Hybrid simulation- key to successful flight-test program

Abstract

The purpose of this paper is to focus on the applica tion of modern analog- and hybrid-computer analysis techniques for both the planning of control test vehicle (CTV) flights, which was instrumental to the success of the flights, and the verification of the design of the missile. The hybrid simulation had features generally not available in existing programs and reflected major advancements in simulation and modeling technology. It permitted tolerances to be analyzed by use of either the individual parameter variation or the Monte Carlo approach. Error sources were modeled as they existed in the actual hardware.

The SAM-D hybrid simulation program was designed to use automatic data-reduction techniques to provide the analyst with detailed technical data on both nominal and toleranced flight performance. Special routines allowed statistical predictions to be made on all important parameters within the system to en sure that all requirements were met under toleranced conditions. The use of a detailed hybrid simulation, including nominal and comprehensive tolerance models, and of automatic data-reduction techniques, provided a high degree of confidence in a successful flight under all possible military flight conditions.

The simulation program described herein was supported by a comprehensive wind-tunnel test program and other subsystem ground tests to provide input data of high quality compatible with the extent of the detailed simulation. The value of this approach to modern flight-vehicle design was confirmed by the close agreement between predicted and flight-test data. Thus the simulation not only enhanced the success of the flight tests, but also enabled the simulation to be used for evaluating system performance under conditions not covered by flight tests.