An experimental comparison of path planning techniques applied to micro-sized magnetic agents

Micro-sized agents can be used in applications suchas microassembly, micromanipulation, and minimally invasive surgeries. Magnetic agents such as paramagnetic microparticles can be controlled to deliver pharmaceutical agents to difficult-toaccess regions within the human body. In order to autonomously move these microparticles toward a target/goal area, an obstaclefree path must be computed using path planning algorithms. Several path planning algorithms have been developed in the literature, however, to the best of our knowledge, only few have been employed in an experimental scenario. In this paper we perform an experimental comparison of six path planning algorithms when applied to the motion control of paramagnetic microparticles. Among the families of deterministic and probabilistic path planners we select the ones that we consider the most fundamental, such as: A* with quadtrees, A* with uniform grids, D* Lite, Artificial Potential Field, Probabilistic Roadmap and Rapidly-exploring Random Tree. We consider a 2D environment made by both dynamic and static obstacles. Four scenarios are evaluated. Three metrics such as computation time, length of the trajectory performed by the microparticle, and time to reach the goal are used to compare the planners. Experimental results reveal equivalence between almost all the considered planners in terms of trajectory length and completion time. Concerning the computation time, A* with quadtrees and Artificial Potential Field achieve the best performances

Uncalibrated Visual Compass from Omnidirectional Line Images with Application to Attitude MAV Estimation

International audienceThis paper presents a new algorithm based on previous results of the authors, for the estimation of the yaw angle of an omnidirectional camera robot undergoing a 6-DoF rigid motion. Our real-time algorithm is uncalibrated, robust to noisy data, and it only relies on the projection of 3-D parallel lines as image features. Numerical and real-world experiments conducted with an eye-in-hand robot manipulator, which we used to simulate the 3-D motion of a Micro unmanned Aerial Vehicle (MAV), show the accuracy and reliability of our estimation algorithm

Donne e violenza domestica. La rete di sostegno nella provincia di Grosseto.

L’intento del mio elaborato finale è stato quello di descrivere il fenomeno della violenza domestica e di come esso viene contrastato dai servizi sia pubblici che privati nello specifico all’interno della provincia di Grosseto. La legislazione internazionale, europea, ma anche nazionale e regionale richiama la concezione del lavoro di rete. Secondo questa visione lo Stato deve avere un ruolo attivo nell’incentivare la formazione del lavoro di squadra, in modo che ogni servizio presente sul territorio, preposto al sostegno della vittima di violenza, possa integrare la propria esperienza con altre figure professionali, oltre a fornire un solido sostegno alle donne. La rappresentazione dell’aspetto psicologico e sociale che vive la vittima, come l’excursus storico legislativo e la presentazione dei dati statistici ricavati dalle ultime ricerche quantitative, sono servite per raccontare il quadro in cui è iscritto il fenomeno della violenza domestica. La provincia di Grosseto è stata la prima istituzione, a livello nazionale, a creare la Task Force Interistituzionale tra Asl e Procura, inoltre è ormai consolidata la presenza del Centro Antiviolenza Olympia de Gouges. L’obiettivo di partenza del mio lavoro di ricerca è stato quello di indagare sulla funzionalità della rete di sostegno grossetana evidenziando soprattutto lo svolgersi della collaborazione tra le varie professionalità che si occupano di maltrattamenti in famiglia (volontarie, forze dell’ordine, medici, assistenti sociali e psicologi) e come questi interagiscono tra di loro. Questo nuovo modello presente nel territorio è ancora in evoluzione. All’interno della mia analisi ho cercato di evidenziarne i punti di forza e le problematiche che il terzo settore e le istituzioni coinvolte devono ancora affrontare al fine migliorare il servizio offerto alle vittime che subiscono violenza domestica. La valutazione è avvenuta attraverso delle interviste semi-strutturate poste ai rappresentanti di ogni servizio che si occupa della presa in carico multidisciplinare della vittima di violenza di genere e analizzato con la metodologia fenomenologica esistenzialista. In conclusione la rete si attiva da qualunque punto la donna chieda aiuto, potendo usufruire di un sostegno interdisciplinare. La mancanza del sistema, secondo gli operatori coinvolti, risulta essere l’assenza di una casa rifugio

KCT: a MATLAB toolbox for motion control of KUKA robot manipulators

Abstract—The Kuka Control Toolbox (KCT) is a collection of MATLAB functions for motion control of KUKA robot manipulators, developed to offer an intuitive and high-level programming interface to the user. The toolbox, which is compatible with all 6 DOF small and low payload KUKA robots that use the Eth.RSIXML, runs on a remote computer connected with the KUKA controller via TCP/IP. KCT includes more than 30 functions, spanning operations such as forward and inverse kinematics computation, point-to-point joint and Cartesian control, trajectory generation, graphical display and diagnostics. The flexibility, ease of use and reliability of the toolbox is demonstrated through two applicative examples. I

Cooperative human-robot haptic navigation

International audienceThis paper proposes a novel use of haptic feedback for human navigation with a mobile robot. Assuming that a path-planner has provided a mobile robot with an obstacle-free trajectory, the vehicle must steer the human from an initial to a desired target position by only interacting with him/her via a custom-designed vibro-tactile bracelet. The subject is free to decide his/her own pace and a warning vibrational signal is generated by the bracelet only when a large deviation with respect to the planned trajectory is detected by the vision sensor on-board the robot. This leads to a cooperative navigation system that is less intrusive, more flexible and easy-to-use than the ones existing in literature. The effectiveness of the proposed system is demonstrated via extensive real-world experiments

Surface plasmon dispersion and luminescence quenching applied to planar waveguide sensors for the measurement Of chemical concentrations

Two novel types of planar waveguide sensors for the chemical domain are introduced. Both are realized by thin film technologies. They consist of multilayered structures coated by a very thin organic overlayer that is able to absorb the species to be measured out of the environment. This absorbtion results in a change in its dielectric function. In the first sensor to be demonstrated this change is measured using a surface plasmon mode as a probe. In the second one the radiationless energy transfer from luminescent centres incorporated in one of the layers to the overlayer serves as a probe

Uncalibrated Visual Compass from Omnidirectional Line Images with Application to Attitude MAV Estimation

International audienceThis paper presents a new algorithm based on previous results of the authors, for the estimation of the yaw angle of an omnidirectional camera robot undergoing a 6-DoF rigid motion. Our real-time algorithm is uncalibrated, robust to noisy data, and it only relies on the projection of 3-D parallel lines as image features. Numerical and real-world experiments conducted with an eye-in-hand robot manipulator, which we used to simulate the 3-D motion of a Micro unmanned Aerial Vehicle (MAV), show the accuracy and reliability of our estimation algorithm

Cooperative Navigation for Mixed Human–Robot Teams Using Haptic Feedback

In this paper, we present a novel cooperative navigation control for human–robot teams. Assuming that a human wants to reach a final location in a large environment with the help of a mobile robot, the robot must steer the human from the initial to the target position. The challenges posed by cooperative human–robot navigation are typically addressed by using haptic feedback via physical interaction. In contrast with that, in this paper, we describe a different approach, in which the human–robot interaction is achieved via wearable vibrotactile armbands. In the proposed work, the subject is free to decide her/his own pace. A warning vibrational signal is generated by the haptic armbands when a large deviation with respect to the desired pose is detected by the robot. The proposed method has been evaluated in a large indoor environment, where 15 blindfolded human subjects were asked to follow the haptic cues provided by the robot. The participants had to reach a target area, while avoiding static and dynamic obstacles. Experimental results revealed that the blindfolded subjects were able to avoid the obstacles and safely reach the target in all of the performed trials. A comparison is provided between the results obtained with blindfolded users and experiments performed with sighted people

Evaluation of a predictive approach in steering the human locomotion via haptic feedback

In this paper, we present a haptic guidance policy to steer the user along predefined paths, and we evaluate a predictive approach to compensate actuation delays that humans have when they are guided along a given trajectory via sensory stimuli. The proposed navigation policy exploits the nonholonomic nature of human locomotion in goal directed paths, which leads to a very simple guidance mechanism. The proposed method has been evaluated in a real scenario where seven human subjects were asked to walk along a set of predefined paths, and were guided via vibrotactile cues. Their poses as well as the related distances from the path have been recorded using an accurate optical tracking system. Results revealed that an average error of 0.24 m is achieved by using the proposed haptic policy, and that the predictive approach does not bring significant improvements to the path following problem for what concerns the distance error. On the contrary, the predictive approach achieved a definitely lower activation time of the haptic interfaces