Horizontal path-following control for deep-sea work-class ROVs based on a fuzzy logic system

ABSTRACT

A path-following control scheme for deep-sea work-class remotely operated vehicles (ROVs) subjected to disturbing forces and moments generated by parameter variations, ocean currents, umbilical cables and other unknown disturbances is designed in this paper. The disturbing forces and moments could be obtained based on a mathematical model of ROVs in a body-fixed reference frame. A fuzzy logic system (FLS) was used to approximate the forces and moments, and then an adaptive speed controller (used as an inner loop of the ROVs’ hover and path-following control) based on a force and moment compensator was designed. The results of numerical simulations and underwater experiments indicated that the disturbing forces and moments acting on ROVs can be approximated precisely by using the FLS, and the designed controller achieves strong anti-disturbance ability, tracking performance and robustness.

KEYWORDS:

• Deep-sea work-class ROVs
• current disturbance
• umbilical cable disturbance
• fuzzy logic system
• hover control
• path-following control