A method for avoiding mutual interference of a2 advance control

Abstract

The application belongs to the field of aero-engine variable control, and particularly relates to a method for avoiding mutual interference of a2 advance control. The method comprises the following steps: step one, identifying data characteristics when a backup system enters a2 advance control function and an electric regulating system does not enter a2 advance control function; and step two, determining a fault judgment logic according to the data characteristics, and giving the electric regulating system an extended regulation time to avoid occurrence of a2 regulation channel fault under the fault judgment logic. The method for avoiding mutual interference of a2 advance control can solve the problem of fault reporting caused by mismatching of the electric regulating system and the backup a2 advance control function without changing hardware; the mode that the backup system enters a2 advance control function and the electric regulating system does not enter a2 advance control function is identified through control software; and the problem of "missing report" of a2 regulation channel fault is solved.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of aero-engine variable control, and particularly relates to a method for avoiding mutual interference of a2 advance control. BACKGROUND

[0002] The aero-engine currently used is an electric regulating control system with mechanical hydraulic backup, wherein a2, the angle of the adjustable blade at the inlet of the compressor, is a key part for adjusting the inlet flow of the engine. If a2 control fails, it may cause engine surge and other risks. Therefore, a2 control is completed by a digital electronic control system and a mechanical hydraulic backup system, which is a double guarantee for engine safety.

[0003] In the electric regulating state, the digital electronic controller outputs a duty ratio according to the deviation between the sensor acquisition value and the set target value, controls the position of the a2 valve sleeve, and then controls the a2 angle. The mechanical hydraulic system feeds back the a2 angle through a steel cable, compares it with the target value set in the main fuel pump regulator, and then controls the position of the a2 oil distribution valve, and then controls the a2 angle. In the electric regulating state, the digital electronic controller and the main fuel pump regulator jointly control the a2 angle, and when backup is switched, only the main fuel pump regulator participates in the a2 angle control. When the engine is decelerating, in order to make the a2 angle quickly follow the set target value, a2 advance control functions in the electric regulating state and the mechanical hydraulic backup state are respectively designed, which can achieve the purpose of quickly closing the a2 angle. Since the a2 advance control function in the electric regulating state is realized by the digital electronic controller, and the a2 advance control function in the backup state is realized by the main fuel pump regulator, it is two relatively independent systems. However, the main fuel pump regulator belongs to a mechanical structure, and there are tolerances in manufacturing and attenuation problems in use, while the control accuracy of the digital electronic controller is unchanged, so there is a mismatch between the a2 advance control functions of the electric regulating and backup. The backup system enters the advance control, while the electric regulating system does not enter the advance control, which causes a2 regulation channel failure, and the control system enters a2 single-channel backup control mode. This kind of failure has a great impact and affects the departure time of the aircraft. Although the mismatch between the a2 advance control functions of the electric regulating and backup does not affect the safety of the engine, it has a great impact after the fault is reported, which belongs to the category of "false reporting". How to report "a2 regulation channel failure" due to the mismatch between the a2 advance control functions of the electric regulating and backup without changing the hardware is a problem to be solved.

[0004] There are two solutions in the prior art to solve the mutual interference of a2 advance control. First, structural improvement is made to separate the a2 loop of electric adjustment control and backup control for design, so as to realize the purpose of mutual non-interference. The disadvantage is that hardware modification is needed, and the production cycle and test verification cycle are relatively long. Second, the fault judgment time of a2 adjustment channel is overall extended, which can solve the problem of "false alarm", but the disadvantage is that if the a2 fault judgment time of all states is simply extended, the a2 fault judgment mode under other conditions will be affected, which may cause the risk of failure to find that the engine a2 control deviates, which belongs to the category of "missed alarm".

[0005] Therefore, it is desirable to have a technical solution to overcome or at least alleviate at least one of the above-mentioned deficiencies of the prior art. SUMMARY

[0006] The purpose of the present application is to provide a method for avoiding mutual interference of a2 advance control to solve at least one problem existing in the prior art.

[0007] The technical solution of the present application is:

[0008] A method for avoiding mutual interference of a2 advance control, comprising:

[0009] Step one, identifying the data characteristics when the backup system enters the a2 advance control function and the electric adjustment system does not enter the a2 advance control function;

[0010] Step two, determining the fault judgment logic according to the data characteristics, giving the electric adjustment system an extended adjustment time to avoid the occurrence of a2 adjustment channel failure under the fault judgment logic.

[0011] In at least one embodiment of the present application, in step one, when the backup system enters the a2 advance control function and the electric adjustment system does not enter the a2 advance control function, the data characteristics are:

[0012] A≤N2-N2Dem<B

[0013] E-F≥C

[0014] P-PBL≥D

[0015] Wherein, A represents the first speed deviation, B represents the second speed deviation, N2 represents the actual engine speed, N2Dem represents the target speed value, E represents the a2 actual angle, F represents the a2 control target value, C represents the a2 deviation, P represents the control duty ratio, and PBL represents the control duty ratio internal setting value.

[0016] In at least one embodiment of the present application, in step two, the fault determination logic determined according to the data characteristics gives the electric regulating system an extended regulating time to avoid the occurrence of a2 regulating channel fault under the fault determination logic includes:

[0017] The fault determination logic determined according to the data characteristics includes entry logic, execution logic and exit logic;

[0018] The entry logic is:

[0019] A≤N2-N2Dem<B ①

[0020] E-F≥C ②

[0021] P-PBL≥D ③

[0022] F-E≥G and T fault ≥T+△T; ④

[0023] F-E≥G and T fault ≥T; ⑤

[0024] Wherein, N2 represents the actual engine speed, N2Dem represents the target speed value, E represents the a2 actual angle, F represents the a2 control target value, C represents the a2 deviation, P represents the control duty ratio, PBL represents the control duty ratio internal set value, G represents the fault determination threshold, T 故障 represents the fault duration, T represents the fault duration judgment threshold, and △T represents the extended time of the backup system entering the a2 advanced control function while the electric regulating system does not enter the a2 advanced control function mode;

[0025] The execution logic is:

[0026] If conditions ①, ② and ③ are met at the same time, a2 regulating channel fault is reported according to condition ④, and a2 single channel backup control is performed;

[0027] Otherwise, a2 regulating channel fault is reported according to condition ⑤, and a2 single channel backup control is performed;

[0028] The exit logic is:

[0029] N2-N2Dem≤M and T 退出 ≥T2

[0030] Wherein, M represents the speed difference judgment threshold of the exit logic, T 退出 represents the exit logic duration, and T2 represents the exit logic time threshold.

[0031] The present application has at least the following beneficial technical effects:

[0032] The method for avoiding mutual interference of a2 advance control of the application can solve the problem of fault reporting caused by the mismatch of the electric governor and the backup a2 advance control function without changing the hardware; the mode of the backup system entering the a2 advance control function and the electric governor system not entering the a2 advance control function is recognized through the control software; and the problem of "missing report" of the a2 regulation channel fault is solved. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 FIG. 1 is a schematic diagram of a fault condition caused by the backup system entering the a2 advance control function and the electric governor system not entering the a2 advance control function according to an embodiment of the application. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical scheme and advantages of the application clearer, the technical scheme of the embodiments of the application will be described in more detail below with reference to the drawings of the embodiments of the application. In the drawings, the same or similar notations represent the same or similar elements or elements with the same or similar functions throughout. The described embodiments are part of the embodiments of the application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to explain the application, and cannot be understood as a limitation of the application. Based on the embodiments in the application, all other embodiments obtained by those of ordinary skill in the art without creative labor fall within the scope of protection of the application. The embodiments of the application will be described in detail below with reference to the drawings.

[0035] In the description of the application, it should be understood that the terms "center", "longitudinal", "transverse", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the scope of protection of the application.

[0036] The embodiments of the application will be described in detail below with reference to the drawings. Figure 1 The application will be described in further detail.

[0037] The application provides a method for avoiding mutual interference of a2 advance control, comprising the following steps:

[0038] Step one, recognizing the data characteristics when the backup system enters the a2 advance control function and the electric governor system does not enter the a2 advance control function;

[0039] Step two, determining the fault judgment logic according to the data characteristics, giving the electric governor system a prolonged regulation time, and avoiding the occurrence of a2 regulation channel fault under the fault judgment logic.

[0040] The method for avoiding mutual interference of a2 advance control of the present application is as follows: Figure 1 As shown in the typical failure mode of backup system entering advance control and electric regulating system not entering advance control, due to the backup system entering advance mode, the actual value of a2 rapidly increases, forming a large deviation from the target value of a2, and the electric regulating system will make corresponding adjustment, gradually making the actual value of a2 consistent with the target value of a2. When the backup system exits a2 advance control, the actual value of a2 will suddenly decrease, again generating a large deviation, and since the electric regulating system does not enter advance control, and the actuator also has a certain response time, it cannot control a2 to the target value in a very short time. When the deviation reaches a certain value and exceeds the fault judgment time, the control system will report "a2 regulation channel failure", and a2 single channel will be switched to backup control. Since the electric regulating and backup control are two systems, the conditions for judging engine deceleration do not match, and the situation that the a2 controlled by the electric regulating system does not meet the advance logic while the backup system meets the a2 advance logic may occur, causing the problem of mismatch between the electric regulating and backup a2 advance control functions.

[0041] In order to solve the above problems, based on the principle of not changing or changing as little as possible the original hardware system, a software algorithm is used to identify the mode of backup system entering advance control and electric regulating system not entering advance control, and then to give the electric regulating system corresponding adjustment time to avoid the occurrence of a2 regulation channel failure in this mode. Although the overall extension of the fault judgment time of a2 regulation channel failure can solve the "false alarm" problem, its disadvantage is that if the a2 fault judgment time of all states is simply extended, it will affect the fault judgment mode of a2 under other conditions, which may cause the risk of not being able to discover the deviation of engine a2 control in time, belonging to the category of "missed report". Therefore, it is of great significance to identify the mode of backup system entering advance control and electric regulating system not entering advance control, and to extend the adjustment time only for this mode.

[0042] The method for avoiding mutual interference of a2 advance control of the present application is as follows:

[0043] According to the above mechanism analysis, when the speed characteristic, a2 actual value and target value deviation characteristic, control duty cycle characteristic all meet certain conditions, the backup system enters a2 advance control function and the electric governor system does not enter a2 advance control function. In an embodiment of the present application, in step one, the data characteristic when the backup system enters a2 advance control function and the electric governor system does not enter a2 advance control function is:

[0044] A≤N2-N2Dem<B

[0045] E-F≥C

[0046] P-PBL≥D

[0047] Wherein, A represents the first speed deviation, B represents the second speed deviation, N2 represents the actual engine speed, N2Dem represents the target speed value, E represents the a2 actual angle, F represents the a2 control target value, C represents the a2 deviation, P represents the control duty cycle, and PBL represents the control duty cycle internal setting value.

[0048] The method for avoiding a2 advance control mutual interference of the present application, in step two, according to the data characteristic to determine the fault judgment logic, to give the electric governor system to extend the adjustment time, to avoid the occurrence of a2 adjustment channel fault under the fault judgment logic includes:

[0049] According to the data characteristic to determine the fault judgment logic, the fault judgment logic includes: entry logic, execution logic and exit logic;

[0050] The entry logic is:

[0051] A≤N2-N2Dem<B ①

[0052] E-F≥C ②

[0053] P-PBL≥D ③

[0054] F-E≥G and T fault≥T+△T; ④

[0055] F-E≥G and T fault≥T; ⑤

[0056] If the engine state meets the conditions ①, ② and ③ in the formula at the same time, it means that the backup system enters a2 advance control function and the electric governor system does not enter a2 advance control function;

[0057] Wherein, N2 represents the actual engine speed, N2Dem represents the target speed value, E represents the a2 actual angle, F represents the a2 control target value, C represents the a2 deviation, P represents the control duty cycle, PBL represents the control duty cycle internal setting value, G represents the fault judgment threshold value, T 故障represents the fault duration, T represents the fault duration judgment threshold, and AT represents the time extended when the backup system enters the a2 advance control function and the electric regulating system does not enter the a2 advance control function mode;

[0058] The execution logic is:

[0059] If the conditions ①, ② and ③ are met at the same time, the a2 regulating channel fault is reported according to the condition ④, and the a2 single-channel backup control is performed;

[0060] Otherwise, the a2 regulating channel fault is reported according to the condition ⑤, and the a2 single-channel backup control is performed.

[0061] The exit logic is:

[0062] N2-N2Dem≤M and T 退出 ≥T2

[0063] Wherein, M represents the speed difference judgment threshold of the exit logic, T 退出 represents the exit logic duration, and T2 represents the exit logic time threshold.

[0064] The method for avoiding mutual interference of a2 advance control of the application can effectively avoid the a2 regulating channel fault caused by the interference between the electric regulating system and the backup system on the premise of keeping the mechanical hydraulic backup a2 advance control and the original hardware structure. The software recognition algorithm and the execution logic can recognize the mode of mutual interference caused by the backup system entering the a2 advance control function and the electric regulating system not entering the a2 advance control function, and avoid the risk of a2 control deviation caused by the extension of all fault reporting time and the failure to discover in time.

[0065] The method for avoiding mutual interference of a2 advance control of the application can prevent both “false reporting” and “omission reporting”, and can be directly applied to various aero-engines, and has good market application prospect.

[0066] The above is only a specific embodiment of the application, but the protection scope of the application is not limited thereto. Any changes or replacements within the technical range disclosed in the application can be easily thought by those skilled in the art, and should be covered in the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

Claims

1. A method for avoiding mutual interference between a2 advance control and other controls, characterized in that, include: Step 1: Identify the data characteristics when the backup system enters the A2 advance control function while the ESC system does not; Step 2: Determine the fault judgment logic based on the data characteristics, extend the adjustment time of the ESC system, and avoid the occurrence of the A2 adjustment channel fault under the fault judgment logic; In step one, the data characteristics when the backup system enters the A2 advance control function while the ESC system does not are as follows: A≤N²-N²Dem<B EF≥C P-PBL≥D Where A represents the first speed deviation, B represents the second speed deviation, N2 represents the actual engine speed, N2Dem represents the target speed value, E represents the actual angle of a2, F represents the target control value of a2, C represents the deviation of a2, P represents the control duty cycle, and PBL represents the internal setting value of the control duty cycle. In step two, determining the fault judgment logic based on the data characteristics and extending the adjustment time of the ESC system to avoid the occurrence of a2 adjustment channel faults under the fault judgment logic includes: The fault judgment logic is determined based on the data characteristics, and the fault judgment logic includes: entry logic, execution logic, and exit logic; The entry logic is as follows: A≤N²-N²Dem<B ① EF≥C ② P-PBL≥D ③ FE≥G and T 故障 ≥T+△T; ④ FE≥G and T 故障 ≥T; ⑤ Where N2 represents the actual engine speed, N2Dem represents the target speed value, E represents the actual angle a2, F represents the target control value of a2, C represents the deviation of a2, P represents the control duty cycle, PBL represents the internal setting value of the control duty cycle, G represents the fault judgment threshold, and T 故障 The fault duration is represented by T, which represents the fault duration judgment threshold. △T represents the extended time when the backup system enters the a2 advanced control function mode while the ESC system does not enter the a2 advanced control function mode. The execution logic is as follows: If conditions ①, ②, and ③ are met simultaneously, then condition ④ will be used to report a fault in the a2 adjustment channel, and a2 single-channel switching to backup control will be performed. Otherwise, report a2 adjustment channel failure according to condition ⑤, and switch a2 single channel to backup control; The exit logic is as follows: N2-N2Dem≤M and T 退出 ≥T2 Where M represents the speed difference judgment threshold for exiting the logic, and T 退出 T1 represents the duration of the exit logic, and T2 represents the time threshold for the exit logic.

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