Active fault tolerant control for vertical tail damaged aircraft with dissimilar redundant actuation system

This paper proposes an active fault-tolerant control strategy for an aircraft with dissim-ilar redundant actuation system (DRAS) that has suffered from vertical tail damage. A damage degree coefficient based on the effective vertical tail area is introduced to parameterize the damaged flight dynamic model. The nonlinear relationship between the damage degree coefficient and the corresponding stability derivatives is considered. Furthermore, the performance degradation of new input channel with electro-hydrostatic actuator (EHA) is also taken into account in the dam-aged flight dynamic model. Based on the accurate damaged flight dynamic model, a composite method of linear quadratic regulator (LQR) integrating model reference adaptive control (MRAC) is proposed to reconfigure the fault-tolerant control law. The numerical simulation results validate the effectiveness of the proposed fault-tolerant control strategy with accurate flight dynamic model. The results also indicate that aircraft with DRAS has better fault-tolerant control ability than the traditional ones when the vertical tail suffers from serious damage.     

非对称结构损伤飞机鲁棒容损控制器设计

当飞机发生非对称结构损伤时,飞机的质量、重心位置和气动特性都会发生突变,飞机机体的对称性遭到破坏,致使飞机的横纵向间运动产生强烈的耦合。针对飞机发生非对称结构损伤时导致的飞行控制问题,建立了非对称结构损伤飞机的损伤模型,并基于一种新型鲁棒容损控制策略,采用非线性扩张状态观测器和非线性动态逆相结合的方法,对飞机的姿态控制器进行了设计,兼顾了飞机系统的性能和对损伤的鲁棒性。最后,基于NASA的通用运输机模型,对所设计控制器的控制效果进行了仿真验证。仿真结果表明,设计的姿态控制器有效地抑制了非对称结构损伤给飞机控制系统带来的不确定性和扰动,具有较好的控制性能。     

Adaptive Fuzzy Torque Control of Passive Torque Servo Systems Based on Small Gain Theorem and Input-to-state Stability

Passive torque servo system (PTSS) simulates aerodynamic load and exerts the load on actuation system, but PTSS endures position coupling disturbance from active motion of actuation system, and this inherent disturbance is called extra torque. The most important issue for PTSS controller design is how to eliminate the influence of extra torque. Using backstepping technique, adaptive fuzzy torque control (AFTC) algorithm is proposed for PTSS in this paper, which reflects the essential characteristics of PTSS and guarantees transient tracking performance as well as final tracking accuracy. Takagi-Sugeno (T-S) fuzzy logic system is utilized to compensate parametric uncertainties and unstructured uncertainties. The output velocity of actuator identified model is introduced into AFTC aiming to eliminate extra torque. The closed-loop stability is studied using small gain theorem and the control system is proved to be semiglobally uniformly ultimately bounded. The proposed AFTC algorithm is applied to an electric load simulator (ELS), and the comparative experimental results indicate that AFTC controller is effective for PTSS.     

机载供电系统双余度控制器的容错控制

介绍双发（Twin-engines）系统的战斗机的机载供电系统控制器的设计和实现。机载供电系统控制器是管理飞机的供电系统的航空电子设备,是飞机供电系统的核心设备,肩负飞机安全的使命。为了提高控制器的可靠性和灵活性,放弃传统的模拟方法,使用先进的数字化技术实现对飞机供电、配电系统的管理。在设计中为了提高可靠性,使用主动复制的容错技术,设计了双余度控制器,在发生单通道错误的情况下,整个系统能够正确工作。对机载供电系统控制器容错技术进行了研究,包括双余度系统的管理策略、同步控制机制、余度管理和故障综合、信号比较监控和通道切换逻辑。     

Robust adaptive fault-tolerant control of a tandem coaxial ducted fan aircraft with actuator saturation

This paper is concerned with the robust adaptive fault-tolerant control of a tandem coaxial ducted fan aircraft under system uncertainty, mismatched disturbance, and actuator saturation. For the proposed aircraft, comprehensive controllability analysis is performed to evaluate the controllability of each state as well as the margin to reject mismatched disturbance without any knowledge of the controller. Mismatched disturbance attenuation is ensured through a structured H-infinity controller tuned by a non-smooth optimization algorithm. Embedded with the H-infinity controller, an adaptive control law is proposed in order to mitigate matched system uncertainty and actuator fault. Input saturation is also considered by the modified reference model. Numerical simulation of the novel ducted fan aircraft is provided to illustrate the effectiveness of the proposed method. The simulation results reveal that the proposed adaptive controller achieves better transient response and more robust performance than classic Model Reference Adaptive Control (MRAC) method, even with serious actuator saturation.     

空天飞行器直接力/气动力复合容错控制

考虑发生发动机推力损失故障的空天飞行器，针对直接力、气动力复合容错控制问题，设计一种基于自适应滑模的容错控制策略。首先，对于发生推力损失故障的摆动发动机，考虑X型安装的实际特点，对线性化后的俯仰通道控制模型进行故障等效，并采用自适应的方法对故障及干扰信息进行估计，综合利用舵面与发动机摆动角进行容错控制器设计。其次，考虑纵向容错控制对飞行器横侧向稳定性的影响，基于自适应反步的方法，利用方向舵与组合工作的左、右升降舵抵消干扰力矩的影响，保证横侧向的稳定。最后，基于李雅普诺夫稳定性理论，对所采用方法进行了分析，并通过仿真结果验证了所设计的复合容错控制方案的有效性。     

Digital Control of High Performance Aircraft Using Adaptive Estimation Techniques

Since the early 1960's, a rapid advance in signal processing, including filtering and estimation techniques, has been evident. In contrast, applied feedback control, particularly for aircraft, is currently based on technology available prior to 1960, i. e., primarily either constant gain feedback or at most a standard gain-scheduling. In this paper, an adaptive signal processing algorithm is joined with gain-scheduling to produce an effective scheme for controlling the dynamics of high performance aircraft. A technique is presented for a reduced-order model (the longitudinal dynamics) of a high performance short-takeoff-and-landing (STOL) aircraft. The actual controller views the nonlinear behavior of the aircraft as being equivalent to a randomly switching sequence of linear models taken from a preliminary piecewise-linear fit of the system nonlinearities. The adaptive nature of the estimator is necessary to select the proper sequence of linear models along the flight trajectory. From the analysis of the reduced-order model the nonlinear behavior has been found to be well approximated by assuming an effective switching of the linear models at random times, the durations of which reflect the motion of the aircraft in response to pilot commands.     

Dynamics modeling and control of a transport aircraft for ultra-low altitude airdrop

The nonlinear aircraft model with heavy cargo moving inside is derived by using the separation body method, which can describe the influence of the moving cargo on the aircraft attitude and altitude accurately. Furthermore, the nonlinear system is decoupled and linearized through the input–output feedback linearization method. On this basis, an iterative quasi-sliding mode(SM)flight controller for speed and pitch angle control is proposed. At the first-level SM, a global dynamic switching function is introduced thus eliminating the reaching phase of the sliding motion.At the second-level SM, a nonlinear function with the property of ‘‘smaller errors correspond to bigger gains and bigger errors correspond to saturated gains' ' is designed to form an integral sliding manifold, and the overcompensation of the integral term to big errors is weakened. Lyapunovbased analysis shows that the controller with strong robustness can reject both constant and time-varying model uncertainties. The performance of the proposed control strategy is verified in a maximum load airdrop mission.     

Design for aircraft engine multi-objective controllers with switching characteristics

The aircraft engine multi-loop control system is described and the switching control theory is introduced to solve the regulating and protecting control problems in this paper. The aircraft engine multi-loop control system is firstly described and the control problems are formulated. Secondly, the theory of the smooth switching control is devoted and a new extended scheme for the smooth switching of a switched control system is introduced. Then, for the key technologies of aero-engines switching control, a design algorithm is presented which can determine which candidate controller should be put in feedback with the plant to achieve a desired performance and the procedure to design the aircraft engine multi-loop control system is detailed. The switching performance objectives and the switching scheme are given and a family of PID controllers and compensators is designed. The simulation shows that using the switching control design method can not only improve the dynamic performance of the aircraft engine control system and reduce the switching times, but also guarantee the stability in some peculiar occasions.     

复合式旋翼飞行器多目标控制分配策略

针对复合式旋翼飞行器操纵冗余多模式切换控制问题，提出一种基于赋权多目标混合优化的控制分配策略。该策略根据复合式旋翼飞行器过渡模式舵面操纵特性，建立飞行器带约束过渡过程控制分配模型；设计混合多目标优化性能指标评价函数，有效处理操纵量控制受限、交叉强耦合及非线性特性，并减少舵面耗能；采用改进的粒子群优化算法动态更新操纵量及控制通道的权系数矩阵，提高控制面操纵效率，加快优化搜索速度，快速求解过渡过程多目标控制分配变量。该策略实现复合式旋翼飞行器模式切换过渡过程实时有效地操纵量控制分配，保证飞行器快速准确跟踪控制指令的能力。同时，通过多目标控制分配策略，飞行控制系统不需要增加额外的模式切换控制器，降低系统设计难度，提高安全性。     

基于解耦矢量控制的五相永磁同步电机容错控制策略

针对五相永磁同步电机两相开路故障的运行工况,提出了一种基于解耦矢量控制理论的故障容错控制策略.该策略通过在两相开路故障下的同步旋转坐标系内建立电机的数学模型,构造解耦变换矩阵,将电流控制中id和iq轴解耦,达到两相开路故障下容错运行的目的 .仿真结果表明,在五相永磁同步电机两相开路故障下,基于解耦矢量控制理论的故障容错控制策略能够实现电机驱动系统的高品质运行,具有控制简单、转矩波动小、容错能力强等优点.     

Switching control of morphing aircraft based on Q-learning

This paper investigates a switching control strategy for the altitude motion of a morphing aircraft with variable sweep wings based on Q-learning. The morphing process is regarded as a function of the system states and a related altitude motion model is established. Then, the designed controller is divided into the outer part and inner part, where the outer part is devised by a combination of the back-stepping method and command filter technique so that the ‘explosion of complexity’ problem is eliminated. Moreover, the integrator structure of the altitude motion model is exploited to simplify the back-stepping design, and disturbance observers inspired from the idea of extended state observer are devised to obtain estimations of the system disturbances. The control input switches from the outer part to the inner part when the altitude tracking error converges to a small value and linear approximation of the altitude motion model is applied. The inner part is generated by the Q-learning algorithm which learns the optimal command in the presence of unknown system matrices and disturbances. It is proved rigorously that all signals of the closed-loop system stay bounded by the developed control method and controller switching occurs only once. Finally, comparative simulations are conducted to validate improved control performance of the proposed scheme.     

控制性能精确可控的自适应鲁棒容错控制方法研究

一般而言,实现控制性能约束精确可控与满足控制系统鲁棒的要求之间存在着难以两全的矛盾。容错控制也是如此,精准的控制性能要求与对故障诊断误差的鲁棒性之间也存在着这样的矛盾。针对这一问题,提出了将参数空间方法、变结构理论以及模型参考自适应理论相结合的自适应鲁棒容错控制方法。该方法的基本思路是将容错控制系统分为内外两部分,内部为基于参数空间的容错控制系统,可以灵活适应精确的控制性能约束(对应极点配置)和一定范围的控制性能约束(对应区域极点配置),外部则为基于变结构模型参考自适应方法的控制系统,主要目的是提高容错控制系统的鲁棒性。通过仿真证明了这种自适应鲁棒容错控制方法既能保证系统满足精确的控制性能约束,又能保证对故障诊断误差有较高的鲁棒性。     

液化天然气船舶动力系统加速性能优化策略研究

目的 针对船舶天然气发动机匹配定距桨直接推进加速速率慢动态性能差的缺陷，提出了一种系统级优化方案，设计并联型式气电混合动力系统，通过轴带电机辅助推进优化系统的加速性能。方法 建立船舶气电混合动力系统仿真模型，根据试验数据对LNG发动机的加速性能进行数据标定保证模型动态精度，以仿真手段分别验证混合动力系统使用变频器动态切换策略和变频器超前控制策略的加速优化效果。结果 综合考虑实际工程控制难度和加速过程优化效果，变频器动态切换策略优于变频器超前控制策略。结论 气电混合动力系统PTI模式使用变频器切换控制策略可达到较好的加速性能，在降低主机机械负荷和热力负荷的同时船舶快速性最大提升16%。PTO模式加速时轴带发电机负载转移至船舶辅机，稳定一段时间后切换至电动模式助推，加速性能可达到PTI模式加速水平。     

基于鲁棒伺服LQR的结冰飞机纵向控制律重构方法

由于防/除冰系统总会出现故障或者除冰不彻底,因此仅依靠防/除冰系统实现结冰条件下的安全飞行并非完全可靠,研究结冰后飞机控制律重构对飞机操纵安全和飞行安全极其重要。针对飞机的纵向运动建立了结冰影响模型和纵向动力学模型,采用鲁棒伺服线性二次型调节器(LQR)最优控制设计了飞机结冰后空中飞行纵向控制律,模拟了飞机在俯仰姿态保持模式下遭遇不同严重程度结冰后的动态响应特性,并与常规PID控制进行对比。结果表明,所设计的控制律能够有效改善结冰飞机的飞行性能和飞行品质,准确跟踪给定的俯仰角指令,且抗干扰能力、动态性能以及鲁棒性均优于常规PID控制。为飞机结冰后的重构控制问题和自动飞行控制,提供了新的思路。     

综合模块化航空电子核心系统技术研究

介绍了一种综合模块化航空电子核心系统.在系统应用需求及技术特征的分析基础上,提出了一种通用的开放式体系结构模型,并对系统的关键技术进行深入研究探讨,包括系统管理、网络通信、时间同步、容错策略等,最后给出系统设计方案的建议.系统具有可重构性、可重用性、可扩展性和健壮性,可满足先进飞机航空电子系统的应用要求,并为未来新型分布式综合模块化航空电子系统的研究与设计提供技术支持.     

Integrated fault estimation and fault-tolerant control for a flexible regional aircraft

The article focuses on the design and application of an active reconfigurable controller that mitigates the effects of gust load and actuator faults on a flexible aircraft. A novel integrated adaptive output feedback scheme is investigated to address the actuator faults. The real-time fault values provided by the fault estimation module are considered in the reconfigurable control law to improve the fault-tolerant capability. The estimate values of faults and control gains are calculated by anal...     

微型飞行器过失速降落轨迹跟踪控制设计

采用基于张量积的T-S模糊建模与控制方法,对微型飞行器过失速降落纵向运动的轨迹跟踪控制问题进行了研究。首先,建立了过失速降落中飞行器纵向运动的线性变参数动力学模型;然后,通过张量积模型转化方法,将线性变参数模型转化为张量积胞体模型,基于该模型设计了并行分布补偿控制器,用Lyapunov稳定性理论证明了闭环系统的稳定性,并推导了区域极点配置条件以获得更好的暂态响应性能;最后,对飞行器的过失速降落过程进行了仿真,验证了所设计的跟踪控制器的有效性。     

准Z源逆变器驱动永磁同步电机的有限集模型预测控制

针对准Z源逆变器(qZSI)驱动永磁同步电机(PMSM)系统的特点,在两相静止坐标系下,提出一种有限集模型预测控制策略。由准Z源网络电容电压闭环与PMSM电磁功率前馈生成电感电流参考值,通过预测电感电流值并引入子代价函数来确定是否选择直通(ST)状态,以实现qZSI的升压控制。在非直通(NST)状态下,分别对8种开关状态下的PMSM定子电流进行预测,并与转速闭环控制生成的参考电流进行比较,选择最优的开关状态,以实现对PMSM的控制。仿真结果表明,所提控制策略可实现对qZSI的升压及PMSM转速的控制,系统具有良好的稳态及动态性能。