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