Non-singular terminal sliding mode guidance and control of trans-medium maritime vehicles with intercept angle constraints

Trans-medium vehicles combine the advantages of underwater supercavitating vehicles and aerial vehicles. This study investigates guidance and control in the vertical plane for a vehicle operating as a supercavitating vehicle underwater and as a conventional missile in the air. Dynamic models are established for the underwater, transition, and aerial segments. A nonsingular terminal sliding mode guidance law is developed to satisfy intercept angle constraints. To track the desired pitch angle, an adaptive controller using a radial basis function (RBF) neural network and a state observer is designed for the underwater segment, while an adaptive sliding mode controller based on an extended state observer is developed for the aerial segment. The research results indicate that the guidance and control system of the trans-medium vehicle has promising application prospects in complex environments, providing a theoretical foundation and technical support for related fields.