Design and verification method of distributed control system for variable cycle engine mode switching

Abstract

The present invention discloses a design and verification method for a distributed control system platform for the mode switching process of a variable-cycle engine. First, a multi-loop PI controller with limited protection is designed, and a multi-loop PI control algorithm for mode switching is developed. Second, a distributed control simulation and verification platform for the variable-cycle engine is designed, and a platform of intelligent simulation nodes is built according to the principle of minimization. Then, a communication scheduling table for the distributed control simulation platform of the multi-loop PI is designed, and communication functions between multiple intelligent nodes are developed. Finally, the engine model and control algorithm are transplanted and deployed to the distributed control simulation platform, and the quality of the control system in an environment containing random noise is verified. The present invention provides a feasible control scheme for the transient state control of the variable-cycle engine, including mode switching, and designs a distributed controller with multiple adjustable parameters for the variable-cycle engine and its simulation platform. Simulation results show that the designed multivariable controller has good robustness to noise under the distributed architecture.

Description

Technical Field

[0001] The present invention belongs to the field of aero-engine control system design, and in particular relates to a distributed control system design and verification method for variable cycle engine mode switching. Background Art

[0002] Variable-cycle engines, with their mode switching and variable geometry characteristics, are becoming a research and development direction for next-generation power plants, improving key performance indicators such as fuel consumption and thrust-to-weight ratio. Inevitably, with the increased control complexity and control logic required for variable-cycle engines, traditional centralized control structures are no longer sufficient. Therefore, distributed engine control structures are key to the further development of variable-cycle engine control systems. Once a complete control system is designed, it is unrealistic to directly apply it to a real engine for test runs. Digital and hardware simulations of the control system are required to correct any issues. Simulation research on distributed control systems for variable-cycle engines can help reduce control system design cycles and costs, improve cost-effectiveness, and positively impact the application of advanced control systems in variable-cycle engines. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiency that the multivariable controller of a variable cycle engine can only be simulated under a centralized control architecture, and provide a distributed control system design and verification method for variable cycle engine mode switching, and build a simulation platform for experimental verification, which not only verifies the effectiveness of the control algorithm, but also improves the development efficiency of the distributed control system of the variable cycle engine, and provides an experimental basis for the application of other advanced control algorithms under a distributed architecture.

[0004] Technical solution: The present invention adopts the following technical solution to solve the above technical problems:

[0005] Step 1) Designing a transient control plan for a variable cycle engine including the mode switching process, and developing a multi-loop PI control algorithm and controller with limit protection for the mode switching process;

[0006] Step 2) Design a variable cycle engine distributed control simulation platform based on the TTP / C bus protocol, and build a simulation platform that includes five intelligent nodes, including an engine simulator node, a data processing node, and a control node;

[0007] Step 3) Design a communication schedule for a distributed control simulation platform based on the TTP toolset for multi-loop PI and develop communication functions between multiple intelligent nodes;

[0008] Step 4) Build a distributed control system for variable-cycle engine mode switching, complete the migration and deployment of the engine mathematical model and control algorithm to the hardware platform, and verify the control quality of the multi-loop PI controller with limit protection during the mode switching process on a distributed simulation platform with a noisy environment.

[0009] As an implementation scheme of a distributed control system design and verification method for variable cycle engine mode switching of the present invention, step 1) includes:

[0010] Step 1.1) Design a multivariable control scheme for the variable cycle engine in single / dual bypass mode, using the main fuel flow rate and tail nozzle throat area to control the high-pressure rotor speed and engine pressure ratio. Open-loop control is used for the adjustable ejector area and the guide vane angle of the adjustable component. Limiting parameters such as thrust and surge margin are added during mode switching to ensure safe, reliable, and stable operation of the variable cycle engine during mode switching.

[0011] Step 1.2) Develop a multi-loop PI control algorithm and controller with limiting protection for the transient process of the variable cycle engine including mode switching;

[0012] As an implementation scheme of the distributed control system design and verification method for variable cycle engine mode switching of the present invention, step 1.2) specifically includes: including adopting the Min-Max structure to design a limiting protection module, wherein the limiting protection parameters selected in this paper are specifically (1) high-pressure rotor speed; (2) high-pressure compressor outlet total pressure; (3) low-pressure turbine outlet total temperature; (4) minimum fuel quantity limit; in the mode switching process, it is also necessary to add limiting protection parameters (5) engine thrust; (6) surge margin. The fuel increment calculated by each limiting controller and the fuel increment calculated by the acceleration and deceleration controller are compared with the minimum fuel quantity through the high-low selection logic strategy to finally determine the optimal fuel instruction and select the appropriate W f as input to the engine.

[0013] As an implementation of the adaptive cycle engine embedded control system simulation method of the present invention, step 2) includes:

[0014] Step 2.1) Design a distributed control simulation platform architecture. Given limited computing resources, divide the tasks of computing engine control variables among control nodes to meet real-time requirements.

[0015] Step 2.2) Use CodeWarrior software to complete the configuration of the underlying hardware environment;

[0016] As an implementation scheme of the distributed control system design and verification method for variable cycle engine mode switching of the present invention, step 2.1) specifically includes: including intelligent control node A to control the high-pressure rotor speed for the main fuel flow, intelligent control node B to control the engine pressure ratio for the tail nozzle throat area, intelligent control node C to control the angle of each guide vane and the open-loop control of the ejector area of ​​the front and rear ducts, the data processing node is used to calculate and process the engine output signal and the actuator output signal, and the engine simulator node is used to calculate the mathematical model of the variable cycle engine. After receiving the mode switching frame, each simulation node switches to the second working mode, and the intelligent control node C adjusts the adjustable ejector area A of the switching process according to the preset instructions. 114 、A 163 、A 224 and adjustable guide vane angle α Fan , α CDFS , α Comp , α LTurb Write to the TTP / C bus.

[0017] As an implementation scheme of a distributed control system design and verification method for variable cycle engine mode switching of the present invention, step 3) includes:

[0018] Step 3.1) Use TTP_Plan software to design a distributed control simulation platform cluster scheduling plan for the variable cycle engine acceleration and deceleration process and mode switching process;

[0019] Step 3.2) Generate a portable schedule using TTP_Build software and complete hardware platform deployment via TTP_Download;

[0020] Step 3.3) Use CodeWarrior software to develop communication functions between each intelligent node in a Ram simulation environment;

[0021] As an implementation of the present invention's distributed control system design and verification method for variable-cycle engine mode switching, step 3.1 specifically includes: designing a TDMA_Round containing twelve intelligent nodes. The TDMA_Round length is 25,000 μs, consistent with the engine control period of 25 ms. The bus is set to have three operating modes: Mode 1 is the startup mode, with identifiers 0 to 11, whose primary function is to transition each node from sleep to active after power-up; Mode 2 is the normal operating mode, with identifiers 0 to 23, facilitating monitoring of data sent by each node during normal operation; and Mode 3 is the maintenance mode, with identifiers 0 to 11, facilitating post-replacement debugging when a node experiences a hardware failure. The main configuration information for each intelligent node in the simulation platform is shown in Table 1.

[0022] Table 1

[0023]

[0024] As an implementation scheme of a distributed control system design and verification method for variable cycle engine mode switching of the present invention, step 4) includes:

[0025] Step 4.1) Build a distributed control system for variable cycle engine mode switching;

[0026] Step 4.2) Use Flagramer software to complete the code transplantation of the engine simulator node, control node, and data processing node;

[0027] Step 4.3) Add a certain amount of Gaussian white noise to the outputs of the three control nodes to simulate a real environment and conduct simulation verification of the distributed control platform during the variable cycle engine mode switching process;

[0028] The beneficial effects of the present invention are: 1. The present invention designs a multi-loop PI control algorithm and controller with limit protection using a Min-Max structure for the transition state control process of a variable cycle engine including mode switching. When conducting simulation experiments on a distributed platform, after adding a certain amount of noise to the control signal, the controller still maintains good robustness, which meets the design requirements of the variable cycle engine controller and also provides an experimental basis for the application of other advanced control algorithms on this platform.

[0029] 2. Aiming at the problems of multiple control variables and complex control structure in variable cycle engines, the present invention designs a distributed control simulation platform based on the time-triggered TTP / C bus protocol, which includes five intelligent simulation nodes: engine simulator node, data processing node, and intelligent control node. This platform not only provides a reliable simulation verification platform for the variable cycle engine multivariable controller, but also integrates various stages such as control algorithm design, software development, and hardware platform construction during the simulation process. It can quickly deploy and verify engine models and controllers, greatly improving the development efficiency of engine control systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a variable cycle engine control strategy;

[0031] Figure 2 This is the structure diagram of the variable cycle engine multivariable controller with limit protection;

[0032] Figure 3 This is the architecture diagram of the distributed control simulation platform;

[0033] Figure 4 This is a physical picture of the distributed control simulation platform;

[0034] Figure 5It is the curve diagram of the open-loop control parameters of the variable cycle engine;

[0035] Figure 6 It is a curve diagram of closed-loop control parameters of variable cycle engine;

[0036] Figure 7 It is the simulation result of distributed control platform. DETAILED DESCRIPTION

[0037] In order to help those skilled in the art better understand the technical solution of the present invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0038] The idea of ​​the present invention is to address the problem that variable-cycle engines have many control variables and complex control structures, and the traditional centralized control platform can no longer meet the requirements of simulation experiments. Based on the TTP / C bus protocol, a distributed control simulation platform is designed and built. Furthermore, under the premise of limited hardware computing resources, the tasks of each intelligent simulation node are divided, and a multi-loop PI controller with limited protection in the mode switching process is designed based on this platform. During the experiment, a certain amount of noise is added to the control signal to simulate the real environment.

[0039] The specific embodiment of the present invention takes the transient state control simulation of a variable cycle engine including the mode switching process as an example to introduce the content of the present invention in detail, including the following steps:

[0040] Step 1) Designing a transient control plan for a variable cycle engine including the mode switching process, and developing a multi-loop PI control algorithm and controller with limit protection for the mode switching process;

[0041] Step 1.1) Design a multivariable control scheme for the variable cycle engine in single / dual bypass mode, using the main fuel flow rate and tail nozzle throat area to control the high-pressure rotor speed and engine pressure ratio. Open-loop control is used for the adjustable ejector area and the guide vane angle of the adjustable component. Limiting parameters such as thrust and surge margin are added during mode switching to ensure safe, reliable, and stable operation of the variable cycle engine during mode switching.

[0042] Step 1.2) Develop a multi-loop PI control algorithm and controller with limiting protection for the transient process of the variable cycle engine including mode switching;

[0043] Step 2) Design a variable cycle engine distributed control simulation platform based on the TTP / C bus protocol, and build a simulation platform that includes five intelligent nodes, including an engine simulator node, a data processing node, and a control node;

[0044] Step 2.1) Design a distributed control simulation platform architecture. Given limited computing resources, divide the tasks of computing engine control variables among control nodes to meet real-time requirements.

[0045] Step 2.2) Use CodeWarrior software to complete the configuration of the underlying hardware environment;

[0046] Step 3) Design a communication schedule for a distributed control simulation platform based on the TTP toolset for multi-loop PI and develop communication functions between multiple intelligent nodes;

[0047] Step 3.1) Use TTP_Plan software to design a distributed control simulation platform cluster scheduling plan for the variable cycle engine acceleration and deceleration process and mode switching process;

[0048] Step 3.2) Generate a portable schedule using TTP_Build software and complete hardware platform deployment via TTP_Download;

[0049] Step 3.3) Use CodeWarrior software to develop communication functions between each intelligent node in a Ram simulation environment;

[0050] Step 4) Complete the deployment of the engine mathematical model and control algorithm to the simulation platform, and conduct experimental verification after introducing noise into the control variables.

[0051] Step 4.1) Build a distributed simulation control system;

[0052] Step 4.2) Complete the code transplantation of the engine simulator node, control node, and data processing node;

[0053] Step 4.3) Add the following N(0,0.002) to the output of the three control nodes respectively. 2 ) Normally distributed Gaussian white noise, complete experimental verification;

[0054] In order to verify the effectiveness of the distributed control system design and verification method for variable cycle engine mode switching proposed in this invention, the above-mentioned distributed platform was used to conduct simulation verification of the variable cycle engine multi-loop control. The specific scheme is as follows:

[0055] (1) The distributed platform simulation verification is carried out at the ground point (H = 0 km, Ma = 0), the simulation time is 60s, the single culvert mode is used from 0 to 25s, the single culvert mode is switched to the dual culvert mode from 25 to 28s, and the dual culvert mode is maintained from 28 to 60s. At t = 0 to 8s, the control instruction [N H ,EPR]=[0.908,0.631], when t=8~38s, the control instruction is [N H,EPR]=[0.955,0.880], at t=38~60s, the control command is transformed into [N H ,EPR]=[0.970,0.820], the changes of open loop parameters are shown in the attached Figure 5 As shown, the outputs of the three control nodes are added with N(0,0.002 2 ) Normally distributed Gaussian white noise is used to verify the effect of random noise on the stability of the controller during the simulation of the distributed control platform. The controller output is shown in the attached figure. Figure 6 The engine output is shown in the attached Figure 7 shown.

[0056] By the attached Figure 7 It can be seen that the distributed control simulation platform built based on the TTP / C communication protocol of the present invention can complete the experimental verification of the multivariable control of the variable cycle engine. And the controller output is added to obey N(0,0.002 2 ) After the normally distributed Gaussian white noise is input, the control steady-state error is less than 1%. During the switching process, the high-pressure rotor speed fluctuation does not exceed 2%, and the thrust fluctuation does not exceed 5%. Although the other parameters change to varying degrees, the rotor components do not overheat or overspeed, meeting the engineering design requirements for the controller.

[0057] A distributed control system design and verification method for variable cycle engine mode switching can meet the transition state control requirements of variable cycle engines, including mode switching. The distributed simulation platform designed and built based on the TTP / C communication protocol can realize experimental verification of the multivariable controller. By adding a certain amount of noise to the control signal, it is verified that the multivariable controller designed in the present invention has a certain robustness. At the same time, the control algorithm design, hardware platform construction, simulation experiment verification and other stages can be integrated in the simulation process, and the engine model and controller can be quickly deployed and verified, which greatly improves the development efficiency of the distributed control system of the variable cycle engine.

[0058] It should be noted that the above description is merely a specific embodiment of the present invention, and the scope of protection of the present invention is not limited thereto. Any changes and substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A distributed control system design and verification method for variable cycle engine mode switching, characterized in that: The following steps are involved: Step 1) Designing a transient control plan for a variable cycle engine including the mode switching process, and developing a multi-loop PI control algorithm and controller with limit protection for the mode switching process; Step 2) Designing a variable cycle engine distributed control simulation platform based on the TTP / C bus protocol, and building a simulation platform including intelligent nodes such as engine simulator nodes, data processing nodes, and control nodes; Step 3) Design a communication schedule for a distributed control simulation platform based on the TTP toolset for multi-loop PI and develop communication functions between multiple intelligent nodes; Step 4) Build a distributed control system for variable-cycle engine mode switching, complete the migration and deployment of the engine mathematical model and control algorithm to the simulation platform, and verify the control quality of the multi-loop PI controller with limit protection during the mode switching process on the distributed simulation platform in a noisy environment; The step 1) comprises: Step 1.1) Design a multivariable control scheme for the variable cycle engine in single / dual bypass mode, using the main fuel flow rate and tail nozzle throat area to control the high-pressure rotor speed and engine pressure ratio. Open-loop control is used for the adjustable ejector area and the adjustable component guide vane angle. Thrust and surge margin constraints are incorporated during mode switching to ensure safe, reliable, and stable operation of the variable cycle engine. Step 1.2) Develop a multi-loop PI control algorithm and controller with limit protection for the transition process of the variable cycle engine including mode switching, including the design of a limit protection module using a Min-Max structure, where the limit protection parameters are (1) high-pressure rotor speed; (2) high-pressure compressor outlet total pressure; (3) low-pressure turbine outlet total temperature; (4) minimum fuel quantity limit; in the mode switching process, it is also necessary to add a limit protection parameter (5) engine thrust; (6) surge margin; the fuel increment calculated by each limit controller and the fuel increment calculated by the acceleration and deceleration controller are compared with the fuel increment through a high-low selection logic strategy to finally determine the optimal fuel instruction and the minimum fuel quantity, and select the appropriate W f As input to the engine; The step 2) comprises: Step 2.1) Design a distributed control simulation platform architecture. Under the premise of limited computing resources, divide the tasks of calculating engine control variables for control nodes to meet real-time requirements, including intelligent control node A for controlling the high-pressure rotor speed for the main fuel flow, intelligent control node B for controlling the engine pressure ratio for the tail nozzle throat area, intelligent control node C for open-loop control of each guide vane angle and the area of ​​the front and rear duct ejectors, data processing nodes for calculating and processing engine output signals and actuator output signals, and engine simulator nodes for calculating the mathematical model of the variable cycle engine; after receiving the mode switching frame, each simulation node switches to the second working mode, and the intelligent control node C adjusts the adjustable ejector area A during the switching process according to the preset instructions. 114 、A 163 、A 224 and adjustable guide vane angle α Fan , α CDFS , α Comp , α LTurb Write to TTP / C bus; Step 2.2) Use CodeWarrior software to complete the configuration of the hardware underlying environment.

2. The method for designing and verifying a distributed control system for variable cycle engine mode switching according to claim 1 is characterized in that: The step 3) comprises: Step 3.1) Use TTP_Plan software to design a distributed control simulation platform cluster scheduling plan for the variable cycle engine acceleration and deceleration process and mode switching process; Step 3.2) Generate a portable schedule using TTP_Build software and complete hardware platform deployment via TTP_Download; Step 3.3) Use CodeWarrior software to develop communication functions between each intelligent node in the Ram simulation environment.

3. The method for designing and verifying a distributed control system for variable cycle engine mode switching according to claim 2 is characterized in that: Step 3.1) includes: designing a TDMA_Round containing twelve intelligent nodes, the TDMA_Round length is 25000us, which is consistent with the engine control cycle of 25ms, and setting the bus to have three working modes, wherein mode 1 is the startup mode, with planning identifiers 0 to 11, and its function is to allow each node to switch from sleep state to working state after power-on; mode 2 is the normal working mode, with planning identifiers 0 to 23, which is convenient for monitoring the data information sent by each node under normal working state; mode 3 is the maintenance mode, with planning identifiers 0 to 11, and its function is to facilitate debugging after replacement when a node has hardware failure.

4. The method for designing and verifying a distributed control system for variable cycle engine mode switching according to claim 1 is characterized in that: The step 4) comprises: Step 4.1) Build a distributed control system for variable cycle engine mode switching; Step 4.2) Use Flagramer software to complete the code transplantation of the engine simulator node, control node, and data processing node; Step 4.3) Add a certain amount of Gaussian white noise to the output of the three control nodes to simulate the real environment and perform simulation verification of the distributed control platform of the variable cycle engine mode switching process.

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