Towards Hybrid Testing For Helicopter Comfort

Abstract

Helicopters are notorious for their high vibration levels, and occupant comfort remains one of the key challenges of vertical flight. Occupant comfort can be evaluated through numerical analysis or flight testing. While numerical models are very useful in early design, they may fail to address uncertainty and non-linearity in seat and human biodynamics. On the other hand, the tests can only be performed after flying prototypes are ready, which is a very late stage to make significant improvements. A hybrid solution could reduce the drawbacks of both approaches by combining the flexibility of modern simulation tools with a physical set-up of seat and occupant therefore, allowing realistic, safe and repeatable comfort evaluations at early design phases. A hybrid testing framework offers evaluation of helicopter ride comfort through real-time coupling of a numerical model representing the loads and structural dynamics of the airframe and a physical model of the occupant. The numerical helicopter model simulates the transmission of vibratory loads to the cabin floor, while a physical system consisting of a seat, cushion, and mannequin is placed on a multi-axis shaker table. In this study, before implementing the full hybrid simulation, the physical shaker table is temporarily replaced by validated simulation model of MASTto allow tuning of the control parameters and detailed investigation of coupled dynamics before testing.