Validation of an autopilot through hardware in loop simulation

These days computer aided simulations are being used to perform hardware in loop (HIL) simulations. This is to ensure the safety and economics, as the real flight test cannot easily be done. Moreover due to the latest controller design techniques, which have further complicated the design implementation, the use of computer is inevitable for control system realization. The HIL simulation in real time validates the theoretical design of attitude control system, the stability of autopilot during the real flight and the consistency between the hardware characteristics and the theoretical analysis. This simulation is carried out in a real time environment and is a major step before the finalization of autopilots and overall control system for the actual flight. This paper presents various steps taken during HIL simulation and the discussion on major test results.