Other earlier systems installed in closed-circuit continuous-flow tunnels alleviated the need for generating store trajectories in the brief time frame dictated by blowdown tunnels. By using a digital computer to generate trajectories, the initial system setup and checkout times were greatly shortened and electronic drifts were virtually eliminated.

The digital computer, using the balance forces and moments in conjunction with the equation of motion, would output store model coordinates and attitude for the next point on the trajectory to some peripheral device that generated hard copy. An operator seated at this output device would then manually position the store model to these coordinates. The disadvantage of this method was its extreme slowness since the operation was open looped. 

Most of the early captive trajectory testing development effort was performed at the David Taylor Model Basin, Chance Vought Corporation, the Convair Division of General Dynamics, and the Cornell Aeronautical Laboratories.

另外一些早期配備在閉回路連續(xù)式風(fēng)洞中的裝置，不像在下吹式風(fēng)洞情況下那樣，要求在很短的時間內(nèi)生成外掛軌跡。利用數(shù)字計算機生成軌跡的方法，大大縮短了裝置的初始準(zhǔn)備與檢查時間，并實際消除了電子漂移現(xiàn)象。

利用天平測得的力與力矩連同外掛運動方程，數(shù)字電子計算機可將軌跡上下一個點的外掛模型座標(biāo)及姿態(tài)作為輸出量，輸給某個可產(chǎn)生硬拷貝的外圍設(shè)備。隨后，坐在這臺輸出設(shè)備旁的操作員就用手工把外掛模型移動到這些座標(biāo)上。這種方法的缺點是速度極其緩慢，因為采用的是開環(huán)式的操作。

初期的捕獲軌跡試驗研究工作，大部分是在查恩斯·沃特公司大衛(wèi)·泰勒模型試驗池、通用動力公司康維爾分部以及柯內(nèi)爾航空實驗室等處進行的。

In 1967, the captive trajectory system shown in Figure 1 was installed in the Propulsion Wind Tunnel (PWT) Facility at the AEDC. This system, which is still operational, is a closed-loop six-degree-of-freedom system utilizing a digital computer to solve the equations of motion and to position the store model. This system uses a position-based control technique that initially positions store model to the carriage position, reads the forces and moments acting on the store model, combines these forces and moments with the initial conditions to provide input parameters to the store model equations of motion, and then solves these equations and integrates to obtain the coordinates of the next point on the trajectory. "The store model is then moved to this set of coordinates and allowed to remain there while data are taken that can be used in conjunction with those previously obtained to determine succeeding points on the trajectory.

In 1975 another captive trajectory system was made operational in the von Kármán Gas Dynamics Facility (VKF) at the AEDC. The operation of this system is very similar to that used in the PWT.

1967年，圖1(此略）上所示的捕獲軌跡試驗裝置安裝到AEDC推進風(fēng)洞（PWT)設(shè)備中。這個裝置現(xiàn)在仍可工作，是一個利用數(shù)字計算機求解運動方程并將外掛模型定位的閉環(huán)六自由度系統(tǒng)。該裝置利用速過位置進行控制的技術(shù)，具體做法是：一開始，將外掛模型置于掛架位置上，讀取作用于外掛模型上的力與力矩數(shù)據(jù)，將這些力與力矩數(shù)據(jù)與初始條件結(jié)合起來，給出外掛模型運動方程組的輸入?yún)?shù)；然后，求解運動方程組并進行積分，獲得軌跡上下一點的座標(biāo)值。此后，將外掛模型移動到這一組座標(biāo)設(shè)定的位置上，并使其停留在那里，同時測取部件可與前面獲得的數(shù)據(jù)配套使用的數(shù)據(jù)，來決定軌跡上的后面各點。

1975年，另一臺捕獲軌跡裝置在AEDC馮·卡門氣體動力學(xué)設(shè)備（VKF）上投入使用。這臺裝置的工作原理與PWT上部一臺的非常相似。

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