A performance self-adaptive adjustment method and system based on performance attenuation law

Abstract

The application belongs to the technical field of aero-engine starting control, and particularly relates to a use performance self-adaptive adjustment method and system based on a performance attenuation rule. The method comprises the following steps: S1, acquiring an actual engine rotating speed and an engine inlet total temperature at a takeoff point of an airplane; S2, interpolating a current engine theoretical rotating speed according to a preset total temperature-rotating speed table, wherein the total temperature-rotating speed table gives different engine inlet total temperatures and engine theoretical rotating speed values corresponding to the engine inlet total temperatures; and S3, adjusting an exhaust restriction temperature of the engine according to a set step length until the actual engine rotating speed is equivalent to the engine theoretical rotating speed. The application compensates for use performance reduction caused by engine performance attenuation by appropriately increasing an engine control plan value, thereby meeting use requirements of a user.

Description

Technical Field

[0001] This application belongs to the field of aero-engine start-up control technology, specifically relating to a performance adaptive adjustment method and system based on performance decay law. Background Technology

[0002] In the early days, due to limitations in aircraft engine design and manufacturing capabilities, engine performance could only meet user specifications with virtually no margin for improvement. Whether the engine's performance met user needs was the primary concern during operation. As engine design and manufacturing capabilities have continuously improved, and engine performance now has a certain margin, the issue of performance degradation has become the main concern during operation.

[0003] In the existing technology, in order to ensure that all engines can be delivered and that the amount of engine adjustment work is minimized while meeting user requirements, so as to further improve the engine delivery capability, the range of requirements for engine performance at the factory is relatively wide. This results in some engines having performance that is significantly higher than the required value when they leave the factory. Although the excessively high performance brings some advantages, the engine condition of this type of engine is relatively high when used in the field, and the amount of engine performance degradation will increase accordingly, which is not conducive to the later use of the engine in the field. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a performance adaptive adjustment method and system based on performance degradation patterns, which accurately identifies engine performance degradation and then formulates appropriate adaptive adjustment strategies.

[0005] The first aspect of this application provides a performance adaptive adjustment method based on performance degradation laws, mainly including:

[0006] Step S1: Obtain the actual engine speed and total engine inlet temperature at the takeoff point;

[0007] Step S2: Interpolate the current theoretical engine speed according to the preset total temperature and tachometer. The total temperature and tachometer gives different engine inlet total temperatures and their corresponding theoretical engine speed values.

[0008] Step S3: Adjust the engine exhaust temperature limit according to the set step size until the actual engine speed is equivalent to the theoretical engine speed.

[0009] Preferably, step S3 further includes, when the actual speed of the engine is less than the theoretical speed of the engine, adjusting the overall control plan value of the engine exhaust temperature limit by k1, wherein the value of k1 is in the range of 5 to 15°C.

[0010] Preferably, step S3 further includes:

[0011] Set the upper limit of exhaust temperature k2 for the process of increasing the exhaust temperature limit of the engine. k2 is taken from any value in the range of 700 to 1000°C.

[0012] Preferably, the step S1 further includes:

[0013] Step S11: Determine that the aircraft is in the state of being off the ground and continue for a set time, and at the same time determine that the engine is in the intermediate state or above the intermediate state. The intermediate state refers to the engine state corresponding to the maximum thrust when the engine is not in afterburner.

[0014] Step S12: Set this time as the aircraft takeoff point.

[0015] Preferably, determining that the engine is off the ground includes: determining that the aircraft's current Mach number is greater than the aircraft's Mach number when it is off the ground, or determining that the aircraft's wheel load signal is empty.

[0016] The second aspect of this application provides a performance adaptive adjustment system based on performance degradation laws, corresponding to the above method, mainly including:

[0017] The parameter acquisition module is used to acquire the actual engine speed and total engine inlet temperature at the takeoff point.

[0018] The engine theoretical speed calculation module is used to interpolate the current engine theoretical speed based on a preset total temperature tachometer, which provides different engine inlet total temperatures and their corresponding engine theoretical speed values.

[0019] The exhaust temperature limit adjustment module is used to adjust the engine's exhaust temperature limit by a set step size until the engine's actual speed is equivalent to its theoretical speed.

[0020] Preferably, the exhaust temperature limit adjustment module includes: a speed increase unit, used to increase the overall control plan value of the engine exhaust temperature limit by k1 when the actual engine speed is less than the theoretical engine speed, wherein the value of k1 is in the range of 5 to 15℃.

[0021] Preferably, the exhaust temperature limit adjustment module includes: a speed increase limit unit, used to control the increase based on a set exhaust temperature limit upper limit k2 during the process of increasing the exhaust temperature limit of the engine, where k2 is taken from any value within 700 to 1000℃.

[0022] Preferably, the parameter acquisition module includes: an aircraft state determination unit, used to determine that the aircraft is in a state of takeoff and to maintain this state for a set time, and to determine that the engine is in an intermediate or above-intermediate state, wherein the intermediate state refers to the engine state corresponding to the maximum thrust when the engine is not using afterburner; and an aircraft takeoff point determination unit, used to set this moment as the aircraft takeoff point.

[0023] Preferably, the aircraft state determination unit includes at least one of a Mach number determination unit or a wheel load determination unit. The Mach number determination unit is used to determine that the aircraft is in a takeoff state when the current Mach number of the aircraft is greater than the Mach number when the aircraft takes off. The wheel load determination unit is used to determine that the aircraft is in a takeoff state when the aircraft wheel load signal is empty.

[0024] This application compensates for the reduced performance caused by engine performance degradation by appropriately increasing the engine control plan value, thereby meeting the user's needs. Attached Figure Description

[0025] Figure 1 This is a flowchart of a preferred embodiment of the performance adaptive adjustment method based on the performance degradation law in this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are only some, not all, of the embodiments of this application. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application. The embodiments of this application will be described in detail below with reference to the accompanying drawings.

[0027] The first aspect of this application provides a performance adaptive adjustment method based on performance degradation laws, such as... Figure 1 As shown, it mainly includes:

[0028] Step S1: Obtain the actual engine speed and total engine inlet temperature at the takeoff point;

[0029] Step S2: Interpolate the current theoretical engine speed according to the preset total temperature and tachometer. The total temperature and tachometer gives different engine inlet total temperatures and their corresponding theoretical engine speed values.

[0030] Step S3: Adjust the engine exhaust temperature limit according to the set step size until the actual engine speed is equivalent to the theoretical engine speed.

[0031] First, it should be noted that, according to the principles of aero-engines, engine performance is sufficient to meet user needs in cold weather; however, in hot weather, the engine exhaust temperature rises, and performance may decrease due to exhaust temperature restrictions. Therefore, it is only necessary to identify the engine performance degradation under exhaust temperature restrictions. As engine performance degrades, the engine's performance will decline further under the same exhaust temperature restrictions (e.g., engine speed will decrease). Therefore, this application determines whether engine performance has degraded by controlling engine speed. Once performance degrades, the overall exhaust temperature control scheme is increased, indirectly lifting the upper limit of engine speed, thereby compensating for the performance degradation caused by the performance decline.

[0032] Regarding engine speed, this application establishes the relationship between the theoretical engine speed under factory conditions and the total temperature at the engine inlet, namely the total temperature speed table preset in step S3. This total temperature speed table can be provided by the manufacturer or obtained through experiments or simulations, as shown in Table 1.

[0033] Table 1 Total Temperature and Speed ​​Table

[0034]

[0035] In Table 1, T1 represents the engine inlet total temperature, in Kelvin (K). This represents the engine's theoretical speed, which can be either the high / low pressure speed or the converted high / low pressure speed.

[0036] In step S2 of this application, the corresponding theoretical engine speed is first interpolated from Table 1 based on the current T1, and then compared in step S3. For example, in some optional embodiments, when the actual engine speed is less than the theoretical engine speed, the control plan value of the engine exhaust temperature limit is increased by k1 based on the limit exhaust temperature T6 at the takeoff point. In this embodiment, the adjustment amount of the exhaust temperature control plan value each time cannot be too large, otherwise this logic will not work; nor can it be too small, otherwise it will not play a role in performance compensation. Based on test run adjustment experience, the value range of k1 is usually 5-15℃. After one increase, the current engine speed is obtained again to determine whether further increase is needed. If the determination condition is met multiple times, the adjustment can be accumulated multiple times until the actual engine speed is equivalent to the theoretical engine speed. Here, "equivalent" means that the actual engine speed is the same as the theoretical engine speed without considering errors.

[0037] In some alternative embodiments, step S3 further includes: setting an upper limit k2 for the exhaust temperature limit during the process of increasing the exhaust temperature limit of the engine. It should be noted that in order to avoid excessive adjustment of the control system, it is necessary to give its maximum exhaust temperature adjustment range k2. k2 is given based on development experience and is generally taken from any value within 700 to 1000°C.

[0038] In some optional implementations, step S1 is further preceded by: step S11, determining that the aircraft is in a state of takeoff and continuing for a set time, and at the same time determining that the engine is in an intermediate or above-intermediate state, wherein the intermediate state refers to the engine state corresponding to the maximum thrust when the engine is not using afterburner; step S12, setting this time as the aircraft takeoff point.

[0039] First, it should be noted that in this embodiment, the aero-engine is a device that provides the thrust required for aircraft flight. Based on the magnitude of thrust, the operating states of an aero-engine can generally be divided into shutdown, idle, intermediate and above-intermediate, and maximum operating states. These states correspond to different engine throttle positions and are conventional terms used in the art to describe engine control states. Under different operating states, the aero-engine employs different adjustment mechanisms to provide thrust, and its performance parameters exhibit different functional forms and mapping relationships. In this embodiment, the engine's intermediate state, i.e., maximum thrust without afterburner, includes controlling the engine using maximum thrust, speed, etc., primarily used for rapid takeoff / climb or maneuvering flight. States above the intermediate level include, for example, low afterburner or full afterburner states.

[0040] Secondly, it should be noted that in this embodiment, to avoid the influence of engine intake conditions on engine performance degradation identification, the same flight state point is selected for engine performance degradation identification. Given that the engine state is basically the same (maximum or intermediate state) and the intake conditions are basically similar during each takeoff flight, it is preferable to select the aircraft's "takeoff point" for performance degradation identification.

[0041] In some alternative implementations, determining that the engine is off the ground includes: determining that the aircraft's current Mach number is greater than the aircraft's Mach number when it is off the ground, or determining that the aircraft's wheel load signal is empty.

[0042] In this embodiment, the takeoff point identification includes: (1) the engine is in a combat or training intermediate or higher state; (2) the Mach number is greater than Ma (the Mach number when the aircraft leaves the ground) or the wheel-mounted signal is in the air and lasts for t seconds. For each flight sortie (from the start of the engine on the ground to the ground shutdown is counted as one flight sortie), the time point when conditions (1) and (2) are met simultaneously for the first time is the takeoff point. In this embodiment, t is usually 5 to 10 seconds.

[0043] This application can accurately identify engine performance degradation, thereby formulating appropriate adaptive adjustment strategies to achieve adaptive compensation of engine performance and consistent performance throughout the engine's entire lifespan.

[0044] The second aspect of this application provides a performance adaptive adjustment system based on performance degradation law, corresponding to the above method. It mainly includes: a parameter acquisition module for acquiring the actual engine speed and engine inlet total temperature at the takeoff point; an engine theoretical speed calculation module for interpolating the current engine theoretical speed based on a preset total temperature tachometer, which provides different engine inlet total temperatures and their corresponding engine theoretical speed values; and an exhaust limit temperature adjustment module for adjusting the engine exhaust limit temperature in set steps until the actual engine speed is equivalent to the engine theoretical speed.

[0045] In some optional embodiments, the exhaust temperature limit adjustment module includes: a speed increase unit, used to increase the overall control plan value of the engine exhaust temperature limit by k1 when the actual engine speed is less than the theoretical engine speed, wherein the value of k1 is in the range of 5 to 15°C.

[0046] In some optional embodiments, the exhaust temperature limit adjustment module includes: a speed increase limit unit, used to control the increase based on a set exhaust temperature limit upper limit k2 during the process of increasing the exhaust temperature limit of the engine, where k2 is taken from any value within the range of 700 to 1000°C.

[0047] In some optional embodiments, the parameter acquisition module includes: an aircraft state determination unit, used to determine that the aircraft is in a state of takeoff and for a set time, and to determine that the engine is in an intermediate or above-intermediate state, wherein the intermediate state refers to the engine state corresponding to the maximum thrust when the engine is not using afterburner; and an aircraft takeoff point determination unit, used to set the time as the aircraft takeoff point.

[0048] In some optional embodiments, the aircraft state determination unit includes at least one of a Mach number determination unit or a wheel load determination unit. The Mach number determination unit is used to determine that the aircraft is in a takeoff state when the current Mach number of the aircraft is greater than the Mach number when the aircraft takes off. The wheel load determination unit is used to determine that the aircraft is in a takeoff state when the aircraft wheel load signal is empty.

[0049] This application utilizes a control system to automatically identify engine performance degradation, adaptively adjust the engine's control plan, and appropriately improve engine performance, thus gradually releasing the engine's performance margin. Under current design and manufacturing capabilities, this alleviates the conflict between engine performance requirements and performance degradation, ensuring consistent performance throughout the engine's entire lifespan. It avoids the problem of "excessive performance in the early stages of its lifespan and insufficient performance in the later stages," thereby improving the user experience.

[0050] Although this application has been described in detail above with general descriptions and specific embodiments, some modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, such modifications or improvements made without departing from the spirit of this application are all within the scope of protection claimed in this application.

Claims

1. A performance self-adaptive adjustment method based on performance degradation law, characterized in that, The method comprises: Step S1, obtaining the actual engine speed and the engine inlet total temperature at the takeoff point of the aircraft; Step S2, interpolating the current engine theoretical speed according to a preset total temperature-speed table, the total temperature-speed table giving different engine inlet total temperatures and corresponding engine theoretical speed values; Step S3, adjusting the exhaust gas restriction temperature of the engine by a set step size until the actual engine speed is equal to the engine theoretical speed; Wherein, step S3 further comprises, when the actual engine speed is less than the engine theoretical speed, adjusting the control plan value of the exhaust gas restriction temperature of the engine as a whole by k1, and k1 is selected from the range of 5-15℃.

2. The method of claim 1, wherein the performance-based degradation law is determined based on a plurality of performance parameters of the system. Step S3 further comprises: Setting an upper limit k2 of the exhaust gas restriction temperature during the process of adjusting the exhaust gas restriction temperature of the engine, and k2 is selected from any value within the range of 700-1000℃.

3. The method of claim 1, wherein the performance-based degradation law is determined based on a plurality of performance parameters of the system. Before step S1, further comprising: Step S11, determining that the aircraft is in a state of taking off and continuously setting a time, and simultaneously determining that the engine is in an intermediate or above intermediate state, the intermediate state being the state of the engine corresponding to the maximum thrust when the engine is not in afterburner; Step S12, setting the time as the takeoff point of the aircraft.

4. The method of claim 3, wherein the performance degradation law is determined by the following equation: ###0001### where, P is the performance degradation law, P0 is the initial performance, t is the time, T is the time constant, and P0 is the initial performance. Determining that the engine is in a state of taking off comprises: determining that the current Mach number of the aircraft is greater than the Mach number when the aircraft takes off, or determining that the wheel load signal of the aircraft is empty.

5. A performance self-adaptive adjustment system based on performance degradation law, characterized in that, The method comprises: A parameter acquisition module for acquiring the actual engine speed and the engine inlet total temperature at the takeoff point of the aircraft; An engine theoretical speed calculation module for interpolating the current engine theoretical speed according to a preset total temperature-speed table, the total temperature-speed table giving different engine inlet total temperatures and corresponding engine theoretical speed values; An exhaust gas restriction temperature adjustment module for adjusting the exhaust gas restriction temperature of the engine by a set step size until the actual engine speed is equal to the engine theoretical speed; Wherein, the exhaust gas restriction temperature adjustment module comprises a speed adjustment unit for adjusting the control plan value of the exhaust gas restriction temperature of the engine as a whole by k1 when the actual engine speed is less than the engine theoretical speed, and k1 is selected from the range of 5-15℃.

6. The performance degradation rule based usage performance self-adaptive adjustment system of claim 5, wherein, The exhaust gas restriction temperature adjustment module comprises a speed adjustment limiting unit for adjusting the control plan value of the exhaust gas restriction temperature of the engine based on a set upper limit k2 of the exhaust gas restriction temperature during the process of adjusting the exhaust gas restriction temperature of the engine, and k2 is selected from any value within the range of 700-1000℃.

7. The performance degradation rule based usage performance self-adaptive adjustment system of claim 5, wherein, The parameter acquisition module comprises an aircraft state determination unit for determining that the aircraft is in a state of taking off and continuously setting a time, and simultaneously determining that the engine is in an intermediate or above intermediate state, the intermediate state being the state of the engine corresponding to the maximum thrust when the engine is not in afterburner; and an aircraft takeoff point determination unit for setting the time as the takeoff point of the aircraft.

8. The system for self-adapting adjustment of performance based on performance degradation law according to claim 7, wherein, The aircraft state determination unit comprises at least one of a Mach number determination unit or a wheel load determination unit, the Mach number determination unit being used for determining that the aircraft is in a state of taking off when the current Mach number of the aircraft is greater than the Mach number when the aircraft takes off, and the wheel load determination unit being used for determining that the aircraft is in a state of taking off when the wheel load signal of the aircraft is empty.

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