Experiments in autonomous navigation with an under-actuated surface vessel via the Null-Space based Behavioral control

This paper presents an autonomous navigation technique for an under-actuated surface vessel based on the use of a behavior-based technique, namely the null-space based behavioral (NSB) control. The NSB control is used to generate motion directives for the vessel in order to sequentially visit various locations in the environment, while avoiding collisionswith static obstacles. To work with under-actuated vessels, the NSB controller is coupled with a low-level maneuvering controller that generates the actuator forces to cause the vessel to follow the motion directives generated by the NSB. The overall control technique has been experimentally validated in the field with an autonomous under-actuated surface vessel navigating in a lake, avoiding collisions with small islands and a fountain.