A damper, system and optimization method for controlling aeroengine vibrations

Abstract

The application relates to a damper, a system and an optimization method for controlling aero-engine vibration, taking a piezoelectric ceramic actuator as a damper driver, combining the structural features, spatial layout and weight reduction requirements of an engine rotor support, adopting a disc type static friction plate mounting ring and rotor support structure fusion design, establishing an integrated configuration design technology of the damper and the aero-engine rotor support, while guaranteeing compact structure, not only overcoming the problem that the radial stiffness of the static friction plate of the existing piezoelectric folding type active elastic support dry friction damper is small and cannot be accurately designed, but also solving the engineering practical problems of the radial gap of the static friction plate installation, the friction debris between the dynamic and static friction plates cannot be discharged, the oil cannot enter, the friction plate anti-twist and amplitude limitation, and laying a foundation for further application of the damper.

Description

Technical Field

[0001] This invention pertains to active vibration control technology for aero-engines, and relates to a damper, system, and optimization method for controlling aero-engine vibration. In particular, it relates to a master-controlled spring-loaded dry friction damper structure and its control parameter optimization method for aero-engine vibration control, belonging to the field of active rotor vibration control. Background Technology

[0002] Rotor system vibration reduction is key to solving engine vibration problems. New-generation and future adaptive engines exhibit several modes in their rotor systems within their operating speed range. During operation, the rotor frequently crosses critical speeds, making it difficult to guarantee optimal vibration reduction for each mode using conventional passive damping mechanisms. This necessitates dampers that actively track the rotor's operating state and adaptively adjust parameters to ensure the most effective control of vibrations across multiple modes within the operating range.

[0003] Research on active control of rotor vibration has always been an important research direction for scholars both at home and abroad. Research on active vibration reduction technology mainly focuses on electromagnetic bearings, magnetorheological fluids, electrorheological fluids, shape memory alloys, and piezoelectric regulators. However, considering the structural characteristics of current and next-generation engine rotor support systems, the stringent requirements for engine weight and space layout, and control response issues, the above technologies are not yet applicable to the active control of engine rotor vibration. For example, the volume and mass of electromagnetic bearings, electrorheological fluids, and magnetorheological fluids, and the long heating and deformation time required for shape memory alloys, make it difficult to achieve active control of transient engine vibration. To address these issues, the Institute of Rotating Machinery and Wind Energy Device Measurement and Control at Northwestern Polytechnical University has proposed a novel rotor damping vibration reduction device based on dry friction energy dissipation using elastic supports—the elastic support dry friction damper. The paper "Integrated Configuration Design and Vibration Reduction Experiment of Main-Controlled Spindle Dry Friction Damper [J]. Propulsion Technology, 2023, 44(08): 187-196." (DOI: 10.13675 / j.cnki.tjjs.2203011.) points out the working principle of dry friction damper: When the rotor vibrates, the dynamic friction plate installed on the free end of the elastic support will move together with the free end of the elastic support, while the static friction plate remains relatively stationary. Thus, under the relative sliding action of the dynamic and static friction plates, the vibration energy of the rotor system is consumed. During the rotor operation, the additional stiffness and additional damping of the rotor can be changed simultaneously by controlling the positive pressure. It can adjust the critical speed and provide damping for vibration reduction. It has the advantages of high reliability and active control of dry friction, and has the characteristics of simple structure, fast response, wide applicability, and application in special environments such as vacuum and high and low temperatures. It has become the structural and technical basis for active control of rotor vibration of aero-engines. However, current research on master-controlled spring-loaded dry friction dampers mainly focuses on structural feasibility design and passive control of the constant pressure. There is little research on structural integration design considering operating conditions and stiffness, as well as control methods applicable to various operating conditions and parameter adjustments. In controllers already in use, operation is typically based on experience accumulated in practical work, resulting in less than ideal control effects or complex parameter adjustments. Therefore, establishing an integrated configuration design technology for the damper and the aero-engine rotor support, solving the problems of high radial stiffness and low axial stiffness required for damper vibration reduction, and selecting various parameters of the master-controlled spring-loaded dry friction damper control system have become important issues that need to be overcome in its application to aero-engine development. Summary of the Invention

[0004] Technical problems to be solved

[0005] To overcome the shortcomings of existing technologies, this invention proposes a damper, system, and optimization method for controlling the vibration of aero-engines. Addressing the limitations of existing active vibration reduction technologies applied to aero-engines, this invention first designs a master-controlled spring-loaded dry friction damper suitable for engine operating conditions. This damper provides normal pressure to alter the additional stiffness and damping. Simultaneously, to achieve active vibration control of the engine, this invention designs a particle swarm optimization algorithm that combines vibration reduction ratio, economy, and stability, tailored to the engine's operating characteristics. This algorithm can specifically optimize existing control parameters, thereby enabling active vibration control of the rotor and overcoming the limitations of existing master-controlled spring-loaded dry friction damper active control methods, making it applicable to various operating conditions.

[0006] One of the objectives of this invention is to provide a novel master-controlled elastic dry friction damper structure that integrates the damper with the engine's elastic support, achieving an integrated configuration design that ensures a compact structure. This solves problems such as adjustable axial stiffness design, debris removal and lubricating oil ingress, and friction plate fixing to prevent torsion, facilitating the addition of different types of actuators and the implementation of control methods.

[0007] The second objective of this invention is to provide a method for optimizing control parameters based on a master-controlled spring-loaded dry friction damper using a particle swarm optimization algorithm, which can be used to guide the parameter adjustment of the master-controlled spring-loaded dry friction damper for controlling the vibration of an aero-engine.

[0008] Technical solution

[0009] A damper for controlling the vibration of an aero-engine is characterized by a main-controlled spring-supported dry friction damper; it includes a dynamic friction plate 1, a mounting ring 3, a static friction plate 4, a piezoelectric ceramic actuator 5, and a damper mounting cylinder 6; the damper mounting cylinder 6 is connected to the engine load-bearing structure for load transfer; multiple piezoelectric ceramic actuators 5 are located inside the damper mounting cylinder 6; one end of the damper mounting cylinder 6 is connected to the mounting ring 3, the static friction plate 4 is connected to the mounting ring 3, and the dynamic friction plate 1 is bolted to one end of an elastic support 8, which undergoes relative sliding due to the vibration of the engine bearing and the elastic support 8 to achieve frictional vibration reduction and energy dissipation; the mounting ring is provided with a sealing structure.

[0010] The plurality of piezoelectric ceramic actuators 5 are evenly distributed circumferentially on the inner wall of the damper mounting cylinder 6.

[0011] The inner wall of the damper mounting cylinder 6 is provided with a plurality of grooves evenly distributed for placing the piezoelectric ceramic actuator 5.

[0012] The piezoelectric ceramic actuator 5 has a cylindrical structure.

[0013] The sealing structure uses a sealing ring 2.

[0014] The static friction pad is a disc-type static friction pad.

[0015] An application system for a damper used to control the vibration of an aero-engine is characterized in that: an engine bearing 9 is installed in an engine elastic support 8, the engine elastic support 8 is installed on an engine load-bearing frame 7 via a flange, and a damper mounting cylinder 6 is also installed on the engine load-bearing frame 7; the other end of the engine elastic support 8 is connected to the dynamic friction plate 1 of the damper via bolts; a sealing structure is provided between the engine elastic support and the damper mounting cylinder; the sealing structure uses a sealing ring.

[0016] A method for reducing rotor vibration using the aforementioned application system is characterized by: after the application system is connected, acquiring the speed increase amplitude-frequency curve of the engine rotor, and presetting the operating speed control range of the damper; when the rotor is running, the speed signal and vibration signal are input to the damper controller; when the speed approaches the control speed range of the damper or the vibration reference value, the damper starts to work; based on the rotor state feedback, the damper controller drives the piezoelectric ceramic actuator, which expands and extends to press against the static friction plate, thereby changing the friction force between the dynamic and static friction plates, providing friction damping for the rotor, thereby reducing the rotor vibration; outside the preset operating speed, or when the rotor vibration is below the vibration reference value, the damper will be in a standby state.

[0017] A parameter optimization method for an application system of a damper for controlling vibration of an aero-engine, characterized by the following steps:

[0018] Step 1: Set the rotor control reference object, damper combination, and vibration control target A. refer and control interval;

[0019] Step 2: Compare the rotor displacement amplitude A collected by the sensor with the control target A. refer By comparison, the error function e(t) is obtained;

[0020] The error function e(t) is fed into the control system in real time for PI initial calculation to obtain the signal output u(t):

[0021] Step 3: Use the particle swarm optimization algorithm to construct an optimization model for the PI control gain parameters. The control requirement is to minimize the optimized objective function within the constraints in order to achieve the ideal operating condition.

[0022] The damper is controlled based on the signal output u(t) obtained in step 2. The damper adjusts the normal force F, changes the friction force, and provides additional damping and additional stiffness, thereby controlling the rotor vibration.

[0023] The signal output u(t) = K P e(t)+K i(e(t)+e(t-1)+...e(1))

[0024] The normal pressure F and rotor vibration control results are input into the particle swarm optimization algorithm to find the optimal parameter K. P K i Using the obtained optimal parameter K P K i The optimal signal output u(t) is obtained;

[0025] When the positive pressure F exceeds the maximum positive pressure of the damper, only the maximum positive pressure is provided.

[0026] The objective function in step 3 is:

[0027] Fit=[c1f1+c2f2+c3f3+c4f4]4+f penalty

[0028]

[0029] Where Fit is the fitness function value, f penalty The penalty function value for not meeting the constraints, c is the weight value of the relevant parameters, λ is the normalization parameter, the first number of the subscript represents which evaluation parameter, and the second number represents which critical speed.

[0030] The fitness f1 is related to the vibration reduction ratio, where A is the amplitude at the rotor critical speed and the normalization parameter λ is the reciprocal of the peak value of the rotor critical speed amplitude.

[0031] The fitness f2 is related to the vibration reduction ratio, which is related to the speed range in which the rotor amplitude exceeds the reference target within the rotor control range. λ is taken as the reciprocal of the speed range in which the rotor amplitude exceeds the reference target within the control range.

[0032] The fitness f3 is related to economy, where F is the sum of the normal pressures within the critical speed of the damper, and λ is the reciprocal of the maximum sum of normal pressures.

[0033] The fitness f4 is related to stability, where P is the number of peak values ​​occurring in the rotor control range and λ is the reciprocal of the number of allowed peak fluctuations.

[0034] Beneficial effects

[0035] This invention proposes a damper, system, and optimization method for controlling the vibration of aero-engines. Using a piezoelectric ceramic actuator as the damper drive, and considering the structural characteristics, spatial layout, and weight reduction requirements of the engine rotor support, it employs a design that integrates the disc-type static friction plate mounting ring with the rotor support structure. This establishes an integrated configuration design technology for the damper and the aero-engine rotor support. While ensuring a compact structure, it not only overcomes the problem of low radial stiffness of the static friction plate in existing piezoelectric reciprocating active spring-loaded dry friction dampers, which makes precise design impossible, but also solves practical engineering problems such as radial clearance in the static friction plate mounting, inability to discharge friction debris and allow lubricating oil to enter between the moving and static friction plates, friction plate anti-torsion, and amplitude limitation. This lays the foundation for further applications of the damper.

[0036] To address the characteristics and requirements of a master-controlled spring-loaded dry friction damper applied to an engine, particle swarm optimization (PSO) is used for parameter selection in the damper's PI controller. The adopted PI controller structure is a closed-loop structure. The acquired engine rotor speed and amplitude are used as inputs to the damper control system. The proportional gain K of the damper's PI controller is then selected using the PSO algorithm. p Integral coefficient K i Optimize and adjust the positive pressure output of the damper to achieve active control and save parameter adjustment time.

[0037] This invention simplifies complex mechanical models to a one-dimensional plane and uses the particle swarm optimization algorithm to find the overall optimal control parameters, thereby achieving active control of rotor vibration, reducing rotor parameter adjustment time, and improving the efficiency and safety performance of the damper controller system.

[0038] This invention proactively divides the vibration control target, damper combination, and control range for targeted control, enabling control of sudden working conditions and reducing costs.

[0039] Compared to passive control, the active control method of this invention does not require additional hardware, thus avoiding a series of problems such as high system cost, performance degradation in system vibration suppression due to hardware aging, reliability, and maintenance. Therefore, the aforementioned active control structure and parameter optimization method is one of the effective designs for aero-engine rotor shaft systems, and can also be used for complex vibration suppression of rotor shaft systems in other large rotating machinery. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the damper structure of the present invention.

[0041] (a) Overall schematic diagram of the damper structure; (b) Schematic diagram of the piezoelectric ceramic installation location.

[0042] Figure 2 This is a schematic diagram of the low-pressure rotor of the engine of the present invention.

[0043] Figure 3 This invention relates to the method for determining the control interval.

[0044] Figure 4 This refers to the selection of the control target in this invention;

[0045] Figure 5 This is a flowchart of the active rotor vibration control method based on particle swarm optimization algorithm for damper PI controller according to the present invention.

[0046] Figure 6 This is a schematic diagram of the damper PI controller of the present invention;

[0047] Figure 7 This is a schematic diagram of the PI control law of the damper in this invention. Detailed Implementation

[0048] The present invention will now be further described in conjunction with the embodiments and accompanying drawings:

[0049] One objective of this invention is to provide a novel master-controlled elastic dry friction damper structure that integrates the damper with the engine's elastic support, achieving an integrated configuration design that ensures a compact structure. This solves problems such as adjustable axial stiffness design, debris removal and lubricating oil ingress, and friction plate fixing to prevent torsion, facilitating the addition of different types of actuators and the implementation of control methods.

[0050] The objective of this invention is achieved through the following technical solution:

[0051] The main-controlled elastic dry friction damper includes a dynamic friction plate, a sealing ring, a mounting ring, a static friction plate, a piezoelectric ceramic actuator, a damper mounting cylinder, an engine load-bearing frame, an engine elastic support, and an engine bearing. The dynamic friction plate is connected to the engine elastic support via bolts or other means to transmit vibration. The sealing ring prevents lubricating oil from entering the damper and affecting the friction effect. The mounting ring has an annular spoke structure for mounting the static friction plate and fixing it to prevent torsion. The piezoelectric ceramic actuator is an encapsulated product placed inside the mounting cylinder to provide the main control force. The damper mounting cylinder has an annular groove structure to support and protect the piezoelectric ceramic actuator. The engine elastic support is a folded-back integrated structure, with the engine bearing mounted on one side to transmit bearing vibration, and connected to the engine load-bearing frame on the other side.

[0052] Application systems of dampers for controlling vibrations in aircraft engines:

[0053] The engine bearing 9 is installed in the engine elastic support 8, which is mounted on the engine load-bearing frame 7 via a flange. The piezoelectric ceramic actuator 5 is installed in the damper mounting sleeve 6, which is also mounted on the engine load-bearing frame 7. The static friction plate 4 is connected to the mounting ring 3, which in turn is connected to the damper mounting sleeve 6. The sealing ring 2 is installed in the mounting ring 3, and the dynamic friction plate 1 is bolted to one end of the engine elastic support 8.

[0054] like Figure 1 As shown, the main-controlled elastic dry friction damper includes a dynamic friction plate, a sealing ring, a mounting ring, a static friction plate, a piezoelectric ceramic actuator, a damper mounting cylinder, an engine load-bearing frame, an engine elastic support, and an engine bearing. The engine bearing 9 is installed in the engine elastic support 8, which is mounted on the engine load-bearing frame 7 via a flange. The piezoelectric ceramic actuator 5 is installed in the damper mounting cylinder 6, which is also mounted on the engine load-bearing frame 7. The static friction plate 4 is connected to the mounting ring 3, which in turn is connected to the damper mounting cylinder 6. The sealing ring 2 is installed in the mounting ring 3, and the dynamic friction plate 1 is bolted to one end of the engine elastic support 8.

[0055] (1) Damper dynamic friction plate 1

[0056] The dynamic friction plate is a ring-shaped structure that is bolted to the spring support. When vibration occurs, it is first transmitted to the spring support and the dynamic friction plate through the engine bearing, so that the dynamic and static friction plates can slide relative to each other to reduce friction and dissipate energy.

[0057] (2) Damper sealing ring 2

[0058] The damper has two sealing rings, one located inside the mounting ring and the other between the engine elastic support and the damper mounting sleeve. The stiffness of the sealing rings is much less than that of the elastic support, ensuring that no gaps appear between the dynamic friction plates at their maximum precession radius. The sealing rings create a closed environment inside the damper, preventing lubricating oil from entering and ensuring dry friction characteristics between the dynamic and static friction plates. They also prevent wear debris from scattering and contaminating the engine lubricating oil.

[0059] (3) Damper mounting ring 3

[0060] The damper's mounting ring comprises a static friction plate mounting ring and a sealing ring mounting ring, which are integrated into one piece via an axial transition design to improve strength and avoid stress concentration. The radial clearance between the mounting ring's ring structure and the dynamic friction plate can be designed to function as a limiter, restricting excessive rotor vibration. Specifically, the radial and axial stiffness can be varied by adjusting the mounting ring's thickness, rib width, rib length, and number of ribs, resulting in zero radial clearance for the damper's static friction plate, with radial stiffness significantly greater than the spring support stiffness and axial stiffness significantly less than the spring support stiffness. Under the axial force of the actuator, this allows for minute axial displacement. The mounting ring solves the problems of high radial stiffness and low axial stiffness required for damper vibration reduction, and the difficulty in precisely designing the mounting stiffness of the static friction plate due to its need for minute axial displacement.

[0061] (4) Damper static friction plate 4

[0062] The static friction plate is an annular plate structure with the same inner and outer diameters as the dynamic friction plate. There are several regularly arranged circular holes between the inner and outer diameters of the static friction plate to discharge friction debris between the dynamic and static friction plates, thereby ensuring sliding friction between them.

[0063] (5) Damper piezoelectric ceramic actuator 5

[0064] The piezoelectric ceramic actuator of the damper has a cylindrical structure, and its main components include: a moving end (hemispherical head rod), a stainless steel shell, a piezoelectric ceramic plate, and an anti-torsional structure. The piezoelectric ceramic actuator exhibits electrostrictive effect, providing positive pressure to the friction pair. The magnitude of this positive pressure is related to the control voltage of the piezoelectric ceramic actuator; by controlling the voltage, the magnitude of the positive pressure in the friction pair can be changed. Three piezoelectric ceramic actuators are evenly distributed circumferentially, allowing the stationary friction plate to move parallel to the circumference while ensuring that the positive pressure is uniformly applied between the moving and stationary friction plates. For redundancy, six piezoelectric ceramic actuators can be designed.

[0065] (6) Damper actuator mounting sleeve 6

[0066] The actuator mounting cylinder mainly houses the piezoelectric ceramic actuator and has a transition fit with it. The actuator mounting cylinder is connected to the mounting ring and the engine load-bearing structure to facilitate load transfer.

[0067] (7) Engine elastic support

[0068] The elastic support is a component of the engine and can be used for vibration transmission and critical speed regulation.

[0069] When maintaining the damper, first disassemble the dynamic friction plate 1, then disassemble the damper unit (i.e., disassemble the damper mounting sleeve 6). After maintenance, reassemble it into the engine load-bearing frame 7. When the engine vibrates, the dynamic friction plate 1 moves with the vibration of the spring support 8. Due to the small axial stiffness of the disc-type mounting ring 3, the static friction plate 4 moves slightly along the axial direction under the axial force of the piezoelectric ceramic actuator 5, realizing the controllability of the normal pressure between the dynamic and static friction plates, thereby achieving active control of rotor vibration.

[0070] Working process and vibration reduction principle:

[0071] After the damper is assembled, the damper can be debugged to obtain the speed increase amplitude-frequency curve of the engine rotor and preset the operating speed control range of the damper.

[0072] When the rotor is running, speed and vibration signals are input to the damper's controller. When the speed approaches the damper's control speed range or vibration reference value, the damper begins to operate. At this time, based on rotor state feedback, the damper controller drives the piezoelectric ceramic actuator, which expands and extends, pressing against the stationary friction plate, thereby changing the frictional force between the moving and stationary friction plates and providing frictional damping for the rotor, thus reducing rotor vibration. Outside the preset operating speed, or when the rotor vibration is below the vibration reference value, the damper will be in a standby state.

[0073] In summary, based on piezoelectric ceramic actuators, this paper integrates the damper with the engine's elastic support design, achieving an integrated configuration design of the damper and the engine rotor support. This not only overcomes the problem of the small radial stiffness of the static friction plate in existing piezoelectric reciprocating active elastic dry friction dampers, which makes precise design impossible, but also solves practical engineering problems such as radial clearance in the static friction plate installation, inability to discharge friction debris and lubricating oil between the dynamic and static friction plates, friction plate anti-torsion, and amplitude limitation. This lays the foundation for the further application of dampers in engines.

[0074] The second objective of this invention is to provide a method for optimizing control parameters based on a master-controlled spring-loaded dry friction damper using a particle swarm optimization algorithm, which can be used to guide the parameter adjustment of the master-controlled spring-loaded dry friction damper for controlling the vibration of aero-engines.

[0075] This invention is based on Figure 1 The method for optimizing control parameters of the master-controlled spring-loaded dry friction damper shown is based on the particle swarm optimization algorithm. The optimization process of the control parameters of the master-controlled spring-loaded dry friction damper is as follows, using a low-pressure rotor test device similar to a certain type of engine as a basis.

[0076] Step 1: Set the rotor control reference object, damper combination, and vibration control target A. refer and control interval;

[0077] The main control parameters for vibration control include the control reference object, control area, damper combination, and control target. These four are interconnected and influence each other. There are no fixed requirements for their selection. They need to be planned in a comprehensive manner in combination with rotor dynamic characteristics and rotor design criteria.

[0078] The rotor control reference object refers to the measuring point used to evaluate the overall vibration level of the rotor during operation and to provide feedback for active control. The selection of the rotor vibration control reference object needs to be based on the rotor dynamic characteristics; one or more can be selected. Furthermore, since the mode shapes and dynamic characteristics of the rotor differ under different modes, different reference objects will be selected for different modes. If one control reference object is selected, the sensor type and spatial location must be considered, generally selecting the node with the largest amplitude at each critical level. If multiple control reference objects are selected, the mode shape and damper combination should be comprehensively considered during selection. The rotor damper combination is determined based on the rotor dynamic characteristics and damper characteristics, using different combinations of dampers for each mode. For low-pressure rotors, a single-point, five-point, or one-five-point combination can be used. The rotor vibration control target is the allowable vibration amplitude A set according to the rotor safety operation criteria. refer The rotor control range is generally designed based on the reference critical speed margin design criterion, and modified in conjunction with the rotor vibration control target, where A refer The goal is to control vibration.

[0079] Step 2: Obtain the actual rotor speed measured by the photoelectric sensor, and record it as the current speed ω; obtain the actual rotor amplitude A measured by the displacement sensor; compare the current amplitude A with the control target A. refer In comparison, the difference e(t) is used as the input to the PI controller;

[0080] Furthermore, specifically including

[0081] The rotor operating speed ω collected by the photoelectric sensor is compared with the control range. If it is within the speed control range, the rotor displacement amplitude A collected by the sensor during operation is compared with the control target A. refer By comparison, the error function e(t) is obtained;

[0082] The error function e(t) is fed into the control system in real time for PI initial calculation to obtain the signal output u(t). The further output is u(t) = K. P e(t)+K i (e(t)+e(t-1)+...e(1))

[0083] If the speed is not within the speed control range, the controller will not perform calculations.

[0084] Step 3: Use the particle swarm optimization algorithm to construct an optimization model for the PI control gain parameters. The control requirement is to minimize the optimized objective function within the constraints to achieve the ideal operating condition.

[0085] Furthermore, specifically including

[0086] The damper is controlled based on the signal output u(t) obtained in step two. The damper adjusts the normal force F, changes the friction force, and provides additional damping and additional stiffness, thereby controlling the rotor vibration.

[0087] The normal pressure F and rotor vibration control results are input into the particle swarm optimization algorithm to optimize the parameter K. p K i Then use the obtained optimal parameter K p K i A damper controller was developed to guide simulation calculations and real tests. By changing the positive pressure F output by the damper, the rotor system was actively controlled to suppress the vibration of the rotor system.

[0088] Furthermore, when the positive pressure F exceeds the damper's maximum positive pressure, only the maximum positive pressure is provided.

[0089] Furthermore, for the current rotor experimental apparatus, since the dynamic characteristics of each mode of the rotor are different, the required normal pressure F and combination of the rotor under each mode are quite different. Therefore, it is more appropriate to use different proportional-integral coefficients for vibration control at different critical speeds.

[0090] Furthermore, the objective function in step 3 is:

[0091] Fit=[c1f1+c2f2+c3f3+c4f4]4+f penalty

[0092]

[0093] Where Fit is the fitness function value, f penalty The penalty function value is the value of the penalty function for not meeting the constraints. c is the weight value of the relevant parameters, and the specific value is selected according to the focus. λ is the normalization parameter. The first number of the subscript represents which evaluation parameter and the second number represents which critical speed.

[0094] 1) The fitness f1 is related to the vibration reduction ratio, where A is the amplitude at the rotor critical speed and the normalization parameter λ is the reciprocal of the peak value of the rotor critical speed amplitude;

[0095] 2) The fitness f2 is related to the vibration reduction ratio, which is related to the speed range in which the rotor amplitude exceeds the reference target within the rotor control range. λ is taken as the reciprocal of the speed range in which the rotor amplitude exceeds the reference target within the control range.

[0096] 3) The fitness f3 is related to economy, where F is the sum of the normal pressures within the critical speed range of the damper, and λ is the reciprocal of the maximum sum of normal pressures;

[0097] 4) The fitness f4 is related to stability, where P is the number of peaks that occur in the rotor control range and λ is the reciprocal of the number of allowed peak fluctuations.

[0098] Figure 2 This is a schematic diagram of the engine's low-pressure rotor. The low-pressure rotor system includes a low-pressure fan disc, a low-pressure turbine disc, a low-pressure rotor shaft, a first elastic support, a second rigid support, and a fifth elastic support. Main-controlled dry friction dampers are installed at support points 1 and 5. Different damper combinations are activated for active vibration reduction control based on the rotor's different modes.

[0099] Figure 3 This diagram illustrates the method for determining the control range. The horizontal axis represents the rotor speed ω, and the vertical axis represents the rotor amplitude A. The control range refers to the dangerous speed area near the critical speed, requiring vibration control, and provides the controller with crucial control judgment criteria. By monitoring whether the rotor speed ω is within the control range, the controller determines whether to control the rotor and then sends an open or closed signal to the main-controlled spring-loaded dry friction damper. For rotor control under normal operating conditions, the control range is set with reference to the critical speed margin design criteria, designing the control range near the rotor's critical speed while comprehensively considering the control reference target.

[0100] Figure 4 This diagram illustrates the selection of the control target. The horizontal axis represents the rotor speed ω, and the vertical axis represents the rotor amplitude A. The control target A... refer This refers to the control standard set based on the rotor operating amplitude safety standard. Control objective A refer The reference target is typically selected as the rotor unbalance response value at the endpoint of the control region. However, if the control target is too small, far below the amplitude safety limit standard, this control target design is meaningless, and the control region needs to be readjusted and a new control target selected based on the rotor dynamics characteristics. Furthermore, to retain a certain safety margin, the actual reference target should be selected slightly lower than the control target. In actual operation, feedback control generally uses the reference target as the research object to characterize the overall rotor vibration level. Based on its vibration, feedback is given to the controller, which then drives the damper to output a positive pressure F for vibration reduction.

[0101] Figure 5 This is a flowchart of an active rotor vibration control method based on particle swarm optimization (PSO) algorithm to optimize the PI controller of the damper. To facilitate the implementation of a master-controlled spring-loaded dry friction damper, this invention first designs, based on rotor dynamics characteristics, damper working principle, and control parameters, as follows: Figure 5The control flow shown below has the following specific implementation steps:

[0102] (1) The rotor system is modeled and modal calculations are performed using the finite element method to obtain the rotor mode shape, critical speed and other related rotor dynamic characteristics.

[0103] (2) Determine the damper combination and the reference object for each critical speed under different modes.

[0104] (3) Determine the control region, control object, and control objective A for different modes by combining rotor imbalance response iteration. refer .

[0105] (4) Particle Swarm Optimization PI Parameters

[0106] Figure 6 This is a schematic diagram of a PI controller for a damper. The system for active vibration control based on a particle swarm optimization (PSO) algorithm for PI control includes: a damper system, a monitoring system, a control system, and a rotor system. The monitoring system first monitors the rotor's rotational speed and amplitude, inputting these values ​​into the control system. The control system outputs a signal to control the piezoelectric ceramic actuator of the damper system to provide a positive pressure F.

[0107] The input parameters collected in step 3 are compared with the set parameter values. If they are within the control range, the error function e(t) is input into the damper control system for PI initial calculation to obtain u(t). u(t) is input into the damper system to output the positive pressure F. The positive pressure F acts on the rotor system to obtain the control result. Then, the control result is input in reverse into the particle swarm optimization algorithm to find the optimal parameter K. p K i Then use the obtained optimal parameter K p K i A controller is created to guide real experiments or simulation calculations, changing the positive pressure F output by the damper to actively control the rotor system and suppress its vibration.

[0108] Figure 7 This is a schematic diagram of the PI control law for the damper. When the rotor speed is within the control range, it is first determined whether the rotor amplitude exceeds the reference target. If the rotor amplitude is higher than the reference target, the positive pressure F is output according to control law one; if the rotor amplitude is lower than the reference target, the positive pressure F is output according to control law two. Then, the positive pressure F is substituted into the calculation of the rotor amplitude.

[0109] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A method of parameter optimization of an application system of a damper for controlling vibrations of an aeroengine, characterized in that The structure is a main-controlled spring-supported dry friction damper. It includes a dynamic friction plate (1), a mounting ring (3), a static friction plate (4), a piezoelectric ceramic actuator (5), and a damper mounting cylinder (6); the damper mounting cylinder (6) is connected to the engine load-bearing structure for load transfer; multiple piezoelectric ceramic actuators (5) are located inside the damper mounting cylinder (6); one end of the damper mounting cylinder (6) is connected to the mounting ring (3), the static friction plate (4) is connected to the mounting ring (3), and the dynamic friction plate (1) is bolted to one end of the elastic support (8), and undergoes relative sliding due to the vibration of the engine bearing and the elastic support (8) to reduce friction and dissipate energy; the mounting ring is provided with a sealing structure; An engine bearing (9) is installed in an engine elastic support (8), which is mounted on an engine load-bearing frame (7) via a flange. A damper mounting sleeve (6) is also installed on the engine load-bearing frame (7). The other end of the engine elastic support (8) is connected to the dynamic friction plate (1) of the damper via bolts. A sealing structure is provided between the engine elastic support and the damper mounting sleeve. The sealing structure uses a sealing ring. Application system parameter optimization methods: Step 1: Set the rotor control reference object, damper combination, and vibration control target. and control interval; Step 2: Obtain the actual rotor speed measured by the photoelectric sensor and record it as the current speed. The rotor operating speed collected by the photoelectric sensor The sensor is used to determine the rotor displacement amplitude during operation. If the rotor is within the speed control range, the sensor will collect the displacement amplitude during the rotor's operation. With control objectives By comparison, the error function is obtained. ; Error function The real-time input control system performs PI initial calculations to obtain the signal output. : The signal output Step 3: Use the particle swarm optimization algorithm to construct an optimization model for the PI control gain parameters. The control requirement is to minimize the optimized objective function within the constraints in order to achieve the ideal operating condition. Output the signal obtained in step 2 Control the damper and adjust the normal pressure of the damper. By changing the frictional force, additional damping and additional stiffness are provided, thereby controlling rotor vibration; positive pressure The rotor vibration control results are input into the particle swarm optimization algorithm to find the optimal parameters globally. , Using the obtained optimal parameters , Obtain the optimal signal output This, in turn, controls the piezoelectric ceramic actuator to provide positive pressure; The positive pressure When the damper's maximum normal pressure is exceeded, only the maximum normal pressure is provided; The objective function in step 3 is: Where, in the formula For the fitness function value, Here, c represents the penalty function value for not meeting the constraints, and c represents the weight values ​​of the relevant parameters. For normalized parameters, the first number in the subscript represents which evaluation parameter, and the second number represents which critical speed. The fitness f 1 is related to the vibration reduction ratio, where The amplitude at the rotor's critical speed, normalized parameter It is the reciprocal of the peak value of the rotor's critical speed amplitude; The fitness f 2 is related to the vibration reduction ratio, where N is the speed range within the rotor control range where the rotor amplitude exceeds the reference target, taken as... It is the reciprocal of the speed range in which the rotor amplitude exceeds the reference target within the control range; The fitness f 3. Related to economic efficiency, among which The sum of the normal pressures within the critical speed range of the damper is taken as... It is the reciprocal of the sum of the maximum normal forces; The fitness f 4 is related to stability, among which This represents the number of peak values ​​occurring within the rotor control range. It is the reciprocal of the allowed number of peak fluctuations.

2. The parameter optimization method for the application system of the damper for controlling the vibration of an aero-engine according to claim 1, characterized in that: The plurality of piezoelectric ceramic actuators (5) are evenly distributed circumferentially on the inner wall of the damper mounting cylinder (6) inside the damper mounting cylinder (6).

3. The parameter optimization method for the application system of the damper for controlling the vibration of an aero-engine according to claim 1, characterized in that: The inner wall of the damper mounting cylinder (6) is provided with a plurality of grooves evenly distributed for placing the piezoelectric ceramic actuator (5).

4. The parameter optimization method for the application system of the damper for controlling the vibration of an aero-engine according to claim 1, characterized in that: The piezoelectric ceramic actuator (5) has a cylindrical structure.

5. The parameter optimization method for the application system of the damper for controlling the vibration of an aero-engine according to claim 1, characterized in that: The sealing structure uses a sealing ring (2).

6. The parameter optimization method for the application system of the damper for controlling the vibration of an aero-engine according to claim 1, characterized in that: The static friction pad is a disc-type static friction pad.

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