应用六西格玛方法提高TCAS系统可靠性

在大型民用飞机中,TCAS系统是保证飞机安全运行重要的航电系统之一。本文结合航空公司波音737NG机队运行中TCAS系统的故障情况,介绍了运用六西格玛方法的分析过程,有效地改进了TCAS系统的使用可靠性。     

A320系列飞机TCAS故障签派放行处置研究

空中交通警报与避撞系统( traffic alert and collision avoidance system,简称 TCAS)是机载监视系统中的重要组成部分, 对于避免航空器危险接近,保证航空器安全有着重要作用。 针对签派工作中 TCAS 故障放行难点问题,分别从飞机以自身动力滑出前、以自身动力滑出后、起飞后三个阶段展开分析。 首先,由于 TCAS 系统依托的设备多,关联系统复杂,先介绍了 TCAS 系统的组成以及依托设备的常见故障。 其次,以 TCAS 的工作原理为基础,分析了各个关联设备如应答机、惯性导航和大气数据基准等故障导致 TCAS 故障的机理。 再次,给出了关于 TCAS 失效能否继续实施缩小垂直间隔( reduced vertical separation minimum, 简称 RVSM)的说明,指出 TCAS 不是运行 RVSM 空域的基本设备,需要区分造成 TCAS 失效的原因。 最后,从三个阶段对 TCAS 故障及关联设备故障展开分析,分别给出了滑出前 AP / FD TCAS 方式丢失、导航 TCAS 失效,滑出后及起飞后 TCAS 故障和关联系统故障并给出签派解决方案。     

TCAS 系统故障隔离及容错架构设计方法研究

针对TCAS 系统运行过程典型功能危险场景和架构设计过程，本文采用系统工程过程的正向设计流 程方法，针对潜在的功能失效风险，开展TCAS 系统域的故障检测和容错设计技术研究，形成覆盖系统、软件 和硬件层级的故障检测及隔离架构设计方案，以提高装机运行过程中防撞告警的置信度，减少由于误警和虚警 对飞行安全产生的不利影响。     

BAe146-300型飞机TCAS系统特点

BAel46-300型飞机的TCAS系统是该飞机在中国运行了10年后，在大修时加装的，是二类TCAS系统，具有垂直避让功能，在欧洲称作ACAS(Airborne Collision Avoidance System)系统。在实际使用中多次出现故障，本文对该系统的特点和组成进行介绍。     

TCAS防撞系统空中故障分析

介绍TCAS防撞系统的工作原理及交联设备之间的关系,分析TCAS防撞系统在试飞过程中显示＂TCAS OFF＂故障的原因,并提出解决措施,以期对提高机务工作质量、降低产品故障率起到积极的作用。     

空中交通防撞系统(TCAS Ⅱ)的排故与维护

主要以空客A320飞机为例,介绍了TCAS Ⅱ(空中交通防撞系统)系统原理、组成、功能及常见的故障、排故方法等,希望能增进对TCAS Ⅱ系统的了解,有助于TCAS Ⅱ系统的设计和维护。     

B-2950飞机TCAS系统故障的分析

本文通过对一起B737飞机TCAS系统故障的排除过程的分析，阐述了TCAS系统的工作原理，重点分析了TEAS与ATC及DME之间抑制信号的作用。     

基于人工神经网络的TCAS板卡深度故障诊断系统

提出了一种基于人工神经网络的故障定位算法,用于TCAS板卡深度故障诊断系统。     

多跑道独立进近中的TCAS告警风险仿真与分析

为减少民航飞机在多跑道独立进近中产生不必要的TCAS(机载防撞系统)告警,研究了多跑道独立进近中TCAS告警风险仿真计算方法。首先,建立飞机冲突探测模型,模拟独立进近中的飞机位置并探测冲突风险大小,再根据TCAS告警逻辑与流程判定TCAS告警情况;其次,采用蒙特卡洛方法随机生成按正态分布的飞机位置、速度、定位误差等参数,并通过大量计算得出TCAS告警概率及易触发位置;最后,采用控制变量法,对触发TCAS告警的影响因素进行计算分析。研究结果表明,所用模型与计算方法能够有效计算出TCAS告警风险,同时通过对影响因素的相关分析可以提出相应的改进措施。     

一起TCAS干扰所致电子设备通风系统故障分析

针对一起电子设备通风系统故障进行了深入分析,在排故过程中发现其原因是导航系统的TCAS计算机干扰所致,这种非相关系统的关联故障在航线维护中较为罕见。     

对TCAS的原理分析

本文基于对防撞基本概念的理解，分析了ＴＣＡＳ工作原理，并结合实际工作过程进行了论证。     

自由飞行下基于分段维纳过程的碰撞风险研究

在自由飞行下,飞机的碰撞风险与通信导航监视(CNS)定位误差、机载防撞系统可靠性等因素有关。CNS引起的定位误差可视为正态分布,以机载防撞系统告警区为界,在告警区外飞机视为匀速,相对距离视为一般维纳过程;在告警区内飞机为避撞进行航迹和速度调整,视为变速,相对距离视为伊藤过程。根据此相对运动特点,建立了基于维纳过程的分段碰撞概率模型,并对不同初始状态时的情形进行求解。算例结果表明了模型的可行性。     

New Concepts in Collision Avoidance Logic

Airborne collision avoidance logic is being developed to take advantage of the accurate bearing measurements provided by the Enhanced TCAS II system. This system issues horizontal and vertical resolution advisories, and should give fewer unnecessary alarms than earlier systems. Design tradeoffs and new techniques are described for threat detection, modeling of potential escape maneuvers, and the selection of resolution advisories. Plans for further development and evaluation are described.     

Independent validation and verification of the TCAS II collisionavoidance subsystem

This paper describes the specification-based testing, analysis tools, and associated processes used to independently validate, verify, and ultimately, provide for certifying safety-critical software developed for the Traffic Alert and Collision Avoidance System (TCAS II) program. These tools and processes comprise an effective and Independent Validation and Verification (IV and V) activity applied to the Collision Avoidance Subsystem (GAS) software development process. A requirements specification language called the Requirements State Machine Language (RSML), originally developed by the University of California, Irvine (UCI), was employed for the specification of GAS. The end result is the next generation of TCAS II collision avoidance logic, referred to as Version 7, that is of a higher quality than its predecessors, meets the certification requirements of DO-178B Level B (Ref. 1), and can be shown to satisfy the new operational requirements it was developed to address     

A visionary look at aviation surveillance systems

The FAA's future aviation surveillance systems fall into four categories: Automatic Dependent Surveillance (ADS) will be used in the oceanic environment; ADS-Broadcast (ADS-B) will be used in the domestic en route environment; ADS-B will be used with a secondary radar backup in the terminal area; and ADS-B will be used with primary radar backup within the Airport Surface Traffic Automation (ASTA) system on the airport's surface environment. Two other systems introduced in this paper are Cockpit Display of Traffic Information (CDTI) and Traffic Advisory and Collision Avoidance System (TCAS). All these systems will use navigational signals emitted by the Global Positioning System (GPS) constellation of satellites     

Experimental Detection of Anomalous Mode-C Reports Using Radar Data

A new methodology to scan automated radar terminal system (ARTS-III) data for aircraft tracks exhibiting probable mode-C encoder/transponder faults is described. The tracks of more than 8000 climbing or descending aircraft, recorded at the Seattle-Tacoma terminal area, were analyzed using this method. Based on this sample, the probability of the previously recognized "stuck C-bit" error is estimated to be 0.44 percent (0.31-0.61 percent, 95 percent confidence). In addition, a new, more subtle error, here termed the "deficient response," was discovered which is estimated to occur with a probability of 0.77 percent (0.59-0.98 percent, 95 percent confidence). Subsequent tests found this new error to have much less impact on traffic alert and collision avoidance system (TCAS) performance than does the stuck C-bit error.