Design and simulation methods of a full envelope controller for a turbofan engine

Abstract

The present application proposes a design method and simulation method for a full envelope controller of a turbofan engine, comprising the following steps: S1, establishing an NPV model of the turbofan engine including external disturbances, and converting the NPV model into an uncertain model according to the external disturbances; S2, designing a large envelope robust controller based on the uncertain model; S3, designing a preset performance parameter matrix in the large envelope robust controller according to the performance index requirements of the closed-loop system of the turbofan engine; S4, solving the state feedback gain matrix in the large envelope robust controller using the SOS technology, thereby solving the large envelope robust controller; S5, designing a PI controller of the turbofan engine in the throttling state, and combining the PI controller and the large envelope robust controller into the full envelope controller using a switching module. The full envelope controller of the present application can better adapt to the nonlinear model of the turbofan engine, thereby having better control stability.

Description

Technical Field

[0001] The present application relates to the field of aero-engine control technology, and in particular to a design method and a simulation method for a full-envelope controller for a turbofan engine. Background Art

[0002] Turbofan engines have been widely used in defense and civilian fields due to their high thrust and high propulsion efficiency. However, since the flight parameters and internal parameters of turbofan engines vary over a large range and the engine mechanical structure is complex, the aerodynamic thermodynamic behavior of the turbofan engine system is complex, and has significant nonlinearity, time-varying, strong coupling and uncertainty, which brings great challenges to the design of the turbofan engine full envelope controller.

[0003] In the control systems of turbofan engines currently in service, the design of full-envelope controllers mostly adopts a gain scheduling scheme. The controller gain is adjusted online to adapt to the nonlinear and parameter variation characteristics of the system. However, simple gain scheduling lacks theoretical rigor, and the effectiveness of its control effect depends on a large number of ground-based and control flight simulation experiments. In addition, the controller parameters are changed in an open-loop manner. When the scheduling variables change rapidly and it is difficult to capture the nonlinear characteristics of the controlled object, the stability of the system is difficult to guarantee. With the development and improvement of nonlinear system modeling methods, linear parameter-varying (LPV) models for nonlinear system control have emerged. However, the LPV model is only a first-order approximation of the original system at the corresponding operating point and cannot reflect the complete dynamics of the system. The nonlinear parameter-varying (NPV) model can describe the time-varying and nonlinear dynamic characteristics of the controlled object. On the one hand, this model makes up for the shortcomings of LPV in describing the nonlinear characteristics of the controlled object. On the other hand, by referring to the implementation of Prajna's representation of nonlinear systems as state-dependent quasi-linear systems, nonlinear time-varying problems can be handled with the help of mature tools. On this basis, establishing the performance analysis method and control design theory of this type of nonlinear time-varying system can effectively solve the problems related to turbofan engine control.

[0004] Based on the above background, the present application provides a design method and simulation method for a full envelope controller of a turbofan engine. Aiming at the steady-state and transitional state control problems of the full envelope of a turbofan engine, a full envelope robust nonlinear controller is designed based on a fully digital simulation platform of a turbofan engine to ensure that the closed-loop system meets the expected performance indicators under full envelope flight conditions and has good robustness. Summary of the invention

[0005] In order to solve the technical problem of poor control stability of a full envelope controller for a turbofan engine in the prior art, the present application proposes a design method and a simulation method for a full envelope controller for a turbofan engine.

[0006] According to the first aspect of the present application, a method for designing a full envelope of a turbofan engine is proposed, comprising the following steps:

[0007] S1, establishing an NPV model of the turbofan engine including external disturbances, and converting the NPV model into an uncertain model according to the external disturbances;

[0008] S2. Based on the uncertain model, design a large envelope robust controller;

[0009] S3. Designing a preset performance parameter matrix in the large envelope robust controller according to the performance index requirements of the turbofan engine closed-loop system;

[0010] S4, using the SOS technology to solve the state feedback gain matrix in the large envelope robust controller, thereby solving the large envelope robust controller;

[0011] S5. Design a PI controller for the turbofan engine in the throttling state, and use a switching module to combine the PI controller and the large envelope robust controller into the full envelope controller, so that the turbofan engine uses the PI controller in the throttling state, and switches to the large envelope robust controller through the switching module in other states.

[0012] Through the above technical scheme, for the full envelope steady-state and transition state control problems of turbofan engines, a large envelope robust controller and a PI controller are designed to form a full envelope controller. The turbofan engine control system adopts a PI-PP (Proportion-Integral & Prescribed-Performance) hybrid control strategy, that is, the turbofan engine uses a PI controller in the throttling state and a large envelope robust controller in other flight states. The control system converts the system's performance indicators into design indicators of the controller based on a preset performance method, so that the controller can better adapt to the engine nonlinear model and thus have better control stability.

[0013] Preferably, the NPV model including external disturbance is specifically:

[0014]

[0015] Where x∈R n is the system state, u∈R n is the control input, ρ(t)∈R sis a time-varying parameter vector, A(·,·), B(·,·) and C(·,·) are polynomial matrices with respect to x and ρ(t), ω(t) is an external perturbation, and E1 is a constant matrix of appropriate dimension;

[0016] The uncertainty model is specifically:

[0017]

[0018] Among them, △F1x(t) is the transformed external disturbance, △ is the uncertainty matrix, and satisfies △ T △≤I, F1, I are constant matrices and unit matrices of appropriate dimensions, respectively, satisfying F1 T F1≥0.

[0019] Preferably, the expression of the large envelope robust controller is specifically:

[0020]

[0021] in, is the state feedback gain matrix to be designed, k R is an adjustable coefficient, is the preset performance parameter matrix to be designed.

[0022] Through the above technical solution, it can be seen from the formula that as long as a suitable preset performance parameter matrix is ​​selected The problem of making the turbofan engine closed-loop system meet the given performance indicators can be solved.

[0023] Preferably, the performance index requirements of the turbofan engine are specifically as follows: the high-pressure rotor speed control steady-state error, dynamic overshoot, step response time, nozzle closed-loop control pressure ratio steady-state error and speed dynamic overshoot under high-pressure rotor speed disturbance of the turbofan engine closed-loop system are all within the preset threshold value;

[0024] The design process of the preset performance parameter matrix is ​​specifically as follows: based on the preset performance parameter matrix to be designed, the value of the system state at any time is subjected to a difference operation with a preset expected value to obtain a state error, a performance function is introduced and an error transformation function is defined, and the preset performance parameter matrix is ​​designed. The expression of the preset performance parameter matrix is ​​specifically as follows:

[0025]

[0026]

[0027] Among them, the continuous function T is defined as the error transformation function T i (x,t), is the state error of the turbofan engine closed-loop system, ρ i(t) is the introduced performance function.

[0028] Through the above technical solution, a preset performance parameter matrix is ​​constructed by introducing a performance function and defining an error transformation function.

[0029] Preferably, the process of solving the state feedback gain matrix specifically includes:

[0030] The solvability condition of the state feedback gain matrix to be designed is designed, and the specific expression is:

[0031]

[0032]

[0033] in, and is a given positive number, Φ SOS is a set of SOS polynomials,

[0034] is an n×n dimensional symmetric polynomial matrix, is an m×n dimensional polynomial matrix, k R is a constant;

[0035] The solvability condition of the state feedback gain matrix to be designed is solved by using the SOS technology to obtain the state feedback gain matrix. The expression of the state feedback gain matrix is ​​specifically as follows:

[0036]

[0037] Through the above technical solution, according to the constructed preset performance parameter matrix, the state feedback gain matrix is ​​solved using the SOS technology.

[0038] Preferably, the control law expression of the PI controller is specifically:

[0039]

[0040] Among them, K p and T i is a constant and e(t) is the system error.

[0041] Preferably, the control law expression of the full envelope controller is specifically:

[0042]

[0043] Where PLA is the throttle stick angle and V is a constant.

[0044] Through the above technical scheme, since the large envelope NPV model of the turbofan engine does not have the characteristics of the low working state, the large envelope robust controller designed based on the NPV model has a poor control effect below the throttling state. Therefore, the turbofan engine adopts a PI controller in the throttling state. PI control is a classic control algorithm. It forms a control deviation based on a given value and an actual output value, and uses a linear combination of the proportion and integral of the deviation to form a control quantity to control the controlled object.

[0045] According to a second aspect of the present application, a simulation method for a full envelope controller of a turbofan engine is proposed, and the full envelope controller in the above-mentioned design method is simulated, comprising the following steps:

[0046] a) constructing the full envelope controller on a full digital simulation platform;

[0047] b) optimizing the full envelope controller by using a gain adjustment method;

[0048] c) performing full digital simulation on the optimized full envelope controller;

[0049] Wherein, the step b) specifically comprises:

[0050] b1) determining a plurality of typical operating points according to the flight altitude and Mach number of the turbofan engine, and selecting the parameters in the full envelope controller that optimize the dynamic performance of the turbofan engine closed-loop system by using a grid search method under different typical operating points and different operating conditions, thereby setting the parameters;

[0051] b2) The parameters adjusted by combining the linear interpolation method are adopted so that the closed-loop system of the turbofan engine meets the performance index requirements at all operating points and is integrated into a variable gain full envelope controller.

[0052] Through the above technical scheme, in view of the strong nonlinear characteristics of the nonlinear component model of the turbofan engine, the gain adjustment method is used to adjust the parameters of the controller at different working points, so that the controller can better adapt to the nonlinear model of the engine and the control effect is further improved.

[0053] Preferably, the control law expression of the full envelope controller to be optimized in step b) is specifically:

[0054]

[0055] Among them, K u , K1, K R , K p , T i are the parameters to be adjusted.

[0056] Through the above technical scheme, the full envelope controller parameters are adjusted at different typical operating points based on the gain adjustment method, thereby ensuring that the designed full envelope controller has good robustness to unmodeled dynamics on the basis of the performance of the turbofan engine closed-loop system meeting the given control effect.

[0057] Preferably, the method further comprises: performing steady-state experiments and dynamic experiments on the full envelope controller in hardware form on a hardware-in-the-loop platform and a semi-physical platform.

[0058] Through the above technical solutions, the hardware-in-the-loop simulation system has real I / O interfaces, controller hardware devices and virtual controlled object models, which is a high-confidence control algorithm test and verification method. Semi-physical simulation has a real oil circuit system, which can integrate and test the controller, hydraulic mechanical system and related sensors, and has higher realism than hardware-in-the-loop simulation.

[0059] This application proposes a design method and simulation method for a full envelope controller of a turbofan engine. Aiming at the steady-state and transitional control problems of the full envelope of a turbofan engine, a full envelope robust nonlinear controller is designed based on a full digital simulation platform of a turbofan engine to ensure that the closed-loop system meets the expected performance indicators under full envelope flight conditions and has good robustness. The turbofan engine control system adopts a PI-PP hybrid control strategy, that is, a PI controller is used in the throttling state, and a large envelope robust controller is used in the remaining flight states. The control system converts the performance indicators of the system into the design indicators of the controller based on the preset performance method, and uses the gain adjustment method to adjust the parameters of the controller at different typical working points, so that the controller can better adapt to the nonlinear model of the engine. The designed full envelope controller was simulated on a full digital simulation platform, a hardware-in-the-loop platform (HIL) and a semi-physical platform. The simulation results show that the designed controller can ensure that the system has global stability within the full envelope range, meets the given performance indicators, and has good robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and are used together with the description to explain the principles of the present application. It will be easy to recognize other embodiments and many expected advantages of the embodiments because they become better understood by reference to the following detailed description. The elements of the drawings are not necessarily to scale with each other. The same reference numerals refer to corresponding similar parts.

[0061] Figure 1 is a flow chart of a design method of a turbofan engine full envelope controller according to an embodiment of the present application;

[0062] Figure 2 is a structural diagram of a turbofan engine control system according to a specific embodiment of the present application;

[0063] Figure 3 is a flow chart of a simulation method of a turbofan engine full envelope controller according to an embodiment of the present application;

[0064] Figure 4 This is a schematic diagram of the main structural division of a fully digital simulation platform according to a specific embodiment of the present application;

[0065] Figure 5 is a block diagram of a full envelope controller for main fuel quantity according to a specific embodiment of the present application;

[0066] Figure 6 is a block diagram of a full envelope controller for throat area according to a specific embodiment of the present application;

[0067] Figure 7 is a given PLA variation diagram when a turbofan engine is in a throttle state according to a specific embodiment of the present application;

[0068] Figure 8 is a given PLA variation diagram when a turbofan engine is in an intermediate state according to a specific embodiment of the present application;

[0069] Fig. 9 is a given PLA variation diagram when a turbofan engine is in an afterburner state according to a specific embodiment of the present application;

[0070] Fig.10 is a graph showing the change of the flight altitude, Mach number and throttle lever angle over time within the envelope of a turbofan engine according to a specific embodiment of the present application;

[0071] Fig.11 It is a high-pressure rotor speed variation curve diagram obtained from a flight trajectory simulation experiment according to a specific embodiment of the present application;

[0072] Fig.12 This is a graph of engine pressure ratio variation obtained from a flight trajectory simulation experiment according to a specific embodiment of the present application;

[0073] Fig.13 It is a high-pressure rotor speed variation curve obtained by simulating a single-operating-condition simulation experiment under a throttling state at the working point (0, 0) according to a specific embodiment of the present application;

[0074] Fig.14 It is a high-pressure rotor speed variation curve obtained by simulating at the intermediate state of the working point (0, 0) in a single-operating-condition simulation experiment according to a specific embodiment of the present application;

[0075] Fig.15It is a high-pressure rotor speed variation curve obtained by simulating at the working point (0, 0) under the force-added state according to a single-operating-condition simulation experiment of a specific embodiment of the present application;

[0076] Fig.16 The engine pressure ratio variation curve is obtained by simulating the engine pressure ratio variation curve in the intermediate state of the working point (0, 0) according to a single working condition simulation experiment of a specific embodiment of the present application;

[0077] Fig.17 The engine pressure ratio variation curve is obtained by simulating the engine at the working point (0, 0) under the boost state according to a single working condition simulation experiment of a specific embodiment of the present application. DETAILED DESCRIPTION

[0078] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and Examples. It should be understood that the specific embodiments described herein are only configured to explain the present application and are not configured to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0079] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0080] According to the first aspect of the present application, a design method for a full envelope controller of a turbofan engine is proposed.

[0081] The following will take a certain type of small bypass ratio twin-shaft turbofan engine as the research object and introduce the design method of the turbofan engine full envelope controller.

[0082] Figure 1 A flow chart of a design method for a turbofan engine full envelope controller according to an embodiment of the present application is shown. Figure 1 As shown, the design method includes the following steps:

[0083] S1. Establish the NPV model of the turbofan engine including external disturbances, and transform the NPV model into an uncertain model according to the external disturbances.

[0084] In a specific embodiment, consider the following NPV model of a turbofan engine in the form of state variables:

[0085]

[0086] Where x∈R n is the system state, u∈R n is the control input, ρ(t)∈R s is a time-varying parameter vector, A(·,·), B(·,·) and C(·,·) are polynomial matrices with respect to x and ρ(t), and n L is the low pressure rotor speed, n H is the high pressure rotor speed, W f is the main fuel quantity, and A8 is the throat area. ij , b ij and c ij (i, j = 1, 2) The detailed expression is as follows:

[0087] a 11 =-0.01452H 3 +0.1052H 2 +0.7103H-3424.0n H 3 -10270.0n H 2 n Href +10010.0n H 2 -10270.0n H n Href 2 +20010.0n H n Href -9708.0n H -3424.0n Href 3 +10010.0n Href 2 -9708.0n Href -4.357Ma+3123.0

[0088] a 12 =2.038Ma-0.8023H+200.5W fref +42500.0A 8ref -9708.0n Lref -5998.0n Href -413.6Wfref n Href -88810.0A 8ref n Href +20010.0n Lref n Href +0.007449H 2 +0.006477H 3 +212.1W fref n Href 2 +46220.0A 8ref n Href 2 -10270.0n Lref n Href 2 +n H 2 (70.71W fref +15410.0A 8ref -3424.0n Lref -4646.0n Href +3241.0)-1162.0n H 3 -1.0n H (206.8W fref +44410.0A 8ref -10010.0n Lref -9724.0n Href -212.1W fref n Href -46220.0A 8ref n Href +10270.0n Lref n Href +6969.0n Href 2 +2999.0)+9724.0n Href 2 -4646.0n Href 3 +924.8

[0089] a 21 =-0.01538H 3 +0.1659H 2 -0.5276H-817.5n H 3 -2452.0n H 2 n Href +2347.0n H 2 -2452.0n H nHref 2 +4695.0n H n Href -2239.0n H -817.5n Href 3 +2347.0n Href 2 -2239.0n Href +1.359Ma+708.5

[0090] a 22 =1.121H-2.098Ma-204.3W fref -11090.0A 8ref -2239.0n Lref +10980.0n Href +430.8W fref n Href +23540.0W fref n Href +4695.0n Lref n Href -1.0nH 2 (75.66W fref +4148.0A 8ref +817.5n Lref -8143.0n Href +5802.0)-0.3035H 2 +0.0255H 3 -227.0W fref n Href 2 -12440.0A 8ref n Href 2 -2452.0n Lref n Href 2 +n H (215.4W fref +11770.0A 8ref +2347.0n Lref -17400.0n Href -227.0W fref n Href -12440.0A 8ref n Href -2452.0n Lref n Href +12210.0n Href 2 +5489.0)+2036.0n H3 -17400.0n Href 2 +8143.0n Href 3 -1726.0

[0091] b 11 =0.0002945H 3 -0.00616H 2 +0.01127H+70.71n H 3 +212.1n H 2 n Href -206.8n H 2 +212.1n H n Href 2 -413.6n H n Href +200.5n H +70.71n Href 3 -206.8n Href 2 +200.5n Href +0.1605Ma-64.06

[0092] b 12 =0.01606H 3 -0.2997H 2 +0.6669H+15410.0n H 3 +46220.0n H 2 n Href -44410.0n H 2 +46220.0n H n Href 2 -88810.0n H n Href +42500.0n H +15410.0n Href 3 -44410.0n Href 2 +42500.0n Href +5.999Ma-13510.0

[0093] b 21 =-0.0003558H 3 +0.003819H<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -0.005397H-75.66n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> -227.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> +215.4n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -227.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +430.8n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> -204.3n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> -75.66n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> +215.4n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -204.3n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> -0.01056Ma+64.74<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0094] <h2 style=";text-align:left;direction:ltr"> b<h2 style=";text-align:left;direction:ltr"> 22 <h2 style=";text-align:left;direction:ltr"> =-0.03469H<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> +0.4663H<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -2.014H-4148.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> -12440.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> +11770.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -12440.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +23540.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> -11090.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> -4148.0n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> +11770.0n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> -11090.0n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> +2.938Ma+3470.0<h2 style=";text-align:left;direction:ltr"> <h2 style=";text-align:left;direction:ltr">

[0095] <h2 style=";text-align:left;direction:ltr"> c<h2 style=";text-align:left;direction:ltr"> 21 <h2 style=";text-align:left;direction:ltr"> <0.01922H<h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> -0.1625H<h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +0.155H+5873.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> 3 <h2 style=";text-align:left;direction:ltr"> +17620.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> n<h2 style=";text-align:left;direction:ltr"> Href <h2 style=";text-align:left;direction:ltr"> -17030.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> 2 <h2 style=";text-align:left;direction:ltr"> +17620.0n<h2 style=";text-align:left;direction:ltr"> H <h2 style=";text-align:left;direction:ltr"> n<h2 style=";text-align:left;direction:ltr"> Href2 -34060.0n H n Href +16390.0n H +5873.0n Href 3 -17030.0n Href 2 +16390.0n Href -0.03688Ma-5236.0

[0096] c 22 =16390.0n Lref -0.04604Ma-0.1191H-31400.0n Href -34060.0n Lref n Href +n H 2 (5873.0n Lref -22530.0n Href +16320.0)+0.1541H 2 -0.0185H 3 +17620.0n Lref n Href 2 -5633.0n H 3 +48960.0n Href 2 -22530.0n Href 3 -1.0n H (17030.0n Lref -48960.0n Href -17620.0n Lref n Href +33800.0n Href 2 +15700.0)+5011.0

[0097] Among them, n Href represents the expected value of the high-pressure rotor speed, n Lref represents the expected value of the low-pressure rotor speed, W fref is the expected value of the main fuel quantity, A 8ref represents the expected value of the throat area, H represents the flight altitude, and Ma represents the Mach number.

[0098] On the basis of the NPV model, external disturbances are introduced to establish the NPV model including external disturbances:

[0099]

[0100] Wherein, ω(t) is the external disturbance. In this embodiment, ω(t)=0.1(n Href -n H (0))sint,n Href =0.9437, n H (0) = 0.8632. E1 is a constant matrix of appropriate dimension.

[0101] Let ω(t) = △F1x(t). △ is the uncertainty matrix, satisfying △ T △≤I. F1,I are constant matrices and unit matrices of appropriate dimensions, respectively, satisfying F1 T F1≥0. Thus, the external disturbance ω(t) is transformed into the uncertainty of the system structure. Then, the NPV model including external disturbance is transformed into the following uncertain model:

[0102]

[0103] Continue to refer to Figure 1 , after step S1,

[0104] S2. Design a large envelope robust controller based on the uncertain model.

[0105] In a specific embodiment, for an uncertain model, a large envelope robust controller based on a preset performance method is designed, as follows:

[0106]

[0107] in, is the state feedback gain matrix to be designed, k R is an adjustable coefficient, is the preset performance parameter matrix to be designed.

[0108] Continue to refer to Figure 1 , after step S2,

[0109] S3. According to the performance index requirements of the turbofan engine closed-loop system, design the preset performance parameter matrix in the large envelope robust controller.

[0110] In a specific embodiment, the preset performance method is to design a large envelope robust controller by making the turbofan engine closed-loop system meet the preset performance index requirements. The preset performance method is to limit the maximum overshoot of the system's dynamic response, the convergence speed and the steady-state error of the system so that the system meets the desired performance index. It can be seen from the expression of the large envelope robust controller that as long as a suitable preset performance parameter matrix is ​​selected The problem of making the closed-loop system meet the given performance indicators can be solved.

[0111] In this embodiment, the performance indicators that the closed-loop system of the turbofan engine should meet are: the steady-state error of the high-pressure rotor speed control of the turbofan engine is no greater than δ1, the dynamic overshoot is no greater than σ1, and the step response time is No more than T1. The steady-state error of the nozzle closed-loop control pressure ratio is no more than δ2. Under this condition, the dynamic overshoot of speed is not greater than σ2, that is:

[0112]

[0113]

[0114]

[0115]

[0116] Among them, n H (0),n H (∞) respectively represent the initial and final values ​​of the high-pressure rotor speed, n Href represents the expected value of the high-pressure rotor speed, t p represents the overshoot moment, π(∞) represents the final value of the nozzle pressure ratio, π ref represents the expected value of the nozzle pressure ratio, δ1, σ1, T1, δ2 and σ2 are respectively the preset thresholds of the performance indicators in this embodiment. In this embodiment, δ1=0.1%, σ1=1%, T1=4s, δ2=0.5%, σ2=1%.

[0117] The design process of the preset performance parameter matrix is ​​as follows: based on the preset performance parameter matrix to be designed, the value of the system state at any time is calculated by difference with the preset expected value to obtain the state error, the performance function is introduced and the error transformation function is defined, and the preset performance parameter matrix is ​​designed. The design process is as follows:

[0118] Assume state error By introducing the performance function, the transient and steady-state performance of the state error are set to satisfy the following inequality constraints:

[0119]

[0120] Among them, ρ i (t) is the introduced performance function, t∈[0,∞); The performance function given exponential convergence is as follows:

[0121]

[0122] Among them, γ i >0,ρ i (0) represents the initial error bound, ρ i(∞) represents the maximum state error allowed in steady state.

[0123] Design the performance function of high pressure rotor speed according to the given performance index:

[0124]

[0125] And let the performance function of low-pressure rotor speed be ρ1(t)=ρ2(t). Where ρ2(∞)≤n Href δ1, α is a constant and T1 is the step response time constant.

[0126] In this embodiment, take ω H =max{0.1(n Href -n H (0))sint}=0.00805, α=1, According to the calculation, we can get:

[0127] ρ1(0)=ρ2(0)=0.08, γ1=γ2=1.73, ρ1(∞)=ρ2(∞)=10 -3

[0128] thereby,

[0129] ρ i (t) = 0.079e -1.73t +0.001

[0130] Define the continuous function T as the error transformation function if the following conditions are met:

[0131] 1)

[0132] 2)

[0133] Then, the given error transformation function is:

[0134]

[0135] Among them, T i (x, t) is the error transformation function, is the state error of the turbofan engine closed-loop system.

[0136] Then, the preset performance parameter matrix is:

[0137]

[0138] In this embodiment,

[0139] Continue to refer to Figure 1, after step S3,

[0140] S4. Use the SOS technology to solve the state feedback gain matrix in the large envelope robust controller, thereby solving the large envelope robust controller.

[0141] In a specific embodiment, the solvability condition of the state feedback gain matrix to be designed is designed, and the expression is specifically:

[0142]

[0143] in, and is a given positive number, Φ SOS is a set of SOS polynomials,

[0144] is an n×n dimensional symmetric polynomial matrix, is an m×n dimensional polynomial matrix, k R is a constant.

[0145] Solving the state feedback matrix using SOS technology The solvability condition of , the state feedback gain matrix is ​​obtained as:

[0146]

[0147] In this embodiment, ε1=ε2=ε3=10 -6 , k R =0.01. The large envelope robust controller obtained by using the SOS toolbox in Matlab is: K = [k 11 ,k 12 ;k 21 ,k 22 ],in,

[0148] k 11 =0.07907n L 2 +1.124*10 -10 n L n H -1.631*10 -8 n L +0.000403n H 2 -17.55n H -10.21

[0149] k 12 =-0.3095n L 2 -4.398*10 -10 n Ln H +6.369*10 -8 n L -0.001578n H 2 +115.4n H -44.61

[0150] k 21 =-0.0007736n L 2 -1.099*10 -12 n L n H +1.593*10 -10 n L -3.943*10 -6 n H 2 -0.04534n H +0.2149

[0151] k 22 =0.00412n L 2 +5.855*10 -12 n L n H -8.538*10 -10 n L +2.1*10 -5 n H 2 -0.5422n H +0.7073

[0152] Continue to refer to Figure 1 , after step S4,

[0153] S5. Design a PI controller for the turbofan engine in the throttling state, and use a switching module to combine the PI controller and the large envelope robust controller into a full envelope controller, so that the turbofan engine uses the PI controller in the throttling state, and switches to the large envelope robust controller through the switching module in other states.

[0154] In a specific embodiment, since the large envelope NPV model of the turbofan engine does not have the characteristics of a low working state, the large envelope robust controller designed based on the NPV model has a poor control effect below the throttling state. Therefore, a traditional PI controller is used below the throttling state. PI control is a classic control algorithm that forms a control deviation based on a given value and an actual output value, and controls the controlled object by linearly combining the proportion and integral of the deviation to form a control quantity. The control law expression of the PI controller is as follows:

[0155]

[0156] Among them, K p and T i is a constant, and e(t) is the system error. In this embodiment, K p =150, T i =1.

[0157] The designed large envelope robust controller and PI controller are combined through a switching module. In this embodiment, the switching module is specifically a switching switch. In this way, a PI-PP hybrid control strategy is adopted, that is, the turbofan engine is controlled by a traditional PI controller when it is below the throttle state, and a large envelope robust controller is used when it is above the throttle state, which ultimately ensures the control effect of the turbofan engine closed-loop system under full envelope flight conditions. The control law of the combined full envelope controller is:

[0158]

[0159] Where PLA is the throttle lever angle, V is a constant, K R , K p , T i is the parameter to be adjusted. In this embodiment, V=41.

[0160] Figure 2 FIG. 4 shows a structure diagram of a turbofan engine control system according to a specific embodiment of the present application. Figure 2 As shown, the implementation principle of this application is:

[0161] Aiming at the steady-state and transitional control problems of the full envelope of turbofan engines, a large envelope robust controller and a PI controller are designed, and a full envelope controller is combined by using a switch. The turbofan engine control system converts the performance indicators of the system into the design indicators of the full envelope controller based on the preset performance method, so that the full envelope controller can better adapt to the nonlinear model of the engine and thus have better control stability. The turbofan engine control system adopts a PI-PP hybrid control strategy, that is, the turbofan engine uses a PI controller in the throttling state, and a large envelope robust controller is used in other flight states, which ultimately ensures the control effect of the turbofan engine closed-loop system under full envelope flight conditions.

[0162] According to a second aspect of the present application, a simulation method for a turbofan engine full envelope controller is proposed, and the simulation method is used to simulate the software part and the hardware part of the above-mentioned full envelope controller.

[0163] Figure 3 A flow chart of a simulation method of a turbofan engine full envelope controller according to an embodiment of the present application is shown, as shown in FIG. Figure 3 As shown, the simulation method includes the following steps:

[0164] a) Build a full envelope controller on a fully digital simulation platform.

[0165] In a specific embodiment, the all-digital simulation platform can use Matlab or Simulink. In this embodiment, the all-digital simulation platform specifically uses Simulink, which can achieve rapid modeling and simulation, and use the automatic code generation function in Simulink to generate C code from the packaged component-level real-time model. The generated code can be used for hardware-in-the-loop and semi-physical simulation verification.

[0166] Figure 4 A schematic diagram showing the main structural division of a fully digital simulation platform according to a specific embodiment of the present application is shown in FIG. Figure 4 As shown in the figure, the turbofan engine full digital simulation platform is a full digital simulation of the turbofan engine component-level real-time model, which is mainly composed of five modules: flight control command signal, controller, actuator, engine and observation signal. The flight control command signal module can realize the setting of the aircraft's flight altitude (H), Mach number (Ma) and throttle lever angle (PLA) to adjust the aircraft's working state; the controller is the implementation part of the engine control algorithm to ensure that the engine runs smoothly under a given working state.

[0167] In order to control the input main fuel quantity and throat area, the corresponding PI control module is provided in the all-digital simulation platform to realize closed-loop control below the throttling state. On this basis, the large envelope robust controller designed in the first aspect of this application is substituted into the component-level model of the all-digital simulation platform for control to ensure the stable operation of the turbofan engine system within the large envelope range. Then, different controllers are switched by switching the switch, that is, the PI controller is used below the throttling state, and the large envelope robust controller is used above the throttling state to form a full envelope controller to ensure the control effect of the closed-loop system under the full envelope flight conditions. Figure 5 A block diagram of a full envelope controller for main fuel quantity according to a specific embodiment of the present application is shown. Figure 6 A block diagram of a full envelope controller of throat area according to a specific embodiment of the present application is shown.

[0168] Continue to refer to Figure 3 , after step a),

[0169] b) Use the gain adjustment method to optimize the full envelope controller.

[0170] Specifically, step b) specifically includes:

[0171] b1) Determine multiple typical operating points according to the flight altitude and Mach number of the turbofan engine, and use a grid search method to select the parameters in the full envelope controller that optimize the dynamic performance of the turbofan engine closed-loop system under different typical operating points and different operating conditions, so as to achieve parameter tuning;

[0172] b2) The parameters are adjusted by combining the linear interpolation method so that the closed-loop system of the turbofan engine meets the performance index requirements at all operating points and is integrated into a variable gain full envelope controller.

[0173] In a specific embodiment, in order to further improve the control effect of the full envelope controller, the full envelope controller parameters are adjusted at different typical working points based on the gain adjustment method, so as to ensure that the performance of the closed-loop system meets the given control effect. The designed full envelope controller has good robustness to the unmodeled dynamics. Increase the adjustable parameter K u , K1, then the control law of the full envelope controller to be optimized is:

[0174]

[0175] Among them, K u Like K1, it is a parameter to be adjusted.

[0176] In a specific embodiment, five typical working points (0, 0), (8, 1.2), (3, 0.3), (6, 0.6) and (4, 0.8) are selected according to the flight altitude H and the Mach number Ma. The controller parameters of the three working states of throttling, intermediate and afterburner at the five typical working points are grid searched respectively to select the parameters with the best dynamic performance. The optimization index function variable is taken as the engine high pressure rotor speed n H and pressure ratio π, and define the deviation e nH and e π The normalized deviation is:

[0177]

[0178] Among them, e * nH (t) is the normalized deviation of the high-pressure rotor speed deviation, e * π (t) is the normalized deviation of the pressure ratio deviation, n H (0), n Href They represent the initial value and expected value of the high-pressure rotor speed of the closed-loop system respectively; π(0), π ref They represent the initial value and expected value of the pressure ratio respectively.

[0179] Then, the normalized ITAE index is defined for the high-pressure rotor speed and pressure ratio:

[0180]

[0181] Therefore, the normalized form of the objective function is:

[0182]

[0183] Among them, ω1, ω2 are the weight coefficients corresponding to each indicator component, which are dimensionless. The weight coefficients of the indicator components are taken as: ω1 = 1, ω2 = 1.

[0184] Therefore, the controller parameter optimization problem is transformed into solving the optimization According to the normalized form of the objective function, the grid search method can be used to adjust the parameters. In the parameter adjustment of the large envelope robust controller, K u The search range of K is (0, 1) and the search step is 0.1; the search range of K1 is (0, 0.1) and the search step is 0.01; R The search range is (-0.1, 0) and the search step is 0.01. In the parameter setting of the PI controller, K P The search range is (0, 200) and the search step is 1; T i The search range is (0, 10), the search step is 0.1, and the search results are shown in Tables 1 and 2.

[0185] Table 1 Parameters of large envelope robust controller

[0186]

[0187]

[0188] Table 2 PI controller parameters

[0189]

[0190] After the parameters are adjusted, the linear interpolation method is used to combine the adjusted parameter values ​​so that the turbofan engine closed-loop system meets the performance index requirements at all operating points and is integrated into a variable gain full envelope controller.

[0191] Continue to refer to Figure 3 , after step b),

[0192] c) Perform full digital simulation on the optimized full envelope controller.

[0193] d) The full envelope controller is used in hardware form to conduct steady-state and dynamic experiments on hardware-in-the-loop platforms and semi-physical platforms.

[0194] Among them, the hardware-in-the-loop simulation system has real I / O interfaces, controller hardware equipment, and virtual controlled object models, and is a control algorithm test and verification method with high confidence. Semi-physical simulation has a real oil circuit system, which can integrate and test the controller, hydraulic mechanical system, and related sensors, and has higher realism than hardware-in-the-loop simulation. Therefore, hardware-in-the-loop simulation and semi-physical simulation tests have become the most important tests in the development of engine control systems. Newly developed control systems must undergo hardware-in-the-loop simulation and semi-physical simulation tests before they can be installed and tested on the bench.

[0195] In a specific embodiment, a flight trajectory and five typical working points are randomly selected within the flight envelope of a certain type of small bypass ratio twin-shaft turbofan engine, and the designed full envelope controller is tested in software form on a full digital simulation platform, and the designed full envelope controller is tested in hardware form on a hardware-in-the-Loop (HIL) platform and a semi-physical platform. At the five working points (0, 0), (8, 1.2), (3, 0.3), (6, 0.6) and (4, 0.8), a large range of throttle lever steps are made respectively, and the control effect is observed according to the dynamic response curve, so as to verify the performance of the designed full envelope controller.

[0196] Full digital simulation experiment:

[0197] The full digital simulation experiment includes arbitrary flight trajectory simulation experiments and single working condition simulation experiments. The single working condition simulation experiment includes steady-state simulation experiments and dynamic simulation experiments at five points: (0, 0), (8, 1.2), (3, 0.3), (6, 0.6) and (4, 0.8). The steady-state simulation test mainly verifies the controller performance when the throttle lever has a small step in the throttle state, the intermediate state, and the afterburner state, and the throttle lever has a small step (±5°). The dynamic (or transition state) simulation test mainly verifies the performance of the full envelope controller when the throttle lever quickly and significantly steps when the slow car enters throttling, the slow car enters the intermediate state, the slow car enters full afterburner, the throttle enters slow car, the intermediate enters slow car, and the full afterburner enters slow car.

[0198] Figure 7 FIG. 1 shows a given PLA variation diagram when a turbofan engine is in a throttling state according to a specific embodiment of the present application. Figure 8 FIG. 1 shows a given PLA variation diagram when a turbofan engine is in an intermediate state according to a specific embodiment of the present application. Fig. 9 FIG. 4 shows a given PLA variation diagram when a turbofan engine is in an afterburner state according to a specific embodiment of the present application, as shown in FIG. Figure 7-9As shown, 0 to 20 seconds and 80 to 100 seconds in the throttling state are dynamic simulation experiments, and 20 to 80 seconds are steady-state simulation experiments. 0 to 20 seconds and 100 to 120 seconds in the intermediate and boost states are dynamic simulation experiments, and 20 to 100 seconds are steady-state simulation experiments.

[0199] (1) Simulation experiment of arbitrary flight trajectory within the envelope:

[0200] Fig.10 : is a graph showing the change of the flight altitude, Mach number and throttle lever angle over time within the envelope of a turbofan engine according to a specific embodiment of the present application, such as Fig.10 As shown, the flight trajectory includes processes such as taxiing, take-off, climbing, cruising, accelerating, climbing, and accelerating. Fig.11 shows a high-pressure rotor speed variation curve obtained by a flight trajectory simulation experiment according to a specific embodiment of the present application, Fig.12 FIG. 4 shows a curve diagram of engine pressure ratio variation obtained by a flight trajectory simulation experiment according to a specific embodiment of the present application. Fig.11 , 12 As shown in the figure, it can be seen from the simulation results that with the change of flight conditions, the speed and pressure ratio of the engine high-pressure rotor can track the control target given by the control plan, and the dynamic response is good. The full-envelope controller shows good robustness and stability, and can meet the requirements of turbofan engine control within the envelope.

[0201] (2) Single working condition simulation experiment:

[0202] The performance index requirements of the full digital simulation test are as follows: the adjustment time of the high-pressure rotor speed control is within 4 seconds, the steady-state error is no more than 0.1%, and the overshoot is no more than 1%; the steady-state error of the low-pressure rotor is no more than 0.1%. The steady-state error of the engine pressure ratio is no more than 0.5%.

[0203] The steady-state test results of each working point are shown in Table 3.

[0204] Table 3 Steady-state experimental results record

[0205]

[0206]

[0207] In the dynamic experiment, the experimental results of the PLA rising process are shown in Table 4.

[0208] Table 4 Dynamic experiment (PLA rising process) result record

[0209]

[0210] The experimental results of the PLA falling process are shown in Table 5.

[0211] Table 5 Dynamic experiment (PLA falling process) result record

[0212]

[0213]

[0214] Among them, NA means that the corresponding value cannot be calculated. The simulation result diagram of point (0, 0) is selected for display.

[0215] Fig.13 The figure shows the high-pressure rotor speed variation curve obtained by simulating the throttling state of the working point (0, 0) in a single-operating-condition simulation experiment according to a specific embodiment of the present application. Fig.14 The figure shows the high-pressure rotor speed variation curve obtained by simulating the intermediate state of the working point (0, 0) in a single-operating-condition simulation experiment according to a specific embodiment of the present application. Fig.15 The high-pressure rotor speed variation curve obtained by simulating the single-operating-condition simulation experiment under the force-added state at the working point (0, 0) according to a specific embodiment of the present application is shown; Fig.16 The figure shows the engine pressure ratio variation curve obtained by simulating the intermediate state of the working point (0, 0) in a single working condition simulation experiment according to a specific embodiment of the present application. Fig.17 The figure shows the engine pressure ratio variation curve obtained by simulating the engine pressure ratio variation curve at the working point (0, 0) in the boost state according to a single working condition simulation experiment of a specific embodiment of the present application.

[0216] It can be seen from the experimental result record that in the steady-state control experiment, the control effect of each working point meets the performance index requirements; in the dynamic control experiment, except that the high-pressure rotor speed adjustment time in some states exceeds 4 seconds, other performances meet the index requirements. The reason for the long adjustment time is that when the reference state changes significantly, it cannot change significantly due to the physical limitation of the fuel amount.

[0217] From the simulation results, it can be seen that the steady-state error of the high-pressure rotor speed is no more than 0.1%, and the overshoot is no more than 1%; the speed can quickly and smoothly keep up with the system's instructions, and the error converges quickly. The steady-state error of the engine pressure ratio is no more than 0.5%. At slow speed and below, the engine pressure ratio is open-loop control, so it does not track the reference value. The full digital simulation results show that the turbofan engine large envelope controller can ensure the stability of the system within the full envelope range, meet the requirements of multiple performance indicators, and the system has good dynamic characteristics, the controller has good control effect, and has a certain robust stability.

[0218] Hardware-in-the-loop (HIL) simulation and semi-physical simulation experiments:

[0219] In addition to completing the steady-state and dynamic experiments of the five working points in the full digital simulation experiment, the hardware-in-the-loop simulation and semi-physical simulation experiments also conducted a pull-off experiment on the three working points (0, 0), (3, 0.3) and (8, 1.2), that is, the high and low rotor moments of inertia were pulled off by 10% throughout the entire process. The dynamic and steady-state experimental results of the five single-operating experimental points and the three pull-off single-operating experimental points obtained by the hardware-in-the-loop simulation experiment are shown in Table 6, Table 7 and Table 8 respectively. The transition state and steady-state experimental results of the five single-operating experimental points and the three pull-off single-operating experimental points obtained by the semi-physical are shown in Table 9, Table 10 and Table 11 respectively.

[0220] Table 6 HIL dynamic experiment (PLA rising process) result record

[0221]

[0222]

[0223] Table 7 HIL dynamic experiment (PLA descent process) result record

[0224]

[0225] Table 8 HIL steady-state test result record

[0226]

[0227]

[0228] Table 9 Results of semi-physical dynamic experiment (PLA rising process)

[0229]

[0230]

[0231] Table 10 Result record of semi-physical dynamic experiment (PLA descent process)

[0232]

[0233] Table 11 Semi-physical steady-state experimental results record

[0234]

[0235] It can be seen from the experimental result record table that in the dynamic test, the steady-state errors and overshoots of the five single-operating condition test points and the three single-operating condition test points with deviations all meet the performance index requirements. In addition, the adjustment time of some pressure ratios is too long and the overshoot is too large. The reason for the adjustment time timeout is that when the high-pressure rotor speed changes significantly, the speed cannot be changed significantly due to the limitation of the fuel amount. In the steady-state test, the high-pressure rotor adjustment time, steady-state error and overshoot of the five single-operating condition test points and the three single-operating condition test points with deviations all meet the performance index requirements.

[0236] In summary, the full envelope controller can meet the design requirements of the control system, and can theoretically guarantee the global stability of the system, so that the control system has good performance in the entire envelope range. The experimental results show that under the condition of a wide range of engine speed changes, the full envelope controller can keep the system stable in the full envelope range, meet the given multi-performance index requirements, and have good dynamic performance and robustness.

[0237] This application proposes a design method and simulation method for a full envelope controller for a turbofan engine. In the fully digital simulation stage, in order to overcome the problem that the controller designed by the NPV model of the turbofan engine has poor control effect below the throttling state, a PI-PP hybrid control strategy is proposed. The control effect of the turbofan engine closed-loop system under full envelope flight conditions is finally guaranteed by the switching strategy of the full envelope controller designed given. In view of the strong nonlinear characteristics of the nonlinear component model of the turbofan engine, the gain adjustment method is used to optimize the full envelope controller, so that the full envelope controller can better adapt to the nonlinear model of the engine, and the control effect is further improved. In the hardware-in-the-loop simulation and semi-physical simulation experiments, the full envelope controller built based on the above strategy can ensure that the system has global stability within the full envelope range. On the basis of meeting the steady-state performance, it can also ensure that the transition (dynamic) process can fully meet the given multi-performance index requirements, and the turbofan engine closed-loop system has good robustness.

[0238] In the embodiments of the present application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device / system / method embodiments described above are only schematic. For example, the division of the units can be a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of units or modules, which can be electrical or other forms.

[0239] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple units. Some or all of the units may be selected according to actual needs to achieve the purpose of the present embodiment.

[0240] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0241] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions to enable a computer device (which can be a personal computer, a server or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), mobile hard disk, disk or optical disk and other media that can store program codes.

[0242] Obviously, those skilled in the art can make various modifications and changes to the embodiments of the present application without departing from the spirit and scope of the present application. In this way, if these modifications and changes are within the scope of the claims of the present application and their equivalents, the present application is also intended to cover these modifications and changes. The word "comprising" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are recorded in mutually different dependent claims does not indicate that the combination of these measures cannot be used to profit. Any figure mark in the claims should not be considered to limit the scope.

Claims

1. A design method for a turbofan engine full envelope controller, characterized in that: The following steps are involved: S1, establishing an NPV model of the turbofan engine including external disturbances, and converting the NPV model into an uncertain model according to the external disturbances; S2. Based on the uncertain model, a large envelope robust controller is designed. The expression of the large envelope robust controller is specifically: in, is the state feedback gain matrix to be designed, k R is an adjustable coefficient, is the preset performance parameter matrix to be designed; S3. According to the performance index requirements of the turbofan engine closed-loop system, a preset performance parameter matrix in the large envelope robust controller is designed. The design process of the preset performance parameter matrix is ​​specifically as follows: based on the preset performance parameter matrix to be designed, a difference operation is performed between the value of the system state at any time and the preset expected value to obtain a state error, a performance function is introduced and an error transformation function is defined, and the preset performance parameter matrix is ​​designed; S4. Using the SOS technology, a state feedback gain matrix in the large envelope robust controller is solved, thereby solving the large envelope robust controller. The process of solving the state feedback gain matrix specifically includes: The solvability condition of the state feedback gain matrix to be designed is designed, and the specific expression is: in, and is a given positive number, Φ SOS is a set of SOS polynomials, is an n×n dimensional symmetric polynomial matrix, is an m×n dimensional polynomial matrix, k R is a constant; The solvability condition of the state feedback gain matrix to be designed is solved by using the SOS technology to obtain the state feedback gain matrix. The expression of the state feedback gain matrix is ​​specifically as follows: S5. Design a PI controller for the turbofan engine in the throttling state, and use a switching module to combine the PI controller and the large envelope robust controller into the full envelope controller, so that the turbofan engine uses the PI controller in the throttling state, and switches to the large envelope robust controller through the switching module in other states.

2. The design method according to claim 1, characterized in that: The NPV model including external disturbance is specifically: in, is the system status, is the control input, is the time-varying parameter vector, is an n-dimensional real vector space, is an s-dimensional real vector space, A(·,·), B(·,·) and C(·,·) are polynomial matrices with respect to x and ρ(t), ω(t) is an external perturbation, and E1 is a constant matrix of appropriate dimension; The uncertainty model is specifically: Among them, ΔF1x(t) is the transformed external disturbance, Δ is the uncertainty matrix, and satisfies Δ T Δ≤I, F1, I are constant matrices and unit matrices of appropriate dimensions, respectively, satisfying F1 T F1≥0.

3. The design method according to claim 2, characterized in that: The performance index requirements of the turbofan engine closed-loop system are specifically as follows: the high-pressure rotor speed control steady-state error, dynamic overshoot, step response time, nozzle closed-loop control pressure ratio steady-state error and speed dynamic overshoot under high-pressure rotor speed disturbance of the turbofan engine are all within the preset thresholds; The expression of the preset performance parameter matrix is ​​specifically: Among them, the continuous function T is defined as the error transformation function T i (x,t), is the state error of the turbofan engine closed-loop system, ρ i (t) is the introduced performance function and i is the index variable.

4. The design method according to claim 3, characterized in that: The control law expression of the PI controller is specifically: Among them, K p and T i is a constant and e(t) is the system error.

5. The design method according to claim 4, characterized in that: The control law expression of the full envelope controller is specifically: Where PLA is the throttle lever angle, V is a constant, K R are the parameters to be adjusted.

6. A turbofan engine full envelope controller simulation method, characterized in that: The full envelope controller in the design method according to any one of claims 1 to 5 is simulated, comprising the following steps: a) constructing the full envelope controller on a full digital simulation platform; b) optimizing the full envelope controller by using a gain adjustment method; c) performing full digital simulation on the optimized full envelope controller; Wherein, the step b) specifically comprises: b1) determining a plurality of typical operating points according to the flight altitude and Mach number of the turbofan engine, and selecting the parameters in the full envelope controller that optimize the dynamic performance of the turbofan engine closed-loop system by using a grid search method under different typical operating points and different operating conditions, thereby setting the parameters; b2) The parameters adjusted by combining the linear interpolation method are adopted so that the closed-loop system of the turbofan engine meets the performance index requirements at all operating points and is integrated into a variable gain full envelope controller.

7. The simulation method according to claim 6, characterized in that: The control law expression of the full envelope controller to be optimized in step b) is specifically: Among them, K u , K1, K R , K p , T i are the parameters to be adjusted.

8. The simulation method according to claim 6, characterized in that: Also includes: The full envelope controller is used in hardware form to carry out steady-state experiments and dynamic experiments on a hardware-in-the-loop platform and a semi-physical platform.

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