Engine direct thrust control method and system based on thrust response trajectory optimization

Abstract

The present application belongs to the technical field of aero-engine control, and particularly relates to an engine direct thrust control method and system based on thrust response trajectory optimization. According to initial state parameters and target state parameters of the engine, a target open-loop slope with the shortest engine thrust response time is iteratively found under constraint conditions by an interior point method, with the thrust response time as a target function; and a target thrust control quantity is obtained according to an initial fuel flow value, an initial value of a nozzle throat area and the target open-loop slope. The control method of the present application can greatly improve the engine thrust response speed and enhance the aircraft limit maneuverability under the premise of ensuring safe operation; compared with conventional proportional integral control, the present application avoids the transfer process of state quantities of indirect control, and directly controls the thrust in the target range, thereby greatly shortening the thrust response time.

Description

Technical Field

[0001] This invention belongs to the field of aero-engine control technology, and particularly relates to a direct thrust control method and system for engines based on thrust response trajectory optimization. Background Technology

[0002] Modern aircraft place higher performance demands on propulsion systems, particularly in areas such as agile handling, rapid acceleration, and safety. In highly dynamic flight environments, aircraft require frequent and rapid thrust adjustments to cope with environmental disturbances, correct flight attitude, or execute emergency evasive maneuvers. Currently, traditional aero-engine control systems primarily rely on closed-loop regulation of internal state parameters to achieve thrust management, such as controlling high-pressure turbine speed by adjusting fuel supply or controlling engine pressure ratio by adjusting nozzle area. These control methods are typically combined with safety protection mechanisms to ensure the engine always operates at its planned power point, thus indirectly achieving thrust control. However, such indirect thrust control strategies have inherent limitations and cannot achieve optimal thrust response performance. Summary of the Invention

[0003] This invention provides a direct thrust control method and system for engines based on thrust response trajectory optimization, which shortens the thrust adjustment response time and improves the maneuverability of aircraft, thereby solving the technical problems mentioned in the background art.

[0004] One technical solution of the present invention is as follows: A direct thrust control method for an engine based on thrust response trajectory optimization, comprising: S10: Based on the engine's initial state parameters and target state parameters, and with thrust response time as the objective function, the target open-loop slope with the shortest engine thrust response time is iteratively found under constraints using the interior point method. S20; Based on the initial value of fuel flow, the initial value of nozzle throat area, and the target open-loop slope, obtain the target thrust control quantity.

[0005] Furthermore, the initial state parameters of the engine include: the initial high-pressure rotor speed, the initial pressure ratio, and the initial thrust. The target state parameters include: engine target high-pressure rotor speed, engine target pressure ratio, and engine target thrust. ; Get the engine thrust at the current moment Based on the previous thrust Initial thrust of the engine and engine target thrust Obtain the thrust of the previous moment With engine initial thrust First thrust difference and engine target thrust and engine initial thrust Second thrust difference With the first thrust difference First time reaching the second thrust difference The time is used as the objective function; Based on the initial high-pressure rotor speed, initial engine pressure ratio, target high-pressure rotor speed, and target engine pressure ratio, set function constraints and the maximum number of iterations; According to the interior point method, the objective function is iterated under constraints. When the termination condition is met, the optimal value is returned, which is the target open-loop slope.

[0006] Further, step S20 includes: Based on the target open-loop slope and the current fuel flow rate and the nozzle throat area at the current moment Update the theoretical value of fuel flow control for the next moment. Theoretical value for nozzle throat area control Based on the maximum and minimum limits of fuel flow and nozzle throat area in the control plan, the expected value of the fuel flow control quantity at the next moment is obtained through high-low selection. And the expected value of nozzle throat area control The target thrust control quantity includes: the expected value of the fuel flow control quantity at the next moment. And the expected value of nozzle throat area control .

[0007] Furthermore, ; in, This is the theoretical value for fuel flow control. This is the theoretical value for nozzle throat area control. This represents the current fuel flow rate. T represents the nozzle throat area at the current moment. s R is the interval time. wf and R A8 Let be the target open-loop slope.

[0008] Furthermore, it also includes the theoretical value of fuel flow control. Theoretical value for nozzle throat area control To obtain the thrust in the next moment: ; in, For the thrust at the next moment, the f mapping relationship is provided by the engine's onboard data-driven thrust estimation module, and v represents other inputs to the engine model, the value of which follows the control plan according to the changes in fuel flow and nozzle throat area.

[0009] Another technical solution of the present invention is as follows: an engine direct thrust control system based on thrust response trajectory optimization, used to execute any of the above-described engine direct thrust control methods based on thrust response trajectory optimization, comprising: The thrust response dynamic trajectory optimization calculation module is used to find the target open-loop slope with the shortest engine thrust response time under constraints by using the interior point method, based on the engine's initial state parameters and target state parameters and with the thrust response time as the objective function. An equal-slope open-loop controller is used to obtain the target thrust control quantity based on the initial value of fuel flow, the initial value of nozzle throat area, and the target open-loop slope.

[0010] The beneficial effects of the present invention are as follows: Under the premise of ensuring safe operation, the control method of the present invention can significantly improve the engine thrust response speed and enhance the aircraft's extreme maneuverability. Compared with conventional proportional-integral control, the present invention avoids the state quantity transfer process of indirect control and directly controls the thrust within the target range, thereby significantly shortening the thrust response time. Attached Figure Description

[0011] Figure 1 This is a flowchart of the engine direct thrust control method based on thrust response trajectory optimization according to the present invention.

[0012] Figure 2 This is a schematic diagram of the optimal dynamic response thrust control of the present invention.

[0013] Figure 3 This is a schematic diagram of the engine direct thrust control system based on thrust response trajectory optimization according to the present invention.

[0014] Figure 4 This is a schematic diagram of the structure of the equal slope open-loop controller of the present invention. Detailed Implementation

[0015] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. The described embodiments are merely some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0016] Currently, most aero-engine thrust control uses PI controllers, with fuel flow rate W as the reference value.f The closed-loop control method utilizes the airspeed control and the A8 closed-loop control of the nozzle throat area as an indirect control method for EPR. When a flight command requires a thrust change, the control unit transfers the propulsion system from its current steady-state point to the target state according to the control plan. The traditional thrust dynamic response state transfer path is as follows: Figure 2 As shown, this path struggles to ensure the most efficient thrust adjustment, primarily because the state adjustment controller design directly considers state adjustment performance. However, in a multivariable system, the combination of various state adjustment performance parameters does not yield optimal thrust adjustment performance. Therefore, this method aims to directly target thrust adjustment performance by designing a direct thrust dynamic controller that incorporates thrust response optimization, thereby unlocking thrust response potential and enhancing aircraft performance limits and maneuverability. This method designs a dynamic thrust trajectory optimization architecture that, within a small linearization range of the engine, further focuses on engine thrust response performance while maintaining state safety constraints, improving the engine's dynamic thrust response speed. The thrust response control architecture design is as follows: Figure 2 As shown.

[0017] In one technical solution of the present invention, Figure 1 This is a flowchart illustrating a specific process of an engine direct thrust control method based on thrust response trajectory optimization according to the present invention, including: S10: Based on the engine's initial state parameters and target state parameters, with thrust response time as the objective function, the target open-loop slope that minimizes the engine's thrust response time is iteratively searched under constraints using the interior point method.

[0018] The initial state parameters of the engine include: the initial high-pressure rotor speed, the initial pressure ratio, and the initial thrust. The target state parameters include: engine target high-pressure rotor speed, engine target pressure ratio, and engine target thrust. .

[0019] Get the engine thrust at the current moment Based on the previous thrust Initial thrust of the engine and engine target thrust Obtain the thrust of the previous moment With engine initial thrust First thrust difference and engine target thrust and engine initial thrust Second thrust difference With the first thrust difference First time reaching the second thrust difference The time is used as the objective function.

[0020] Based on the initial high-pressure rotor speed, initial engine pressure ratio, target high-pressure rotor speed, and target engine pressure ratio, set function constraints and the maximum number of iterations.

[0021] According to the interior point method, the objective function is iterated under constraints. When the termination condition is met, the optimal value is returned, which is the target open-loop slope.

[0022] The interior-point optimization algorithm is invoked to find the combination of control parameter change rates that achieves the fastest thrust response. Based on the acceleration / deceleration plan, a reasonable range for parameter changes is set; and the initial thrust value is set. Initial state The value at time, the target thrust of the engine For the target state The thrust value at that time, and read the thrust at the current moment. .remember , ,by First time reaching Let time be the objective function, denoted as . Based on the input parameters, evaluate the objective function value and constraints at the current point, calculate the gradients of the objective function and constraints, set the maximum number of iterations, update the current point using the interior point method, and return the optimal solution and the objective function value at that point when the termination condition is met.

[0023] The specific formula is as follows: ; Among them, At that moment, the thrust satisfies: >0 represents the tolerance parameter.

[0024] S20; Based on the initial value of fuel flow, the initial value of nozzle throat area, and the target open-loop slope, obtain the target thrust control quantity.

[0025] like Figure 4 As shown, based on the target open-loop slope and the current fuel flow rate... and the nozzle throat area at the current moment Update the theoretical value of fuel flow control for the next moment. Theoretical value for nozzle throat area control Based on the maximum and minimum limits of fuel flow and nozzle throat area in the control plan, the expected value of the fuel flow control quantity at the next moment is obtained through high-low selection. And the expected value of nozzle throat area control The target thrust control quantity includes: the expected value of the fuel flow control quantity at the next moment. And the expected value of nozzle throat area control .

[0026] ; in, This is the theoretical value for fuel flow control. This is the theoretical value for nozzle throat area control. This represents the current fuel flow rate. T represents the nozzle throat area at the current moment. s R is the interval time. wf and R A8 Let be the target open-loop slope.

[0027] Specifically, R wf Optimal open-loop slope for fuel flow, R A8 The optimal open-loop slope for the nozzle throat area.

[0028] Constant slope open-loop control is based on the given fuel flow rate and initial values ​​of the injector throat area, using W... f The optimal open-loop slope of A8 is used to update the theoretical value of the control quantity at the next time step. , Based on the maximum and minimum limits of fuel flow and nozzle throat area in the control plan, the expected value of the target control quantity is obtained through high-low selection. and Then it is input into the engine via the actuator.

[0029] The process of this invention also includes controlling the theoretical value of fuel flow. Theoretical value for nozzle throat area control To obtain the thrust in the next moment: ; in, For the thrust at the next moment, the f mapping relationship is provided by the engine's onboard data-driven thrust estimation module, and v represents other inputs to the engine model, the value of which follows the control plan according to the changes in fuel flow and nozzle throat area.

[0030] In another technical solution of the present invention, Figure 3 This is a schematic diagram of a direct thrust control system for an engine based on thrust response trajectory optimization, according to the present technical solution. This system is used to execute any of the aforementioned direct thrust control methods for an engine based on thrust response trajectory optimization, including: The thrust response dynamic trajectory optimization calculation module is used to find the target open-loop slope with the shortest engine thrust response time under constraints by using the interior point method, based on the engine's initial state parameters and target state parameters and with the thrust response time as the objective function. An equal-slope open-loop controller is used to obtain the target thrust control quantity based on the initial value of fuel flow, the initial value of nozzle throat area, and the target open-loop slope.

[0031] The engine direct thrust control system architecture based on thrust response trajectory optimization provided by this invention is as follows: Figure 4 As shown, it includes two main modules: a thrust response dynamic trajectory optimization calculation module and a constant-slope open-loop controller. The thrust response dynamic trajectory optimization calculation module uses the state variables (high-pressure rotor speed) of the engine under initial and target states. The engine thrust response control is achieved by taking the pressure ratio (EPR) and thrust (F) as inputs and calculating the optimal open-loop slope of the control quantity during the thrust transfer process. The constant-slope open-loop controller inputs the calculated optimal open-loop slope into the controller to obtain the control quantity, thereby achieving the fastest coordinated engine thrust response control.

[0032] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A direct thrust control method for an engine based on thrust response trajectory optimization, characterized in that, include: S10: Based on the engine's initial state parameters and target state parameters, and with thrust response time as the objective function, the target open-loop slope with the shortest engine thrust response time is iteratively found under constraints using the interior point method. S20; Based on the initial value of fuel flow, the initial value of nozzle throat area, and the target open-loop slope, obtain the target thrust control quantity.

2. The engine direct thrust control method based on thrust response trajectory optimization as described in claim 1, characterized in that, The initial state parameters of the engine include: the initial high-pressure rotor speed of the engine, the initial pressure ratio of the engine, and the initial thrust of the engine. The target state parameters include: the target high-pressure rotor speed of the engine, the target pressure ratio of the engine, and the target thrust of the engine. ; Get the engine thrust at the current moment Based on the previous thrust Initial thrust of the engine and engine target thrust Obtain the thrust of the previous moment With engine initial thrust First thrust difference and engine target thrust and engine initial thrust Second thrust difference With the first thrust difference First time reaching the second thrust difference The time is used as the objective function; Based on the initial high-pressure rotor speed, initial pressure ratio, target high-pressure rotor speed, and target pressure ratio of the engine, set the function constraints and the maximum number of iterations; According to the interior point method, the objective function is iterated under constraints. When the termination condition is met, the optimal value is returned, which is the target open-loop slope.

3. The engine direct thrust control method based on thrust response trajectory optimization as described in claim 1, characterized in that, Step S20 includes: Based on the target open-loop slope and the current fuel flow rate and the nozzle throat area at the current moment Update the theoretical value of fuel flow control for the next moment. Theoretical value for nozzle throat area control Based on the maximum and minimum limits of fuel flow and nozzle throat area in the control plan, the expected value of the fuel flow control quantity at the next moment is obtained through high-low selection. And the expected value of nozzle throat area control The target thrust control quantity includes: the expected value of the fuel flow control quantity at the next moment. And the expected value of nozzle throat area control .

4. The engine direct thrust control method based on thrust response trajectory optimization as described in claim 3, characterized in that, ； in, This is the theoretical value for fuel flow control. This is the theoretical value for nozzle throat area control. This represents the current fuel flow rate. T represents the nozzle throat area at the current moment. s R is the interval time. wf and R A8 Let be the target open-loop slope.

5. The engine direct thrust control method based on thrust response trajectory optimization as described in claim 4, characterized in that, This also includes the theoretical value of fuel flow control. Theoretical value for nozzle throat area control To obtain the thrust in the next moment: ； in, For the thrust at the next moment, the f mapping relationship is provided by the engine's onboard data-driven thrust estimation module, and v represents other inputs to the engine model, the value of which follows the control plan according to the changes in fuel flow and nozzle throat area.

6. An engine direct thrust control system based on thrust response trajectory optimization, characterized in that, The method for executing the engine direct thrust control based on thrust response trajectory optimization as described in any one of claims 1-5 includes: The thrust response dynamic trajectory optimization calculation module is used to find the target open-loop slope with the shortest engine thrust response time under constraints by using the interior point method, based on the engine's initial state parameters and target state parameters and with the thrust response time as the objective function. An equal-slope open-loop controller is used to obtain the target thrust control quantity based on the initial value of fuel flow, the initial value of nozzle throat area, and the target open-loop slope.

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