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In multiple robotic system, the deployment problem consists in the optimal placement of the robots within a given environment. In this paper, a fully decentralized strategy, based on the so called Null-Space-based Behavioral control is proposed. The chosen behavioral approach allows to handle the eventual presence of obstacles in the environment in a task-priority fashion thus surmounting mono-task classical approaches. Numerical simulations confirm the validity of the proposed deployment strategy.

Control of platoon of robots is an important task to achieve ful IIment of missions involving the use of autonomous vehicles. Such missions may include, e.g., exploration of unknown regions and demining using teams of aerial or underwater vehicles. In this paper, based on kinematic control techniques, a possible strategy to generate the driving commands for underwater autonomous vehicles is proposed. The case of obstacle avoidance in an underwater scenario is explicitly taken into account. Simulation results prove the effectiveness of the developed approach

Kinematic control techniques are based on an inverse kinematic transformation which feeds the reference values to the joints corresponding to the assigned end-effector trajectory. In this paper, a inverse kinematics algorithm for redundant robots is developed which takes into account joint velocity and acceleration limits while ensuring tracking of the assigned end-effector path. The desired end-effector trajectory is supposed to be given on-line. Numerical simulation results are reported to demonstrate the application of the proposed technique.

The problem of redundancy resolution and motion coordination between the vehicle and the manipulator in Underwater Vehicle-Manipulator Systems (UVMSs) is addressed in this paper. UVMSs usually possess more degrees of freedom than those required to perform end-effector tasks; therefore, they are redundant system and kinematic control techniques can be applied aimed at achieving additional control objectives besides tracking of the end-effector trajectory. In this paper, a task-priority inverse kinematics approach to redundancy resolution is merged with a fuzzy technique to manage the vehicle-arm coordination. The fuzzy technique is used both to distribute the motion between vehicle and manipulator and to handle multiple secondary tasks. A numerical case study is developed to demonstrate effectiveness of the proposed technique.

In this paper a real-time navigation system for Autonomous Underwater Vehicles (AUVs) is presented. The navigation system is designed to allow fulfillment of a completely autonomous mission of AUVs in unknown and unstructured environments. Two reference missions are considered, namely pipeline/cable inspection and bottom exploration; their accomplishment requires the use of both heteroceptive and proprioceptive sensors. The motion planner provides on-line path generation with obstacle avoidance capabilities, while taking into account the non-holonomic motion constraints of the vehicle and the constant cruise requirement for proper sensor functioning. In addition, it must handle the effects of the ocean current on the vehicle dynamics. Extensive dynamic simulations of a vehicle in different unknown environments, subject to ocean current, have proven the effectiveness of the proposed navigation system.

The goal of this paper is to report the first experimental results of parallel force/position control schemes on an industrial robot manipulator with open control architecture. An inverse dynamics controller, a modified inverse dynamics controller, and a regulator are tested in a task involving interaction of the end effector with an elastically compliant surface having different values of contact stiffness. A performance comparison of the three schemes is developed in terms of the end-effector position tracking capability during unconstrained motion and force regulation capability during constrained motion.

The task-priority strategy allows redundancy resolution by adding a null-space motion to the basic pseudoinverse joint velocity solution such that the fulfillment of the given primary task is not affected while attempting to satisfy also a secondary task. A problem with this technique is related to the occurrence of algorithmic singularities at which the null-space motion required to achieve the secondary task may give infeasible joint velocities; this represents a severe limitation on practical applicability of the method. In this paper a task-priority redundancy resolution technique is introduced which is suitably devised to properly handle the occurrence of algorithmic singularities. The method is applied to a simple three-degree-of-freedom planar manipulator in numerical case studies to illustrate its potential in comparison to the existing techniques.