A combined first-/second-order sliding-mode technique in the control of a jet-propelled vehicle

This note concerns the design and practical implementation of a position/attitude sliding-mode controller for a surface vessel prototype. The prototype is equipped with a special, recently patented (Italian Patent, 2005), propulsion system based on hydro-jets with adjustable output section. The sliding-mode control design is based on the combination between three instances of a second-order sliding-mode velocity observer (Automatica 1998; 34:379-384) and a simplex-based sliding-mode controller (Int. J. Robust Nonlinear Control 1997; 7(4):321-335). We first describe the structure and the working principle of the prototype. Then, we detail the derivation of the motion observer/controller. Finally, we discuss the major implementation issues and show some experimental results.