Autonomous helicopter shipboard recovery flight control design based on tau theory

Abstract

This paper develops an autonomous flight control system to alleviate the heavy workload involved in managing multiple emergencies during manned helicopter shipboard recovery operations. It can operate either partially or fully autonomously preserving the pilot's familiar guidance strategies while allowing pilot intervention when necessary. First, a simulation model of helicopter recovery flight is developed integrating the impacts of ship airwake turbulence and ship motions. A comprehensive flight control system is subsequently established to facilitate multi-mode and multi-response-type capabilities for manned helicopters. Then, the tasks of ‘Precision Hover’ and ‘Vertical Maneuver’ are employed as examples to demonstrate the methodologies for deceleration-to-hover and end-to-end trajectory planning utilizing bio-inspired tau theory. Furthermore, precision trajectory tracking control laws are formulated. Finally, numerical simulations of helicopter recovery flight are conducted to assess the efficacy of the flight control system. The results indicate that the tau theory-based planning results in efficient and smooth helicopter maneuvers, particularly in acceleration, deceleration, and transitions, which mirrors real pilot strategies. The trajectory tracking control laws effectively follow the prescribed trajectory and compensate for ship movements, with robust turbulence rejection capabilities