飞机故障的运行后果及成本分析方法

系统故障的运行后果分析技术是飞机运行可靠性分析的重要分支,可为维修任务的成本效益分析提供有力支撑。为了研究飞机系统故障对运行后果及成本的影响,从系统故障运行后果的相关性分析入手,首先,梳理飞机系统故障类型和放行情况对运行后果的影响;然后,结合航线维修现行做法及事件树思想提出一种支持评估飞机系统故障的运行后果及其相关成本的方法,建立基于飞机系统故障的运行后果与成本评估模型;最后,以某型号飞机燃油系统为例,验证所提方法的可行性和适用性。结果表明：本文所提方法合理有效,可为评估故障运行后果提供支持,为飞机的设计、运行和维护提供一定的参考。     

Closed-loop dynamic control allocation for aircraft with multiple actuators

A closed-loop control allocation method is proposed for a class of aircraft with multiple actuators. Nonlinear dynamic inversion is used to design the baseline attitude controller and derive the desired moment increment. And a feedback loop for the moment increment produced by the deflections of actuators is added to the angular rate loop, then the error between the desired and actual moment increment is the input of the dynamic control allocation. Subsequently, the stability of the closed-loop dynamic control allocation system is analyzed in detail. Especially, the closedloop system stability is also analyzed in the presence of two types of actuator failures: loss of effectiveness and lock-in-place actuator failures, where a fault detection subsystem to identify the actuator failures is absent. Finally, the proposed method is applied to a canard rotor/wing (CRW) aircraft model in fixed-wing mode, which has multiple actuators for flight control. The nonlinear simulation demonstrates that this method can guarantee the stability and tracking performance whether the actuators are healthy or fail.     

基于布谷鸟搜索算法的一类变体飞行器容错控制

针对一类存在执行机构故障的分布式结构变体飞行器的控制分配问题,结合整数规划理论,提出一种基于布谷鸟搜索算法的容错控制方法。首先,设计虚拟控制指令,使得系统状态能够很好地跟踪参考模型;然后,将执行器概率性故障与饱和约束转换为整数规划问题中决策变量的约束,从而将执行器控制分配问题转化为一类整数规划问题;最后,采用改进的布谷鸟搜索算法进行求解,得到实际的执行器控制分配指令。仿真结果表明,在执行器存在概率性故障的情况下,该容错控制方法较无容错策略的情况能够有效提升系统的跟踪性能;与遗传算法相比,该算法得到的执行器控制分配结果更加精确。     

Detection and diagnosis of sensor and actuator failures using IMMestimator

An approach to detection and diagnosis of multiple failures in a dynamic system is proposed. It is based on the interacting multiple-model (IMM) estimation algorithm, which is one of the most cost-effective adaptive estimation techniques for systems involving structural as well as parametric changes. The proposed approach provides an integrated framework for fault detection, diagnosis, and state estimation. It is able to detect and isolate multiple faults substantially more quickly and more reliably than many existing approaches. Its superiority is illustrated in two aircraft examples for single and double faults of both sensors and actuators, in the forms of “total”, “partial”, and simultaneous failures. Both deterministic and random fault scenarios are designed and used for testing and comparing the performance fairly. Some new performance indices are presented. The robustness of the proposed approach to the design of model transition probabilities, fault modeling errors, and the uncertainties of noise statistics are also evaluated     

Fault tolerant control system design with explicit consideration of performance degradation

A new approach is proposed for active fault tolerant control systems (FTCS), which allows one to explicitly incorporate allowable system performance degradation in the event of partial actuator fault in the design process. The method is based on model-following and command input management techniques. The degradation in dynamic performance is accounted for through a degraded reference model. A novel method for,selecting such a model is also presented. The degradation in steady-state performance is dealt with using a command input adjustment technique. When a fault is detected by the fault detection and diagnosis (FDD) scheme, the reconfigurable controller is designed automatically using an eigenstructure assignment algorithm in an explicit model-following framework so that the dynamics of the closed-loop system follow that of the degraded reference model. In the mean time, the command input is also adjusted automatically to prevent the actuators from saturation. The proposed method has been evaluated using the lateral dynamics of an F-8 aircraft against actuator faults subject to constraints on the magnitude of actuator inputs. Very encouraging results have been obtained.     

基于UIO的航空发动机执行机构故障诊断

为了提高航空发动机诊断过程中对噪声干扰和模型参数变化的鲁棒性,应用UIO(Unknown Input Ob-server)理论估计发动机动态系统的工作状态,通过干扰正交投影弱化外界干扰对状态估计的影响,处理了航空发动机执行机构的故障诊断问题。对航空发动机执行机构设计一组UIO观测器,其中每个UIO用于监测估计对应执行机构的故障偏移量,计算系统输出理论估计值与发动机实际测量信号间的残差数据,分析残差队列的幅值特性,实现航空发动机执行机构系统的故障检测和隔离。某型涡扇发动机上的实验结果表明,与Kalman滤波算法相比,UIO诊断方法更能鲁棒地检测和隔离出执行机构故障。     

MMAE-based control redistribution applied to the VISTA F-16

A novel control technique, termed control redistribution, is presented and applied in conjunction with multiple model adaptive estimation (MMAE) to the variable in-night stability test aircraft (VISTA) F-16, to detect and compensate for sensor and/or actuator failures. This ad hoc method redistributes control commands (that would normally be sent to failed actuators) to the nonfailed actuators, accomplishing the same control action on the aircraft. Dither is considered to help disambiguate failures in the longitudinal and lateral-directional channels. Detection of both single-actuator and single-sensor failures is considered. Failures are demonstrated detectable in less than 1 s, with an aircraft output nearly identical to that anticipated from a fully functional aircraft in the same environment     

基于交互多模估计策略的故障检诊方法

针对多模自适应（ＭＭＡＥ）故障检诊（ＦＤＤ）方法的局限性,提出了一种基于交互多模（ＩＭＭ）估计策略的动态系统中多重故障的检诊方法。交互多模估计是针对包含有结构以及参数的系统的一种效率较好的自适应估计技术,它提供了故障检测、诊断和状态估计的集中框架。通过对在传感器和作动器中含有多个故障飞机的仿真。结果表明,所提供的方法比其它方法能够更快、更可靠地检测和隔离出多重故障。     

基于大数据的民用飞机未来运营模式探索

大数据作为一种新兴的IT实现方式,在深刻影响IT业变革的同时,也为航空业带来了新的发展机遇。飞机运行过程中产生的海量运营数据最能体现民机的大数据基因,基于大数据的飞机运营支援将会是其在航空产业施展拳脚的主要战场之一。首先通过对航空大数据的梳理与分析,获得运营数据的种类、结构、数据流程以及相关特点。然后结合航空公司的具体业务需求,针对飞机典型复杂系统,分别以健康监控中的故障诊断、性能退化预测以及维修辅助决策几大关键技术作为大数据应用的切入点介绍技术研究路线,利用数据挖掘、机器学习等方法识别运营数据在系统不同健康状态下的特征表达,准确预测系统退化趋势,设置风险预警模型以提前预知潜在故障,最后从工程应用角度探讨这些关键技术的大数据实现平台以及基于大数据的运营业务流程。     

Reconfigurable NDI controller using inertial sensor failuredetection & isolation

A modified derivation of nonlinear dynamic inversion provides the theoretical underpinnings for a reconfigurable control law for aircraft that have suffered combinations of actuator failures, missing effector surfaces, and aerodynamic changes. The approach makes use of acceleration feedback to extract information pertaining to any aerodynamic change and thus does not require a complete aerodynamic model of the aircraft. The control law does require feedback of effector positions to accommodate actuator dynamics. Both accelerometer and rate gyro failure detection and isolation (FDI) systems are implemented, allowing up to three independent failures for each FDI system as long as they are in different axes. Nonlinear simulation results show that the FDI systems improve the robustness to accelerometer/rate gyro uncertainties. An advanced tailless aircraft model is used to demonstrate the concepts. The simulation includes accelerometer and rate gyro noise and bias, failures due to accelerometers, rate gyros, and actuators, and modeled missing surfaces that cause airplane aerodynamic changes     

MIMO变结构飞行重构控制系统设计

基于滑模变结构控制,提出一种MIMO(multiple input multiple output)的飞行重构控制系统的频域设计方法.将滑模变结构控制与飞行重构控制相结合,解决了飞行重构控制技术中故障检测和系统参数辨识的问题.引入渐近观测器和hedge模型增加重构控制系统对衍生未建模动态的鲁棒性;引入作动器模型、输出饱和限制和驾驶员模型,使变结构重构控制系统设计方法变得更为有效和实用;以某型飞机的横航向飞行控制系统为例,进行设计模拟.结果表明:在飞机气动参数大幅突变和操纵面严重受损的情况下,飞机仍能保持良好的性能.      

Neural network modeling of flight control system

Modeling of angle tracking systems in the presence of actuator non-linearity such as angle, position and rate limits is a very significant and difficult task in the design and implementation of aircraft, target-tracking, and missile guided systems. A new recurrent neural network with time-delayed inputs and output feedback is used for the modeling of angle tracking systems, with emphasis on the neural network architecture, principles and algorithms. The neural network controller with modeling units for angle tracking is designed by using TMS320C25 processors. For time and size requirements, limited precision technology and look-up table technology are used in the design of the hardware and software systems. Given a set of input commands, the network is trained to control the system within the constraints imposed by actuators. The results show that the proposed networks are able to model the angle tracking system through learning without separate consideration of the non-linearity of actuators     

飞机滚转运动的控制余度与重构效能

论证了独立操纵的左右平尾使飞机滚动运动具有较大的控制余度,它增加了飞机正常飞行时的滚转力矩,在飞行中副翼出故障时可进行补偿重构,从而提高了滚动通道的余度等级和飞行的安全性,为减少滚转通道的余度配置提供了依据,通过针对操纵面失效和卡死两类故障的重构设计和仿真也证实了上述结论,同时,初步比较说明了自修复飞控系统在上述故障下的任务可靠性和基本可靠性均高于传统控制系统。     

Future architecture of flight control systems

The development of fault tolerant embedded control systems such as flight control systems (FCS) are currently highly specialized and time-consuming. We introduce a conceptual architecture for the next decade control system where all control and logic are distributed to a number of computer nodes locally linked to actuators and connected via a communication network. In this way, we substantially reduce the life-cycle cost of embedded systems and attain scalable fault tolerance. All fault tolerance is based on redundancy. Our philosophy is to cover permanent faults with hardware replication and handle all error processing caused by both permanent and transient faults with software techniques. With intelligent nodes and use of inherent redundancy we introduce a robust and simple fault tolerant system that utilizes minimum hardware and has bandwidth requirements of less than 300 kbits/s, which can be met with an electrical bus. The study is based on an FCS for JAS 39 Gripen, a multi-role combat aircraft that is statically unstable at subsonic speed.     

飞行器参数辨识的最优方波形输入信号设计

用动态规划法设计了旨在提高飞行器气动参数辨识精度的最优方波形输入信号。设计出的信号不仅在工程上易于实现,还在精度意义上达到了最优。为了避免加输入信号后飞行器状态离开线性工作点,从而导致模型失效,该设计方法还考虑了输出约束。用于某型飞行器的输入信号设计结果表明,该法是有效的。     

Reconfiguration of flight control systems for actuator failures

We consider the problem of designing fault tolerant control for transient failures in the flight control system caused by harsh electromagnetic environments. We examine principles of fault tolerant design and discuss integrated local supervisory control of these systems. As an example, we present a sample design of a control mixer to achieve fault tolerance in the event of failures in the actuators     

用于检测操纵面损伤的故障检测滤波器

针对飞行中典型的操纵面损伤故障,以故障检测滤波器为基础,开发了一种建立在离散模型上的快速、稳定的故障检测及诊断算法,可以在几个采样周期内同时精确检测出多个操纵面的损伤程度,故障检测滤波器的稳定性、收敛性也得到证明,具有较好的实用性。几种组合故障下的仿真研究证实了上述结论。     

Simple adaptive control for aircraft control surface failures

This work extends the so-called simple adaptive control approach to direct model reference adaptive control of multi-input multi-output systems to include loss of control effectiveness failures. It is proven that all signals are bounded for loss of control effectiveness failures during a bounded input disturbance. A state space approach is introduced for computing the feedforward compensator that is required by the stability result. The adaptive algorithm is applied to a three input model of the linearized lateral dynamics of the F/A-18 aircraft. Simulation results are obtained with single, double, and triple control effectiveness failures of 88% during the occurrence of a lateral gust. These results show that the adaptive controller exhibits improved model following as compared with a fixed gain eigenstructure assignment controller.     

基于神经网络和专家系统的电传操纵系统故障诊断

提出了一种神经网络与专家系统相结合的故障诊断方法,研制了相应的诊断模块,并在某型飞机电传操纵系统的故障诊断中得以实现。在实物仿真和实际诊断实例中,该诊断模块均达到了很好的效果。从而证明了所提出的方法作为一种诊断策略,可作为飞机电传操纵系统快速故障诊断的基础。该故障诊断方法可推广应用到其它同类飞机的故障诊断当中,为现代航空维修保障的故障诊断提供了一条有效的新途径。