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History of flight motion simulators used for hardware-in-the-loop testing of missile systems

All hardware-in-the-loop (HWIL) missile simulations use motion platforms that position the missile seeker and simulated target to relative positions and motions that reproduce a live engagement. These motion platforms are usually called Flight Motion Simulators (FMS). Real-time control computers manage the engagement by simulating the aerodynamic and kinematic responses the missile anticipates, and commanding the missile and target motions to simulate the engagement. The advantages of this technique over live firings are well known: shorter development time, reduced development cost, greater variety in the test scenarios, and generation of objective, measurable, and repeatable criteria for subsystem and system evaluation. This paper focuses on the history of the FMS used in HWIL missile testing and the current applications of these systems. Systems with up to nine axes of rotary motion have been developed for infrared missile seeker simulation, and large target positioning systems have been deployed for RF and point IR target movement. As digital computers have become more powerful and semiconductor infrared scene generation systems developed, new demands have been placed on the FMS. Several of these applications are described. The use of aeroload simulators to study the response of missile aerodynamic control surfaces is also briefly described.