Evaluation of a Pilot Assistance System during Simulated Helicopter Shipboard Operations in DVE conditions

The present work reports the design, integration, and piloted evaluation of a visual and control augmented pilot assistance system (PAS) for helicopter near-ship operations in degraded visual environments. The PAS consists of an automatic cluttered-scene-linked 2D and 3D symbology concept, visualized on a helmet-mounted display (HMD). The design was applied by combining operational needs, standard naval requirements, and procedures to support the pilot’s direct perception of critical helicopter operations within the limitations of safety and performance constraints, such as a degraded visual range and high ship motions. An additional advanced flight control mode, optimized together with maritime test pilots, focused on rendering pilots’ control inputs more precisely, while simultaneously decreasing subjective workload. The present approach of the PAS combines a precise and dynamic shiprelative approach and landing enhanced visual augmentation with scene-linked visual clutter modes designed for an HMD with see-through capabilities. For evaluation, traditional subjective workload, visual cues, and handling-qualities ratings were supplemented with analysis techniques, including the approach profile and pilot control activity observations. The results of two simulated flight test campaigns together with 10 maritime test and fleet pilots from the armed forces, industry, and public authorities, completing a total of over 120 simulated flights show that subjective workload and the corresponding handling-qualities ratings kept almost level 1, even when degraded visual environment (DVE) conditions increased. Subjective assessments indicate that most of the pilots preferred higher degrees of helicopter stabilization during the helicopter ship approach and landing maneuvers. Timeseries and frequency domain analysis of pilot control inputs and head motions offer the capability to associate subjective ratings of pilot workload and handling qualities with control inputs observations.