Improving Helicopter Flight Simulation with Rotor Vibrations

Helicopters are complicated flying machines, whose lift is obtained by a main rotor, made by a variable number of blades. The large amount of rotating mass (rotors, engine, gearboxes) is responsible of high level vibrations over the helicopter structure: their amplitude is highly coupled with manoeuvring, so that pilots can feel flight phases not only by noise and external view, but also by vibrations intensity. An experimental campaign has been carried out to acquire vibration data over helicopters. The paper describes the implementation of a simulator which provides also the reproduction of vibration felt in flight by pilot. The attention is focused on the conceptual and preliminary design, CAD modelling, FEM analysis, manufacturing and testing of the device conceived to reproduce vibrations over the pilot’s seat. Only the first frequency of the rotor is reproduced since it is the most important excitations and it is variable, depending on the flight phase. The shaker has been built and installed on a simulator. The final result shows that such a simulator can improve the realism involving not only the senses of sight and hearing, but also providing a more “physical” feedback due to vibrations perception.