Engineering topics

Greiner, H. G.

Publications and source records attributed to Greiner, H. G..

2 records

NASA NTRS1973

Stabilizing the elastic modes of the Space Shuttle vehicle during launch.

The influence of vibration modes on the vehicle control system stabilization problem is examined with a conventional, nonadaptive, single-rate-sensor autopilot. The linear stability analyses are based upon symmetric and antisymmetric modal data generated from flexible-beam models. Primary emphasis is placed upon using only the three orbiter engines as control effectors. Principal control system variables considered are the effective autopilot rate and attitude gains, rate and attitude sensor locations, and lead/lag stability compensation. Results indicate that a multiple-sensor autopilot configuration will be necessary to achieve satisfactory vibration mode stability margins.

Greiner, H. G.↗

NASA NTRS1972

Influence of vibration modes on control system stabilization for space shuttle type vehicles

An investigation was made to determine the feasibility of using conventional autopilot techniques to stabilize the vibration modes at the liftoff flight condition for two space shuttle configurations. One configuration is called the dual flyback vehicle in which both the orbiter and booster vehicles have wings and complete flyback capability. The other configuration is called the solid motor vehicle win which the orbiter only has flyback. The results of the linear stability analyses for each of the vehicles are summarized.

Greiner, H. G.↗