Vector deflection stability control of aero-engine based on linear active disturbance rejection

Aimed at the problem of instability in engine control caused by vector deflection in experiment of turbofan engines with Axisymmetric Vectoring Exhaust Nozzle (AVEN), a vector deflection stability control method of aero-engine based on Linear Active Disturbance Rejection Control (LADRC) is proposed. Firstly, based on CFD numerical simulation, aerodynamic performance model of AVEN is established, and the aerodynamic load change rule of the nozzle throat area actuator during vector deflection is revealed. Subsequently, the integrated model of AVEN/turbofan engine is established by Simulink/AMESim co-simulation. Finally, the nozzle throat area control loop based on LADRC is designed. The simulation results show that the integrated model can reflect the influence of vector deflection on the stability of the control system. The accuracy comparison between the fan rotor speed and the test data during vector deflection is larger than 1%, indicating a high degree of confidence. Compared with the conventional PID control, the designed LADRC control loop reduces the speed of the low-pressure rotor during vector deflection by 70%, which effectively improves the control stability of the vector deflection. Meanwhile, the fuel flow ratechange during the vector deflection process is smaller and more economical, which provides an important reference for engineering applications.     

星载控制软件在轨动态重构技术研究

为使星载控制软件可在轨动态重构，提出一种基于量子编程框架、无须操作系统支持、可实现多版本切换的星载控制软件在轨动态重构方法。在分析影响在轨动态重构关键技术基础上，从量子框架的面向对象运行机制出发来寻求软件框架对动态重构的支持；通过划分函数边界，将函数归类为内部函数和公共函数，避免了模块间的循环依赖；给出了函数向量表维护策略，并以版本号为导向实现了向量表切换。该方法在BM3803星载处理器平台进行了充分测试，结果表明：所提出的在轨重构方法系统无须停机、版本可回退且更新过程可靠。本方法占用内存小、平台依赖性弱、代码可复用性强，可推广应用至硬件资源有限的星载控制器终端。     

Reliability analysis of arresting hook engaging arresting cable for carrier-based aircraft influenced by multifactors

The carrier-based aircraft landing and arrest process is complex and nonlinear, and includes the coupling effect between the aircraft and arresting system. It has many uncertain factors, which lead to difficulty in the reliability analysis. To make the reliability analysis more accurate and effective, this paper presents some studies. Taking a certain type of carrier-based aircraft as the research object, a dynamic model of the landing and arrest cable was established, and the accuracy of the model was verified using laboratory test results. Based on the model, this paper shows how the key parameters, including the sinking velocity, pitch angle and horizontal velocity, affect the collision rebound performance of the arresting hook. After that, a limit state equation of the arresting hook system’s reliability was established. For the implicit limit state equation, a surrogate model of the reliability of the arresting hook was established using the Support Vector Machine (SVM) method, and then reliability analysis was carried out using the Monte Carlo method. Finally, it was explained in detail how the key parameters affect the reliability of the hook engaging the arresting cable, and some meaningful conclusions were obtained. This analysis method and its results can provide a reference for the top-level parameter design of carrier-based aircraft and reliability research on the arresting systems.