Review on uncertainty analysis and information fusion diagnosis of aircraft control system

In the aircraft control system,sensor networks are used to sample the attitude and environmental data.As a result of the external and internal factors(e.g.,environmental and task complexity,inaccurate sensing and complex structure),the aircraft control system contains several uncertainties,such as imprecision,incompleteness,redundancy and randomness.The information fusion technology is usually used to solve the uncertainty issue,thus improving the sampled data reliability,which can further effectively increase the performance of the fault diagnosis decision-making in the aircraft control system.In this work,we first analyze the uncertainties in the aircraft control system,and also compare different uncertainty quantitative methods.Since the information fusion can eliminate the effects of the uncertainties,it is widely used in the fault diagnosis.Thus,this paper summarizes the recent work in this aera.Furthermore,we analyze the application of information fusion methods in the fault diagnosis of the aircraft control system.Finally,this work identifies existing problems in the use of information fusion for diagnosis and outlines future trends.

Adaptive PI Control Based Stability Margin Configuration of Aircraft Control Systems with Unknown System Parameters and Time Delay

The stability margin is a vital indicator for assessing the safety level of aircraft control systems.It should maintain sufficient stability margin to ensure safety during flight,especially in the process of large maneuver operations.The stability margin is generally quantified by the Bode diagram,which strictly depends on the system parameters and the open-loop transfer function.However,due to the uncertain flight environments,transmission delays of sensors and mode switchings,etc.,there exist large parameter and structure uncertainties in the aircraft control systems,which make it difficult to precisely configure the stability margin to the desired value by the usual control methods.To address this problem,an indirect adaptive control strategy is proposed in this paper,where an adaptive PI control law with the capability of self-configuration of stability margin is developed.The developed control law not only achieves stable time-varying command tracking in the time domain,but also is able to automatically configure the phase margin and gain margin in the frequency domain.Finally,the simulation of the one-degree-of-freedom roll rate control model of the air vehicle verifies the validity of the proposed control method.

Consensus intuitionistic fuzzy group decision-making method for aircraft cockpit display and control system evaluation

A novel group decision-making （GDM） method based on intuitionistic fuzzy sets （IFSs） is developed to evaluate the ergonomics of aircraft cockpit display and control system （ACDCS）. The GDM process with four steps is discussed. Firstly, approaches are proposed to transform four types of common judgement representations into a unified expression by the form of the IFS, and the features of unifications are analyzed. Then, the aggregation operator called the IFSs weighted averaging （IFSWA） operator is taken to synthesize decision-makers’ （DMs’） preferences by the form of the IFS. In this operator, the DM’s reliability weights factors are determined based on the distance measure between their preferences. Finally, an improved score function is used to rank alternatives and to get the best one. An illustrative example proves the proposed method is effective to valuate the ergonomics of the ACDCS.

Dynamic Simulation of the Aircraft Environmental Control System

The dynamic research of aircraft environmental control system (ECS) is an important step in the advanced ECS design process. Based on the thermodynamics theory, mathematical models for the dynamic performance simulating of aircraft ECS were set up and an ECS simulation toolbox (ECS_1.0) was created with MATLAB language. It consists of main component modules (ducts, valves, heat exchangers, compressor, turbine, etc.). An aircraft environmental control system computer model was developed to assist engineers with the design and development of ECS dynamic optimization. An example simulating an existing ECS was given which shows the satisfactory effects.

Robust Tracking Control of Uncertain MIMO Nonlinear Systems with Application to UAVs

In this paper, we consider the robust adaptive tracking control of uncertain multi-input and multi-output (MIMO) nonlinear systems with input saturation and unknown external disturbance. The nonlinear disturbance observer (NDO) is employed to tackle the system uncertainty as well as the external disturbance. To handle the input saturation, an auxiliary system is constructed as a saturation compensator. By using the backstepping technique and the dynamic surface method, a robust adaptive tracking control scheme is developed. The closed-loop system is proved to be uniformly ultimately bounded thorough Lyapunov stability analysis. Simulation results with application to an unmanned aerial vehicle (UAV) demonstrate the effectiveness of the proposed robust control scheme. © 2014 Chinese Association of Automation.

Control allocation for aircraft with input constraints based on improved cuckoo search algorithm

The control allocation problem of aircraft whose control inputs contain integer constraints is investigated. The control allocation problem is described as an integer programming problem and solved by the cuckoo search algorithm. In order to enhance the search capability of the cuckoo search algorithm, the adaptive detection probability and amplification factor are designed. Finally, the control allocation method based on the proposed improved cuckoo search algorithm is applied to the tracking control problem of the innovative control effector aircraft. The comparative simulation results demonstrate the superiority and effectiveness of the proposed improved cuckoo search algorithm in control allocation of aircraft.

Simple Adaptive Delta Operator Aircraft Flight Control for Accommodation of Loss of Control Effectiveness

A new proof for stability of delta operator simple adaptive control is presented in terms of a set of Linear Matrix Inequalities (LMIs). The paper shows how to design a feedforward gain to satisfy the LMIs over a polytope of loss of control effectiveness failures. The MATLAB Robust Control Toolbox is used to find the feedforward gain with the smallest norm that satisfies the LMIs. Examples are presented of the F/A-18 aircraft and the Innovative Control Effectors (ICE) tailless aircraft that show the design of a feedforward gain for a loss of control effectiveness in any one control effector. The designs use a fixed eigenstructure assignment controller for an inner loop augmented with the simple adaptive controller. Simulations of both aircraft include simultaneous loss of control effectiveness failure and lateral wind gust. Simulation results for the F/A-18 aircraft show that the adaptive controller achieves almost perfect tracking whereas the nonadaptive controller cannot achieve a coordinated turn when an aileron failure occurs. The ICE tailless aircraft uses sideslip, washed-out stability axis yaw rate, and stability axis roll rate feedback for both the inner loop eigenstructure assignment controller and the simple adaptive controller. However, the adaptive controller also uses bank angle feedback. Simulation results for the ICE tailless aircraft show that the adaptive controller achieves almost perfect tracking whereas the nonadaptive controller diverges when an all moving tip failure occurs.

飞翼布局飞行器研究现状分析

对飞翼布局飞行器的发展脉络进行了梳理,涵盖了从其早期的进化史到现阶段的研究进展,并对未来的发展方向进行了思考和展望。同时,论述了飞翼布局飞行器的几个主要控制难点,具体包括:宽速域非线性状态下的姿态控制问题、多效应耦合下的高精度自主起降控制问题、气动模型近似及强扰动状态下的鲁棒控制难题,以及因多舵面冗余而引起的控制分配问题。此外,还深入讨论了当前重点研究的飞翼布局飞行器的流动控制问题,并对接下来主动流动控制技术的研究动向进行了阐述。

An Efficient Non-Linear Application Algorithm Predictive Model for a Multi Aircraft Landing Dynamic System <i>AIRLADYS R</i>2019<i>A</i>⁺

The aim of this paper is to set up an efficient nonlinear application algorithm predictive model for a multi aircraft landing dynamic system called “Aircraft Landing Dynamic System, Release 2019A+ version “AIRLADYS R2019A+”. This programming software combines dynamic programming technic for mathematical computing and optimisation run under AMPL and KNITRO Solver. It uses also a descriptive programming technic for software design. The user interfaces designed in Glade are saved as XML, and by using the GtkBuilder GTK+ object these can be loaded by applications dynamically as needed. By using GtkBuilder, Glade XML files can be used in numerous programming languages including C, C++, C#, Java, Perl, Python, AMPL, etc. Glade is Free Software released under the GNU GPL License. By these tools, the solved problem is a mathematical modelization problem as a non-convex optimal control governed by ordinary non-linear differential equations. The dynamic programming technic is applied because it is a sufficiently high order and it does not require computation of the partial derivatives of the aircraft dynamic. This application will be coded with Linux system on 64 bit operating system, but it can also be run on the windows system. High running performances are obtained with results giving feasible trajectories with a robust optimizing of the objective function.

Stabilization of switched systems with all unstable modes:application to the aircraft team problem

The method of stabilizing switched systems based on the optimal control is applied,with all modes unstable,for a typical example of the multi-agent system.First,the optimal control method for stabilizing switched systems is introduced.For this purpose,a switching table rule procedure is constructed.This procedure is inspired by the optimal control that identifies the optimal trajectory for the switched systems.In the next step,the stability of a multi-agent system is studied,considering different unstable connection topologies.Finally,the optimal control method is successfully applied to an aircraft team,as an example of the multi-agent systems.Simulation results evaluate and confirm the successful application of this method in the aircraft team example.

面向智能辅助决策的飞行器安控系统构建研究

新一代人工智能技术能够提高飞行器试验安控系统的辅助决策能力,满足地面安控目标数量增多、故判规则量增大、故判时效性高等新需求,具有广阔的应用前景。在对飞行器试验地面安控需求分析的基础上,设计面向智能辅助决策的地面安控系统总体框架,增加了数据与模型管理模块;接着构建了辅助决策知识库,主要包括故障弹判据、速度判据、位置判据和预示落点判据等规则库;在此基础上提出数据和规则协同驱动的故障预测方法。该系统既利用历史积累试验数据对深度神经网络模型进行训练,又利用规则库提高专家经验对模型预测精度的贡献,能够提高故障智能预测能力,满足飞行器安控智能辅助决策需求。

基于LMI的二自由度飞行器多变量控制

针对二自由度飞行器存在非线性特性、强耦合性以及易受外界干扰等问题,提出了基于LMI的二自由度飞行器多变量控制方法。首先,根据二自由度飞行器系统的输入和输出变量,结合空间动力学方程建立了系统的状态空间模型;其次,设计满足静态输出反馈稳定的多变量控制律;然后,通过李亚普托夫稳定性定理与极点配置法,将控制系统稳定性问题转化为优化问题,利用线性矩阵不等式(LMI)求解满足最优性能指标的多变量控制器参数;最后,通过对比仿真分析与单变量PID,表明该方法能有效提升二自由度飞行器的轨迹跟踪精度。

基于安全性的电动垂直起降飞行器飞控系统架构设计

飞行控制系统作为电动垂直起降(electric vertical take-off and landing,eVTOL)飞行器的关键机载系统,需要具备和民机同样的安全性。为了设计满足eVTOL飞行器需求的飞控系统架构,根据适航规章梳理了安全性要求,并基于安全性要求介绍了eVTOL飞行器飞控系统飞控计算机、传感器和作动器余度设计技术,设计了一种基于安全性考虑的eVTOL飞行器飞控系统架构;分析了eVTOL飞行器旋翼构型下的典型功能危险,并采用故障树进行了安全性分析。结果表明,设计的飞控系统架构的典型功能危险能够满足失效概率的要求。

飞机电推进系统高效能电机及其驱动控制技术

飞机动力系统的电气化是继机载二次能源逐步统一为电能之后航空电气化发展的重要方向和高级阶段,能够大幅提升飞机动力系统能量利用效率,是航空业绿色发展的重要途径。电机系统是飞机电推进系统的核心机电能量变换环节,高效能电机、电力电子变换及其驱动控制技术是电推进飞机发展的基础支撑。该文从电推进飞机动力系统架构出发,分析电推进飞机电机系统的特征与要求。总结永磁同步电机、异步电机、电励磁无刷同步电机和超导电机4种类型电机在电推进飞机上的研究和应用现状,系统讨论电推进系统中不同类型电机和电机驱动器的关键技术。最后,展望新材料、新器件、新工艺、人工智能和综合热管理等技术对电推进飞机电机及其驱动控制技术发展的推动作用。

基于离散特性的飞行器姿态智能控制方法研究及实验设计

针对飞行器姿态复合控制问题研究中直接力连续化处理导致的与实际工程特性差距较大问题,研究了体现直接力离散特性的控制系统构建方法及控制参数优化设计方法。首先,搭建了体现直接力离散特性的飞行器姿态复合控制系统框架及模型;然后针对复合控制问题的非线性、强耦合、多约束等复杂特性,采用PSO算法对控制律及控制分配参数进行多目标优化设计,构建了飞行器姿态智能控制系统;再通过数字仿真从控制算法、PSO算法参数、飞行器系统参数三个方面对智能控制问题研究方法进行了说明;最后,依托最新科研成果设计开发了飞行器姿态智能控制实验系统,为自动化专业本科生智能控制类课程实践教学及创新型人才培养提供了自主开放的实验研究平台。

基于DSP的飞机环境控制器设计与实现

针对飞机飞行过程中对机内环境控制要求,为满足飞机环控系统对设定目标的跟踪控制,提出了一种以TMS320F28335为核心的嵌入式控制系统。控制系统采用模糊控制策略实现对典型飞机环境参数——温度、压力的控制。从软、硬件两个方面介绍了该嵌入式控制系统的设计和工作原理,根据系统设计完成了控制器样机研制并进行了地面试验验证。通过试验验证和对试验结果总结分析,证明所设计的控制系统具有较高的工程实践价值。

不同海况条件下舰载无人机着舰安全分析

针对无人机上舰的使用需求,本文对舰载无人机着舰开展了系统的研究。建立了机-舰-环境综合模型和舰载无人机全自动着舰引导控制系统;基于建立的舰载无人机着舰综合模型对不同海况下的着舰过程进行仿真分析,研究不同海况条件以及航母不同航速和遭遇角对着舰安全的影响。仿真研究表明:在复杂海况下,航母可通过适当提高航速以获得更高的着舰成功率,但过高的航速会导致舰尾流扰动加剧,使得着舰成功率显著下降;通过对仿真结果进行统计分析,给出了不同海况下的着舰安全范围,为无人机着舰辅助决策提供参考。

飞机发动机硬式操纵系统非线性传动优化设计

采用特殊机构实现非线性传动在机械式飞行操纵系统中已有应用,通过对传动要求的近似拟合,可以完成对机构设计参数求解;但采用该方法设计机构不能精确满足传动约束要求,在机械式飞机发动机操纵系统中尚无应用。根据飞机发动机硬式操纵系统的工作特点,采用五杆式机构替代四连杆机构实现非线性传动;通过五杆式机构设计参数影响机制分析,将机构设计参数分类为优化决策变量和传动特性控制变量,并基于此建立了机构求解方法和优化设计方法,实现了对机构传动特性控制变量直接求解,保证了机构传动特性能够精确满足约束要求。引入最大传动比和机构磨损因数作为目标函数开展机构优化,能够提升系统性能和使用寿命。通过某型发动机操纵系统设计实例和地面试验验证表明,该方法合理可行,具有工程实用价值。

基于CSP算法的BWB飞机飞控作动系统架构设计

针对翼身融合(Blended Wing Body,BWB)飞机舵面数量多且每个舵面承担两轴或三轴多种功能,可选的动力源和作动器类型多样,导致飞控作动系统架构设计困难的问题,研究分析了BWB飞机飞控作动系统架构安全性设计原则和技术约束,采用约束满足问题(Constraint Satisfaction Problem,CSP)算法为BWB飞机进行飞控作动系统架构设计,对飞控作动系统架构进行变量V、值域D以及约束C建模分析,设计回溯算法对飞控作动系统架构进行筛选,在1049种候选飞控作动系统架构中,用时不到7 min,为飞机筛选出符合安全性设计原则和技术约束的飞控作动系统架构,比其他文献中的初步筛选算法用时更短,且缩短了设计周期。

某型飞机飞行控制系统概述及钢索维护建议

飞行控制系统是飞机最重要的系统之一,它不仅直接影响飞行安全,还很大程度上决定了飞行员的操纵舒适性和旅客的乘坐舒适性。对于软式操纵系统的飞机而言,钢索是飞行操纵的直观载体,是最重要且最易出现问题的部件。本文以Cessna525飞机飞行控制系统为研究对象,从该系统的工作原理及组成入手,描述钢索磨损、断丝等故障的检查方法,并提出维护建议,对后续该机型及类似机型相关故障的排除提供参考借鉴。