically, to a volumetric pump outlet pulsation suppression system and control method based on waveform tracking and active reverse-phase gas replenishment. Background Technology

[0002] Positive displacement pumps, as power devices that achieve fluid transport or hydraulic system pressure control through periodic volume changes, are widely used in industrial scenarios such as oil drilling, chemical transportation, and high-pressure liquid transportation. They are also extensively used in household appliances such as heat pump air conditioning units, energy-saving refrigerators, freezers, and home air conditioners. During actual operation, the output process of a positive displacement pump exhibits a clear periodic characteristic, with its outlet pressure fluctuating continuously during the pump chamber filling and discharging process. To reduce the impact of pressure fluctuations on pipelines and downstream equipment, a buffer tank is typically installed at the pump outlet. This tank absorbs and regulates pressure fluctuations through the compression and expansion of the air chamber. Furthermore, a certain degree of pressure balance control is achieved by adjusting the air chamber state or valve opening using high-frequency electro-hydraulic servo valves, thereby improving the continuity of fluid transport and the overall system operation under certain conditions.

[0003] The existing technology has the following shortcomings: Currently, existing technologies mostly rely on pressure amplitude or average pressure for regulation and control, lacking the ability to continuously track pressure fluctuations and reflect the stage and direction of pressure changes. This can easily lead to asynchronous regulation actions and pressure changes, reducing the pulsation cancellation effect. Existing methods often rely on fixed parameters for regulation, making it difficult to dynamically correct based on the actual gas-liquid response during the gas chamber regulation process. This can easily result in under-regulation or over-regulation. In terms of regulation termination judgment, there is a lack of continuous evaluation of the pressure hysteresis process, making it difficult to accurately determine whether the pulsation has stabilized and returned to normal, leading to a decrease in system operational stability. Therefore, this paper proposes a volumetric pump outlet pulsation suppression system and its control method based on waveform tracking and active reverse-phase gas replenishment. Summary of the Invention

[0004] To overcome the aforementioned deficiencies in the prior art, this invention provides a volumetric pump outlet pulsation suppression system and its control method based on waveform tracking and active reverse-phase gas replenishment. This system utilizes a pressure fluctuation trend construction mechanism combining real-time acquisition of outlet pressure waveforms with phase tracking analysis, along with a gas chamber replenishment and exhaust regulation strategy based on phase reverse matching. Furthermore, it integrates a gas-liquid response dynamic correction mechanism based on liquid level feedback and a closed-loop regulation mechanism for pulsation hysteresis state judgment and control. This achieves synchronous alignment and adaptive correction between the gas chamber regulation action and the pressure fluctuation process, thereby solving the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A volumetric pump outlet pulsation suppression system based on waveform tracking and active reverse-phase gas supply includes a waveform monitoring module, a reverse-phase gas supply module, a response correction module, and a hysteresis detection and control module, with electrical signal connections between the modules. The waveform monitoring module is used to set the pressure monitoring time, collect the outlet pressure signal of the volumetric pump under test during the pressure monitoring time, extract the pressure waveform characteristics, analyze the pressure fluctuation trend of the volumetric pump under test based on the pressure waveform characteristics, and transmit it to the reverse phase gas supply module. The reverse-phase gas replenishment module is used to generate a phase reverse matching index based on the pressure fluctuation trend, calculate the reverse-phase gas replenishment command quantity using the phase reverse matching index, and perform gas chamber pressure regulation on the gas state of the buffer tank through the reverse-phase gas replenishment command quantity. The response correction module is used to collect the liquid level signal of the buffer tank when performing gas chamber pressure regulation, evaluate the gas-liquid response characteristics corresponding to gas chamber pressure regulation based on the liquid level signal and generate compensation correction data. After correcting the reverse phase gas replenishment command quantity according to the compensation correction data, it is transmitted to the hysteresis judgment and control module. The hysteresis detection and control module is used to receive the corrected reverse-phase gas replenishment command quantity to determine whether to stop the gas chamber pressure regulation. When the gas chamber pressure regulation is stopped, the pressure hysteresis data of the volume pump under test is monitored and the pulsation return state of the buffer tank is evaluated. The pulsation return state is used to determine whether to re-execute the gas chamber pressure regulation.

[0006] In a preferred embodiment, the outlet pressure signal in the waveform monitoring module refers to the sequence of pressure values ​​collected point by point by the pressure detection unit installed on the outlet pipeline of the buffer tank at a preset sampling frequency during the pressure monitoring time. The extreme points in the outlet pressure signal are identified one by one, and the pressure amplitude sequence and time sequence corresponding to each maximum point and the pressure amplitude sequence corresponding to each minimum point are extracted. The fluctuation amplitude of each period is calculated according to the pressure difference between adjacent maximum and minimum points, and the fluctuation period of each period is calculated according to the time difference between adjacent maximum points.

[0007] In a preferred embodiment, the waveform monitoring module extracts the fluctuation amplitude and fluctuation period of each cycle, and calculates the average value of the data from the most recent N cycles to obtain the average fluctuation amplitude and average fluctuation period respectively. Using the most recent maximum moment as a reference, calculate the phase shift of the current moment relative to that maximum moment to obtain the current phase angle: ; in: This is the current phase angle, with a value range of [0, 2π). This is the current sampling time; The time closest to the current maximum value; The average fluctuation period is the average of the N most recent complete periods; mod is the remainder operation. It represents the remainder when the time difference is divided by the average fluctuation period; If the current phase angle is less than π, it is determined that the current moment is in the pressure decrease segment, and the rising or falling segment identifier is set to decreasing; If the current phase angle is greater than or equal to π, it is determined that the current moment is in the pressure rising segment, and the rising or falling segment identifier is set to rising.

[0008] In a preferred embodiment, the phase reversal matching index in the phase reversal gas supply module is a quantitative indicator of the degree of reversal between the current air chamber adjustment action and the direction of pressure change. The formula for calculating the phase reversal matching index is: ; in: The phase-reverse matching index has a value range of 1. ; Given the current phase angle and the average fluctuation amplitude, calculate the amount of reverse-phase gas replenishment command applied to the gas chamber this time: ; in: This is the reverse phase gas replenishment command quantity; This represents the average fluctuation amplitude. The preset basic air replenishment gain coefficient; This is the preset reference pressure benchmark value.

[0009] In a preferred embodiment, the reverse-phase gas supply module controls the inlet and outlet valves of the buffer tank based on the calculation result of the reverse-phase gas supply command. When the reverse phase air supply command is greater than zero, an opening command is issued to the intake valve, and the intake operation is performed according to the valve opening degree and opening duration corresponding to the reverse phase air supply command to supply gas to the air chamber. When the reverse-phase air supply command is less than zero, an opening command is issued to the exhaust valve. The exhaust operation is performed according to the valve opening degree and opening duration corresponding to the absolute value of the reverse-phase air supply command, and the gas is released from the gas chamber. When the absolute value of the reverse-phase air replenishment command is less than the preset minimum action dead zone threshold, no action command is issued to any valve, and the current state of the air chamber is maintained.

[0010] In a preferred embodiment, the response correction module uses the liquid level detection unit to collect signals to reflect the dynamic changes in the interface position between the gas chamber and the liquid. The gas-liquid response characteristics include the rate of change of liquid level and the gas-liquid response deviation; When the gas chamber pressure regulation is started, the liquid level value at the start time is recorded as the initial liquid level value; during the regulation process, the difference between the liquid level value at the current sampling time and the initial liquid level value is calculated and divided by the cumulative duration since the regulation started to obtain the liquid level change rate. Based on the reverse-phase gas replenishment command quantity and the preset gas-liquid coupling coefficient, the expected liquid level change rate under the current gas replenishment command quantity is calculated, and the gas-liquid response deviation is obtained by subtracting the expected liquid level change rate from the measured liquid level change rate.

[0011] In a preferred embodiment, the response correction module calculates a compensation correction amount based on the gas-liquid response deviation and adds it to the reverse-phase gas replenishment command amount to obtain the corrected reverse-phase gas replenishment command amount: ; ; in: To compensate for the correction amount, a positive value indicates that the amount of air to be replenished needs to be increased, and a negative value indicates that the amount of air to be replenished needs to be decreased; The preset correction gain coefficient; This is the corrected reverse-phase gas replenishment command quantity.

[0012] The amplitude of the compensation correction is limited: When the absolute value of the compensation correction is less than or equal to the preset correction saturation threshold, the intake valve or exhaust valve is driven to re-execute the chamber adjustment according to the corrected reverse phase air replenishment command. When the absolute value of the compensation correction amount is greater than the preset correction saturation threshold, the compensation correction amount is limited to the preset correction saturation threshold, and the result obtained by superimposing the limited compensation correction amount with the reverse phase gas replenishment command amount is used as the corrected reverse phase gas replenishment command amount.

[0013] In a preferred embodiment, the determination of stopping the air chamber pressure regulation in the hysteresis judgment and control module adopts a dual confirmation mechanism: within each sampling cycle, the absolute value of the corrected reverse phase replenishment command is calculated. When the absolute value is lower than the preset stop threshold, it is recorded as a one-time satisfaction. When the number of consecutive satisfactions reaches the preset number of consecutive confirmation cycles, it is determined that the air chamber regulation demand has approached zero, the air chamber pressure regulation is stopped, the intake valve and exhaust valve are closed, and the current time is recorded as the stop regulation time. Otherwise, the correction cycle of the response correction module continues to be executed, and the pulsation hysteresis monitoring is not entered.

[0014] In a preferred embodiment, after the hysteresis detection and control module stops regulating the gas chamber pressure, it continuously collects the outlet pressure within a preset hysteresis monitoring time window, starting from the time the regulation stops. It calculates the difference between the maximum and minimum pressure values ​​within the time window to obtain the pulsating hysteresis amplitude and judges the pulsating return state of the buffer tank. When the hysteresis amplitude is less than or equal to the preset pulsation stability judgment threshold, the pulsation return state is determined to be stable, the current air chamber state is maintained, and the current air chamber pressure regulation ends. When the hysteresis amplitude is greater than the preset hysteresis stability judgment threshold, the hysteresis return state is determined to be unstable, the outlet pressure acquisition and pressure fluctuation trend analysis in the waveform monitoring module are retried, and the reverse phase gas replenishment adjustment process is executed again.

[0015] A method for controlling the outlet pulsation of a volumetric pump based on waveform tracking and active reverse-phase gas supply, used to implement a volumetric pump outlet pulsation suppression system based on waveform tracking and active reverse-phase gas supply, characterized by comprising the following steps: Step S1: Set the pressure monitoring time, collect the outlet pressure signal of the volumetric pump under test during the pressure monitoring time and extract the pressure waveform characteristics, and analyze the pressure fluctuation trend of the volumetric pump under test based on the pressure waveform characteristics. Step S2: Generate a phase reverse matching index based on the pressure fluctuation trend, calculate the reverse phase gas replenishment command quantity using the phase reverse matching index, and regulate the gas chamber pressure of the buffer tank by adjusting the gas chamber state using the reverse phase gas replenishment command quantity. Step S3: When performing gas chamber pressure regulation, the liquid level signal of the buffer tank is collected, the gas-liquid response characteristics corresponding to the gas chamber pressure regulation are evaluated based on the liquid level signal, and compensation correction data is generated. The reverse phase gas replenishment command is corrected according to the compensation correction data. Step S4: Based on the corrected reverse-phase gas supply command quantity, determine whether to stop the chamber pressure regulation. After stopping the chamber pressure regulation, monitor the pressure hysteresis data of the volumetric pump under test and evaluate the pulsation return state of the buffer tank. Use the pulsation return state to determine whether to re-execute the chamber pressure regulation.

[0016] The technical effects and advantages of this invention are as follows: This invention achieves synchronous alignment between the gas chamber regulation action and the pressure change process by real-time tracking of the outlet pressure waveform of the volumetric pump and constructing the pressure fluctuation trend, thereby improving the timing matching degree of pulsation cancellation. At the same time, it dynamically evaluates and corrects the gas-liquid coupling process based on the liquid level response, enhancing the adaptability of the regulation process and avoiding under-regulation or over-regulation. Furthermore, it achieves closed-loop judgment of regulation termination through continuous judgment and control of pulsation hysteresis state, improving the stability and continuity of pulsation suppression effect, thereby reducing the outlet pressure fluctuation amplitude, improving fluid delivery stability, and enhancing the overall operational reliability of the system. Attached Figure Description

[0017] Figure 1 This is a flowchart illustrating the implementation of a volumetric pump outlet pulsation suppression system based on waveform tracking and active reverse-phase gas replenishment according to the present invention.

[0018] Figure 2This is a schematic diagram of a volumetric pump outlet pulsation suppression system based on waveform tracking and active reverse-phase gas replenishment according to the present invention.

[0019] Figure 3 This is a schematic diagram illustrating the steps of a volumetric pump outlet pulsation control method based on waveform tracking and active reverse-phase gas replenishment according to the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] This invention tracks the outlet pressure waveform of a volumetric pump in real time and extracts the pressure fluctuation trend. Based on phase reversal matching, it generates air chamber replenishment and exhaust adjustment commands, achieving synchronous alignment between adjustment actions and pressure change processes. At the same time, it combines liquid level response to dynamically correct the gas-liquid coupling characteristics and introduces a pulsation hysteresis state judgment and control mechanism, thereby reducing the outlet pressure fluctuation amplitude and improving the system's operational stability.

[0022] Example 1 Please see Figures 1 to 2 A volumetric pump outlet pulsation suppression system based on waveform tracking and active reverse-phase gas supply, characterized in that: it includes a waveform monitoring module, a reverse-phase gas supply module, a response correction module, and a hysteresis detection and control module, and the modules are electrically connected to each other. The functions of each module are as follows: The waveform monitoring module continuously collects the outlet pressure of the volumetric pump at a preset sampling frequency within the set pressure monitoring time, obtains the outlet pressure signal, extracts the pressure waveform characteristics from it, and analyzes the current pressure fluctuation trend of the volumetric pump.

[0023] The outlet pressure signal refers to the sequence of pressure values ​​collected point by point by the pressure detection unit installed on the outlet pipeline of the buffer tank at a preset sampling frequency during the pressure monitoring period. It is used to record the continuous change of outlet pressure over time.

[0024] After obtaining the outlet pressure signal, the extreme points in the time series signal are identified one by one, and the pressure amplitude sequence and its time sequence corresponding to each maximum point, as well as the pressure amplitude sequence corresponding to each minimum point, are extracted. Based on this, the fluctuation amplitude of each period is calculated according to the pressure difference between adjacent maximum and minimum values, and the fluctuation period of each period is calculated according to the time difference between adjacent maximum values. The calculation formulas are as follows: ; ; in: The fluctuation amplitude of the i-th pressure fluctuation cycle reflects the pressure difference between the pressure peaks and valleys within that cycle. The maximum pressure is for the i-th cycle; The pressure at the adjacent minimum values ​​of the i-th cycle; The fluctuation period of the i-th cycle reflects the time interval between two adjacent pressure peaks; and These are the moments when two adjacent maxima are reached.

[0025] After extracting the fluctuation amplitude and fluctuation period for each period, the average of the data from the most recent N periods is calculated to obtain the average fluctuation amplitude and average fluctuation period: ; ; in: The average fluctuation amplitude reflects the overall intensity of the current pressure pulsation; The average fluctuation period reflects the pulsation frequency characteristics of the positive displacement pump under the current operating rhythm; N is the number of periods participating in the average calculation. The smaller the value, the faster the response; the larger the value, the stronger the smoothness.

[0026] After calculating the mean, using the most recent maximum moment as a reference, calculate the phase shift of the current moment relative to that maximum moment to obtain the current phase angle: ; in: The current phase angle has a range of [0, 2π). Taking the most recent maximum value as the starting point, the modulo operation reflects the current position in one pulsation cycle, preventing phase angle overflow when the time difference exceeds the average fluctuation cycle. This is the current sampling time; The time closest to the current maximum value; The average fluctuation period is the average of the most recent N complete periods, which is a known quantity and can be used in real time at each sampling moment; mod is the remainder operation. It represents the remainder obtained by dividing the time difference by the average fluctuation period, and the result is always within the range of [0, T).

[0027] Based on the current phase angle, determine the current stage of the pressure fluctuation: If the current phase angle is less than π, it is determined that the current moment is in the pressure decrease segment, and the rising or falling segment identifier is set to decreasing; If the current phase angle is greater than or equal to π, it is determined that the current moment is in the pressure rising segment, and the rising or falling segment identifier is set to rising.

[0028] The pressure fluctuation trend is composed of the current phase angle, the rising or falling segment identifier, the average fluctuation amplitude, and the average fluctuation period. It is used to characterize the position, rhythm, and amplitude of the current outlet pressure pulsation of the positive displacement pump on the time axis.

[0029] It should be noted that the phase angle calculation uniformly adopts the average fluctuation period as the benchmark, avoiding the use of the current period that has not yet ended, and ensuring that the phase angle can be calculated in real time at each sampling moment; when the interval between two adjacent maximum values ​​is less than the preset minimum period threshold, the extreme value identification result is unreliable, the point is skipped and the current average fluctuation period is continued; the preset minimum period threshold can be determined according to the rated speed range of the matched volumetric pump; the N value can be set according to the system response speed and smoothing requirements.

[0030] By acquiring the aforementioned outlet pressure signal, identifying peaks and valleys, and calculating the phase, the pressure fluctuation trend is obtained and transmitted to the reverse-phase gas replenishment module, providing a timing basis for the subsequent generation of the phase reverse matching index and the calculation of the reverse-phase gas replenishment command quantity.

[0031] To track the amplitude, frequency, and phase of the pulsating waveform in real time at each sampling moment, an adaptive notch filter is embedded in the waveform monitoring module to perform online parameter estimation of the outlet pressure signal. The instantaneous phase estimate θ(t) is defined as 2πft + φ, and the prediction error ε(t) is the difference between the current sampled value and the estimated value. The three update rules of the adaptive notch filter are as follows: ; ; ; Where: ε(t) is the prediction error; A(t) is the amplitude estimate at time t; θ(t) is the instantaneous phase estimate at time t; p_avg is the average pressure; μ and γ are adaptive gains, the larger the value of μ, the faster the phase tracking; the larger the value of γ, the faster the amplitude convergence; the instantaneous frequency is obtained by phase difference estimation. ; Where Ts is the sampling period, and f(t) reflects the estimated real-time pulsation frequency of the volumetric pump at time t, which is used to dynamically update the average fluctuation period T.

[0032] It should be noted that the typical values ​​of the adaptive gain μ and γ are 0.01 and 0.1, respectively. When the frequency change rate is detected to exceed the preset threshold, μ is temporarily increased to speed up the phase tracking speed. After the frequency stabilizes, the original value is restored to improve the estimation accuracy.

[0033] The reverse-phase gas supply module generates a phase reverse matching index based on the pressure fluctuation trend output by the waveform monitoring module, and uses the phase reverse matching index to calculate the reverse-phase gas supply command quantity. The reverse-phase gas supply command quantity is then used to regulate the gas chamber pressure of the buffer tank.

[0034] The phase-reversal matching index is a quantitative indicator calculated based on the current phase angle, used to characterize the degree of reversal between the current chamber regulation action and the direction of pressure change. Taking the moment of maximum value as the starting point of the phase angle, the pressure waveform can be expressed in cosine form, and its rate of change is proportional to the negative of the sine of the phase angle, i.e., the rate of change is proportional to... sin(φ); The ideal reverse-phase gas replenishment command should be opposite to the direction of the pressure change rate, i.e., proportional to sin(φ).

[0035] The formula for calculating the phase reversal matching index is: ; in: The phase-reverse matching index has a value range of 1. ; The current phase angle is derived from the pressure fluctuation trend.

[0036] If the current phase angle is in the range of 0 to π, the phase reversal matching index is positive, the pressure is in the decreasing segment at the current moment, the air chamber intake pressure replenishment is opposite to the pressure decrease direction, forming a phase reversal cancellation; if the current phase angle is in the range of π to 2π, the phase reversal matching index is negative, the pressure is in the increasing segment at the current moment, the air chamber exhaust pressure relief is opposite to the pressure increase direction, forming a phase reversal cancellation.

[0037] After obtaining the phase reversal matching index, and combining it with the average fluctuation amplitude, calculate the amount of reversal gas supply command that needs to be applied to the gas chamber this time: ; in: This is the reverse phase air supply command quantity. A positive value indicates that air is introduced into the air chamber to increase the air chamber pressure, and a negative value indicates that air is discharged from the air chamber to decrease the air chamber pressure. This represents the average fluctuation amplitude, derived from the trend of pressure fluctuations. The preset basic gas replenishment gain coefficient reflects the response intensity of gas chamber volume adjustment under unit pressure difference; This is a preset reference pressure benchmark value used to normalize the amplitude dimensions.

[0038] Based on the calculation results of the reverse-phase air supply command, the inlet and outlet valves of the buffer tank are controlled: When the reverse phase air supply command is greater than zero, an opening command is issued to the intake valve, and the intake operation is performed according to the valve opening degree and opening duration corresponding to the reverse phase air supply command to supply gas to the air chamber. When the reverse-phase air supply command is less than zero, an opening command is issued to the exhaust valve. The exhaust operation is performed according to the valve opening degree and opening duration corresponding to the absolute value of the reverse-phase air supply command, and the gas is released from the gas chamber. When the absolute value of the reverse-phase air replenishment command is less than the preset minimum action dead zone threshold, no action command is issued to any valve, maintaining the current state of the air chamber and preventing invalid valve jitter due to the command amount being too small.

[0039] It should be noted that the preset basic air replenishment gain coefficient can be calibrated based on the rated volume of the buffer tank air chamber, the flow characteristics of the inlet and outlet valves, and the typical pulsation amplitude level; the preset reference pressure benchmark value is taken as the rated outlet pressure value under normal system operating conditions; the preset minimum action dead zone threshold can be set based on the minimum controllable opening degree of the valve and the on-site noise level.

[0040] By generating the phase reversal matching index and calculating the reverse phase replenishment command, the pressure fluctuation trend is transformed into a chamber regulation command with a clear direction and amplitude, which drives the intake valve or exhaust valve to perform corresponding actions, thereby achieving active timing alignment of chamber pressure regulation; the reverse phase replenishment command is synchronously transmitted to the response correction module as a benchmark for gas-liquid response evaluation.

[0041] After obtaining the inverse gas replenishment command, a feedforward gas replenishment command is further synthesized to achieve active lead cancellation of the pulsating waveform: ; in: This is the feedforward gas replenishment command at time t; This is the feedforward gain coefficient, typically with a value of 0.9; To ensure that the feedforward air replenishment action is in phase π with the pressure pulsation, a sinusoidal component that is strictly out of phase with the current pressure waveform is generated, thus achieving active cancellation.

[0042] It should be noted that the feedforward gain coefficient can be calibrated based on the flow-pressure response characteristics of the buffer tank's gas chamber; the feedforward replenishment command and the subsequent feedback correction amount are superimposed to form the total control quantity.

[0043] Furthermore, the pump output pressure signal can be modeled as: ,in, Here, A is the average pressure, f is the pulsation amplitude, φ is the initial phase, and n(t) is the measurement noise. This waveform model provides a mathematical basis for calculating the phase inverse matching index, ensuring that the gas replenishment command quantity and the actual pressure waveform maintain a strict inverse phase relationship.

[0044] Based on the above waveform model, the feedforward air replenishment command can be further expressed as: ,in, The formula is the feedforward gain coefficient, and θ(t) = 2πft + φ is the instantaneous phase estimate. This formula achieves strict phase inversion with the pressure fluctuation by superimposing π on the phase, ensuring that the air replenishment action is synchronized with the pressure drop phase and the exhaust action is synchronized with the pressure rise phase, thereby maximizing the pulsation cancellation effect.

[0045] The response correction module collects the liquid level signal in the buffer tank in real time, evaluates the actual response effect of the gas chamber pressure regulation based on the liquid level signal, generates compensation correction data, and corrects the reverse phase gas replenishment command quantity according to the compensation correction data to obtain the corrected reverse phase gas replenishment command quantity.

[0046] A liquid level detection unit is a sensing device installed on the buffer tank body to detect the height of the drilling fluid level in the tank in real time. The signal it collects reflects the dynamic change of the interface position between the gas chamber and the liquid, and indirectly represents the real-time increase or decrease of the gas chamber volume.

[0047] Gas-liquid response characteristics refer to the pattern of liquid level signal change over time during the gas chamber pressure regulation process. It is used to reflect the coupling relationship between the actual volume regulation of the gas chamber and the gas replenishment or exhaust action, including two quantities: liquid level change rate and gas-liquid response deviation.

[0048] When the gas chamber pressure regulation is initiated, the liquid level value at the initiation moment is recorded as the initial liquid level value. During the regulation process, the rate of liquid level change is obtained by dividing the difference between the current sampling liquid level value and the initial liquid level value by the cumulative duration since the regulation was initiated. ; in: The value represents the rate of change of liquid level. A positive value indicates that the liquid level is rising, the air chamber is contracting, and the exhaust action is effective. A negative value indicates that the liquid level is falling, the air chamber is expanding, and the air intake action is effective. This represents the liquid level at the current sampling time. This is the initial liquid level value at the moment the air chamber pressure regulation is initiated; This is the cumulative duration since the start of the self-regulating air chamber pressure.

[0049] After obtaining the liquid level change rate, based on the reverse-phase gas supply command and the preset gas-liquid coupling coefficient, the expected liquid level change rate under the current gas supply command is calculated, and the gas-liquid response deviation is obtained by subtracting the expected liquid level change rate from the measured liquid level change rate. ; ; in: The expected rate of change of liquid level; The preset gas-liquid coupling coefficient is negative, reflecting the expected displacement velocity of the gas-liquid interface under a unit gas replenishment command (when the gas replenishment command is positive, the liquid level drops at a negative rate, hence the coupling coefficient is negative). The value represents the gas-liquid response deviation. A positive value indicates that the actual regulation effect is insufficient, and the amount of gas replenishment command needs to be increased in the positive direction. A negative value indicates that the actual regulation effect is too strong, and the amount of gas replenishment command needs to be decreased in the negative direction.

[0050] Furthermore, the gas-liquid coupling characteristics of the buffer tank are determined by the following physical parameter: gas spring equivalent stiffness: Equivalent mass of liquid column: Viscous damping coefficient: Where γ is the adiabatic index, P0 is the absolute pressure of the air chamber, and A t V0 is the cross-sectional area of ​​the buffer tank, ρ is the volume of the gas chamber, and h is the fluid density. l A is the height of the liquid column. p Where μ is the cross-sectional area of ​​the pipeline and μ is the fluid dynamic viscosity; the above physical parameters provide a theoretical basis for determining the preset gas-liquid coupling coefficient, and the calculation accuracy of the gas-liquid response deviation increases with the accuracy of the gas-liquid coupling coefficient value.

[0051] Based on the gas-liquid response deviation, a compensation correction is calculated and superimposed on the reverse-phase gas supply command to obtain the corrected reverse-phase gas supply command: ; ; in: To compensate for the correction amount, a positive value indicates that the amount of air to be replenished needs to be increased, and a negative value indicates that the amount of air to be replenished needs to be decreased; The preset correction gain coefficient; This is the corrected reverse-phase gas replenishment command quantity.

[0052] The amplitude of the compensation correction is limited: When the absolute value of the compensation correction is less than or equal to the preset correction saturation threshold, the corrected reverse phase air replenishment command is directly issued to drive the intake valve or exhaust valve to re-execute the air chamber adjustment according to the corrected value. When the absolute value of the compensation correction is greater than the preset correction saturation threshold, the compensation correction is limited to the preset correction saturation threshold. The result of superimposing the limited compensation correction on the reverse phase gas replenishment command is used as the corrected reverse phase gas replenishment command, so as to prevent the air chamber from being over-adjusted or new oscillations from being caused by excessive single correction.

[0053] It should be noted that the preset gas-liquid coupling coefficient is negative, and its absolute value can be determined offline through a pre-charge calibration test based on the ratio of the cross-sectional area of ​​the air chamber to the cross-sectional area of ​​the tank body, as well as the flow coefficient of the inlet and outlet valves. The calibration method is as follows: apply a known positive gas replenishment command, record the corresponding liquid level drop rate, and the ratio of the two is the preset gas-liquid coupling coefficient. The preset correction gain coefficient can be set according to the system response time delay and valve dynamic characteristics. The preset correction saturation threshold can be set according to the maximum allowable adjustment rate and the safe pressure range.

[0054] By acquiring the liquid level signal, calculating the liquid level change rate and the gas-liquid response deviation, and limiting the compensation correction amount, the actual effect of gas chamber regulation is quantitatively evaluated using the liquid level response as a medium. The reverse-phase gas replenishment command is dynamically corrected, and the corrected reverse-phase gas replenishment command is transmitted to the hysteresis judgment and control module for determining the stop condition.

[0055] After obtaining the gas-liquid response deviation, the response correction module uses the mirror descent method to optimize the feedback correction amount online. Liquid level deviation is defined as follows: ; in: Let be the liquid level deviation at time t; Let h(t) be the target liquid level; h(t) be the current liquid level value. Construct the loss function: Where λ is the weighting coefficient, typically 0.1, used to constrain the variation of the feedback correction amount and prevent drastic fluctuations in the control quantity. The update rule of the mirror descent method is: ; Where: η is the learning rate, typically 0.05; As a projection operator, the update results are constrained within the decision variable boundary U=[0,100%]; For the loss function with respect to The gradient.

[0056] After receiving the feedforward air supply command and the feedback correction, calculate the total control quantity: ; in, It combines the rapid response capability of the feedforward channel with the steady-state correction capability of the feedback channel. The combined output is sent to the electronically controlled proportional control valve to drive the air chamber to perform the final intake and exhaust actions.

[0057] The hysteresis detection and control module determines whether to stop the gas chamber pressure regulation based on the corrected reverse-phase gas replenishment command quantity imported by the response correction module. After the regulation stops, it performs pulsation hysteresis monitoring on the outlet pressure of the volumetric pump, evaluates the pulsation return state of the buffer tank, and decides whether to re-trigger the gas chamber pressure regulation based on the pulsation return state.

[0058] The determination to stop chamber pressure regulation employs a dual confirmation mechanism: within each sampling cycle, the absolute value of the corrected reverse-phase replenishment command is calculated. When the absolute value is lower than the preset stop threshold, it is recorded as a single fulfillment. When the number of consecutive fulfillments reaches the preset number of consecutive confirmation cycles, it is determined that the chamber regulation demand has approached zero, chamber pressure regulation is stopped, the inlet and outlet valves are closed, and the current time is recorded as the stop regulation time. Otherwise, the correction cycle of the response correction module continues to execute, without entering hysteresis monitoring. The preset stop threshold reflects the lowest command quantity for which chamber regulation is negligible; the preset number of consecutive confirmation cycles is used to prevent accidental stop action due to a momentary low command quantity in a single instance, ensuring a certain degree of temporal stability in the stop determination.

[0059] After the chamber pressure regulation is stopped, starting from the moment regulation stops, the outlet pressure is continuously collected within a preset hysteresis monitoring window. The difference between the maximum and minimum pressure values ​​within this window is calculated to obtain the pulsating hysteresis amplitude. ; in: The value represents the hysteresis amplitude, reflecting the peak-to-valley difference of the residual pressure pulsation at the outlet of the buffer tank after the active adjustment has stopped. The larger the value, the less effective the pulsation suppression is. This is the moment when the chamber pressure regulation stops; The duration of the preset hysteresis monitoring window.

[0060] The pulsation regression state of the buffer tank is determined based on the pulsation hysteresis amplitude. When the hysteresis amplitude is less than or equal to the preset pulsation stability judgment threshold, the pulsation return state is determined to be stable, the current air chamber state is maintained, and the current air chamber pressure regulation ends. When the hysteresis amplitude is greater than the preset hysteresis stability judgment threshold, the hysteresis return state is determined to be unstable, the outlet pressure acquisition and pressure fluctuation trend analysis in the waveform monitoring module are retried, and the reverse phase gas replenishment adjustment process is executed again.

[0061] It should be noted that the preset stop threshold can be set according to the minimum controllable adjustment accuracy of the valve and the residual command quantity allowed by the system; the value of the preset number of continuous confirmation cycles can be determined based on the sampling frequency and the expected stop response delay; the preset hysteresis monitoring window duration can be set to an integer multiple of the average fluctuation period to ensure that enough complete pulsation cycles can be collected within the monitoring window, so that the calculation of the pulsation hysteresis amplitude has statistical representativeness; the preset pulsation stability judgment threshold can be set according to the maximum allowable outlet pressure fluctuation range on site.

[0062] Through the aforementioned dual confirmation mechanism for stopping judgment and the assessment of pulsation return state, the residual intensity of pulsation is checked after active adjustment is completed. If the pulsation still has not converged, the adjustment process is automatically triggered again, thereby maintaining the continuous effectiveness of pulsation suppression under different operating conditions and speed changes.

[0063] Example 2, as Figure 3 As shown, a method for controlling the outlet pulsation of a volumetric pump based on waveform tracking and active reverse-phase gas supply is used to implement a volumetric pump outlet pulsation suppression system based on waveform tracking and active reverse-phase gas supply. The method is characterized by the following steps: Step S1: Set the pressure monitoring time, collect the outlet pressure signal of the volumetric pump under test during the pressure monitoring time and extract the pressure waveform characteristics, and analyze the pressure fluctuation trend of the volumetric pump under test based on the pressure waveform characteristics. Step S2: Generate a phase reverse matching index based on the pressure fluctuation trend, calculate the reverse phase gas replenishment command quantity using the phase reverse matching index, and regulate the gas chamber pressure of the buffer tank by adjusting the gas chamber state using the reverse phase gas replenishment command quantity. Step S3: When performing gas chamber pressure regulation, the liquid level signal of the buffer tank is collected, the gas-liquid response characteristics corresponding to the gas chamber pressure regulation are evaluated based on the liquid level signal, and compensation correction data is generated. The reverse phase gas replenishment command is corrected according to the compensation correction data. Step S4: Based on the corrected reverse-phase gas supply command quantity, determine whether to stop the chamber pressure regulation. After stopping the chamber pressure regulation, monitor the pressure hysteresis data of the volumetric pump under test and evaluate the pulsation return state of the buffer tank. Use the pulsation return state to determine whether to re-execute the chamber pressure regulation.

[0064] Finally, it should be noted that in this paper, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0065] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0066] In this document, the singular forms “a,” “an,” and “the” may also include the plural forms unless the context clearly indicates otherwise. It should also be understood that terms such as “comprising / including” or “having” specify the presence of the stated features, integrals, steps, operations, components, parts, or combinations thereof, but do not preclude the possibility of the presence or addition of one or more other features, integrals, steps, operations, components, parts, or combinations thereof. Meanwhile, the term “and / or” as used in this specification includes any and all combinations of the associated listed items.

[0067] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0068] The above description of the disclosed embodiments will enable those skilled in the art to make or use various modifications to these embodiments. It will be readily apparent to those skilled in the art that the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A volumetric pump outlet pulsation suppression system based on waveform tracking and active anti-phase gas supply, characterized in that: It includes a waveform monitoring module, a reverse phase gas supply module, a response correction module, and a hysteresis detection and control module. The functions of each module are as follows: The waveform monitoring module is used to set the pressure monitoring time, collect the outlet pressure signal of the volumetric pump under test during the pressure monitoring time, extract the pressure waveform characteristics, analyze the pressure fluctuation trend of the volumetric pump under test based on the pressure waveform characteristics, and transmit it to the reverse phase gas supply module. The reverse-phase gas replenishment module is used to generate a phase reverse matching index based on the pressure fluctuation trend, calculate the reverse-phase gas replenishment command quantity using the phase reverse matching index, and perform gas chamber pressure regulation on the gas state of the buffer tank through the reverse-phase gas replenishment command quantity. The response correction module is used to collect the liquid level signal of the buffer tank when performing gas chamber pressure regulation, evaluate the gas-liquid response characteristics corresponding to gas chamber pressure regulation based on the liquid level signal and generate compensation correction data. After correcting the reverse phase gas replenishment command quantity according to the compensation correction data, it is transmitted to the hysteresis judgment and control module. The hysteresis detection and control module is used to receive the corrected reverse-phase gas replenishment command quantity to determine whether to stop the gas chamber pressure regulation. When the gas chamber pressure regulation is stopped, the pressure hysteresis data of the volume pump under test is monitored and the pulsation return state of the buffer tank is evaluated. The pulsation return state is used to determine whether to re-execute the gas chamber pressure regulation.

2. The volumetric pump outlet pulsation suppression system based on waveform tracking and active anti-phase gas supply according to claim 1, characterized in that: In the waveform monitoring module, the outlet pressure signal refers to the sequence of pressure values ​​collected point by point by the pressure detection unit installed on the outlet pipeline of the buffer tank during the pressure monitoring time, according to the preset sampling frequency. The extreme points in the outlet pressure signal are identified one by one, and the pressure amplitude sequence and time sequence corresponding to each maximum point and the pressure amplitude sequence corresponding to each minimum point are extracted. The fluctuation amplitude of each period is calculated according to the pressure difference between adjacent maximum and minimum points, and the fluctuation period of each period is calculated according to the time difference between adjacent maximum points.

3. The volumetric pump outlet pulsation suppression system based on waveform tracking and active anti-phase gas supply according to claim 2, characterized in that: The waveform monitoring module extracts the fluctuation amplitude and fluctuation period of each cycle, and calculates the average value of the data from the most recent N cycles to obtain the average fluctuation amplitude and average fluctuation period. Using the most recent maximum moment as a reference, calculate the phase shift of the current moment relative to that maximum moment to obtain the current phase angle: in: This is the current phase angle, with a value range of [0, 2π). This is the current sampling time; The time closest to the current maximum value; The average fluctuation period is the average of the most recent N complete periods. mod is the modulo operation. It represents the remainder when the time difference is divided by the average fluctuation period; If the current phase angle is less than π, it is determined that the current moment is in the pressure decrease segment, and the rising or falling segment identifier is set to decreasing; If the current phase angle is greater than or equal to π, it is determined that the current moment is in the pressure rising segment, and the rising or falling segment identifier is set to rising.

4. The volumetric pump outlet pulsation suppression system based on waveform tracking and active anti-phase gas supply according to claim 3, characterized in that: In the phase-reverse matching module, the phase-reverse matching index is a quantitative indicator of the degree of reversal between the current chamber adjustment action and the direction of pressure change. The formula for calculating the phase reversal matching index is: in: The phase-reverse matching index has a value range of 1. ; Given the current phase angle and the average fluctuation amplitude, calculate the amount of reverse-phase gas replenishment command applied to the gas chamber this time: in: This is the reverse phase gas replenishment command quantity; This represents the average fluctuation amplitude. The preset basic air replenishment gain coefficient; This is the preset reference pressure benchmark value.

5. The volumetric pump outlet pulsation suppression system based on waveform tracking and active anti-phase gas supply according to claim 1, characterized in that: The reverse-phase air supply module controls the inlet and outlet valves of the buffer tank based on the calculation results of the reverse-phase air supply command. When the reverse phase air supply command is greater than zero, an opening command is issued to the intake valve, and the intake operation is performed according to the valve opening degree and opening duration corresponding to the reverse phase air supply command to supply gas to the air chamber. When the reverse-phase air supply command is less than zero, an opening command is issued to the exhaust valve. The exhaust operation is performed according to the valve opening degree and opening duration corresponding to the absolute value of the reverse-phase air supply command, and the gas is released from the gas chamber. When the absolute value of the reverse-phase air replenishment command is less than the preset minimum action dead zone threshold, no action command is issued to any valve, and the current state of the air chamber is maintained.

6. The volumetric pump outlet pulsation suppression system based on waveform tracking and active anti-phase gas supply according to claim 5, characterized in that: The response correction module uses the liquid level detection unit to collect signals to reflect the dynamic changes in the interface position between the gas chamber and the liquid; The gas-liquid response characteristics include the rate of change of liquid level and the gas-liquid response deviation; When the gas chamber pressure regulation is started, the liquid level value at the start time is recorded as the initial liquid level value; during the regulation process, the difference between the liquid level value at the current sampling time and the initial liquid level value is calculated and divided by the cumulative duration since the regulation started to obtain the liquid level change rate. Based on the reverse-phase gas replenishment command quantity and the preset gas-liquid coupling coefficient, the expected liquid level change rate under the current gas replenishment command quantity is calculated, and the gas-liquid response deviation is obtained by subtracting the expected liquid level change rate from the measured liquid level change rate.

7. The volumetric pump outlet pulsation suppression system based on waveform tracking and active anti-phase gas supply according to claim 6, characterized in that: The response correction module calculates the compensation correction amount based on the gas-liquid response deviation and adds it to the reverse-phase gas replenishment command amount to obtain the corrected reverse-phase gas replenishment command amount: in: To compensate for the correction amount, a positive value indicates that the amount of air to be replenished needs to be increased, and a negative value indicates that the amount of air to be replenished needs to be decreased; The preset correction gain coefficient; This is the corrected reverse-phase gas replenishment command quantity. The amplitude of the compensation correction is limited: When the absolute value of the compensation correction is less than or equal to the preset correction saturation threshold, the intake valve or exhaust valve is driven to re-execute the chamber adjustment according to the corrected reverse phase air replenishment command. When the absolute value of the compensation correction amount is greater than the preset correction saturation threshold, the compensation correction amount is limited to the preset correction saturation threshold, and the result obtained by superimposing the limited compensation correction amount with the reverse phase gas replenishment command amount is used as the corrected reverse phase gas replenishment command amount.

8. The volumetric pump outlet pulsation suppression system based on waveform tracking and active anti-phase gas replenishment according to claim 7, characterized in that: The hysteresis detection and control module uses a dual confirmation mechanism to determine when to stop chamber pressure regulation: In each sampling cycle, the absolute value of the corrected reverse-phase replenishment command is calculated. When the absolute value is lower than the preset stop threshold, it is recorded as a one-time satisfaction. When the number of consecutive satisfactions reaches the preset number of consecutive confirmation cycles, it is determined that the chamber regulation demand has approached zero, the chamber pressure regulation is stopped, the intake valve and exhaust valve are closed, and the current time is recorded as the stop regulation time. Otherwise, the correction cycle of the response correction module continues to be executed, and the pulsation hysteresis monitoring is not entered.

9. A volumetric pump outlet pulsation suppression system based on waveform tracking and active anti-phase gas supply according to claim 8, characterized in that: After the hysteresis detection and control module stops regulating the gas chamber pressure, it continuously collects the outlet pressure within a preset hysteresis monitoring window, starting from the moment the regulation stops. It calculates the difference between the maximum and minimum pressure values ​​within this window to obtain the pulsating hysteresis amplitude and judges the pulsating return state of the buffer tank. When the hysteresis amplitude is less than or equal to the preset pulsation stability judgment threshold, the pulsation return state is determined to be stable, the current air chamber state is maintained, and the current air chamber pressure regulation ends. When the hysteresis amplitude is greater than the preset hysteresis stability judgment threshold, the hysteresis return state is determined to be unstable, the outlet pressure acquisition and pressure fluctuation trend analysis in the waveform monitoring module are retried, and the reverse phase gas replenishment adjustment process is executed again.

10. A method for controlling outlet pulsation of a volumetric pump based on waveform tracking and active reverse-phase gas supply, based on the volumetric pump outlet pulsation suppression system based on waveform tracking and active reverse-phase gas supply as described in any one of claims 1-9, characterized in that, Includes the following steps: Step S1: Set the pressure monitoring time, collect the outlet pressure signal of the volumetric pump under test during the pressure monitoring time and extract the pressure waveform characteristics, and analyze the pressure fluctuation trend of the volumetric pump under test based on the pressure waveform characteristics. Step S2: Generate a phase reverse matching index based on the pressure fluctuation trend, calculate the reverse phase gas replenishment command quantity using the phase reverse matching index, and regulate the gas chamber pressure of the buffer tank by adjusting the gas chamber state using the reverse phase gas replenishment command quantity. Step S3: When performing gas chamber pressure regulation, the liquid level signal of the buffer tank is collected, the gas-liquid response characteristics corresponding to the gas chamber pressure regulation are evaluated based on the liquid level signal, and compensation correction data is generated. The reverse phase gas replenishment command is corrected according to the compensation correction data. Step S4: Based on the corrected reverse-phase gas supply command quantity, determine whether to stop the chamber pressure regulation. After stopping the chamber pressure regulation, monitor the pressure hysteresis data of the volumetric pump under test and evaluate the pulsation return state of the buffer tank. Use the pulsation return state to determine whether to re-execute the chamber pressure regulation.

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