飞行制导控制一体化设计方法综述

从系统模型和控制设计方法两个方面综述了飞行器制导控制一体化设计方法的研究现状. 论述了制导控制一体化设计中的关键问题, 即系统具有较高的阶数和系统存在大量不确定性. 提出了基于自抗扰控制的三维制导控制一体化设计方法. 该控制方法具有简明的线性结构, 并且可以对飞行控制系统中的非线性时变不确定性进行实时估计和补偿. 仿真结果表明该方法可以对付大范围的不确定性, 具有很好的鲁棒性.     

Automatic terminal guidance for small fixed-wing unmanned aerial vehicles

The research presented in this article focuses on expanding and deepening the prior research of a low-cost terminal guidance system in a previous paper entitled “Design, implementation and verification of a low-cost terminal guidance system for small fixed-wing UAVs.” An automatic terminal guidance workflow is specially designed for an individual in a small fixed-wing unmanned aerial vehicle (SUAV) swarm. The extended work around the proposed workflow primarily involves upgrading onboard hardware modules to improve sensor accuracy and environmental adaptability, the imaging performance of the seeker, as well as the computational capability of the image processor, applying object detection to replace the human-in-the-loop function and adopting the integral proportional guidance law in the vertical direction to reduce the required overload and obtain a larger impact angle. Furthermore, we conducted several field tests on two types of SUAV against a stationary target on the ground in a field scenario. The experiments have generated valuable onboard image data and SUAV status information, all of which are aligned in the time domain. The only remaining data sets that support the findings of this study are available from the corresponding author. Our study into automatic terminal guidance has yielded a solution of the automatic strap-down monocular terminal guidance problem of individual SUAVs. The field trials of a single SUAV demonstrate the robustness and efficiency of the proposed automatic terminal guidance methodology and lays a foundation for the future SUAVs' cooperative attack test.     

非线性末制导系统参数灵敏度分析

末制导系统参数随着飞行环境及飞行条件的改变而存在摄动,针对这一问题本文提出根据动态灵敏度来分析参数摄动对脱靶量的影响.基于伴随法推导出与系统动态方程相同规模的伴随方程,并通过一次伴随求解计算得到脱靶量对所有可调参数及摄动参数的动态灵敏度,有效的提高了计算效率.传统的直接分析法是将系统状态变量直接对参数变量进行微分,需要对每个参数变量求解一组代数或微分方程,对于状态变量及参数变量较多的情况效率较低.本文基于两种方法对末制导系统的参数灵敏度进行分析,分析结果揭示了参数摄动对脱靶量的影响程度,较小的参数灵敏度为提高系统的鲁棒性提供了依据.     

A second generation adaptive autostabilization system for airborne vehicles

The paper is concerned with the initial evaluation of a self adaptive autostabilization system for an airborne vehicle whose dynamic behaviour may vary rapidly and over a wide range during normal operation. The basic design approach could be applied to any airborne vehicle which warranted adaptive control operation, but it is evaluated here in relation to the control of a high performance missile during an 80 second mission. This mission includes a rocket boost phase with accompanying large variations in the model parameters caused by changes in dynamic pressure, mach number, altitude and mass. The adaptive system can be considered as a ‘second generation’ adaptive scheme in the sense that it provides a logical self-adaptive successor to the well known ‘schedule adaptive’ systems used heretofore.     

基于MATLAB的飞行控制实时仿真系统研究

本文在介绍飞行控制系统仿真实验平台研制基础上,重点讨论其核心部分实时仿真系统的分析与设计。考虑到实时仿真系统要求高可靠性、高稳定性、高实时性,本文选用MATLAB为工具,完成对实时仿真系统各个模块的分析与设计。最后通过实时仿真系统独立试验以及整个仿真实验平台的联合试验,证明此实时仿真系统满足飞行控制系统半实物仿真实验平台的要求,效果良好。     

一种新的直接自适应控制方法及其在制导系统中的应用

基于CGT的直接自适应控制器结构简单,不需要滤波器,但要求被控对象是几乎严格正实的,这一点限制了它的应用.通常的改进方法是采用并联前馈补偿器,但这种前馈补偿器有时很难求,甚至找不到.为此,本文提出了一种改进的方法,其思想是:把被控对象按结构分解为满足几乎严格正实性要求和不满足这一要求的两部分,然后,分别对其采用基于CGT自适应控制方法和鲁棒控制方法设计控制器,从而避免了求被控对象并联前馈补偿器这一棘手问题.文中给出了这种方法在某导弹制导系统的应用,仿真结果表明该方法正确可行.     

Digital flight control design for a tandem-rotor helicopter

Methods and results in the continuing development of a digital flight control system (DFCS) for a CH-47B helicopter are presented. The helicopter is the research vehicle for the NASA VTOL Approach and Landing Technology (VALT) Program, and it equipped with comprehensive equipment for the investigation of navigation, guidance, and control requirements for future VTOL aircraft. Two control modes (attitude-command and velocity-command) are implemented, and each mode provides ‘Type 1’ response to guidance commands. DFCS design is based upon optimal estimation and control methods, which are found to provide flexible and efficient means for defining practical digital control systems.     

需求和退货波动环境下库存控制

随着需求和退货波动的增大, 如何有效控制库存, 成为当前零售企业管理者亟待解决的难题. 在库存水平动态变化表示为Markov调制Lévy过程条件下, 利用水平穿越和多维鞅理论, 分别确定了库存水平分布及循环期望费用和时间函数, 在此基础上, 构建了系统长程平均费用率模型. 最后, 通过仿真试验, 对比了3种订货策略下需求和环境状态变化系统的性能, 并分析了退货对最优控制策略的影响. 进而, 得到一些重要的库存管理启示.     

Integrated guidance and control of elastic flight vehicle based on robust MPC

Integrated guidance and control of an elastic flight vehicle based on constrained robust model predictive control is proposed. The design is based on a partial state feedback control law that minimizes a cost function within the framework of linear matrix inequalities. It is shown that the solution of the defined optimization problem stabilizes the nonlinear plant. Nonlinear kinematics and dynamics are taken into account, and internal stability of the closed‐loop nonlinear system is guaranteed. The performance and effectiveness of the proposed integrated guidance and control against non‐maneuvering and weaving targets are evaluated using computer simulations. Copyright © 2014 John Wiley & Sons, Ltd.     

基于UKF的视觉辅助末制导仿真研究

针对巡航导弹中段制导累积误差大的情况,在末制导段采用计算机视觉技术进行辅助制导.介绍了视觉制导的位姿估计方法,并利用无迹卡尔曼滤波器(UKF)对视觉和惯性制导系统进行信息融合,建立了视觉辅助末制导(VATG)的仿真控制模型.实验结果表明:该方法显著提高了末制导系统的精度和可靠性.     

Factors influencing the design of perspective flight path displays for guidance and navigation

Many types of modern commercial aircraft are equipped with an Electronic Flight Instrument System, comprising several programmable displays. The flexibility in information presentation of these systems offers the possibility to improve the pilot-aircraft interface significantly. Future concepts, such as enhanced and synthetic vision, will further increase these possibilities. To benefit from this, research into new display concepts is being performed to allow the pilot to operate in a four-dimensional (4D) air-traffic environment, to provide improved spatial and navigational awareness, and to enable a better transition from supervisory to manual control. A possible display format is the so-called perspective flight path display, which originated approximately 40 years ago. The design of perspective flight path displays for guidance and short-term navigation requires the specification of several parameters. Suitable values for these parameters depend on requirements with respect to range and resolution of the required information, the properties of the positioning and attitude determination system, and the abilities of the human operator with respect to perception, interpretation and evaluation of information. In this paper, a review of the various factors to be considered in the design of perspective flight path displays is presented. The relations between the guidance/short-term navigation task-related requirements and the design parameters of a perspective flight path display are discussed, and the consequences of the differences between today's guidance displays and perspective flight path displays for algorithms controlling the display symbology are explained.     

A flight control system for aerial robots: algorithms and experiments

This paper presents a hierarchical flight control system for unmanned aerial vehicles. The proposed system executes high-level mission objectives by progressively substantiating them into machine-level commands. The acquired information from various sensors is propagated back to the higher layers for reactive decision making. Each vehicle is connected via standardized wireless communication protocol for scalable multi-agent coordination. The proposed system has been successfully implemented on a number of small helicopters and validated in various applications. Results from waypoint navigation, a probabilistic pursuit-evasion game and vision-based target tracking demonstrate the potential of the proposed approach toward intelligent flying robots.     

基于虚拟现实二甲醚工艺流程模拟及监控系统

为模拟二甲醚生产工艺流程,建立虚拟现实模拟及监控平台。通过Multigen Creator、3Dmax构建二甲醚化工设备三维模型,利用视景开发软件Vega Prime进行模型管理。利用MATLAB/Smulink及程序对二甲醚各生产化工单元模拟与控制,并通过VC++接口函数建立与Vega Prime实时数据传输,驱动虚拟现实场景中的三维化工设备对象。实现二甲醚生产工艺流程实时虚拟模拟与监控。该系统经过对实际生产过程数据模拟及验证,可为二甲醚工艺流程模拟及监控仿真培训提供高效、实用支持。     

Distributed multivariable control system design for coal-fired boilers

This paper describes the multivariable characteristics of industrial coal-fired boilers and associated mathematical models, such as combustion model, a water drum level model and a superheated steam model. The purpose of the paper is to design multivariable control systems using multivariable system frequency domain design theory and the Smith-predictor technique. A specific application shows how to design a model-based distributed multivariable control system for coal-fired boilers in a small-scale power station.     

Fault-tolerant control of real-time systems in the presence of single event upsets

High energy radiation environments, such as in space or in the presence of a nuclear event can adversely affect the operation of digital devices, presenting significant problems of reliable control to both Hardware and Software Engineers. These problems, although only recently addressed, have important implications for both military aircraft and space vehicles.The phenomenon known as Single-Event-Upset (SEU) occurs when bistable devices, such as memory, are corrupted by a collision with an high energy particle. These particles are found in abundance in radioactive environments and in outer space. An SEU can produce a variety of undesirable scenarios for a computer that range from annoying to catastrophic and can be either temporary or permanent. Some of these scenarios are; alteration of program memory, corruption of RAM or of a CPU register, and spurious or missed interrupts. A variety of techniques employing hardware, or both have been developed to enable recovery from an SEU. These schemes include RAM scrubbing, coding, fault-tolerant software, and judicious selection of hardware. A unique set of these and other techniques were developed for use on the Space Shuttle Inertial Measurement (IMU) computer.This paper provides an introduction to the phenomenon of the SEU, a review of some of the existing software techniques and hardware selection considerations to combat the effects of SEUs, and a discussion of the application of the techniques in the fault-tolerant, real-time control software for the Space Shuttle IMU's embedded computer.     

基于智能解析余度的容错飞控系统设计

常规的解析余度容错方法容易受到不确定因素和随机干扰的影响,本文以飞行控制系统为研究对象,提出基于智能解析余度的容错飞行控制系统设计方案,使用径向基神经网络的在线学习和全局逼近的性能,建立飞行控制系统传感器之间的解析余度关系,利用不相同传感器之间的解析关系进行残差分析从而进行传感器的故障隔离与信号重构.这样有效地抑制了测量噪声和模型不确定性.应用某型飞机进行仿真,实现了传感器的在线故障隔离与重构,验证了该方法的有效性.     

水平定向对接穿越导向系统设计

水平定向对接穿越技术有效地解决了传统水平定向钻进无法进行长距离穿越,以及含砾石等复杂地层穿越的问题。在已有水平定向钻进工艺的基础上,实现对接穿越的关键在于成功进行导向孔对接。描述了一种水平定向对接穿越导向系统,系统采用三轴加速度计和磁阻传感器作为姿态敏感器件,以轴向磁铁产生的磁场作为对接磁源,介绍了系统的工作原理,以及系统的结构和功能。此系统具有体积小、成本低、精度和可靠性高等一系列优点,适用于水平定向对接穿越的导向。     

基于增量式策略强化学习算法的飞行控制系统的容错跟踪控制

针对发生故障的飞行控制系统,在强化学习算法的基础上,提出了一种基于增量式策略的强化学习容错方法.本方法利用传感器获取的系统状态值,根据系统预先设定的奖励函数对当前控制系统状况做出最优的决策并不断更新价值网络,将系统的容错控制过程转换为强化学习Agent的贯序决策过程,并使用一种改进型的增量式策略实现对当前故障的正确补偿策略的逐渐逼近.同时,针对连续控制系统,提出一种状态转移预测网络来得到下一步状态值.最后,通过南京航空航天大学"先进飞行器导航、控制与健康管理"工信部重点实验室的飞行器故障诊断实验平台验证了该方法的有效性.     

Steering law for roof type configuration control moment gyro system

A steering law is proposed for a roof type configuration Single Gimbal Control Moment Gyro (SGCMG) system for attitude control of the Large Space Telescope, a payload of the Space Shuttle. Although various steering laws have been developed for SGCMG systems, they have some drawbacks because of singular states of the system. The proposed steering law minimizes the effect of singular states by using a new momentum distribution scheme that makes all the singular states unstable. This scheme is formulated by treating the system as a sampled-data system.     

Type-2 fuzzy sliding mode control without reaching phase for nonlinear system

A new sliding mode control (SMC) algorithm for the nth order nonlinear system suffering from parameters uncertainty and subjected to an external perturbation is proposed. The algorithm employs a time-varying switching plane. At the initial time t=t₀, the plane passes through the point determined by the system initial conditions in the error state space. Afterwards, the plane moves to the origin of the state space. Since the nonlinear system is sensible to the perturbations and uncertainties during the reaching phase, the elimination of such phase yields in a considerable amelioration of system robustness. Switching plane is chosen such that: (1) the reaching phase is eliminated, (2) the nonlinear system is insensitive to the external disturbance and the model uncertainty from the initial time (3) the convergence of the tracking error to zero. Furthermore, a Type-2 fuzzy system is used to approximate system dynamics (assumed to be unknown) and to construct the equivalent controller such that: (1) all signals of closed-loop system are uniformly ultimately bounded, (2) the problems related to adaptive fuzzy controllers like singularity and constraints on the control gain are resolved. To ensure the robustness of the overall closed-loop system, analytical demonstration using Lyapunov theorem is considered. Finally, a robot manipulator is considered as a real time system in order to confirm the efficiency of the proposed approach. The experimentation is done for both regulation and tracking control problems.