1,721,092 research outputs found
Sliding Mode Control of an Underwater Robotic Manipulator
No full textThis paper deals with the application of the sliding mode control theory to the specific case of a manipulator for which mono-directional control actions only have to be considered. In particular the control of an underwater gripper is presented. Many even complex robotic structures, can be actuated by mono-directional control actions, for example the so called tendon-arms, the jet-actuated vehicles, underwater vehicles with mono-directional thrusters, etc.. The robotic system which is considered in the paper belongs to the above class, since it is actuated by voice coil motors which, acting on a hydraulic circuit, are able to generate mono-directional forces. In practical realizations actuators often show imprecise relationships between the electrical input signals and the mechanical outputs, that is joint forces or torques. Such a situation constitutes a source of uncertainties we have to deal with. A sliding mode control methodology based on the use of a simplex of constant control vectors is presented, which has revealed to be general enough to work with different applications too
Chattering free simplex sliding mode control for systems with mono-directional actuators.
No full textSliding mode control of an underwater manipulator driven by monodirectional actuation system
No full textProximity operations with obstacles avoidance based on artificial potential field and sliding mode control
No full textThis paper combines Guidance and Control (GC) algorithms for spacecraft proximity operations in presence of multiple obstacles. The proposed guidance algorithm is based on Artificial Potential Field (APF) theory, while the adopted control strategies are first-order Sliding Mode Control (SMC) algorithms. The position control problem is addressed by considering two different first-order methods: the simplex-based and the component-wise SMC. Both control strategies result to be effective and suitable to be implemented by the mono-directional actuation system. These algorithms are suitably designed for a ground test-bed for spacecraft rendezvous and docking experiments, developed within the STEPS project (Systems and Technologies for Space Exploration). The selected algorithms are suitable for autonomous, real-time control of proximity maneuvers with a minimum on-board computational effort. Moreover, the presented strategy is able to avoid obstacles and to manage issues related to the presence of local minima in APF algorithms
Simplex Based Sliding Mode Control of an Underwater Gripper
No full textIn this paper the sliding mode control theory is applied to a particular underwater gripper actuated by linear motors which, acting on a hydraulic circuit, generate mono-directional forces. In practical realizations actuators often show imprecise relationships between electrical input signals and mechanical output; such a situation constitutes a source of uncertainties. A sliding mode control methodology based on the use of a simplex of constant control vectors is presented. The proposed approach is general enough to also work with different applications
Observation and separation principle for the chattering - free control of multi-input systems with simplex sliding modes.
No full textSecond Order Sliding Modes Control of Underwater Vehicles Tracking the Gradient of Artificial Potential Fields
No full textSliding Mode Control with Chattering Attenuation and Hardware Constraints in Spacecraft Applications
Full text linkSecond order sliding mode control of an underwater vehicle: obstacle avoidance in artificial potential fields
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