Nonlinear Control of an Unmanned Amphibious Vehicle

The development and implementation of an experimental sliding mode control law for a 2.5 meter long unmanned amphibious vehicle (the DUKW-Ling) when waterborne is presented. A first-order sliding control surface is used for surge tracking error when a P controller is used to minimize the heading error in the system. The state of the vehicle is measured using onboard sensors with the ability to record surge, sway, yaw and position of the vehicle in real-time. Experimental data collected show the ability of the vessel to maintain a desired heading and speed. This article emphasizes the ability of sliding mode controller to respond to the unpredictable and random water and wind currents acting on the vehicle.