Hybrid simulation of a helicopter

Abstract

The recent and rapid increase in the application of the airmobile concept within the U.S. Army is well known. Accompanying the fact of the airmobile division, brigade, etc., has been the concomitant requirement for the development and improvement of the airborne electronics (avionics) to support this major innovation in conventional warfare. This increased emphasis for the development of new and more sophisticated avionic equipments and subsystems has led to the organization of an Avionics Laboratory within the U.S. Army Electronics Command. In the Avionics Laboratory, the problem of defining system performance characteristics for advanced avionics has in turn generated a requirement for analyzing the tactical mission envelope of both existing and advanced Army aircraft. One aspect of this particular task---that of evaluating avionics systems synthesized to provide particular mission capabilities has resulted in the development of a unique man-machine known as the Tactical Avionics System Simulator (Fig. 1). This simulator system integrates a real-time hybrid digital-analog computer (expanded EAI HYDAC 2400) with two operable cockpits---e.g., functional combination of crew inclosures, motion systems, synthetic instruments, control loading, and acoustic and visual simulators (Fig. 2). As illustrated, the TASS includes all of the necessary subsystem hardware to provide for the simulation of the aircraft, the avionics systems and the external environment. The basic requirement in the implementation of this expensive and sophisticated system was that the crew be able to realistically "fly" the aircraft from hover thru transition to high-speed flight while providing the avionic engineer with a "hands on" simulation capability.