Control-oriented modeling of an underwater biofouling prevention robot

Abstract

The aquaculture industry is a very important provider of food and employment worldwide. This industry faces many challenges with one of the problems being the growth of biofouling on the net cages surrounding the fish. Lately, there has been an increasing trend in using advanced technologies and robotic systems to address several challenges in fish farms and thus increase the level of objectivity and automation during daily operations. As a part of this trend, robots that are attached to the net have been developed to prevent biofouling growth through regular grooming of the nets. This paper presents a control-oriented mathematical model of such a robot that is well-suited for the development of control strategies for autonomous operations of biofouling prevention robots. The model focuses on the degrees of freedom available for control and uses a coordinate transform to a cylindrical coordinate system to reduce the number of degrees of freedom needed to describe the robot's position. For simulation purposes, a feedback linearizing control law ensuring uniformly globally exponentially stable equilibrium points for the robot's controlled states has been proposed. The integrated system consisting of the model of a net cage, the model of the robot and the proposed control strategy have been demonstrated in simulation studies for autonomous navigation of an underwater biofouling prevention and inspection robot.