An experimental study of pilots' control characteristics for flight of an STOL aircraft in backside of drag curve at approach and landing.

In general, most vehicles can be modelled by a multi-variable system which has interactive variables. It can be clearly shown that there is an interactive response in an aircraft's velocity and altitude obtained by stick control and/or throttle control. In particular, if the flight conditions fall to backside of drag curve in the flight of an STOL aircraft at approach and landing then the ratio of drag variation to velocity change has a negative value (delta D/delta u less than 0) and the system of motion presents a non-minimum phase. Therefore, the interaction between velocity and altitude response becomes so complicated that it affects to pilot's control actions and it may be difficult to control the STOL aircraft at approach and landing. In this paper, experimental results of a pilot's ability to control the STOL aircraft are presented for a multi-variable manual control system using a fixed ground base simulator and the pilot's control ability is discussed for the flight of an STOL aircraft at backside of drag curve at approach and landing.     

Landing Auto‐Pilots for Aircraft Motion in Longitudinal Plane using Adaptive Control Laws Based on Neural Networks and Dynamic Inversion

This paper presents two new automatic landing systems (ALSs) for aircraft motion in longitudinal plane; the model of the landing geometry determines the flight trajectory and the aircraft calculated altitude; the flight trajectory during landing consists of two parts: the glide slope and the flare. Both designed ALSs have an adaptive system (ACS) for the aircraft output's control; for the first ALS, the output vector consists of the flying altitude and the longitudinal velocity, while, for the second ALS, the output variables are the pitch angle and the longitudinal velocity of aircraft. The second variant of ALS also contains an altitude controller providing the calculated pitch angle. The calculated altitude (for the first ALS), the calculated pitch angle (for the second ALS), and the desired flight velocity are provided to the ACS by means of a block consisting of two reference models. ACS is based on the dynamic inversion concept and contains an adaptive controller which includes a linear dynamic compensator, a state observer, a neural network, and a Pseudo Control Hedging block. The paper is focused both on the design of the two ALSs and on their complex software implementation and validation.     

Visual scan patterns reflect to human-computer interactions on processing different types of messages in the flight deck

The flight deck of commercial aircraft is sophisticated and searching for the necessary information at the right time is sometimes challenging. This research investigates pilot's visual parameters while interacted with two different designs of crew alerting system by eye tracking technology. There are 24 aviation professionals that participated in this experiment including commercial pilots, private pilots and avionic engineers. Compared with traditional design, the new integrated design applied proximity compatibility principles to assist pilots in searching necessary information to deal with urgent situations. The results demonstrated that the integrated design is superior to traditional design in providing accurate instructions as determined by visual behaviors. However, the integrated design increases pilot's situation awareness by redirecting attention from current task to the most critical task with the cost of a longer total fixation duration time. Pilot's visual parameters demonstrated significant differences while interacting with PFD mainly numeric, ND mostly by symbols and EICAS with presented text messages. Therefore, flight deck design has to adopt a holistic approach as pilot's visual attentions is shifting among all types of different displays to gain situation awareness rather than focus on only one display. The design of integrated EICAS can provide detailed instructions to deal with urgent situations which induced higher cognitive loads as pilot's pupil dilation is significant bigger than interacted with traditional design. By eye tracking technology, it is applicable to design human-centred flight decks to improve safety and human performance in aviation.     

输出重定义方法设计垂直/短距起降飞机高度控制器

垂直/短距起降飞机是一类典型的非最小相位系统.系统的负调特性使得飞机高度响应比较缓慢,并且会在初始阶段响应为负,从而出现不期望的掉高现象.针对该问题,本文设计了新的最小相位输出预估控制器,通过调节近似输出零点的方法提高系统的动态响应;对于负调部分,采用两步参数整定的方法设计PID控制器,达到抑制负调的作用.最后,对飞机的高度俯仰控制进行了仿真验证,结果表明设计的控制器对飞机高度初始负调具有明显的抑制作用,并且缩短了回复上升所需的时间.     

A comparative survey of the utility of cross-cockpit linkages and autoflight systems' backfeed to the control inceptors of commercial aircraft

'Fly-by-wire' (FBW) electronic flight control systems in modern commercial aircraft have removed the requirement for the primary control inceptors in the cockpit to have a cross-cockpit linkage, and also for them to be back-driven from the autoflight systems. This comparative survey of 157 commercial pilots with current type ratings on either an FBW aircraft or a conventional technology aircraft, however, suggests that the deletion of these linkages may have degraded the lines of communication in the cockpit, both between the pilots and between the pilot and the aircraft. It is argued that this may adversely affect a pilot's situation awareness.     

推力矢量垂直短距飞机轨迹优化与控制

推力矢量垂直短距起降(V/STOL)飞机是一种兼顾巡航飞行速度和起降灵活性的新型飞机.本文首先建立了包含执行器饱和的V/STOL飞机动力学模型;然后针对V/STOL飞机在过渡过程阶段面临的强耦合、强非线性的特点,使用梯度下降法进行最优过渡过程轨迹优化并采用适应性矩估计算法(Adam)加速了优化过程;在此基础上,以最优轨迹为基础设计前馈控制器,同时通过对比真实飞行状态与所设计的最优状态给出反馈补偿量,保证了实际的过渡过程沿着最优轨迹进行.经过仿真实验可以发现,该方法具有过渡过程时间短、姿态平稳、鲁棒性强的优点.     

ROBUST GAIN‐SCHEDULED CONTROL OF A VERTICAL TAKEOFF AIRCRAFT WITH ACTUATOR SATURATION VIA THE LMI METHOD

This paper presents a robust gain‐scheduled approach for the control of a vertical/short takeoff. and landing (V/STOL) aircraft. The nonlinear aircraft dynamics exhibit non‐minimum phase characteristics arising from the parasitic coupling effect between the aircraft's lateral force and rolling moment. The undesired coupling effect also causes modelling uncertainy of the aircraft dynamics. The nonlinear aircraft dynamics are considered to be composed of a nominal linear parameter varying (LPV) system and a linear system with a norm bounded uncertainy matrix multiplied by the parasitic uncertain non‐minimum phase coupling parameter. The nominal LPV system is considered to be affinely dependent on a measurable varying parameter. The ranges of the varying parameter and its variation as well as its parasitic induced uncertain matrix are addressed by introducing the parameter‐dependent invariant ellipsoid interpretation for dealing with the issue of affinely quadratic stabilization. In this paper, the relations among the magnitude of actuator saturation, the maximum achievable relative stability, and the sustainable coupling uncertainty are investigated for the considered robust gain‐scheduled design.     

Autonomous landing of airplanes by dynamic machine vision

The 4D approach to dynamic machine vision has been validated for the application area of on-board autonomous landing approaches in the visual flight regime with computing technology available today; sensors are a video-camera, inertial gyros and an air velocity meter. The key feature of the method is the reconstruction and servo-maintained adjustment by prediction error feedback of an internal spatiotemporal model about the process to be controlled. This encompasses both the egomotion state of the aircraft carrying the sensors and the relevant geometric properties of the runway and its spatial environment. The efficiency of the approach is proved both in a hardware-in-the-loop simulation and in real test flights with a twin turbo-prop aircraft. For accuracy evaluation of the data gathered, the results of differential GPS and radiometric altitude measurements have been recorded simultaneously.     

JUMBO—a demonstration program to illustrate the use of BCPL in a real-time graphics application requiring scaled arithmetic

This paper describes the key features of a simple program to simulate the flying characteristics of an aircraft and display in real-time the flight instruments and pilot's view of the ground on a cathode ray tube. The program was written in BCPL using only 16 bit scaled arithmetic for all the numerical calculations.     

基于瑞萨单片机的四旋翼自主飞行器设计

该四旋翼自主飞行器以瑞萨公司的R5F100LEA单片机为控制核心,包括飞行姿态处理模块,超声波测距模块,红外传感器循迹模块,电机驱动模块以及微处理器模块等.飞行姿态处理由MPU6050加速度计陀螺仪提供,保证飞行器平稳飞行.超声波测距模块和红外传感器循迹模块为飞行器提供导航参数使飞行器可以按照规定航线并以一定高度飞行.本设计中应用了PPM控制方法,PID算法,平滑滤波等,使飞行器实现在一定区域内一键式起飞,稳定飞行,精确降落.并且可以拾取物件,完成空投任务,最终精确降落并停机.     

结冰飞机的包线保护与控制裕度研究

飞机结冰具有不确定性和随机性,会破坏飞机的动力学特性,威胁飞行安全.针对这一问题,对结冰飞机的安全边界保护和控制裕度计算展开探究.首先,应用可达集方法,将结冰的作用看作不确定性对抗输入,分析结冰对飞机安全包线边界的影响;然后,基于已知的结冰飞机飞行安全包线,提出两种包线边界保护方法,第1种是改进的最优控制边界保护方法,通过引入新型的最优控制保护动作的切换策略消除传统最优控制保护方法的控制量抖振现象,第2种是保留驾驶员操作权限的安全边界保护方法,通过计算安全边界上的可用控制指引驾驶员完成正确的操作,使得飞机飞行状态不超出安全包线;最后,通过实时计算飞机当前状态点的控制裕度对飞机超出包线进行提前预防,指引驾驶员完成安全程度较高的操作,并提出一种新型的控制裕度迭代计算策略,能够有效降低控制裕度计算的保守性.     

The design of smooth switching control with application to V/STOL aircraft dynamics under input and output constraints

This paper presents a smooth switching gain‐scheduled control approach for linear parameter varying (LPV) system dynamics, indexed by a scalar varying parameter. The proposed approach is demonstrated by application to the planar vertical/short takeoff and landing (V/STOL) aircraft dynamics subject to input and output constraints. In the design of switching control, the switch logic determines the switching process between control laws. The usual switching logics use the instantaneous switching manner, which can cause discontinuous chattering control signal. By performing convex weightings between two individual control laws for neighboring subsystems, the proposed smooth switching gain‐scheduled control approach can provide improved performance but does not arouse control signal chattering. For the studied application, the nonlinear aircraft dynamics are represented in the form of LPV systems with parameter dependence on attitude angle. The resulting design is verified by the obtained relative stability and time response simulations. Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

Design of small hand‐launched solar‐powered UAVs: From concept study to a multi‐day world endurance record flight

We present the development process behind AtlantikSolar, a small 6.9 kg hand‐launchable low‐altitude solar‐powered unmanned aerial vehicle (UAV) that recently completed an 81‐hour continuous flight and thereby established a new flight endurance world record for all aircraft below 50 kg mass. The goal of our work is to increase the usability of such solar‐powered robotic aircraft by maximizing their perpetual flight robustness to meteorological deteriorations such as clouds or winds. We present energetic system models and a design methodology, implement them in our publicly available conceptual design framework for perpetual flight‐capable solar‐powered UAVs, and finally apply the framework to the AtlantikSolar UAV. We present the detailed AtlantikSolar characteristics as a practical design example. Airframe, avionics, hardware, state estimation, and control method development for autonomous flight operations are described. Flight data are used to validate the conceptual design framework. Flight results from the continuous 81‐hour and 2,338 km covered ground distance flight show that AtlantikSolar achieves 39% minimum state‐of‐charge, 6.8 h excess time and 6.2 h charge margin. These performance metrics are a significant improvement over previous solar‐powered UAVs. A performance outlook shows that AtlantikSolar allows perpetual flight in a 6‐month window around June 21 at mid‐European latitudes, and that multi‐day flights with small optical‐ or infrared‐camera payloads are possible for the first time. The demonstrated performance represents the current state‐of‐the‐art in solar‐powered low‐altitude perpetual flight performance. We conclude with lessons learned from the three‐year AtlantikSolar UAV development process and with a sensitivity analysis that identifies the most promising technological areas for future solar‐powered UAV performance improvements.     

A comparison of voice and multifunction controls: logic design is the key

The proper design of the human-computer interface is a key feature for the optimum use of advanced manned systems. In future aircraft cockpits, one of the pilot's principle tasks will be to interact with a very sophisticated computer system—an electronic crewmember. This paper discusses the experimental comparison of two communication mechanisms: voice control and multifunction keyboards. The paper also discusses the crucial role of the software logic used with these devices.     

水陆两栖飞机的无线电高度数据处理方法研究

分析了水陆两栖飞机因水上起降和机腹船体构型导致的对无线电高度表数据进行零位基准修正、天线位置修正、负高度显示等特殊的处理要求.提出了零位基准设置的判据,建立了基于坐标变换矩阵,利用姿态角数据对零位基准设置、天线布置偏离零位基准等因素产生的测高误差进行修正的无线电高度数据处理方法,将姿态角的修正从俯仰角扩展到横滚角.应用...     

低空导航吊舱地形跟随算法设计与仿真

导航吊舱是战斗机超低空突袭作战时的必备外挂设备,可保证飞机超低空飞行的安全;为了提供一种适应作战环境的方法,提高飞机有效低空突防能力,设计了低空导航吊舱地形跟随算法;通过建立雷达工作模型与无线电工作模型分别得到飞行控制角指令,然后对角指令进行数据融合得到最终适合飞机进行地形跟随飞行的指令;在随机地图上利用MATLAB对该算法进行了仿真,结果表明该算法很好地实现了飞机飞行高度为150 m的地形跟随和突防任务。     

Reachability Analysis of Landing Sites for Forced Landing of a UAS

This paper details a method to ascertain the reachability of known emergency landing sites for any fixed wing aircraft in a forced landing situation. With a knowledge of the aircraft’s state and parameters, as well as a known wind profile, the area of maximum glide range can be calculated using aircraft equations of motion for gliding flight. A landing descent circuit technique used by human pilots carrying out forced landings called high key low key is employed to account for the extra glide distance required for an approach and landing. By combining maximum glide range analysis with the descent circuit, all the reachable landing sites can be determined. X-Plane flight simulator is used to demonstrate and validate the techniques presented.     

基于单步最优方法的推力矢量垂直短距飞机过渡过程控制

推力矢量垂直短距起降飞机(V/STOL)具有巡航速度快和起降灵活的特点,近年来受到了广泛的关注.然而,该型飞机需要经历悬停转平飞和平飞转悬停的过渡过程阶段,期间飞机会面临强耦合、强非线性等控制难题,使得传统控制器难以胜任.针对上述问题,通过充分考虑执行器的执行能力,提出一种基于单步最优方法的过渡过程控制策略.所提方法结合推力矢量V/STOL飞机的特点,在确保飞机姿态可控的前提下使飞机水平加速度最大,同时使三轴承推力矢量喷管转角向目标转角不断靠近,从而以最快的速度完成过渡过程,并进行控制器切换.仿真实验验证了所提方法具有过渡过程时间短、姿态平稳的优点.