| Summary: | Presented are the results of a study comparing four proposed control systems for the first stage flight of Saturn V launch vehicles. The primary basis of comparison is the effect on structural loads, using the bending moments at three stations as load indicators. Two of the systems sense only the vehicle attitude and attitude rate, while the other two systems also sense the lateral acceleration. A yaw plane wind response analysis, including rigid body translation, rigid body rotation, four bending modes, five slosh modes, and a non ideal control system, was performed. The winds used in the study were the Marshall synthetic profile and three selected Jimsphere-measured real wind profiles. Load relief obtained from the addition of accelerometer feedback in the control loop amounted to about 10 percent at maximum bending moment station. In view of predicted structural capabilities of the vehicle, this reduction in loads was not considered sufficient to offset the added complexity and the slight reduction in rigid body stability .
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