1,721,053 research outputs found
A Novel Practical Technique to Integrate Inequality Control Objectives and Task Transitions in Priority Based Control
No full textThe task priority based control is a formalism which allows to create complex control laws with nice invariance properties, i.e. lower priority tasks do not affect the execution of higher priority ones. However, the classical task priority framework (Siciliano and Slotine) lacked the ability of enabling and disabling tasks without causing discontinuities. Furthermore, tasks corresponding to inequality control objectives could not be efficiently represented within that framework. In this paper we present a novel technique to integrate both the activation and deactivation of tasks and the inequality control objectives in the priority based control. The technique, called iCAT (inequality control objectives, activations and transitions) task priority framework, exploits novel regularization methods to activate and deactivate any row of a given task in a prioritized hierarchy without incurring in practical discontinuities, while maintaining as much as possible the invariance properties of the other active tasks. Finally, as opposed to other techniques, the proposed approach has a linear cost in the number of tasks. Simulations, experimental results and a time analysis are presented to support the proposed technique
Manipulation and Transportation With Cooperative Underwater Vehicle Manipulator Systems
No full textAutonomous underwater manipulation has been a topic of interest since the early 1990s. In the past few years, several milestone projects such as SAUVIM and TRIDENT have demonstrated autonomy capabilities for a single underwater vehicle manipulator system (UVMS) in performing simple manipulation tasks, e.g., the recovery of an object from the seafloor. The Italian funded MARIS project aims to extend some of these results to multiple UVMSs performing a cooperative transportation task of a long object such as a pipe. This paper presents the results achieved in developing a unifying architecture for the control of both individually and cooperatively operating UVMSs which explicitly makes use of a limited amount of information exchange between the agents, which is needed due to the severe bandwidth limitations of the underwater acoustic communications. A complete execution of the reference transportation mission is presented to support the proposed distributed algorithm. Furthermore, hydrodynamic simulations of the cooperative transportation phase are presented and an analysis of the achievable performances as different communication schemes are employed is given
Real Time Path Planning and Obstacle Avoidance for Security Related USVs Operating in Harbour Fields
No full textDevelopment of Modular USVs For Coastal Zone Monitoring. Two New USVs to Monitor Geophysical, Environmental Parameters
No full textTowards the Use of a Team of USVs for Civilian Harbour Protection: Real Time Path Planning with Avoidance of Multiple Moving Obstacles
No full textCivilian Harbour Protection: Interception of Suspect Vessels with Unmanned Surface Vehicles
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