Design and Control of an Aerial Manipulator to Assist Navy Helicopters in Vertical Replenishment [video]

Abstract

Vertical Replenishment (VERTREP) is one of the procedures used by the U.S. Navy to resupply ships while they are underway. A single supply ship is sent back and forth from port to forward operating ships. The supply ship will carry needed fuel, supplies, mail, and personnel to the operating area for delivery to the receiving ships. As the delivery ship approaches the receiving ships, one or more helicopters can then be used to shuttle passengers, mail, and cargo to receiving ships. Even through the U.S. Navy have been doing VERTREP for over fifty years, little has changed in the way loads are hooked up to helicopters during pickup by ground crew. A manned helicopter with a manipulator controlled autonomously and/or remotely could track and grab a pendant from the back of a ship and place it on the aircraft without assistance from the ground crew, making the operation safer. The use of the manipulator carries several benefits. First and most important is the process reduces the amount of time that operating warships will not be in their operating area. Since one ship moves from the working area to the supply ports, this allows operating warships to remain on station for longer durations. The development of an initial concept is described for a manipulator that could be attached to existing U.S. Naval helicopters for assistance in VERTREP. A design of a 7 DOF manipulator is introduced, then the relative dynamics is derived to track a pendant as a moving target on a ship from a moving base of a helicopter. Using control methods the preliminary manipulator design is verified in a simulated world through the use of MATLAB/Simulink and the built-in Virtual World. The simulation results and future work will be finally discussed.