空中交通防撞系统.ppt

空中防撞系统TCAS,中国民航大学 电子信息工程学院,2,Contents,Introduction to TCAS Function of TCAS TCAS Aler Area TCAS Information Principle of TCAS TCAS Components TCAS Interface TCAS Signal formats TCAS Display,3,TCAS概述,TCAS I能够侦测上下7000至10000呎，前后15至40海里，发现有航机接近时，会提前40秒警告飞行员对方飞机的高度和位置。 第二代空中防撞系统（TCAS II），是目前最被广泛使用的，会用声音及显示警告飞行员，称为Resolution Advisory （RA），并且会用语音指示避撞的动作，例如：“Climb！Climb！Climb！”“Descend！Descend！Descend！”。别架飞机若有装TCAS，也会有相反的警告发出来。 第三代空中防撞系统（TCAS III），除了有上下避撞措施之外，还增加左右避撞能力。 Honeywell公司是唯一一家生产所有类型TCAS的制造商，超过一半的TCAS产品都是出自该公司。 ICAO: the carriage of ACAS II has been mandatory worldwide from 1-1-2005 for all civilian turbine-engined aircraft carrying more than 19 passengers or with the maximum take-off mass more than 5700 kg,4,TCAS Function,5,TCAS Information,根据入侵机的相对距离和方位，以及威胁等级在EHSI 或EADI上显示视觉信息： Others （其它）：相对高度大于1200英尺、小于2700英尺，或距离在6海里以上。 Proximity （接近）：相对高度等于或小于1200英尺，且距离在6海里以内。 Traffic Advisory （交通咨询）：系统判明的与本机存在潜在危险接近的飞机，TCAS会提前一定时间（2048秒）发出交通咨询。音频 Resolution Advisory （决断咨询）：在对已判明为交通咨询的飞机连续监视约15秒后，如果该机与本机危险接近的状况仍然存在，则TCAS会发出解脱咨询。,6,TCAS Information,7,TCAS Information,8,TCAS Information,9,TCAS Information,10,TCAS Information,11,TCAS Information,12,TCAS Information,13,语音信息 含义 TRAFFIC, TRAFFIC 交通，交通 CLIMB, CLIMB 爬升，爬升 DESCEND ,DESCEND 下降，下降 INCREASE CLIMB INCREASE CLIMB 增大爬升，增大爬升 INCREASE DESCEND INCREASE DESCEND 增大下降，增大下降 CLIMB,CROSSING CLIMB CLIMB,CROSSING CLIMB 爬升，穿越爬升爬升，穿越爬升 DESCEND ,CROSSING DESCEND 下降，穿越下降 CLIMB, CLIMB NOW CLIMB, CLIMB NOW 爬升，现在爬升爬升，现在爬升 DESCEND, DESCEND NOW DESCEND , DESCEND NOW 下降，现在下降下降，现在下降 ADJUST VERTICAL SPEED, ADJUST 调节垂直速度，调节 MORNITOR VERTICAL SPEED 监视垂直速度 MAINTAIN VERTICAL SPEED, MAINTAIN 保持垂直速度，保持 MAINTAIN VERTICAL SPEEDCROSSING MAINTAIN 保持垂直速度保持穿越 CLEAR OF CONFLICT 冲突解除 TCAS TEST TCAS 自检 TCAS TEST OK TCAS自检通过 TCAS TEST FAIL TCAS自检失败,TCAS Information,14,TCAS Alert Area,15,TCAS Alert Area,16,TCAS Principle,17,TCAS Principle,18,TCAS Principle,19,TCAS Principle,20,TCAS Principle,21,TCAS Principle,22,Horizontal test: time to reach the Closest Point of Approach (CPA)(or “DMOD“ distance if the closure rate is low) Vertical test: time to reach co-altitude (or “ZTHR“ if the aircraft are steady) The TA/RA threshold values increase with the altitude The bearing is not taken into account (only used for the display) The TA or RA is issued depending upon the relevant thresholds RA sense selection: objective of safe vertical distance “ALIM“, co-ordination If the intruder does not transmit its altitude, there will be no RA,TCAS Principle,23,ILLUSTRATION OF THE HORIZONTAL TEST,35 seconds,Intruder,TCAS,The collision avoidance criterion is a generally a time parameter,TCAS Principle,24,LOW CLOSURE RATE,Air speed,Closure rate,Air speed,Intruder,TCAS,The closure rate can be low even if the air speeds are high.,TCAS Principle,25,VERTICAL TEST,35 seconds,Intruder,TCAS,The time remaining to co-altitude is compared to triggering time threshold (here 35 seconds),In case of steady aircraft, current vertical distance is compared to vertical threshold ZTHR (e.g. 800ft),TCAS Principle,26,ALERTS: “TRAFFIC ADVISORY“,Thresholds: horizontal: 20 to 48 s (or DMOD = 0.3 to 1.3 NM) vertical: 20 to 48 s (or ZTHR = 850 or 1,200 ft) Aural annunciation: “Traffic, traffic” Intruder: solid amber circle Helps to the visual acquisition of the intruder Prepares the crew for a possible RA No maneuver should be made if there is no visual acquisition No associated phraseology,TCAS Principle,27,ALERTS: “RESOLUTION ADVISORY“,Thresholds: horizontal: 15 to 35 s (or DMOD = 0.2 to 1.1 NM) vertical: 15 to 35 s (or ZTHR = 600 to 800 ft) Aural annunciations: “climb“, “descend“, “increase climb“, “increase descent“, “monitor vertical speed“, etc Display of a range of vertical speeds or pitches to avoid Objective: a safe vertical distance ALIM varying from 300 to 700 ft An RA takes into account all existing threats The RA intensity is checked and revised, if necessary, every second,TCAS Principle,28,THRESHOLD VALUES FOR TCAS II V7.0,* vtt: vertical threshold test (processing of 1,000-ft level off geometries),TCAS Principle,29,RA SENSE SELECTION,The downward sense will achieve ALIM, the upward sense will not. The downward option is therefore selected,TCAS Principle,30,RA WITHOUT ALTITUDE CROSSING,Both downward and upward senses will achieve ALIM. The upward sense is selected because it prevents the TCAS aircraft from crossing through the intruders altitude,TCAS Principle,31,RA WITH ALTITUDE CROSSING,The upward sense is not sufficient to achieve ALIM. The downward sense (“Crossing descent“ here) RA is choosen, however it is really issued only when the current vertical separation is less than 600 ft (intruder steady) or 850 ft (intruder evoluting toward the own aircraft). All these cases are rare.,TCAS Principle,32,INCREASE RATE RA,The threat increase its descent rate towards TCAS aircraft after the initial “descent” RA is issued,TCAS Principle,33,RA REVERSAL,TCAS Principle,34,MODE C TARGET ON-THE-GROUND DETERMINATION,TCAS Principle,35,POSSIBLE INITIAL RAs,TCAS Principle,36,TCAS System Architecture,37,TCAS System Architecture,38,TCAS System Architecture,S模式应答机 TCAS计算机 天线 显示器 控制板,39,TCAS System Architecture,40,TCAS的方向性天线,TCAS System Architecture,41,TCAS天线的方向性,TCAS System Architecture,42,TCAS 计算机,TCAS System Architecture,43,TCAS 计算机的基本功用,监视邻近空域中的飞机； 获取所跟踪飞机的数据； 进行威胁评估计算； 产生交通咨询或决断咨询等。,TCAS System Architecture,44,ATC/TCAS控制面板,TCAS System Architecture,45,控制面板,TCAS System Architecture,46,TCAS System Architecture,控制面板,47,TCAS Interface,48,TCAS Interface,49,TCAS Interface,TCAS计算机通过ARINC数据总线与S模式应答机实现数据交换。 S模式应答机通过一条ARINC 429数据总线，将有关信息输往TCAS计算机；TCAS计算机则利用另一条ARINC 429数据总线，将有关信息输往S模式应答机。 S模式应答机输送给TCAS计算机的信息中，包括由大气数据计算机系统获得的高度信息、来自控制面板的各种信息等。 TCAS计算机与控制面板的信号交连 XPNDR/TCAS控制面板对TCAS计算机的模式等控制信息，是通过S模式应答机再输送给TCAS计算机的。 飞机的24位地址码由应答机上的程序销钉输入应答机。,50,TCAS Interface,EFIS控制面板对TCAS显示的控制 （1）EHSI的工作模式（NAV、VOR/ILS、MAP ） （2）TFC按钮 （3）距离选择（小距离：5、10、20） TCAS与EFIS显示器之间的信号交连 TCAS输出的视觉信息，输往两部EFIS的符号发生器，然后再分别输往EHSI和EADI显示。 此外，EHSI和EADI显示器必须将其状态信息输送给TCAS计算机，以便TCAS计算机产生交通咨询和解脱咨询等信息。,51,TCAS Interface,无线电高度信息输入 TCAS在避撞计算中必须利用无线电高度信息。两部无线电高度表输出的数字式高度信息，通过ARINC 429数据总线输送给TCAS计算机。 航向信息输入 航向信息是确定本机飞行轨迹的必要参数。数字式航向信息通过ARINC 429数据总线输送给TCAS计算机。 大气数据计算机信息输入 大气数据计算机产生的有关本机的高度、速度、升降速度等信息，通过ARINC 429数据总线输入TCAS计算机。 L波段设备的互抑制 飞机上的两部应答机、两部测距机和TCAS均工作于L波段。为避免相互干扰，同一时刻只应有一部处于发射状态。在五部L波段设备中的一部开始发射之前，产生一个宽度为28s的外抑制波门加到其它L波段设备，以避免其它L波段设备进入发射状态，并保护其接收设备。 来自近地警告系统的抑制信号 近地警告系统产生的“低于下滑道”、“拉起”和“风切变”警告信息的优先权高于TCAS的咨询信息，所以，在近地警告系统发出上述三种警告信号时，会抑制TCAS输出交通咨询和解脱咨询。,52,TCAS Signal Format,Mode C only interrogation,53,TCAS Signal Format,Whisper-shout interrogation,Remark：用来防止同步串扰的一种方案。,54,TCAS Signal Format,Whisper-shout interrogation,55,TCAS Signal Format,Whisper-shout interrogation,56,TCAS Signal Format,Mode S interrogation,57,TCAS Signal Format,Mode S interrogation,数据脉冲P6包含67个数据区。每个数据区的位数示于图中；各数据区的内容如下： 第一区为数据子标号，5位，用于表明本询问信号的格式； AP：地址/奇偶校验；AQ：特殊询问；DI：识别符；MA：公共A信息；MU：公共U信息；PC：协议；RL：应答长度；RR：应答请求；SD：特殊符。,58,TCAS Signal Format,Mode S interrogation,数据脉冲P6包含67个数据区。第一区为数据子标号，5位，用于表明本应答信号的格式；AA：通告的地址；AC：高度码；AP：地址/奇偶校验；CA：应答机的能力；DR：下行链请求；FS：飞行状态；ID：识别码；MB：公共B信息；MV：公共V信息；PI：奇偶/询问识别；RI：空-空应答信息；SL灵敏度等级；UM：公用信息；VS：垂