Diagnostic method and diagnostic system for servo actuation circuit, readable medium, and gas turbine engine

Abstract

The invention relates to a diagnostic method and diagnostic system of a servo actuation loop, a readable medium, a gas turbine engine and a test system. The diagnosis method comprises the following steps: S1, receiving position feedback and position expectation of a servo actuation loop; s2, obtaining a real-time error between the position feedback and the position expectation according to the S1; according to the position expectation obtained in the step S1, response types corresponding to different time stages from the first time stage to the Nth time stage of the actuating loop are obtained; and S3, according to the real-time errors obtained in the S2 and the response types corresponding to the different time stages, whether the real-time errors of the servo loop in the different time stages meet the error requirements corresponding to the corresponding response types or not is judged.

Description

Technical Field

[0001] The invention relates to a diagnostic method, a diagnostic system, a readable medium and a gas turbine engine for a servo actuation circuit. Background Art

[0002] Gas turbine engines, such as civil aviation engine fuel systems, implement actuation control of multiple servo actuators, such as high-pressure compressor stator adjustable blade actuation, boost stage rear adjustable bleed valve actuation, transient bleed valve actuation, start-up anti-surge valve actuation, etc. The actuation control of such adjustable mechanisms often gives the desired position instruction for the adjustable mechanism actuation based on the working state of the engine, and then the fuel system drives the actuator to complete the actuation by adjusting the servo fuel flow and pressure, and the actuator feeds back the actual position signal of the actuator in real time to complete the servo actuation closed-loop control. The dynamic follow-up between the desired position and the actual feedback position of the servo actuation often represents the dynamic characteristics of such servo actuators. Therefore, accurate and reasonable diagnosis of the dynamic response characteristics of various servo actuators is an important reference for diagnosing the design indicators of various servo actuator circuits in the engine fuel system.

[0003] In existing solutions, the method of diagnosing the servo actuation circuit is generally based on the traditional automatic control principle judgment method, that is, from the response of typical input signals, such as step signals, ramp signals, and steady-state signals, diagnosis is performed based on rise time, overshoot, steady-state error, etc. Figure 1 As shown, the typical unit step response dynamic performance index is defined as Figure 1 The following condition of this type of typical input signal can be evaluated based on the rise time tr, adjustment time ts, overshoot σ% and steady-state error e.

[0004] However, the inventors have found that in the fuel system servo actuation loop control of a gas turbine engine, if Figure 2 As shown in the figure, the change of the servo actuation expected command often does not show typical step and ramp signal characteristics. The servo actuation loop position expectation changes with the engine state at all times, and the rate range of the position expectation change is very large, such as Figure 3 As shown, the range of real-time following error formed with the actual feedback position is also very large. Therefore, if the above-mentioned existing scheme adopts the traditional diagnostic method based on the actual position feedback to the expected following situation, it is often difficult to accurately describe the following situation of the servo actuator loop feedback position to the expected position, and the traditional dynamic performance indicators are mixed with many subjective factors, such as the reasonable definition of the steady-state error band. In the actual servo actuator control, there is often a situation where the judgment standard is adjusted according to the main assessment factors, and it is difficult to use a clear logical language for evaluation and diagnosis, and it is difficult to accurately reflect the compliance of the servo actuator loop design indicators.

[0005] Therefore, there is a need in the art for a more accurate and reliable diagnostic method to accurately diagnose the dynamic characteristics of the servo actuation loop, thereby making the closed-loop control of the fuel system of the gas turbine engine more precise and optimizing emission performance and / or economy. Summary of the invention

[0006] An object of the present invention is to provide a method for diagnosing a servo actuation circuit.

[0007] An object of the present invention is to provide a computer readable medium.

[0008] An object of the present invention is to provide a diagnostic system for a servo actuation circuit.

[0009] An object of the present invention is to provide a gas turbine engine.

[0010] An object of the present invention is to provide a test system for a gas turbine engine.

[0011] A diagnostic method for a servo actuation circuit according to the first aspect of the present invention comprises S1. receiving position feedback and position expectation of a servo actuation circuit; S2. obtaining a real-time error between the position feedback and the position expectation according to S1; obtaining a response type corresponding to different time stages from a first time stage to an Nth time stage according to the position expectation obtained by S1; and S3. judging whether the real-time errors of the servo circuit at different time stages satisfy the error requirements corresponding to the corresponding response types according to the response types corresponding to the different time stages according to the real-time error obtained by S2.

[0012] The diagnostic method introduced in the above embodiment identifies the response characteristics at different time stages, that is, obtains the expected rate of change of position according to the expected position of the servo loop, converts it into the expected position change angle, and defines the servo loop dynamic characteristic index by segmentation according to the angle range, thereby evaluating and diagnosing the dynamic response characteristics of the servo actuation loop of the fuel system. Compared with the existing methods, the diagnostic method can accurately diagnose servo actuation loops containing atypical response characteristics, especially for the fuel system of the gas turbine engine, and can provide accurate and reliable diagnostic results.

[0013] In one or more embodiments, in S2, the step of expecting a corresponding response type according to the location includes:

[0014] Define the expected rate of change of position:

[0015]

[0016] Among them, the unit of the operation cycle is s; the expected position change angle is defined as A, and the relationship between the change angle A and its corresponding expected position change rate is: expected position change angle = arctan (expected position change rate); according to different expected change angles, the response type is a step response, a ramp response or a steady-state response.

[0017] In one or more embodiments, in S3, if the response type corresponding to the time stage is a step response, the diagnostic parameter is the adjustment time; if the response type corresponding to the time stage is a ramp response, the diagnostic parameters are the maximum following error and the adjustment time; if the response type corresponding to the time stage is a steady-state response, the diagnostic parameters are the maximum following error and the adjustment time.

[0018] In one or more embodiments, in S3, if in adjacent time stages, the response type of the latter time stage is different from the response type of the previous time stage, but is still within the adjustment time corresponding to the response type of the previous time stage, the requirement for following the error is diagnosed according to the response type of the previous time stage.

[0019] A computer readable medium according to a second aspect of the present invention has a computer program thereon, and the program is executed by a processor to implement the steps of the diagnostic method as described in the first aspect.

[0020] According to a third aspect of the present invention, a diagnostic system for a servo actuation circuit comprises: a memory for storing instructions executable by a processor; and a processor for executing the instructions to implement the steps of the diagnostic method as described in the first aspect.

[0021] In one or more embodiments, the diagnostic system is connected to a display module for displaying the diagnostic result of the engine servo actuation circuit determined by the processor.

[0022] In one or more embodiments, the processor and / or memory are integrated into a full authority digital engine controller.

[0023] According to a fourth aspect of the present invention, a gas turbine engine has a servo actuation circuit, and during the operation of the gas turbine engine, the diagnostic method as described in the first aspect is executed; or, the gas turbine engine also includes a diagnostic system as described in the third aspect.

[0024] According to a gas turbine engine test system of a fifth aspect of the present invention, during a test of the gas turbine engine, the diagnostic method as described in the first aspect is executed. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0026] Figure 1 It is a schematic diagram of the dynamic performance of a typical unit step response;

[0027] Figure 2 It is a graph of position expectation and position feedback of a typical fuel system servo actuation loop;

[0028] Figure 3 is based on Figure 2 A graph showing the desired position and the following error of the position feedback;

[0029] Figure 4 is a flow chart of a method for diagnosing a servo actuation circuit according to an embodiment;

[0030] Figure 5 is a graph of a following error and a desired position change angle of a servo actuation loop of an embodiment;

[0031] Figure 6 It is a schematic block diagram of the structure of a diagnostic system for a servo actuation circuit according to an embodiment. DETAILED DESCRIPTION

[0032] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0033] At the same time, the present application uses specific words to describe the embodiments of the present application. The reference to "embodiment" herein means that the specific features, structures or characteristics described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0034] It is understood that flow charts are used in the present application to illustrate the operations performed by the system according to the embodiments of the present application. It should be understood that, according to the actual situation, the previous or following operations are not necessarily performed precisely in order. Other operations may also be added to these processes, or one or more operations may be removed from these processes.

[0035] It should be noted that in the following embodiments, the gas turbine engine described in the following embodiments takes an aircraft and its turbofan engine as an example, but is not limited thereto. For example, ships and their gas turbine engines, and ground gas turbines can also be used to apply the diagnostic method of the servo actuation circuit described in the following embodiments. The servo actuation circuit takes the servo actuation circuit of the fuel system of the gas turbine engine as an example to achieve closed-loop control of the fuel system, but is not limited thereto. Any scenario that requires accurate and reliable diagnosis of the servo actuation circuit can use the technical solution described in the following embodiments.

[0036] refer to Figure 4 As shown, in some embodiments, the diagnosis method of the servo actuation circuit may include the following steps:

[0037] S1. Receive position feedback and position expectation of servo actuation loop;

[0038] S2. According to S1, the real-time error between the position feedback and the desired position is obtained;

[0039] According to the position expectation obtained by S1, the response types corresponding to the different time stages of the actuation circuit from the first time stage to the Nth time stage are obtained;

[0040] S3. Based on the real-time error obtained in S2 and the response types corresponding to the different time stages, determine whether the real-time errors of the servo loop in different time stages all meet the error requirements corresponding to the corresponding response types.

[0041] In S1, the position feedback and position expectation data of the servo actuation loop are received, for example, Figure 2 As shown, time is the horizontal axis and the vertical axis represents the form of position feedback and position expectation.

[0042] In S2, according to S1, the real-time error between the position feedback and the expected position is obtained, which can be Figure 3 As shown, the horizontal axis is time, and the vertical axis is position feedback and position expectation, as well as the percentage of position feedback and position expectation.

[0043] For the judgment of response type, such as Figure 4 As shown, in some embodiments, the step of expecting a corresponding response type according to the position includes:

[0044] Define the expected rate of change of position:

[0045]

[0046] The unit of operation cycle is s;

[0047] Define the expected position change angle as A, then the relationship between the change angle A and its corresponding expected position change rate is:

[0048] Expected position change angle = arctan (expected position change rate);

[0049] Depending on the desired change angle, the response type may be a step response, a ramp response or a steady-state response.

[0050] According to the operation cycle determined by the system and the possible expected position change rate, the expected position change angle range can be obtained, which should be between [0,90°).

[0051] Specifically, take the operation cycle ΔT as 15ms, that is, 0.015s as an example:

[0052] If the expected position change accounts for more than 5% of the full stroke, that is, arctan (5% / 0.015) < A, that is, 73° < A < 90°, the system response type is a step response;

[0053] If the expected position change accounts for more than 2% and less than 5% of the full stroke, that is, arctan (2% / 0.015)<A≤arctan (5% / 0.015), that is, 53°<A≤73°, the system response type is ramp response;

[0054] If the expected position change is less than 2% of the full stroke, A≤arctan(2% / 0.015), that is, 0≤A≤53°, the system response type is a steady-state response.

[0055] Different servo loop dynamic following characteristics can be defined according to different angle ranges. For example, as introduced above, when the expected position change angle is 73°<A<90°, the expected change is regarded as a step signal, and the adjustment time requirements are clarified according to the dynamic indicators of the step response, and the maximum following error is not evaluated within the adjustment time range, that is, there is no need to use the maximum following error as a diagnostic parameter, only record it; when the expected position change angle is 53°<A≤73° (this angle should be determined according to the expected position slope requirement allowed by the servo actuator system), the expected change is regarded as a ramp signal, and the maximum following error requirements and adjustment time requirements are clarified according to the dynamic indicators of the ramp response; when the expected position change angle is 0≤A≤53° (this angle should be determined according to the expected steady-state error requirement allowed by the servo actuator system), the expected change is regarded as a steady-state signal, and the maximum following error requirements and adjustment time requirements are clarified according to the dynamic indicators of the steady-state response. For example, corresponding to Figure 2 , Figure 3 In the figure, the horizontal axis 0s-1.5s is the steady-state response stage, while the stage from 1.5s to 5s can be regarded as the step response stage. Figure 5The diagnosis shown is performed according to the expected change angle of the position, which can intuitively reflect the relationship between the angle and the following error.

[0056] As can be seen from the above, if the response type corresponding to the time stage is a step response, the diagnostic parameter is the adjustment time; if the response type corresponding to the time stage is a ramp response, the diagnostic parameters are the maximum following error and the adjustment time; if the response type corresponding to the time stage is a steady-state response, the diagnostic parameters are the maximum following error and the adjustment time.

[0057] In addition, in some embodiments, if in adjacent time stages, the response type of the latter time stage is different from the response type of the previous time stage, but is still within the adjustment time corresponding to the response type of the previous time stage, the requirement for the following error is diagnosed according to the response type of the previous time stage. That is, if after the position expectation changes according to the step signal, within the adjustment time requirement of the step response, the actual position is still in the process of the response expectation at all times, if at this time the position expectation continues to change, and no longer changes according to the step signal, but changes according to the steady-state signal, then the following error should still be evaluated according to the previous step response within the adjustment time of the step signal.

[0058] In S3, for example, the reference Figure 5 As shown, it can be seen that the following error of the steady-state response under normal circumstances is within 2%. If during the diagnosis process, the response type corresponding to a certain time period is a steady-state response, and the following error is greater than 2%, then it is judged that the servo actuation circuit is faulty, or it is used as a fault precursor signal for further diagnosis.

[0059] The beneficial effect of the above embodiment lies in that, by identifying the response characteristics at different time stages, that is, obtaining the normalized amount of position expectation change according to the servo loop position expectation, converting it into the expected position change angle, and defining the servo loop dynamic characteristic index in segments according to the angle range, and then evaluating and diagnosing the dynamic response characteristics of the servo actuation loop of the fuel system, the diagnostic method can accurately diagnose the servo actuation loop containing atypical response characteristics compared to the existing methods, especially for the fuel system of the gas turbine engine, which can provide accurate and reliable diagnostic results.

[0060] It can be understood that the diagnostic method introduced in the above embodiment is described from the perspective of post-test data analysis for ease of understanding. It is an analysis performed on complete experimental data. Since there is a premise of known complete data, it is similar to an offline diagnosis. The data analysis can be manual statistical analysis or scripts written in programming languages ​​such as VBA and Python to automatically process data. However, it can be understood that the diagnostic method introduced in the above embodiment can also perform online servo actuation circuit diagnosis.

[0061] As mentioned above, please refer to Figure 6 As shown, in some embodiments, the present application also provides a diagnostic system 100 for a servo actuation circuit, including a memory 101 and a processor 102, wherein the memory 101 is used to store instructions executable by the processor, and the processor 102 is used to execute the instructions to implement the steps of the diagnostic method described in the above embodiments.

[0062] In some embodiments, the diagnostic system 100 may also be connected to a display module 103 for displaying the diagnostic result of the servo actuation circuit determined by the processor 102, so that the gas turbine engine operator, generally the pilot, can know the working condition of the fuel system servo actuation circuit of the engine in real time, or the test personnel of the gas turbine engine can check the working condition of the fuel system servo actuation circuit of the engine in real time during the gas turbine engine test. The display module 103 may have a variety of presentation forms, for example, in an aircraft, the display module 103 may be a dashboard or a display screen, or even a head-up display (HUD) of the pilot's helmet.

[0063] The memory 101 and / or processor 102 of the diagnostic system 100 described above may be integrated into a full authority digital engine controller (FADEC), so that the control system of the gas turbine engine has a high degree of integration. However, this is not a limitation, and the above-mentioned memory 101 and processor 102 are not limited to a specific memory or processor. In some cases, both the memory 101 and the processor 102 may have a distributed structure. For example, they may include a memory and a processor located on the aircraft side and the background cloud, respectively, and the above-mentioned diagnostic method is jointly implemented by the aircraft side and the background cloud. Furthermore, in an embodiment using a distributed structure, each step can adjust the specific execution terminal according to actual conditions, and the specific scheme of each step implemented in a specific terminal should not unduly limit the scope of protection of the present invention. It can be understood that the processor 101 in the previous embodiment is a combination of one or more of a system on a chip (SOC), a microcontroller, a microprocessor (e.g., a single-chip microcomputer), a reduced instruction set computer (RISC), an application-specific integrated circuit (ASIC), an application-specific instruction integrated processor (ASIP), a central processing unit (CPU), a graphics processing unit (GPU), a physical processing unit (PPU), a microcontroller unit, a digital signal processor (DSP), a field programmable gate array (FPGA), an advanced RISC machine (ARM), a programmable logic device (PLD), any circuit or processor capable of performing one or more functions, etc.

[0064] According to another aspect of the present invention, a computer-readable medium is also provided.

[0065] The computer-readable medium provided by the present disclosure has computer instructions thereon. When the computer instructions are executed by a processor, the program can be executed by the processor to implement the steps executed by the program in the diagnostic method described in the above embodiment.

[0066] As described above, it can be understood that the diagnostic method and / or diagnostic system 100 described in the above embodiments can be set in a gas turbine engine having a servo actuation circuit to realize accurate and reliable real-time diagnosis of the working condition of the servo actuation circuit during the actual operation of the gas turbine engine. This makes the closed-loop control of the fuel system of the gas turbine engine more precise and optimizes emission performance and / or economy. It can also be set in a test system of the gas turbine engine to realize accurate and real-time diagnosis of the working condition of the servo actuation circuit during the test process.

[0067] The steps of the method described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. The software module may reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor so that the processor can read and write information from / to the storage medium. In an alternative, a storage medium may be integrated into a processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and the storage medium may reside in a user terminal as discrete components.

[0068] In one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented as a computer program product in software, each function may be stored on or transmitted by a computer-readable medium as one or more instructions or codes. Computer-readable media include both computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one place to another. Storage media may be any available medium that can be accessed by a computer. As an example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disk storage, disk storage or other magnetic storage device, or any other medium that can be used to carry or store the desired program code in the form of an instruction or data structure and can be accessed by a computer. Any connection is also properly referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwaves, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwaves are included in the definition of the medium. Disk and disc as used herein include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc, wherein disk often reproduces data magnetically, while disc reproduces data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0069] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for diagnosing a servo actuation circuit, characterized in that: include: S1. Receive position feedback and position expectation of servo actuation loop; S2. According to S1, the real-time error between the position feedback and the desired position is obtained; According to the position expectation obtained by S1, the response types corresponding to the different time stages of the actuation circuit from the first time stage to the Nth time stage are obtained; S3. Based on the real-time error obtained in S2 and the response types corresponding to the different time stages, determine whether the real-time errors of the servo loop in different time stages all meet the error requirements corresponding to the corresponding response types.

2. The diagnostic method according to claim 1, characterized in that In S2, the step of selecting a response type corresponding to the position expectation includes: Define the expected rate of change of position: Among them, the unit of operation cycle is s; Define the expected position change angle as A, then the relationship between the change angle A and its corresponding expected position change rate is: Expected position change angle = arctan (expected position change rate); Depending on the desired change angle, the response type may be a step response, a ramp response or a steady-state response.

3. The diagnostic method according to claim 2, characterized in that In S3, if the response type corresponding to the time stage is a step response, the diagnostic parameter is the adjustment time; if the response type corresponding to the time stage is a ramp response, the diagnostic parameters are the maximum following error and the adjustment time; if the response type corresponding to the time stage is a steady-state response, the diagnostic parameters are the maximum following error and the adjustment time.

4. The diagnostic method according to claim 3, characterized in that In S3, if in adjacent time stages, the response type of the latter time stage is different from the response type of the previous time stage, but is still within the adjustment time corresponding to the response type of the previous time stage, the requirement for following the error is diagnosed according to the response type of the previous time stage.

5. A computer readable medium having a computer program thereon, characterized in that The program is executed by a processor to implement the steps of the diagnostic method according to any one of claims 1 to 4.

6. A diagnostic system (100) for an engine servo actuation circuit, characterized in that: include: A memory (101) for storing instructions executable by a processor; A processor (102) is used to execute the instructions to implement the steps of the diagnostic method according to any one of claims 1 to 4.

7. The engine servo actuation circuit diagnostic system (100) according to claim 6, characterized in that: A display module (103) is connected to display the diagnosis result of the engine servo actuation circuit determined by the processor (102).

8. The engine servo actuation circuit diagnostic system (100) according to claim 6, characterized in that: The processor (102) and / or the memory (101) are integrated into a Full Authority Digital Engine Control (FADEC).

9. A gas turbine engine having a servo actuation circuit, characterized in that: During the operation of the gas turbine engine, the diagnostic method according to any one of claims 1 to 4 is executed; or, the gas turbine engine further comprises a diagnostic system (100) according to any one of claims 6 to 8.

10. The gas turbine engine according to claim 9, characterized in that The fuel system of the gas turbine engine has the servo-actuation circuit.

11. A gas turbine engine test system, characterized in that: During a test of a gas turbine engine, a diagnostic method as claimed in any one of claims 1 to 4 is performed.

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