A Novel Practical Technique to Integrate Inequality Control Objectives and Task Transitions in Priority Based Control

The 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

Robotized underwater interventions

Working in underwater environments poses many challenges for robotic systems. One of them is the low bandwidth and high latency of underwater acoustic communications, which limits the possibility of interaction with submerged robots. One solution is to have a tether cable to enable high speed and low latency communications, but that requires a support vessel and increases costs. For that reason, autonomous underwater robots are a very interesting solution. Several research projects have demonstrated autonomy capabilities of Underwater Vehicle Manipulator Systems (UVMS) in performing basic manipulation tasks, and, moving a step further, this chapter will present a unifying architecture for the control of an UVMS, comprehensive of all the control objectives that an UVMS should take into account, their different priorities and the typical mission phases that an UVMS has to tackle. The proposed strategy is supported both by a complete simulated execution of a test-case mission and experimental results

A task-priority based control approach to distributed data-driven ocean sampling

The paper illustrates the basic ideas and relevant algorithmic developments underlying the proposal for a task-priority based control approach to distributed data-driven ocean sampling applications. This approach is deemed allowing a better formalization of the overall motion problem of the involved team of agents; that apart the ultimate mission objective, also result characterized by other different control objectives directly related with both operability and safety aspects of the entire sampling system. Also, the proposed approach, other than leading to a unifying algorithmic structure, also seems allowing to foresee good possibilities for different types of downgrading toward efficient decentralized implementations

Flexible human-robot cooperation models for assisted shop-floor tasks

The Industry 4.0 paradigm emphasizes the crucial benefits that collaborative robots, i.e., robots able to work alongside and together with humans, could bring to the whole production process. In this context, an enabling technology yet unreached is the design of flexible robots able to deal at all levels with humans' intrinsic variability, which is not only a necessary element for a comfortable working experience for the person but also a precious capability for efficiently dealing with unexpected events. In this paper, a sensing, representation, planning and control architecture for flexible human-robot cooperation, referred to as FlexHRC, is proposed. FlexHRC relies on wearable sensors for human action recognition, AND/OR graphs for the representation of and reasoning upon cooperation models, and a Task Priority framework to decouple action planning from robot motion planning and control.Comment: Submitted to Mechatronics (Elsevier

Decoupled Sampling-Based Motion Planning for Multiple Autonomous Marine Vehicles

There is increasing interest in the deployment and operation of multiple autonomous marine vehicles (AMVs) for a number of challenging scientific and commercial operational mission scenarios. Some of the missions, such as geotechnical surveying and 3D marine habitat mapping, require that a number of heterogeneous vehicles operate simultaneously in small areas, often in close proximity of each other. In these circumstances safety, reliability, and efficient multiple vehicle operation are key ingredients for mission success. Additionally, the deployment and operation of multiple AMVs at sea are extremely costly in terms of the logistics and human resources required for mission supervision, often during extended periods of time. These costs can be greatly minimized by automating the deployment and initial steering of a vehicle fleet to a predetermined configuration, in preparation for the ensuing mission, taking into account operational constraints. This is one of the core issues addressed in the scope of the Widely Scalable Mobile Underwater Sonar Technology project (WiMUST), an EU Horizon 2020 initiative for underwater robotics research. WiMUST uses a team of cooperative autonomous ma- rine robots, some of which towing streamers equipped with hydrophones, acting as intelligent sensing and communicat- ing nodes of a reconfigurable moving acoustic network. In WiMUST, the AMVs maintain a fixed geometric formation through cooperative navigation and motion control. Formation initialization requires that all the AMVs start from scattered positions in the water and maneuver so as to arrive at required target configuration points at the same time in a completely au- tomatic manner. This paper describes the decoupled prioritized vehicle motion planner developed in the scope of WiMUST that, together with an existing system for trajectory tracking, affords a fleet of vehicles the above capabilities, while ensuring inter- vehicle collision and streamer entanglement avoidance. Tests with a fleet of seven marine vehicles show the efficacy of the system planner developed.Peer reviewe

ISME trends: Autonomous surface and underwater vehicles for geoseismic survey

The paper presents the recent and ongoing activities of the Italian Center named ISME on the use of Autonomous Surface Crafts (ASCs) and Autonomous Underwater Vehicles (AUVs) for geoseismic survey. In particular, the paper will focus on the technologies and the algorithms developed in the framework of the H2020 European Project WiMUST

Validation and verification of modular GNC by means of TAS-I robot management framework in outdoor rovers exploration facility

The objective of STEPS2 “Rover Surface Navigation” work package was the design, development, validation and verification of innovative solutions suitable for the future (manned and unmanned) space robotics mission. A particular focus has been put in the autonomous capabilities to be implemented for the baseline mission scenario: sample canister acquisition and return, simulated in TAS-I ROvers eXploration facilitY.This paper gives an overview of the adopted System Development Life Cycle, that is based on V-model and agile methodologies. Then the infrastructure, including the ROXY facility and research robots are detailed. The paper focuses on the Test activities and relevant results for the Modular GNC developed on the TAS-I Robot Management Framework architecture. Finally, the future envisaged activities are presented, including upgrades to Methodology, ROXY facility and GNC modules and their usage in the frame of TAS-I research activities and ESA funded contracts