飞机新原理电液自馈能刹车系统设计与优化

当前,传统飞机液压刹车系统普遍采用集中式的机载液压源作为动力,液压能通过能源管路传输到刹车作动器,整个系统零部件数目众多,管路布局复杂,由此带来的管路振动、液压油泄漏等问题突出,限制了飞机刹车系统可靠性和可维护性的提升。近年来,一种飞机新原理电液自馈能刹车系统被提出,将模块化的"自馈能装置"安装在机轮附近,回收机轮着陆时的旋转动能,并将其转换成液压能,用于刹车作动。提出了一种利用波浪曲面进行取能的专用取能机构,设计了自馈能系统紧凑型专用取能机构,研制了高可靠、低能耗、高抗污染的自馈能刹车系统原理样机,完全实现了自馈能,即使飞机失去全部动力也能正常完成刹车功能,使抗污染等级从NAS6级提升到NAS10级,可靠性和可维护性优于传统液压刹车。     

Moving towards a more electric aircraft

The latest advances in electric and electronic aircraft technologies from the point of view of an "all-electric" aircraft are presented herein. Specifically, we describe the concept of a "more electric aircraft" (MEA), which involves removing the need for on-engine hydraulic power generation and bleed air off-takes, and the increasing use of power electronics in the starter/generation system of the main engine. Removal of the engine hydraulic pumps requires fully-operative electrical power actuators and mastery of the flight control architecture. The paper presents a general overview of the electrical power generation system and electric drives for the MEA, with special regard to the flight controls. Some discussion regarding the interconnection of nodes and safety of buses and protocols in distributed systems is also presented     

Reliable electro-mechanical actuators in aircraft

There is a general trend in the aerospace industry toward increasing the use of electrically-powered equipment. This trend is usually referred to as "Power-by-Wire" in the "More Electric Aircraft" (MEA) concept and it leads, among others, to the substitution of hydraulic actuators by Electro-Mechanical Actuators (EMA). Its benefits are a decrease in maintenance effort and weight, and an increase in efficiency. However, jamming case obstacles stop the massive use of EMAs in flight-control actuators. The aim herein is to introduce the safety needs of electro-mechanical actuators in aircraft applications, and Its major goal is to present the suitability and reliability of such actuator systems, including electric motors and power converters.     

多电飞机作动系统的体系结构优化(英文)

多电技术的深入发展使得飞机上可选择的功率源和作动器种类越来越多,这导致在机载作动系统体系结构优化设计过程中出现了不同功率源和作动器组合的极端复杂性,传统的"试凑"法已无法完成设计任务。首先介绍了多电飞机飞控作动系统(Flight Control Actuation System,FCAS)的组成,计算了其可能的体系结构数量;其次提出了FCAS体系结构在安全性、重量和效率方面的评价指标,计算了全机各舵面均采用同类作动器时的评价指标值;最后对比分析了现有的各种多目标优化算法,采用遗传算法给出了多电飞机FCAS体系结构的多目标优化设计结果。对比传统的只采用阀控液压伺服作动器的作动系统体系结构,优化后的体系结构可以在满足安全可靠性要求的前提下使系统的重量减轻6%左右,效率提高30%左右。     

机载液压系统的主要发展趋势

对飞机特别是军用飞机机载液压系统的主要发展趋势进行了综述,并对国内外的机载液压系统的研究工作进行了一定的介绍,重量轻、体积小、高压化、大功率、变压力等是机载液压系统的主要发展趋势,尤其是高压变压力泵源系统对未来飞机的发展尤为重要。     

Fault diagnosis of an intelligent hydraulic pump based on a nonlinear unknown input observer

Hydraulic piston pumps are commonly used in aircraft. In order to improve the viability of aircraft and energy efficiency, intelligent variable pressure pump systems have been used in aircraft hydraulic systems more and more widely. Efficient fault diagnosis plays an important role in improving the reliability and performance of hydraulic systems. In this paper, a fault diagnosis method of an intelligent hydraulic pump system (IHPS) based on a nonlinear unknown input observer (NUIO) is proposed. Different from factors of a full-order Luenberger-type unknown input observer, nonlinear factors of the IHPS are considered in the NUIO. Firstly, a new type of intelligent pump is presented, the mathematical model of which is established to describe the IHPS. Taking into account the real-time requirements of the IHPS and the special structure of the pump, the mechanism of the intelligent pump and failure modes are analyzed and two typical failure modes are obtained. Furthermore, a NUIO of the IHPS is performed based on the output pressure and swashplate angle signals. With the residual error signals produced by the NUIO, online intelligent pump failure occurring in real-time can be detected. Lastly, through analysis and simulation, it is confirmed that this diagnostic method could accurately diagnose and isolate those typical failure modes of the nonlinear IHPS. The method proposed in this paper is of great significance in improving the reliability of the IHPS.     

High-efficiency aircraft antiskid brake control algorithm via runway condition identification based on an on-off valve array

The aircraft antiskid braking system is an important hydraulic system for preventing tire bursts and ensuring safe take-off and landing. The brake system adjusts the force applied on the brake discs by controlling the brake pressure. Traditional aircraft antiskid braking systems achieve antiskid performance by controlling the braking pressure with an electrohydraulic servo valve. Because the pilot stage of an electrohydraulic servo valve is easily blocked by carbonized hydraulic oil, the servo valve would become a dangerous weak point for aircraft safety. This paper proposes a new approach that uses an on-off valve array to replace the servo valve for pressure control. Based on this new pressure control component, an efficient antiskid control algorithm that can utilize this discontinuous feature is proposed. Furthermore, the algorithm has the ability to identify the runway circumstances. To overcome the discontinuity in the process of using an on-off valve array, the Filippov framework is introduced. The conditions of convergence of the system are also discussed. The results of the digital simulations and the hardware-in-the-loop (HIL) braking experiments are used to verify the efficiency and stability of the proposed control algorithm. The method also proves that the on-off valve array can replace the servo valve perfectly as a new type of antiskid braking pressure control component.     

低性能代偿损失的环境控制系统方案研究

从集成能源子系统的概念出发,提出了一种以环控系统为核心的热能管理组合方案。建立了该组合方案在巡航模式下工作时的数学模型,对其参数匹配的方法进行了探讨。并对主要附件性能的影响进行了分析。     

The All-Electric Fighter Airplane Flight Control Issues, Capabilities, and Projections

The prime issues raised in any all-electric airplane discussion are (1) is the electric power system as reliable and trustworthy as a hydraulic power system; (2) can electromechanical flight control actuators perform satisfactorily, i.e., can the performance match that of hydraulic actuators; (3) can redundant electromechanical actuation systems (EMAS) be designed to equal the flight safety reliability of dual tandem hydraulic actuators; and (4) can satisfactory solutions be found or developed for dissipating the heat generated in actuators and power controllers. The first question should be inconsequential since it is assumed that the all-electric aircraft will be equipped with a fly-by-wire (FBW) flight control system (FCS) which is already dependent upon an uninterrupted supply of electrical power. Design studies and hardware already developed show that the answer to question (2) is that EMAS outperform hydraulic actuators, particularly under load. The answer to question (3) is not as clear primarily because the issue has not been addressed in any depth. As posed the answer must be yes, but with the proviso that the weight might be greater than currently predicted. Studies have shown that we can cope with the heat dissipation issue addressed in question (4) in the case of motors and inverter/power controllers. The projections regarding usage of EMAS and the future of the all-electric airplane must be based on the type of vehicle (small subsonic transport, large transport, or military tighter) and the economics involved.     

液压系统清洗装置的工艺研究

飞机所有的操纵舵面和运动部件几乎全由液压系统来操纵。随着飞机液压系统中液压舵机和伺服阀等高精度附件的大量应用,为保证系统的可靠性和延长附件寿命,降低全寿命费用,必须大幅度提高液压系统的清洁度。液压系统清洗装置是用于对被污染的飞机液压系统进行清洗,对液压管路单独进行脉动清洗的设备。因此,液压系统清洗装置的工艺研究就显得极其重要,本文介绍了液压系统清洗装置的零部件加工、重要成品、液压系统和电气系统的安装过程,并从液压系统清洗装置的加工工艺、装配工艺、表面处理工艺等多角度进行了研究,为飞机液压系统提供了高质量的清洗装置。     

Braking systems — Towards modular architectures and smart modules — the SAMBA project

The use of smart actuators, in a modular braking system architecture, offers the possibility of simplifying central braking control and of developing versatile standard components applicable to braking systems in different families of aircraft. The SAMBA (Smart Actuator and Modular Braking Application) project has investigated these possibilities together with techniques for control of brake torque instead of brake pressure.     

Motor drive technologies for the power-by-wire (PBW) program:options, trends and tradeoffs. I. Motors and controllers

The Power-By-Wire (PEW) program involves the replacement of hydraulic and pneumatic systems currently used in aircraft with an all-electric secondary power system. One of the largest loads of the all-electric secondary power system will be the motor loads which include pumps, compressors and Electrical Actuators (EAs). Issues of improved reliability, reduced maintenance and efficiency, among other advantages, are the motivation for replacing the existing aircraft actuators with electrical actuators. The EA system contains the motor, the power electronic converters, the actuator and the control system, including the sensors. This paper and a companion paper give a comparative literature review in motor drive technologies, with a focus on the trends and tradeoffs involved in the selection of a particular motor drive technology. The reported research comprises the induction motor (IM), the brushless dc motor (BLDCM) and the switched reluctance motor (SRM) drive technologies. Each of the three drives has the potential for application in the PEW program. Many issues remain to be investigated and compared between the three motor drives, using actual mechanical loads expected in the PBW program     

基于模型的多电飞机能源优化特性仿真分析

多电飞机是一种用电能部分取代原来的液压能和气压能的飞机,其二次能源系统以电能为主。为实现多电飞机能源系统的优化设计,将飞机的发电、配电和用电集成在一个统一的系统内,实行发电、配电和用电的统一规划、统一管理和集中控制。为快速有效地分析多电飞机能源系统优化特性,本文采用基于模型的系统工程方法论,针对多电飞机能源优化仿真分析平台开展研究,提出了一种面向电气设备的多物理域模型建模方法,以实现机载系统的大规模集成仿真。并以飞控系统为对象,建立了多电飞机飞控系统和传统飞机飞控系统的能量利用、能量传送、能量变换设备等仿真模型,仿真分析了两种飞控系统的能源应用特性,为多电飞机能源系统的优化设计提供了有效支撑。     

多电飞机混合储能系统的设计与仿真

多电飞机直流配电系统是电功率传输的核心,由于涡轮电机的单向性,系统并不完全可逆。为了维持直流汇流条的稳定、提高能源效率,需建立相应的存储和消耗系统。研究了一种带有超级电容器的多电飞机储能系统,分析了该系统中超级电容器的作用及其控制策略,根据超级电容器本身的特性利用Matlab/Simulink软件建立相应仿真模型,并针对于飞机电网突加和突卸负载时电压不同状态设计了相应控制策略,通过仿真实验验证了带有超级电容器的混合储能系统的有效性。     

Energy-saving and accurate motion control of a hydraulic actuator with uncertain negative loads

Pump controlled hydraulic actuators are wildly used in the aerospace industry owing to the advantages of energy-saving and integrated configurations. Negative loads may occur to actuators due to external force loads or the inertial force when the actuator decelerates significantly. Uncertain negative load working conditions may cause cavitation, actuator vibration, and even instability to the motion control if the actuator is without sufficient meter-out damping. Various types of hydraulic configuration schemes have been proposed to deal with negative loads of hydraulic actuators. However, few of them can simultaneously achieve energy saving and high control accuracy. This study proposes an energy-saving and accurate motion tracking strategy for a hydraulic actuator with uncertain negative loads. The actuator’s motion is driven by a servomotor pump, which gives full play to the advantage of energy-saving. The meter-out pressure is controlled by proportional valves to provide the optimized meter-out damping. The nonlinear adaptive robust control law is designed, which guarantees the control stability and achieve high tracking accuracy. An integrated direct/indirect adaptation law obtains satisfactory parameter estimations and model compensation for asymptotic motion tracking. Comparative experiments under different working conditions were performed to validate the advantages of the proposed control strategy.     

飞机轮胎爆破喷流模式下管路的强度计算方法

飞机起落架作为飞机唯一的支撑结构,是不可或缺的飞机部件,而轮胎作为飞机起落架的重要部件,在飞机起飞、降落到滑跑过程中承受着巨大的冲击力和摩擦力,从而可能导致轮胎爆破的事故发生,也可能引起轮胎的空气喷流效应,导致其空气喷流效应影响范围内的液压管路破坏。而液压管路的破坏将会导致飞机液压能源系统和与之相关联的液压设备非正常工作,进而威胁飞机的飞行安全。在进行喷流模式下的液压管路的强度计算时,由于该模式下轮胎爆破产生的喷流是瞬间的、巨大的,因此计算其喷流载荷是非常困难的。针对该模式下提出一种喷流载荷拟合方法,并将拟合后的载荷加载到管路的有限元模型中,从而计算出液压管路的强度,为轮胎爆破下喷流模式的液压管路计算提供了工程实用的方法。     

液压管路系统随机振动下疲劳分析

民用飞机液压管路系统受到飞机振动环境的影响,可能产生振动引发的管路及安装结构疲劳破坏。为了分析液压管路系统在飞机振动环境下的承受能力,参考RTCA/DO-160G中对于固定翼飞机振动环境的定义及要求,对某民用飞机液压管路进行振动模态和随机振动响应分析。通过有限元分析得出了液压管路及安装结构的随机振动Von Mises均方根应力,采用基于高斯分布和Miner线性累计损伤定律的三区间法,计算管路系统的随机振动疲劳损伤,得到了疲劳薄弱部位及疲劳分析结果,为民用飞机液压管路在随机振动环境下的疲劳分析提供参考。     

民用飞机机轮最大刹车能量研究

机轮刹车装置是飞机起落架的重要组成部分,在地面减速过程中吸收飞机大部分动能,对飞机起降安全至关重要。 其中,最大刹车能量设计是刹车装置的关键参数之一,与机轮刹车装置的安全性和经济性紧密相关。 对民用飞机机轮刹车装置最大刹车能量的计算进行研究,按照适航规章相关要求,结合适航当局对刹车装置最大刹车能量计算的关注要点和飞机的设计构型,以某民用飞机为例,分析了机轮最大刹车能量计算中的影响因素,并通过计算对比该飞机在预定的不同使用场景与可能遇到的单个及多个故障叠加工况着陆时的刹车能量,确定该型飞机最大刹车能量出现在典型高原机场两个机轮刹车装置失效着陆工况,最大刹车能量为 32. 44 MJ,为飞机机轮刹车装置的设计提供关键参数。     

Hydraulic piston pump in civil aircraft: Current status,future directions and critical technologies

The piston pump is the key power component in the civil aircraft hydraulic system, and the most common pump used in the aviation field is the pressure compensated variable displacement type. In this review paper, a basic introduction to the civil aircraft piston pump is presented, including the classification, structure, working principle, design features, and achievements by some research groups. Then, the future directions of the aircraft pump are reported from various perspectives. Further, the critical technologies are analyzed and summarized in detail from six thrust areas: friction couples, noise reduction, inlet boost, thermal management, fault diagnosis and health management, and mechanical seal. Finally, the challenges and limitations of the research on the aircraft pump are discussed to provide valuable insight for future scholars.