Landing path generation algorithm for autonomous shipboard helicopter recovery

A landing path generation algorithm is developed to enable autonomous shipboard helicopter recovery, and the algorithm is demonstrated in high fidelity simulations. The algorithm uses a forecasting algorithm (developed in previous work) that predicts future motion of the deck. Deck forecasts are used to set terminal conditions for the path. This approach enables less dynamic motion during descent and smaller relative velocity at touchdown. The algorithm generates inertial paths with certain kinematic constraints. The approach includes a polynomial representation of the path geometry with unknown parameters, and an optimization algorithm determines the parameters that satisfy the path constraints while minimizing accelerations. Landing quality was assessed by extensive simulations performed using a high fidelity FLIGHTLAB simulation of a utility helicopter with the SCONE ship motion data. Results show that the algorithm is able to generate a reasonable trajectory to support the autonomous landing task. Some ad hoc control logic was needed to ensure desired performance with landing gear touchdown, by matching the deck attitude just before deck contact.