Model of helicopter pilot's controls activity for shipboard operations

Abstract

The only approved means available to evaluate the dynamic behavior of the helicopter/pilot combination in the complex turbulent environment of the moving flight deck of a ship is the execution of actual at-sea flight tests. The development of an off-line simulation tool of helicopter shipboard operations for engineering and design purpose is desirable. The objective of this study is to identify the pilot's controls strategy in order to provide prediction of the controls' positions when flying typical on-shore representative shipboard maneuvers, namely, hover, "fore/aft" and "estern" approaches, into four different wind environment conditions. Operational pilots A, B, C and D performed a pilot-in-the-loop flight test simulation in the helicopter engineering flight simulator facility of ONERA Salon de Provence Center, so called PycsHel, in order to provide data to calibrate and validate the prediction of the basic SYCOS (SYnthesis through COnstrained Simulation) pilot model. The optimization process for training the pilot model from the piloted simulations data is divided into hover task and approach tasks, and uses the DIMSS PM (Dynamic Interface Modeling and Simulation System Product Metric) as metrics for estimating the pilot's controls activity. Pilots A and B models are considered valid for the validation data set in hover. However, basic SYCOS model is not able to keep the predictions stable over 50 sec of flight of the approach tasks. Therefore, extensions to the basic SYCOS model are studied by implementing an attitude or an acceleration feedback parallel line, in order to provide stability strategy to the pilot's controls activity prediction. The attitude feedback strategy is the only able to restore the SYCOS model stability for the approach data set. The extended SYCOS model with attitude feedback strategy is used for training and allows the validation of pilot's activity model to approach type "estern" (pilot B). None pilot's controls activity model is valid for the "fore/aft" approach task. The pilots C ("estern" approach) and D ("fore/aft" approach) extended SYCOS models are able to provide satisfactory predictions only for collective and pedals activities.