Turbofan engine fan unbalanced vibration fault self-healing regulation and control system and method

Abstract

The invention discloses a turbofan engine fan unbalanced vibration fault self-healing regulation and control system and method. The turbofan engine fan unbalanced vibration fault self-healing regulation and control system comprises an online monitoring and diagnosis system, an intelligent control system and an unbalanced vibration self-healing regulation and control actuator which are in communication connection in sequence. The on-line monitoring and diagnosis system is used for carrying out real-time acquisition and characteristic analysis on vibration signals of a fan rotor of the turbofan engine so as to obtain the occurrence position of an unbalance fault; the intelligent control system is used for generating an optimal control instruction according to a diagnosis result of the online monitoring and diagnosis system based on a nonlinear active-disturbance-rejection control algorithm; the unbalanced vibration self-healing regulation and control actuator is installed on a fan rotor of the turbofan engine and used for receiving a control instruction of the intelligent control system and executing physical actions so as to adjust mass distribution of a fan rotor system in real time to achieve dynamic balance. The problem of poor timeliness existing in unbalanced vibration fault elimination is solved.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine fault diagnosis and treatment technology, specifically relating to a self-healing control system and method for turbofan engine fan imbalance vibration fault. Background Technology

[0002] High-bypass turbofan engines, with their large-diameter, high-speed fan rotors, are the core components responsible for generating thrust. During actual operation, the fan rotor is susceptible to mass imbalance due to factors such as foreign object impacts, coating peeling, or icing, leading to severe vibrations throughout the engine. This imbalance is transmitted sequentially through bearings, rotor, and mounting joints to the engine casing and aircraft pylons, potentially causing cracks or even breakage in critical structural components. When the vibration level exceeds the threshold of the vibration monitoring system, it can force the pilot to reduce engine thrust or even shut down the engine, posing a serious threat to flight safety, especially during critical phases of flight such as takeoff and climb.

[0003] Currently, the main method for handling fan imbalance vibration relies on ground maintenance. The conventional approach is to manually install counterweight bolts through the threaded plug holes on the fan inlet rectifier cone after the aircraft lands to achieve dynamic balancing. This method has significant drawbacks: First, it has poor timeliness, unable to cope with sudden imbalance failures during flight, and difficult to intervene in a timely manner when a failure occurs; second, it is not economical, as imbalance failures can easily lead to unplanned aircraft groundings and flight delays, while also increasing manual maintenance time and costs; third, it has a delayed response, as the engine remains in a non-ideal vibration state from the occurrence of the failure to the completion of ground handling, which can cause potential cumulative damage to components. Summary of the Invention

[0004] Therefore, embodiments of the present invention provide a self-healing control system and method for turbofan engine fan imbalance vibration faults to solve at least one technical problem existing in the prior art.

[0005] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0006] This invention provides a self-healing control system for unbalanced vibration faults in turbofan engines, comprising an online monitoring and diagnostic system, an intelligent control system, and an unbalanced vibration self-healing control actuator connected in sequence via communication; wherein: The online monitoring and diagnostic system is used to collect and analyze the vibration signals of the turbofan engine fan rotor in real time to determine the location of the imbalance fault. The intelligent control system is used to generate optimal control commands based on the diagnostic results of the online monitoring and diagnostic system, using a nonlinear active disturbance rejection control algorithm. The unbalanced vibration self-healing control actuator is installed on the fan rotor of the turbofan engine. It is used to receive control commands from the intelligent control system and perform physical actions to adjust the mass distribution of the fan rotor system in real time to achieve dynamic balance.

[0007] In some embodiments, the online monitoring and diagnostic system includes a signal acquisition layer, a data processing and feature extraction layer, and an intelligent diagnosis and decision-making layer; wherein: The signal acquisition layer arranges vibration sensors at key vibration measurement points in the engine casing to collect time-domain vibration data including speed signals in real time. The data processing and feature extraction layer preprocesses the collected vibration signals and then extracts the frequency vibration amplitude and phase synchronized with the rotor speed through fast Fourier transform, while monitoring the total vibration level and its changing trend. The intelligent diagnosis and decision-making layer analyzes frequency characteristics through a built-in diagnostic algorithm. When the vibration amplitude continuously exceeds the preset safety warning threshold and the phase characteristics are stable, it is determined to be a fan rotor imbalance fault and triggers the self-healing control process.

[0008] In some embodiments, the installation position of the unbalanced vibration self-healing control actuator is: The connection point between the rear cone of the fan inlet rectifier cone and the fan disc; or, The connection point between the rear of the fan plate and the fan booster stage.

[0009] In some embodiments, the unbalanced vibration self-healing control actuator includes an ultrasonic motor and two counterweights with equal balancing capacity. The ultrasonic motor is used to drive the counterweights to rotate a counterweight disk, thereby changing the mass distribution of the fan rotor by adjusting the phase of the counterweight disk.

[0010] This invention also provides a self-healing control method for fan imbalance vibration faults in turbofan engines, based on the control system described above, the method comprising: The initial vibration value of the fan rotor at the current moment is obtained by the vibration sensor, and the initial counterweight plate phase of the unbalanced vibration self-healing control actuator is also obtained. Change the phase of the counterweight plate and obtain the vibration value of the fan rotor and the phase of the counterweight plate of the actuator at the next moment; Based on the vibration values ​​collected twice and the phase of the counterweight plate, the influence coefficient and compensation vector of the fan rotor at the current moment are calculated, and the target phase of the counterweight plate is determined. The direction of movement of the counterweight plate is determined based on the optimal path method and the monotonically decreasing vibration amplitude algorithm. The rotation speed of the counterweight disk is optimized by a nonlinear active disturbance rejection controller. Control commands are generated based on the direction of movement and rotation speed. These control commands are used to drive the counterweight disk to move according to a preset strategy until the fan rotor achieves dynamic balance.

[0011] In some embodiments, the influence coefficient and compensation vector of the fan rotor at the current moment are calculated, and the target phase of the counterweight disk is determined, specifically including: The initial vibration magnitude and phase of the fan rotor at the current moment are measured by the sensor. and , The corresponding initial imbalance magnitude and phase are respectively and , ; The counterweights A and B of the motor actuator have equal balancing capabilities and are both... The initial phases of the counterweight disk were measured to be as follows: and The equilibrium vectors corresponding to counterweight A and counterweight B are respectively and ; By changing the phase of the counterweight disk, the phases of counterweight A and counterweight B become respectively... and Then the equilibrium vectors corresponding to counterweight A and counterweight B are respectively and At this time, the unbalanced vibration vector is The influence coefficient is then expressed as: ; Given the influence coefficients, the initial imbalance vector is: ; To counteract this imbalance, a compensation vector of equal magnitude but opposite direction to the imbalance needs to be generated. ,Right now: ; In the formula, Represents the compensation vector The corresponding phase is 180° out of phase with the unbalanced vector.

[0012] Target positions of counterweights A and B and They are respectively: .

[0013] In some embodiments, the direction of movement of the counterweight plate is determined based on the optimal path method and the monotonically decreasing vibration amplitude algorithm, specifically including: The phase distance between each counterweight plate and the target phase is determined using the following formula: ; The phases with the smallest phase distances are used as the final phases of the counterweight plate using the following formula: .

[0014] In some embodiments, the rotational speed of the counterweight disk is optimized by a nonlinear active disturbance rejection controller, and control commands are generated based on the direction of movement and the rotational speed, specifically including: A nonlinear active disturbance rejection controller is constructed, consisting of a tracking-differentiator, an extended state observer, and a nonlinear state error feedback control law. The tracking-differentiator (TD) is represented as follows: ; In the formula, This represents the input reference signal, which in this paper represents the desired rotational speed of the input counterweight disk; The state variable is 1, indicating that Smooth tracking signal; for The rate of change; This represents the output of a nonlinear function. fhan() express fhan function; h This indicates the sampling period, which is the time interval calculated by the controller; and These represent the speed factor and the filter factor, respectively. These two parameters determine the response speed and filtering strength of the tracking-differentiator. The larger the value, the faster the tracking, but the coarser the signal may be. It is usually related to the sampling period and is used to adjust the discrete characteristics of the algorithm.

[0015] The Extended State Observer (ESO) is represented as: ; in, The actual output of the system, in this paper, represents the actual rotational speed of the input ultrasonic motor; The first-state estimate represents the actual output of the system. The estimate, i.e., the estimated location; This is the second-state estimate, representing an estimate of the system velocity, i.e., the estimated velocity. The value is the expansion state estimate, representing the disturbance encountered by the ultrasonic motor during rotation; Observation error represents the deviation between the estimated value and the measured value; , and These three parameters—observer gain, observer gain, and observer convergence speed—determine the observer's convergence rate. A higher gain results in a faster estimation speed. , and The faster it approximates the true value, the better, but too large an approximation can easily introduce noise. fal() Represents a nonlinear function; bTo control the input gain, it represents the input quantity of the system. u Influence coefficient on system state; The width of the linear interval is fal The threshold used in the function to distinguish between linear and nonlinear regions; The nonlinear state error feedback (NLSEF) control law is expressed as follows: ; in, and To track the output of the differentiator, i.e., the one mentioned earlier and ; This represents the first error, which is the difference between the expected rotational speed and the estimated rotational speed. This represents the second error, i.e. The difference between the expected rate and the estimated rate corresponding to the rate of change; and These are the proportional and derivative gains, used to adjust the intensity of the control. and As a parameter of nonlinearity, it determines fal The degree of nonlinearity of the function; The synthesized control quantity is used to eliminate errors. and The calculated preliminary control commands.

[0016] Finally, the control quantity is obtained: ; The magnitude and phase of the unbalance vector are compared with a set vibration threshold to determine whether to perform automatic balancing.

[0017] In some embodiments, the control instructions specifically include: When the deviation between the current phase of the counterweight disk and the target phase is greater than the deviation threshold, the speed of the ultrasonic motor is increased so that the counterweight disk can quickly approach the target phase. When the deviation between the current phase of the counterweight disk and the target phase is less than the deviation threshold, the speed of the ultrasonic motor is reduced.

[0018] In some embodiments, control commands are generated based on the direction of movement and the rotational speed, and then the method further includes: The unbalance vector amplitude and phase of the fan rotor are detected in real time and compared with the set vibration threshold. If the unbalance vector amplitude still exceeds the vibration threshold, the adjustment steps are repeated until the vibration level of the fan rotor is restored to within the safe threshold.

[0019] In one or more of the above specific embodiments, the self-healing control system and method for turbofan engine fan imbalance vibration fault provided by the present invention has at least the following technical effects: 1. Flexible installation and high integration: The actuator of the fan rotor unbalanced vibration self-healing control system of the present invention has a variety of flexible installation options: it can be installed at the connection position between the rear cone of the fan inlet rectifier cone and the fan disk, or it can be placed on the rear side of the fan disk and the connection position between the fan booster stage, and both are connected by standardized bolts, which facilitates engineering implementation and system integration.

[0020] 2. Rapid and significant suppression: The automatic balancing method based on nonlinear active disturbance rejection control adopted in this invention can achieve real-time dynamic optimal suppression of unbalanced vibration. Simulation results show that under different working conditions, this method can rapidly and monotonically reduce the vibration amplitude, with a total suppression time of no more than 10 seconds, and the final vibration suppression effect is stable at over 95%, meeting the engineering requirements for rapid and high-precision vibration control. Attached Figure Description

[0021] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0022] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0023] Fig. 1 This is a structural diagram of a turbofan engine. Fig. 2 Structural diagram of the fan booster stage rotor; Fig. 3 This is a schematic diagram of the automatic balancing of the cone after rectification at the fan inlet; Fig. 4 A schematic diagram of the automatic balancing mechanism at the rear of the fan disc; Fig. 5 This is a flowchart illustrating an automatic balancing control method based on nonlinear active disturbance rejection control. Fig. 6 The diagram shows the structure of rotor unbalance vibration self-healing regulation based on nonlinear active disturbance rejection control. Fig. 7 The automatic balancing simulation reduction curve is shown when the imbalance is 3500 g·mm. Fig. 8The automatic balancing simulation reduction curve is shown when the unbalance is 4000 g·mm. Fig. 9 The automatic balancing simulation reduction curve is shown when the unbalance is 4500 g·mm. Detailed Implementation

[0024] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0025] To address the problems existing in the prior art, the present invention aims to overcome the shortcomings of poor timeliness in handling fan imbalance vibration in existing technologies, and provides a self-healing control system and method for turbofan engine fan imbalance vibration faults. This system can achieve online real-time monitoring, intelligent fault diagnosis, and active dynamic suppression of fan imbalance vibration, thereby automatically and quickly restoring the vibration level to within a safe threshold during engine operation, significantly improving the engine's online health management capabilities. The purpose of this invention is to establish a self-healing control system for turbofan engine fan imbalance vibration faults to solve the problem of poor timeliness in current methods that eliminate imbalance vibration faults by using the counterweight bolt holes of the rear cone of the fan inlet rectifier cone after the aircraft lands when the engine fan rotor experiences imbalance vibration faults.

[0026] In one specific implementation, such as Figs. 1-4As shown, this invention provides a self-healing control system for unbalanced vibration faults in turbofan engines, comprising an online monitoring and diagnostic system, an intelligent control system, and an unbalanced vibration self-healing control actuator connected in sequence via communication. The online monitoring and diagnostic system is used to collect and analyze the vibration signals of the turbofan engine fan rotor in real time to determine the location of the unbalanced fault. In practical use, after the online monitoring and diagnostic system is started, it first completes self-checks of each component to ensure that the vibration sensor, signal transmission module, and data processing unit are working properly. Subsequently, the vibration sensor continuously collects the time-domain vibration signal during the operation of the fan rotor and simultaneously collects the engine speed signal. The collected raw signals are transmitted to the data processing unit via wired or wireless communication. The data processing unit performs preprocessing such as filtering, denoising, and normalization on the raw signals to remove invalid data caused by environmental interference and sensor errors. Then, it extracts the frequency domain and time domain features of the vibration signal through feature extraction algorithms. The extracted features may include amplitude, phase, peak value, and RMS value. Combined with the speed signal, correlation analysis is performed to locate the specific location of the fan rotor imbalance fault and transmit the diagnostic results to the intelligent control system in real time. The diagnostic results may include fault location, vibration amplitude, and phase data.

[0027] The intelligent control system is used to generate optimal control commands based on the diagnostic results of the online monitoring and diagnostic system, using a nonlinear active disturbance rejection control algorithm. In its operation, after receiving fault diagnosis data from the online monitoring and diagnostic system, the intelligent control system first verifies the data to confirm its integrity and accuracy. Then, it calls the built-in nonlinear active disturbance rejection control algorithm, inputting parameters such as fault location, current vibration amplitude, phase, and engine speed. The algorithm tracks the changing trend of the vibration signal through a tracking-differentiator, estimates external disturbances (such as interference from airflow fluctuations and temperature changes) and internal uncertainties through an extended state observer, corrects the error through a nonlinear state error feedback control law, and calculates the optimal control parameters (such as actuator rotation direction, speed, and phase adjustment) to counteract unbalanced vibration, combined with a preset vibration safety threshold. Finally, it generates standardized control commands, which are transmitted to the unbalanced vibration self-healing control actuator.

[0028] This solves the problems of weak anti-interference ability and low control accuracy of traditional control algorithms. The nonlinear active disturbance rejection algorithm can effectively suppress the influence of external disturbances such as airflow and temperature on the control effect, accurately generate the optimal control command, and ensure the accuracy and effectiveness of subsequent actuator actions. At the same time, the algorithm has a fast response speed and can adjust the control command in real time according to the fault changes, realize dynamic optimal control, and improve the timeliness and reliability of self-healing control.

[0029] The unbalanced vibration self-healing control actuator is installed on the fan rotor of the turbofan engine. It receives control commands from the intelligent control system and executes physical actions to adjust the mass distribution of the fan rotor system in real time to achieve dynamic balance. The unbalanced vibration self-healing control actuator is fixed to the fan rotor at a preset position, and calibration is performed after installation to ensure that the actuator rotates synchronously with the fan rotor without interference. After receiving the control commands transmitted by the intelligent control system, the actuator analyzes parameters such as rotation direction, speed, and phase adjustment amount in the commands, drives the internal power component (such as an ultrasonic motor) to operate, causing the actuator's counterweight structure (such as a counterweight block or counterweight disc) to rotate or move, changing the spatial position of the counterweight structure, thereby adjusting the overall mass distribution of the fan rotor system and counteracting the rotor's imbalance. During the execution of the action, the actuator feeds back its own operating status (such as current phase and speed) to the intelligent control system in real time, forming a closed-loop control to ensure that the mass distribution adjustment meets expectations. It achieves real-time self-healing control of fan rotor imbalance vibration, and can complete mass distribution adjustment without manual intervention, solving the drawbacks of traditional dynamic balancing adjustment that requires machine shutdown and manual operation, and improving the engine's continuous operation capability; at the same time, the actuator moves precisely and responds quickly, which can quickly offset the imbalance and control the fan rotor vibration within a safe threshold, reducing the wear of vibration on engine casing, bearings and other components, extending engine service life and reducing maintenance costs.

[0030] Thus, the turbofan engine fan unbalanced vibration fault self-healing control system provided by this invention, through an online monitoring and diagnostic system, is responsible for real-time acquisition of vibration signals, feature analysis, and intelligent identification and location of unbalanced faults; through an intelligent control system, based on advanced control algorithms, it generates optimal control commands according to the monitoring and diagnostic results; through an unbalanced vibration self-healing control actuator, it receives control commands, executes physical actions, and adjusts the mass distribution of the rotor system in real time to achieve dynamic balance. This system achieves real-time monitoring and precise location of fan rotor unbalanced vibration faults, breaking the limitations of traditional offline detection, avoiding missed or false fault diagnoses, and providing accurate data sources and decision-making basis for subsequent self-healing control; simultaneously, real-time acquisition and analysis can promptly capture vibration changes in the early stages of the fault, enabling early intervention, preventing fault escalation (such as increased rotor wear, blade breakage, etc.), and improving engine operating safety.

[0031] Furthermore, the online monitoring and diagnostic system includes a signal acquisition layer, a data processing and feature extraction layer, and an intelligent diagnosis and decision-making layer.

[0032] The signal acquisition layer deploys vibration sensors at key vibration measurement points on the engine casing to collect time-domain vibration data, including engine speed signals, in real time. Specifically, the signal acquisition layer first determines the key vibration measurement points on the engine casing based on the structural characteristics and vibration transmission laws of the turbofan engine's fan rotor. Vibration sensors are then fixed at these key measurement points, connected to the signal acquisition module, and calibrated to ensure the acquisition accuracy meets requirements. These key measurement points can be, for example, the fan inlet casing, the casing corresponding to the fan disc, or the turbocharger stage casing, ensuring comprehensive capture of rotor vibration signals. The vibration sensors can be piezoelectric vibration sensors, offering advantages such as high sensitivity and strong anti-interference capabilities. After engine startup, the signal acquisition layer collects time-domain vibration signals from each measurement point in real time, simultaneously acquiring engine speed signals through the speed sensor. The vibration signals and speed signals are synchronously correlated to form time-domain vibration data containing speed information, which is transmitted in real time to the data processing and feature extraction layer. Simultaneously, the collected data is initially buffered to prevent data loss.

[0033] In this way, the reasonable arrangement of key vibration measurement points ensures the comprehensiveness and accuracy of vibration signal acquisition, avoiding signal distortion and missed fault diagnosis caused by unreasonable acquisition points; synchronous acquisition of rotational speed signals provides a rotational speed correlation basis for subsequent feature extraction and fault diagnosis, improving the accuracy of diagnosis; the selection and calibration of vibration sensors ensures the reliability of the acquired data, laying the foundation for subsequent data processing and diagnostic decision-making.

[0034] The data processing and feature extraction layer preprocesses the acquired vibration signals and then extracts the fundamental frequency vibration amplitude and phase synchronized with the rotor speed using Fast Fourier Transform (FFT). Simultaneously, it monitors the total vibration level and its changing trend. Specifically, after receiving the time-domain vibration data transmitted from the signal acquisition layer, the data processing and feature extraction layer first performs preprocessing: low-pass filtering removes high-frequency interference signals, wavelet denoising removes random noise, interpolates missing data, and identifies and removes abnormal data to ensure data validity. After preprocessing, the time-domain vibration signal is converted into a frequency-domain signal using FFT, and the fundamental frequency vibration amplitude and phase synchronized with the rotor speed are extracted. Simultaneously, the total vibration level (i.e., the effective value of the vibration signal) is calculated, and the changing trend of the total vibration level, such as the rate of rise and steady-state, is monitored in real time. The extracted frequency-domain features, such as amplitude and phase, along with the total vibration level and its changing trend data, are transmitted to the intelligent diagnosis and decision-making layer. The preprocessing steps effectively remove invalid interference, improve data quality, and avoid the impact of interference signals on feature extraction and diagnostic results; the fast Fourier transform can efficiently and accurately extract the core features (fundamental frequency amplitude and phase) of rotor imbalance faults, providing key basis for fault diagnosis; real-time monitoring of the total vibration level and its changing trend can promptly capture the development state of the fault, providing a reference for fault classification and self-healing control triggering, and preventing the fault from further deteriorating.

[0035] The intelligent diagnosis and decision-making layer analyzes frequency characteristics through a built-in diagnostic algorithm. When the vibration amplitude continuously exceeds the preset safety warning threshold and the phase characteristics are stable, it is determined to be a fan rotor imbalance fault and triggers the self-healing control process. Specifically, after receiving the frequency domain characteristics, total vibration level, and trend data transmitted by the data processing and feature extraction layer, the intelligent diagnosis and decision-making layer calls the built-in diagnostic algorithm (such as support vector machine, neural network, or threshold judgment algorithm) to analyze the fundamental frequency vibration amplitude and phase. First, it compares the current fundamental frequency vibration amplitude with the preset safety warning threshold (preset according to engine model and operating conditions, which can be dynamically adjusted), and at the same time determines whether the phase characteristics are stable (i.e., the phase fluctuation is within the preset range, excluding vibration abnormalities caused by temporary interference such as airflow fluctuations). If the fundamental frequency vibration amplitude continuously exceeds the safety warning threshold (duration ≥ preset duration, such as 3-5 seconds) and the phase characteristics are stable, it is determined to be a fan rotor imbalance fault. Subsequently, a fault diagnosis result (including fault type, fault location, and current vibration parameters) is generated, and the self-healing control process is triggered, sending a start signal to the intelligent control system to initiate subsequent self-healing control operations. If the above conditions are not met, it is determined to be temporary interference, and self-healing control is not triggered; only the vibration signal change is continuously monitored. The built-in diagnostic algorithm enables accurate identification of imbalance faults, avoiding false triggers caused by temporary disturbances (such as airflow fluctuations and instantaneous load changes), thus improving the accuracy of fault diagnosis. The setting of duration thresholds and phase stability conditions further enhances the reliability of fault identification. The timely triggering of the self-healing control process enables early intervention in faults, preventing the aggravation of imbalance vibrations and ensuring the safe and stable operation of the engine.

[0036] In general, the online monitoring system provided by this invention is a self-healing and regulated sensory nerve, and its core functional chain is as follows: (1) Signal acquisition layer: High-performance vibration sensors 12 are arranged at key vibration measurement points of the engine casing to collect time-domain vibration data including speed signals in real time.

[0037] (2) Data processing and feature extraction layer: After the collected vibration signal is preprocessed, the amplitude and phase of the first harmonic vibration synchronized with the rotor speed are extracted by fast Fourier transform as the core feature quantity of the unbalanced state. At the same time, the system continuously monitors the total vibration level and its changing trend.

[0038] (3) Intelligent diagnosis and decision-making layer: The built-in diagnostic algorithm performs real-time analysis on the extracted 1st harmonic features. When the vibration amplitude continuously exceeds the preset safety warning threshold and the phase features are stable, the system determines that the fan rotor has an imbalance fault and triggers the self-healing control process. The system has the ability to distinguish between instantaneous interference and continuous faults to prevent malfunctions.

[0039] In some embodiments, the unbalanced vibration self-healing control actuator includes an end-mounted unbalanced vibration self-healing control actuator 15 and an through-shaft unbalanced vibration self-healing control actuator 16. The end-mounted unbalanced vibration self-healing control actuator 15 is installed at the connection point between the rear cone of the fan inlet rectifier cone and the fan disc, while the through-shaft unbalanced vibration self-healing control actuator 16 is installed at the connection point between the rear side of the fan disc and the fan booster stage. Both installation positions are located in the core stress area and vibration-sensitive area of ​​the fan rotor, enabling the most direct and effective adjustment of the rotor mass distribution and improving the efficiency and accuracy of self-healing control. The installation positions avoid critical components such as fan blades and airflow channels, preventing the actuator from affecting the aerodynamic performance of the engine during operation, while also facilitating installation, maintenance, and calibration. The two installation positions can be flexibly selected according to the engine model and structural dimensions, improving the system's versatility and adaptability.

[0040] Furthermore, the unbalanced vibration self-healing control actuator includes an ultrasonic motor and two counterweights with equal balancing capacity. The ultrasonic motor is used to drive the counterweight disk formed by the counterweights to rotate, and the mass distribution of the fan rotor is changed by adjusting the phase of the counterweight disk. The assembly process of the unbalanced vibration self-healing control actuator can be as follows: Two counterweights with equal balancing capacity (the mass of the counterweights is determined based on the mass of the fan rotor and the unbalance adjustment requirements to ensure consistent balancing capacity) are symmetrically installed on a counterweight plate to form a complete counterweight structure. An ultrasonic motor is connected to the counterweight plate via a coupling, ensuring that the output shaft of the ultrasonic motor is coaxial with the counterweight plate to guarantee transmission accuracy. The assembled actuator is fixed to the fan rotor according to the above installation position. The control end of the ultrasonic motor is connected to the intelligent control system to receive control commands. During operation, the ultrasonic motor receives control commands (rotation direction, speed) from the intelligent control system, drives the output shaft to rotate, and then drives the counterweight plate to rotate synchronously, adjusting the phase of the counterweight plate (i.e., the spatial position of the two counterweights), changing the overall mass distribution of the fan rotor, and counteracting the rotor's unbalance. During rotation, the ultrasonic motor provides real-time feedback of its own speed and angle information, forming a closed-loop control to ensure accurate phase adjustment of the counterweight plate.

[0041] Among them, the ultrasonic motor has the advantages of small size, light weight, fast response speed, high control precision and no electromagnetic interference, which makes it suitable for the compact installation space of turbofan engines and avoids interference with other electrical components of the engine. The two counterweights with equal balancing capacity are symmetrically arranged, which can realize bidirectional phase adjustment, expand the mass distribution adjustment range and improve the flexibility of self-healing control. By adjusting the phase of the counterweight plate to change the mass distribution, the control method is simple and efficient, which can quickly offset the imbalance and ensure the dynamic balance of the fan rotor. At the same time, the counterweight structure is stable and there is no risk of loosening or falling off during operation, which improves the reliability and service life of the actuator.

[0042] Specifically, in the turbofan engine structure and actuator integration installation scheme... Fig. 1 The diagram shows a typical structure of a turbofan engine, mainly consisting of a high-pressure rotor 1, a low-pressure rotor 2, a fan rotor 4, and a casing 3. The casing 3 is equipped with a casing sensor 12 for vibration measurement. The turbofan engine fan imbalance vibration fault self-healing control system primarily targets the turbofan engine fan rotor 4, and its specific structure is shown below. Fig. 2 As shown, the structure mainly consists of a front cone 5 (fan inlet rectifier cone), a rear cone 6 (fan inlet rectifier cone), a fan 8, a booster stage 10, a fan shaft 11, and a fan disc 13. The front cone 5 and the rear cone 6 are bolted together, as are the rear cone 6 and the fan disc 13. The connection point between the rear cone and the fan disc is 14. The booster stage 10 is bolted to the rear side of the fan disc 13. 9 is the connection point between the booster and the fan disc. The rear cone has threaded plug holes 7 for fan balancing and static balance adjustment, such as static balancing after fan blade replacement (after foreign object damage) or fan balancing after engine vibration levels exceed the limit. The unbalanced vibration self-healing control actuator is divided into an end-mounted unbalanced vibration self-healing control actuator 15 and a through-shaft unbalanced vibration self-healing control actuator 16. The end-mounted unbalanced vibration self-healing control actuator 15 is installed at the connection position between the rear cone of the fan inlet rectifier cone and the fan disk, while the through-shaft unbalanced vibration self-healing control actuator 16 is installed at the connection position between the rear side of the fan disk and the fan booster stage.

[0043] In actual operation, if an engine fan imbalance vibration fault occurs during aircraft operation, maintenance often needs to be performed after the aircraft has landed. This includes replacing blades and adding balancing bolts to the threaded plug hole 7 to achieve dynamic balancing, which suffers from poor balancing timeliness. By analyzing the specific structure of the fan rotor 4, an imbalance vibration self-healing actuator can be installed at one of the two locations on the fan rotor, such as… Fig. 3 and Fig. 4 As shown. Fig. 3 This is a schematic diagram of the automatic balancing of the rear cone of the fan inlet rectifier. Specifically, the end-mounted unbalanced vibration self-healing control actuator 15 is installed at the connection position 14 between the rear cone of the fan inlet rectifier and the fan disc, and is connected by bolts. Fig. 4 The diagram shows the automatic balancing mechanism on the rear side of the fan disc. The self-healing actuator 16 for unbalanced vibration through the shaft is installed on the rear side of the fan disc at the connection point 9 with the fan booster stage and is connected by bolts.

[0044] For self-healing actuators, an automatic balancing control method based on nonlinear active disturbance rejection control is invented. First, the initial vibration value of the fan rotor and the initial phase of the counterweight plate of the self-healing actuator are obtained by sensors. By changing the phase of the counterweight plate, the vibration value of the fan rotor and the phase of the counterweight plate of the self-healing actuator at the next moment are obtained. The influence coefficient and compensation vector at the current moment are calculated. Based on the optimal path method and the principle of monotonically decreasing vibration amplitude, the movement direction of the counterweight plate is determined. The rotation speed of the counterweight plate is optimized by the nonlinear active disturbance rejection controller. Control commands are generated according to the movement direction and rotation speed, and the counterweight plate is driven to move according to the commands.

[0045] This invention also provides a self-healing control method for turbofan engine fan imbalance vibration faults, based on the control system described above, such as... Fig. 5 As shown, the method includes the following steps: S510: The initial vibration value of the fan rotor at the current moment is obtained through a vibration sensor, and the initial phase of the counterweight plate of the unbalanced vibration self-healing control actuator is also obtained. Specifically, after the control method is started, the control system is first initialized to ensure that the online monitoring and diagnostic system, intelligent control system, and actuator are all working properly. The vibration sensor of the online monitoring and diagnostic system collects the vibration signal of the fan rotor in real time. After preprocessing and feature extraction, the initial vibration value is obtained. At the same time, the intelligent control system obtains the initial phase of the counterweight plate in the unbalanced vibration self-healing control actuator through communication with the actuator. The initial vibration value and the initial counterweight plate phase are stored in the data cache unit as the reference data for subsequent calculations and control. In this way, this step of obtaining the initial vibration value and the initial counterweight plate phase provides reference data for subsequent influence coefficient calculation and target phase determination, ensuring the accuracy of subsequent control calculations. The initialization step ensures that all components of the system work together, avoids control errors caused by component failures, and lays the foundation for the smooth implementation of self-healing control.

[0046] S520: Change the phase of the counterweight plate and obtain the vibration value of the fan rotor and the phase of the counterweight plate of the actuator at the next moment; specifically, the intelligent control system generates a temporary control command, sends it to the ultrasonic motor, drives the counterweight plate to rotate by a preset angle, changes the phase of the counterweight plate, and makes the phases of the two counterweights change. and After the counterweight plate has stabilized (ensuring the phase no longer changes), the vibration sensor collects the vibration signal of the fan rotor again, and after processing, obtains the vibration value (vibration amplitude) for the next moment. and phase Simultaneously, the intelligent control system acquires the phase of the actuator's counterweight disc at this moment, stores this data in correspondence with the initial data, and uses it for subsequent calculation of the influence coefficient. Thus, this step, by changing the phase of the counterweight disc and collecting the corresponding vibration values, obtains two sets of vibration data under different phases, providing necessary sample data for calculating the influence coefficient; a preset reasonable phase adjustment angle ensures both the data's variability, facilitating accurate calculation of the influence coefficient, and avoids excessive adjustment angles that could lead to increased vibration, ensuring engine operating safety.

[0047] S530: Based on the vibration values ​​and counterweight phase collected twice, the influence coefficient and compensation vector of the fan rotor at the current moment are calculated, and the target phase of the counterweight is determined. Specifically, the intelligent control system calls a preset calculation algorithm, inputs the vibration values ​​collected twice and the corresponding counterweight phase, and combines the balancing ability of the counterweight to first calculate the influence coefficient of the fan rotor (the influence coefficient reflects the degree of influence of the counterweight phase change on the vibration value). Based on the influence coefficient and the initial vibration value, the initial imbalance vector of the fan rotor at the current moment (i.e., the magnitude and phase of the imbalance that causes the vibration) is calculated. To counteract this imbalance, the compensation vector that needs to be generated is calculated (equal in magnitude and opposite in direction to the initial imbalance vector). Finally, based on the compensation vector and the balancing ability of the counterweight, the target phase of the two counterweights is calculated, which is the final phase that the counterweight needs to be adjusted to. Accurate calculation of the influence coefficient using two sample data points ensures the accuracy of subsequent compensation vector and target phase calculations. The calculation of the compensation vector can accurately locate the amount of counterweight adjustment required to counteract the imbalance, and the determination of the target phase provides clear guidance for the actuator's action, avoiding blind adjustments and improving control efficiency and accuracy.

[0048] S540: Based on the optimal path method and the monotonically decreasing vibration amplitude algorithm, the movement direction of the counterweight disk is determined. The intelligent control system calls the optimal path method and the monotonically decreasing vibration amplitude algorithm. First, based on the current phase of the counterweight disk and the target phase, it calculates multiple possible movement paths (clockwise, counterclockwise, and different movement angles) from the current phase to the target phase. The algorithm calculates the vibration amplitude change trend corresponding to each path and selects the path that can make the vibration amplitude monotonically decrease (i.e., the vibration amplitude continuously decreases during the movement, avoiding vibration aggravation). At the same time, it calculates the phase distance of each path (the difference between the current phase and the target phase) and selects the path with the smallest phase distance and satisfying the monotonically decreasing vibration amplitude as the final movement direction of the counterweight disk. The optimal path method ensures that the counterweight disk reaches the target phase with the shortest path, improving control efficiency; the monotonically decreasing vibration amplitude algorithm ensures that the vibration amplitude of the fan rotor continuously decreases during the movement of the counterweight disk, avoiding vibration aggravation due to improper movement direction, ensuring engine operation safety, and shortening the control time, improving the reliability of self-healing control.

[0049] S550: The nonlinear active disturbance rejection controller optimizes the rotation speed of the counterweight disk. Based on the direction of movement and rotation speed, control commands are generated to drive the counterweight disk to move according to a preset strategy until the fan rotor achieves dynamic balance. The intelligent control system constructs a nonlinear active disturbance rejection controller, consisting of three parts: a tracking-differentiator, an extended state observer, and a nonlinear state error feedback control law. The tracking-differentiator tracks the phase change and vibration amplitude change trend of the counterweight disk, generating a smooth tracking signal. The extended state observer estimates and compensates for external disturbances (such as airflow fluctuations and temperature changes) and internal uncertainties (such as actuator wear and transmission errors) in real time. The nonlinear state error feedback control law optimizes the rotation speed of the counterweight disk based on the error between the tracking signal and the actual phase and vibration signal. Combined with the previously determined direction of movement, control commands (including the rotation direction and optimized rotation speed) are generated and sent to the ultrasonic motor. The ultrasonic motor drives the counterweight disk to move according to the control commands, collecting vibration signals and the counterweight disk phase in real time during the process, feeding them back to the intelligent control system, and dynamically adjusting the control commands until the vibration amplitude of the fan rotor drops below a preset safety threshold, achieving dynamic balance. Nonlinear active disturbance rejection controller can effectively suppress the influence of external disturbances and internal uncertainties on the control effect. The optimized rotation speed not only ensures the control efficiency, but also avoids phase overshoot caused by excessive speed and excessive control time caused by excessively slow speed. Closed-loop control ensures the accuracy of the counterweight plate movement process, and can quickly and stably achieve dynamic balance of the fan rotor, improving the reliability and robustness of self-healing control.

[0050] Calculate the influence coefficient and compensation vector of the fan rotor at the current moment, and determine the target phase of the counterweight disk, specifically including: The initial vibration magnitude and phase of the fan rotor at the current moment are measured by the sensor. and , The corresponding initial imbalance magnitude and phase are respectively and , ; The counterweights A and B of the motor actuator have equal balancing capabilities and are both... The initial phases of the counterweight disk were measured to be as follows: and The equilibrium vectors corresponding to counterweight A and counterweight B are respectively and ; By changing the phase of the counterweight disk, the phases of counterweight A and counterweight B become respectively... and Then the equilibrium vectors corresponding to counterweight A and counterweight B are respectively and At this time, the unbalanced vibration vector is The influence coefficient is then expressed as: ; Given the influence coefficients, the initial imbalance vector is: ; To counteract this imbalance, a compensation vector of equal magnitude but opposite direction to the imbalance needs to be generated. ,Right now: ; In the formula, Represents the compensation vector The corresponding phase is 180° out of phase with the unbalanced vector.

[0051] Target positions of counterweights A and B and They are respectively: .

[0052] In this way, through precise vector calculation and formula derivation, the accuracy of the calculation of influence coefficient, initial imbalance vector, and compensation vector is ensured, providing a scientific basis for determining the target phase; clear calculation steps and formulas avoid human calculation errors and improve the precision of control; the reasonable setting of the target phases of counterweights A and B can maximize the balancing ability of the counterweights, quickly offset the initial imbalance, shorten the control time, and ensure the dynamic balance effect.

[0053] Furthermore, based on the optimal path method and the monotonically decreasing vibration amplitude algorithm, the direction of movement of the counterweight plate is determined, specifically including: The phase distance between each counterweight plate and the target phase is determined using the following formula: ; The phases with the smallest phase distances are used as the final phases of the counterweight plate using the following formula: .

[0054] In this way, the control distance of different paths is accurately calculated by the phase distance formula, ensuring that the selected path is the shortest path and improving control efficiency. Combined with the vibration amplitude monotonically decreasing algorithm, it is ensured that the optimal path not only has the shortest distance, but also guarantees that the vibration amplitude continues to decrease during the control process, avoiding vibration aggravation and ensuring engine operation safety. The clear formula and screening steps make the judgment of the movement direction more scientific and operable, and improve the reliability of self-healing control.

[0055] Furthermore, the rotational speed of the counterweight disk is optimized using a nonlinear active disturbance rejection controller, generating control commands based on the direction of movement and rotational speed, specifically including: A nonlinear active disturbance rejection controller is constructed, consisting of a tracking-differentiator, an extended state observer, and a nonlinear state error feedback control law. The tracking-differentiator is expressed as follows: ; In the formula, This represents the input reference signal, which in this paper represents the desired rotational speed of the input counterweight disk; The state variable is 1, indicating that Smooth tracking signal; for The rate of change; This represents the output of a nonlinear function. fhan() express fhan function; h This indicates the sampling period, which is the time interval calculated by the controller; and These represent the speed factor and the filter factor, respectively. These two parameters determine the response speed and filtering strength of the tracking-differentiator. The larger the value, the faster the tracking, but the coarser the signal may be. It is usually related to the sampling period and is used to adjust the discrete characteristics of the algorithm.

[0056] The extended state observer is represented as: ; in, The actual output of the system, in this paper, represents the actual rotational speed of the input ultrasonic motor; The first-state estimate represents the actual output of the system. The estimate, i.e., the estimated location; This is the second-state estimate, representing an estimate of the system velocity, i.e., the estimated velocity. The value is the expansion state estimate, representing the disturbance encountered by the ultrasonic motor during rotation; Observation error represents the deviation between the estimated value and the measured value; , and These three parameters—observer gain, observer gain, and observer convergence speed—determine the observer's convergence rate. A higher gain results in a faster estimation speed. , and The faster it approximates the true value, the better, but too large an approximation can easily introduce noise. fal() Represents a nonlinear function; b To control the input gain, it represents the input quantity of the system. u Influence coefficient on system state; The width of the linear interval is fal The threshold used in the function to distinguish between linear and nonlinear regions; The nonlinear state error feedback control law is expressed as: ; in, and To track the output of the differentiator, i.e., the one mentioned earlier and ; This represents the first error, which is the difference between the expected rotational speed and the estimated rotational speed. This represents the second error, i.e. The difference between the expected rate and the estimated rate corresponding to the rate of change; and These are the proportional and derivative gains, used to adjust the intensity of the control. and The nonlinearity parameter determines fal The degree of nonlinearity of the function; The synthesized control quantity is used to eliminate errors. and The calculated preliminary control commands.

[0057] Finally, the control quantity is obtained: ; The magnitude and phase of the unbalance vector are compared with a set vibration threshold to determine whether to perform automatic balancing.

[0058] Thus, as Fig. 6 As shown, the tracking-differentiator enables smooth tracking of vibration signals, avoiding control errors caused by signal abrupt changes and improving control stability; the extended state observer can accurately estimate and compensate for external disturbances and internal uncertainties, solving the problem of weak anti-interference capability of traditional controllers and improving the robustness of regulation; the nonlinear state error feedback control law can quickly correct control errors, optimize rotation speed, and ensure that the counterweight plate rotation speed is reasonable, which not only improves regulation efficiency but also avoids overshoot; through precise calculation of control quantities and threshold comparison, intelligent judgment of automatic balance is achieved, improving the automation level and reliability of self-healing regulation.

[0059] The aforementioned control commands specifically include: When the deviation between the current phase of the counterweight disk and the target phase is greater than the deviation threshold, the speed of the ultrasonic motor is increased so that the counterweight disk can quickly approach the target phase. When the deviation between the current phase of the counterweight disk and the target phase is less than the deviation threshold, the speed of the ultrasonic motor is reduced.

[0060] By setting a phase deviation threshold, the speed of the ultrasonic motor can be dynamically adjusted, balancing control efficiency and accuracy. When the deviation is large, the speed is increased to quickly approach the target phase and shorten the control time. When the deviation is small, the speed is decreased to avoid phase overshoot and ensure accurate adjustment. Closed-loop feedback adjustment ensures the real-time and rationality of speed adjustment, improves the stability and reliability of self-healing control, and avoids vibration aggravation or control failure caused by improper speed.

[0061] The amplitude and phase of the unbalance vector are compared with a set vibration threshold to determine whether automatic balancing should be performed. After the parameters are calibrated, the nonlinear active disturbance rejection controller corrects the overall deviation between the current phase and the target phase of each counterweight plate during the control process, accurately outputs control quantities, and determines the rotation speed of the ultrasonic motor. When the deviation between the current phase and the target phase of the counterweight plate is large, the speed of the ultrasonic motor is increased to make the counterweight plate quickly approach the target phase. When the deviation between the current phase and the target phase of the counterweight plate is small, the speed of the ultrasonic motor is decreased to achieve fine adjustment of the phase of the counterweight plate, improve the speed and accuracy of automatic balancing, and further reduce the vibration value.

[0062] Furthermore, control commands are generated based on the direction of movement and rotation speed, and this process also includes: The unbalance vector amplitude and phase of the fan rotor are detected in real time and compared with the set vibration threshold. If the unbalance vector amplitude still exceeds the vibration threshold, the adjustment steps are repeated until the vibration level of the fan rotor is restored to within the safe threshold.

[0063] Real-time detection and threshold comparison ensure dynamic balancing, avoiding residual vibration due to incomplete adjustment and improving the reliability of self-healing control; the repeated adjustment mechanism can cope with complex imbalance faults (such as multiple imbalance points and dynamic imbalance), ensuring that vibration can be controlled within the safe threshold regardless of the severity of the fault; the storage of control records provides data support for subsequent system optimization and fault analysis, improving the maintainability and iterative capability of the system.

[0064] In one or more of the above specific embodiments, the self-healing control system and method for turbofan engine fan imbalance vibration fault provided by the present invention has at least the following technical effects: 1. Flexible installation and high integration: The actuator of the fan rotor unbalanced vibration self-healing control system of the present invention has a variety of flexible installation options: it can be installed at the connection position between the rear cone of the fan inlet rectifier cone and the fan disk, or it can be placed on the rear side of the fan disk and the connection position between the fan booster stage, and both are connected by standardized bolts, which facilitates engineering implementation and system integration.

[0065] 2. Rapid suppression and significant effect; the automatic balancing method based on nonlinear active disturbance rejection control adopted in this invention can achieve real-time dynamic optimal suppression of unbalanced vibrations. According to... Figs. 7-9The simulation results show that under different working conditions, the method can make the vibration amplitude decrease rapidly and monotonically, with a total suppression time of no more than 10 seconds, and the final vibration suppression effect is stable at over 95%, meeting the engineering requirements for rapid and high-precision vibration control.

[0066] In one embodiment, a computer device, which may be a server, is provided. The computer device includes a processor, memory, and a network interface connected via a system bus. The processor provides computing and control capabilities. The memory includes a non-volatile storage medium and internal memory. The non-volatile storage medium stores an operating system, computer programs, and model predictions. The internal memory provides an environment for the operation of the operating system and computer programs in the non-volatile storage medium. The model predictions of the computer device store static and dynamic information data. The network interface of the computer device is used to communicate with external terminals via a network connection. When the computer program is executed by the processor, it implements the steps in the above method embodiment.

[0067] Those skilled in the art will understand that the block diagrams are merely partial structural diagrams related to the present invention and do not constitute a limitation on the computer device to which the present invention is applied. Specific computer devices may include more or fewer components than those shown in the figures, or may combine certain components, or may have different component arrangements.

[0068] Corresponding to the above embodiments, this invention also provides a computer storage medium containing one or more program instructions. These one or more program instructions are used to execute the method described above.

[0069] The present invention also provides a computer program product, the computer program product including a computer program, the computer program being stored on a non-transitory computer-readable storage medium, and the computer being able to perform the above-described method when the computer program is executed by a processor.

[0070] In this embodiment of the invention, the processor can be an integrated circuit chip with signal processing capabilities. The processor can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components.

[0071] The various methods, steps, and logic diagrams disclosed in the embodiments of this invention can be implemented or executed. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this invention can be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software modules can reside in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The processor reads information from the storage medium and, in conjunction with its hardware, completes the steps of the above methods.

[0072] The storage medium can be memory, such as volatile memory or non-volatile memory, or may include both volatile and non-volatile memory.

[0073] Among them, non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory.

[0074] Volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDRSDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous linked dynamic random access memory (Synchlink DRAM, SLDRAM), and direct memory bus RAM (DRRAM).

[0075] The storage media described in the embodiments of the present invention are intended to include, but are not limited to, these and any other suitable types of memory.

[0076] Those skilled in the art will recognize that, in one or more of the examples above, the functions described in this invention can be implemented using a combination of hardware and software. When applied as software, the corresponding functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transmission of computer programs from one place to another. Storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0077] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made on the basis of the technical solution of the present invention should be included within the scope of protection of the present invention.

Claims

1. A self-healing control system for fan imbalance vibration faults in a turbofan engine, characterized in that, It includes an online monitoring and diagnostic system, an intelligent control system, and an unbalanced vibration self-healing control actuator, all connected in sequence; wherein: The online monitoring and diagnostic system is used to collect and analyze the vibration signals of the turbofan engine fan rotor in real time to determine the location of the imbalance fault. The intelligent control system is used to generate optimal control commands based on the diagnostic results of the online monitoring and diagnostic system, using a nonlinear active disturbance rejection control algorithm. The unbalanced vibration self-healing control actuator is installed on the fan rotor of the turbofan engine. It is used to receive control commands from the intelligent control system and perform physical actions to adjust the mass distribution of the fan rotor system in real time to achieve dynamic balance.

2. The self-healing control system for turbofan engine fan imbalance vibration fault according to claim 1, characterized in that, The online monitoring and diagnostic system comprises a signal acquisition layer, a data processing and feature extraction layer, and an intelligent diagnosis and decision-making layer; wherein: The signal acquisition layer arranges vibration sensors at key vibration measurement points in the engine casing to collect time-domain vibration data including speed signals in real time. The data processing and feature extraction layer preprocesses the collected vibration signals and then extracts the frequency vibration amplitude and phase synchronized with the rotor speed through fast Fourier transform, while monitoring the unbalanced vibration and its changing trend. The intelligent diagnosis and decision-making layer analyzes frequency characteristics through a built-in diagnostic algorithm. When the unbalanced vibration amplitude continuously exceeds the preset safety warning threshold and the phase characteristics are stable, it is determined to be a fan rotor imbalance fault and triggers the self-healing control process.

3. The self-healing control system for turbofan engine fan imbalance vibration fault according to claim 2, characterized in that, The installation location of the unbalanced vibration self-healing control actuator is: The connection point between the rear cone of the fan inlet rectifier cone and the fan disc; or, The connection point between the rear of the fan plate and the fan booster stage.

4. The self-healing control system for turbofan engine fan imbalance vibration fault according to claim 3, characterized in that, The unbalanced vibration self-healing control actuator includes an ultrasonic motor and two counterweights with equal balancing capacity. The ultrasonic motor is used to drive the counterweights to rotate a counterweight disk, and the mass distribution of the fan rotor is changed by adjusting the phase of the counterweight disk.

5. A self-healing control method for fan imbalance vibration fault in a turbofan engine, based on the control system described in any one of claims 1-4, characterized in that, The method includes: The initial vibration value of the fan rotor at the current moment is obtained by the vibration sensor, and the initial counterweight plate phase of the unbalanced vibration self-healing control actuator is also obtained. Change the phase of the counterweight plate and obtain the vibration value of the fan rotor and the phase of the counterweight plate of the actuator at the next moment; Based on the vibration values ​​collected twice and the phase of the counterweight plate, the influence coefficient and compensation vector of the fan rotor at the current moment are calculated, and the target phase of the counterweight plate is determined. The direction of movement of the counterweight plate is determined based on the optimal path method and the monotonically decreasing vibration amplitude algorithm. The rotation speed of the counterweight disk is optimized by a nonlinear active disturbance rejection controller. Control commands are generated based on the direction of movement and rotation speed. These control commands are used to drive the counterweight disk to move according to a preset strategy until the fan rotor achieves dynamic balance.

6. The method according to claim 5, characterized in that, Calculate the influence coefficient and compensation vector of the fan rotor at the current moment, and determine the target phase of the counterweight disk, specifically including: The initial vibration magnitude and phase of the fan rotor at the current moment are measured by the sensor. and , The corresponding initial imbalance magnitude and phase are respectively and , ; The counterweights A and B of the motor actuator have equal balancing capabilities and are both... The initial phases of the counterweight disk were measured to be as follows: and The equilibrium vectors corresponding to counterweight A and counterweight B are respectively and ; By changing the phase of the counterweight disk, the phases of counterweight A and counterweight B become respectively... and Then the equilibrium vectors corresponding to counterweight A and counterweight B are respectively and At this time, the unbalanced vibration vector is The influence coefficient is then expressed as: ； Given the influence coefficients, the initial imbalance vector is: ； To counteract this imbalance, a compensation vector of equal magnitude but opposite direction to the imbalance needs to be generated. ,Right now: ； in, Represents the compensation vector Corresponding phase; Target positions of counterweights A and B and They are respectively: 。 7. The method according to claim 5, characterized in that, Based on the optimal path method and the monotonically decreasing vibration amplitude algorithm, the direction of movement of the counterweight plate is determined, specifically including: The phase distance between each counterweight plate and the target phase is determined using the following formula: ； The phases with the smallest phase distances are used as the final phases of the counterweight plate using the following formula: 。 8. The method according to claim 5, characterized in that, The rotational speed of the counterweight disc is optimized using a nonlinear active disturbance rejection controller. Control commands are generated based on the direction of movement and rotational speed, specifically including: A nonlinear active disturbance rejection controller is constructed, consisting of a tracking-differentiator, an extended state observer, and a nonlinear state error feedback control law. The tracking-differentiator is expressed as follows: ； In the formula, This represents the input reference signal, which in this paper represents the desired rotational speed of the input counterweight disk; The state variable is 1, indicating that Smooth tracking signal; for The rate of change; This represents the output of a nonlinear function. fhan() express fhan function; h This indicates the sampling period, which is the time interval calculated by the controller; and These represent the velocity factor and the filter factor, respectively. The extended state observer is represented as: ； in, This is the actual output of the system. This is the estimate of the first state. This is the second state estimate. The value is the expansion state estimate, representing the disturbance encountered by the ultrasonic motor during rotation. For observation error, , and For observer gain, fal() Represents a nonlinear function. b To control the input gain, The width of the linear interval; The nonlinear state error feedback control law is expressed as: ； in, and To track the output of the differentiator, This represents the difference between the desired rotational speed and the estimated rotational speed. express The difference between the expected rate and the estimated rate corresponding to the rate of change; and These are the proportional and differential gains, respectively. and The nonlinearity parameter determines fal The degree of nonlinearity of the function; For synthesis control quantity; Finally, the control quantity is obtained: ； The magnitude and phase of the unbalance vector are compared with a set vibration threshold to determine whether to perform automatic balancing.

9. The method according to claim 8, characterized in that, The control commands specifically include: When the deviation between the current phase of the counterweight disk and the target phase is greater than the deviation threshold, the speed of the ultrasonic motor is increased so that the counterweight disk can quickly approach the target phase. When the deviation between the current phase of the counterweight disk and the target phase is less than the deviation threshold, the speed of the ultrasonic motor is reduced.

10. The method according to claim 5, characterized in that, Control commands are generated based on the direction of movement and rotation speed, and then include: The unbalance vector amplitude and phase of the fan rotor are detected in real time and compared with the set vibration threshold. If the unbalance vector amplitude still exceeds the vibration threshold, the adjustment steps are repeated until the vibration level of the fan rotor is restored to within the safe threshold.

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