基本簡介
著陸引導系統(landing guidance system)用無線電設備引導駕駛員或自動駕駛儀使飛機安全著陸的導航系統。無線電著陸引導系統向飛機提供精確的著陸方位、下滑道和距離等引導信息,飛機依據這些信息對準跑道並按給定的下滑角進場和著陸,以保證接地點的偏差在規定的範圍以內。
基本分類
著陸系統有以下3種①儀表著陸系統
在各種氣象條件下,駕駛員憑藉儀表使飛機安全著陸的無線電導航系統。這種系統最早出現於1939年,1949年國際民航組織將其定為國際標準著陸系統。它的優點是:能在複雜氣象條件下提供精確直觀的引導著陸信息;可根據氣象和機場條件選擇不同的工作類型(決斷高度和跑道視距);使用國際通用的標準設備。缺點是:只能提供一條下滑角固定不變的對準跑道中心線的進場著陸航道,不適用於短距起落和垂直起落的飛機;通道少(40個),不能滿足國際民航的新要求(200個);系統要求平坦和淨化的場地(草、雪等都會影響引導信號質量)。因而國際民航組織規定這類系統使用保護期截止到1995年1月1日。②地面控制進場系統
能準確地測量進場和著陸過程中飛機位置並引導著陸的雷達系統。其優點是:機上無需加裝電子設備,對駕駛員無需進行特殊訓練;適用於各種場地,機動性好;根據不同機種對下滑角度的要求可選擇不同的下滑線。缺點是:因靠地面管制員指揮,駕駛員工作被動;靠管制員手控天線跟蹤飛機,只能一架一架地引導;引導距離受氣象條件限制。但它不斷採用新技術,這些缺點正在克服中。③微波著陸系統
工作於微波頻段(5031.0~5090.7兆赫)、由機上設備獲得引導數據的無線電著陸系統。其優點是:系統精度高,能滿足全天候工作要求;允許飛機任意選擇機場航道,適用於作各種起落的各型飛機;系統容量大(200個通道),能滿足空中交通量增加的要求;設備體積小,對場地要求低;系統抑制多徑干擾能力強。國際民航組織於1978年選定時基掃描波束微波著陸系統作為新的標準著陸系統。它能提供連續的、精確的3坐標(方位、仰角、距離)信息。阿波羅的AGC
在月球軌道上的每個航班任務的月亮(有一個例外的阿波羅8號登月艙,而沒有考慮)有,分別在兩個遊戲機中心的指令艙和登月艙 。 The AGC in the Command Module was at the center of that spacecraft's guidance & navigation system (G&C).在命令模組的AGC是中心,在飛船的指導及導航系統(G及丙類)。 The AGC in the Lunar Module ran its Primary Guidance, Navigation and Control System , called by the acronym PGNCS (pronounced pings ).該模組的AGC運行在農曆其主要指導方針,導航和控制系統 )的縮寫省地名委員會所要求的(發音坪 。Each lunar mission had two additional computers:每一個月球的任務有兩個額外的計算機:
The Launch Vehicle Digital Computer (LVDC) on the Saturn V booster instrumentation ring, and該運載火箭數字計算機(LVDC)對土星五號助推器儀器戒指,
the Abort Guidance System (AGS) of the Lunar Module, to be used in the event of failure of the LM PGNCS.在中止制導系統(AGS)的登月艙,將用於省地名委員會的活動LM滾動失敗的。 The AGS could be used to take off from the Moon, and to rendezvous with the Command Module, but not to land.的AGS可用於從月球起飛,並與指令艙會合,而不是土地。
設計
自動增益控制的目的是在麻省理工學院實驗室儀器下的Charles Stark Draper ,硬體的設計與領導埃爾登三館 。 早期的建築作品來自JH拉寧小阿爾伯特霍普金斯 , 拉蒙阿隆索 , [2]和休布萊爾,史密斯 。 [3]這次飛行是由硬體製造雷聲公司 ,其香草泰勒 [4]的研究小組還對建築。The Apollo flight computer was the first to use integrated circuits (ICs) .阿波羅飛行計算機是第一個使用積體電路)積體電路( 。 While the Block I version used 4,100 ICs, each containing a single 3-input NOR gate , the later Block II version (used in the crewed flights) used 5,600 ICs, each with two 3-input NOR gates. :34 The ICs, from Fairchild Semiconductor , were implemented using resistor-transistor logic (RTL) in a flat-pack .雖然我的版本用4100塊輸入積體電路,每個包含一個單一的3 或非門 ,後來的第二座版本(載人飛行中使用的)使用5600晶片,蓋茨每兩個3輸入或非。 :34從積體電路, 仙童半導體公司 ,實施了利用電阻電晶體邏輯 )在(RTL的扁平封裝 。 They were connected via wire wrap , and the wiring was then embedded in cast epoxy plastic.他們通過連線線包裝 ,電線和當時投嵌入在環氧樹脂膠。 The use of a single type of IC (the dual NOR3) throughout the AGC avoided problems that plagued another early IC computer design, the Minuteman II guidance computer , which used a mix of diode-transistor logic and diode logic gates. AGC的使用類型單一雙NOR3)在整個積體電路(避免問題的困擾另一個早期計算機積體電路的設計, 民兵Ⅱ 指導計算機 ,它使用了混合二極體,電晶體邏輯和二極體邏輯門。
軟體
當為自動增益控制的設計要求的定義,必需的軟體和編程技術,以便它不存在,必須從頭設計的。AGC software was written in AGC assembly language and stored on rope memory .自動增益控制AGC的軟體是寫在彙編語言和存儲繩記憶 。 There was a simple real-time operating system consisting of the Exec , a batch job-scheduling system that could run up to 8 'jobs' at a time using cooperative multi-tasking (each job had to periodically surrender control back to the Exec).有一個簡單的實時作業系統組成的Exec的工作,批處理作業調度系統,可8'工作'在運行時使用最多的合作多任務(每人都必須定期交出控制權返回給Exec的) 。 There was also an interrupt-driven component called the Waitlist which could schedule multiple timer-driven 'tasks'.還有一個中斷驅動的組件稱為候補可安排多個定時器驅動的'工作'。 The tasks were short threads of execution which could reschedule themselves for re-execution on the Waitlist, or could kick off a longer operation by starting a 'job' with the Exec.執行的任務都是可以重新安排重新對自己的候補執行,短期或將引發執行緒通過啟動一個'工作與執行'一個較長的運作。
The Exec jobs were priority-based.這位管理工作是基於優先權的。 The lowest priority job, called the dummy job, was always present.最低的優先工作,被稱為虛擬工作,是始終存在。 It did diagnostic checks and controlled a green computer activity light on the DSKY: If the dummy job was running, this meant the computer had nothing better to do, so the light was turned off.它確實診斷檢查和控制活動光照對DSKY綠色電腦 :如果正在運行的虛擬工作,這意味著計算機有沒事做,所以燈關閉。 The dummy job exited if there was some higher priority job to be done and this was indicated by the computer activity light being illuminated.如果退出的虛擬工作有更高的優先處理的工作要做,這是由計算機活動指示燈提示被照亮。
The AGC also had a sophisticated software interpreter, developed by MIT, that implemented a virtual machine with more complex and capable pseudo-instructions than the native AGC. AGC的也有複雜的軟體翻譯,由麻省理工學院開發的,即實施更複雜,有能力的偽比本土的AGC指令虛擬機。 They were used for navigational computations where greater precision was required.他們在那裡被用於更精確的計算,需要航行。 Interpreted code, which featured double precision scalar and vector arithmetic, even an MXV (matrix × vector) instruction, could be mixed with native AGC code.解釋代碼,其中精選雙精度標量和矢量運算,甚至是MXV (矩陣×向量)指令,可與本機的AGC混合代碼。 While the execution time of the pseudo-instructions was increased (due to the need to interpret these instructions at runtime) the interpreter provided many more instructions than AGC natively supported and the memory requirements were much lower (memory capacity was very expensive at the time).雖然偽指令的執行時間增加(由於需要在運行時解釋這些指令)的解釋提供了很多詳細說明,比原生支持自動增益控制和記憶體的要求明顯降低(記憶體容量為當時非常昂貴) 。 The average pseudo-instruction required about 24 ms to execute.平均偽指令需要約24毫秒執行。 The assembler and version control system, named YUL for an early prototype Christmas Computer [ 5 ] , enforced proper transitions between native and interpreted code.彙編器和版本控制系統,命名為原型栗早日聖誕計算機 [5] ,執行代碼正確理解和本土之間的過渡。
A set of interrupt-driven user interface routines called Pinball provided keyboard and display services for the jobs and tasks running on the AGC. A接口設定中斷驅動的用戶提供日常所謂彈球在AGC運行鍵盤和顯示服務的工作和任務。 A rich set of user-accessible routines were provided to let the operator (astronaut) display the contents of various memory locations in octal or decimal in groups of 1, 2, or 3 registers at a time. Monitor routines were provided so the operator could initiate a task to periodically redisplay the contents of certain memory locations.阿訪問的例程豐富的用戶提供了讓經營者(太空人)顯示的內容,地點不同的記憶八進制或十進制暫存器,在組1 2或3,在規定的時間。 監視器例程是如此的經營者可以發起一個任務來定期重新顯示某些記憶體位置的內容。 Jobs could be initiated.賈伯斯可能會啟動。 The Pinball routines performed the (very rough) equivalent of the UNIX shell.該彈球例程進行的UNIX外殼(非常粗糙)相同。