A navigation system for real-time path planning and obstacle avoidance of an autonomous underwater vehicle is presented. The vehicle is designed to accomplishing two missions: pre-deployment survey of sea bottom, and visual inspection of pipelines. In the first mission the navigation system must be able to track a predefined path while avoiding the unplanned occurrence of obstacles. In the second mission the navigation system must track a pipeline by locally reconstructing its location from visual information; also in this case, the unplanned occurrence of obstacles must be handled. Furthermore, the navigation system must properly take into account the presence of ocean current and some drastic constraints due to sensor and actuator characteristics.

The kinetostatic analysis of manipulator performances at the end effector (EE) has traditionally been based on the computation of the so-called manipulability ellipsoids rather than on polytopes which are more accurate a representation. A reason why polytopes have received less attention is their being less tractable from a computational viewpoint. This paper presents an effective computation tool based on polytopes, with separation between translational and rotational analyses. This eliminates the ambiguity inherent in the conventional rototranslational formulation. Examples of application of this tool to the kinetostatic performance analysis of a redundant arm are finally provided, with numerical results.