### Show only items where

#### Bioactive polyurethanes trough new functionalisation stretegies

 Title Bioactive polyurethanes trough new functionalisation stretegies Publication Type Conference Paper Year of Publication 2007 Conference Name Biotechnical functionalisation of renewable polymeric materials Date Published 16-17 April Publication Language eng Authors Ciardelli, G, Sartori, S, Rechichi, A, CAPORALE, A, BRONCO, S, Vozzi, G, Giusti, P Keywords Bioengineering

#### Molecularly Imprinted Polymers with Recognition Properties Toward Fibronectin H-Gly-Arg-Gly-Asp-Ser-OH Sequence

 Title Molecularly Imprinted Polymers with Recognition Properties Toward Fibronectin H-Gly-Arg-Gly-Asp-Ser-OH Sequence Publication Type Conference Paper Year of Publication 2007 Conference Name European Polymer Congress 2007 Date Published 2-6 July Publication Language eng Authors Rechichi, A, Rosellini, E, Ciardelli, G, Barbani, N, Vozzi, G, Giusti, P, Cristallini, C Conference Location Portoroz, Slovenia Keywords Bioengineering

#### Biomimetic materials for tissue engineering through enzyme mediated protein modification

 Title Biomimetic materials for tissue engineering through enzyme mediated protein modification Publication Type Conference Paper Year of Publication 2007 Conference Name European Polymer Congress 2007 Date Published 2-6 July Publication Language eng Authors Ciardelli, G, GENTILE, P, Mandrile, R, Chiono, V, Barbani, N, Mattioli-Belmonte, M, Vozzi, G, Giusti, P Conference Location Portoroz, Slovenia Keywords Bioengineering

#### New strategies in polymer functionalisation

 Title New strategies in polymer functionalisation Publication Type Conference Paper Year of Publication 2007 Conference Name Biosurf, 28-31 August 2007 Pagination European Cells and Materials Vol. 14. Suppl. 3 Publication Language eng Authors Sartori, S, Rechichi, A, Ciardelli, G, CAPORALE, A, Vozzi, G, MAZZUCCO, L Conference Location Zurich (Switzerland) Keywords Bioengineering

#### Hydroxyapatite/collagen composite matrices for bone reconstruction

 Title Hydroxyapatite/collagen composite matrices for bone reconstruction Publication Type Conference Paper Year of Publication 2007 Conference Name Termis Eu-Meeting - Tissue Engineering 2007 Pagination 13 (7): 1708 Publication Language eng Authors Ciardelli, G, GENTILE, P, Mandrile, R, Chiono, V, Barbani, N, Mattioli-Belmonte, M, Vozzi, G, Giusti, P Conference Location London (UK) Keywords Bioengineering

#### Cardiac and Mesenchymal Stem Cell Growth and Selective Differentiation on Three Dimensional Bioerodable Scaffolds

 Title Cardiac and Mesenchymal Stem Cell Growth and Selective Differentiation on Three Dimensional Bioerodable Scaffolds Publication Type Conference Paper Year of Publication 2007 Conference Name Termis Eu-Meeting London (UK) 4-7 September 2007 Tissue Engineering 2007, 13 (7): 1647 Pagination – Publication Language eng Authors Forte, G, CAROTENUTO, F, Vozzi, G, COSSA, P, FIACCAVENTO, R, Minieri, M, Pagliari, F, Pagliari, S, Romano, R, Ahluwalia, A, Traversa, E, Di Nardo, P Keywords Bioengineering

#### Microfabrication of fractal polymeric structures for capillary morphogenesis: applications in therapeutic angiogenesis and in the engineering of vascularized tissue

 Title Microfabrication of fractal polymeric structures for capillary morphogenesis: applications in therapeutic angiogenesis and in the engineering of vascularized tissue Publication Type Journal Article Year of Publication 2007 Authors BIANCHI, F, ROSI, M, Vozzi, G, EMANUELI, C, MADEDDU, P, Ahluwalia, A Journal JOURNAL OF BIOMEDICAL MATERIALS RESEARCH. PART B, APPLIED BIOMATERIALS Volume 81 Pagination 462–468 ISSN 1552-4981 Keywords Bioengineering

#### Acute retinal ganglion cell injury caused by intraocular pressure spikes is mediated by endogenous extracellular ATP

 Title Acute retinal ganglion cell injury caused by intraocular pressure spikes is mediated by endogenous extracellular ATP Publication Type Journal Article Year of Publication 2007 Authors RESTA, V, NOVELLI, E, Vozzi, G, SCARPA, C, CALEO, M, Ahluwalia, A, SOLINI, A, SANTINI, E, PARISI, V, DI VIRGILIO, F, GALLI-RESTA, L Journal EUROPEAN JOURNAL OF NEUROSCIENCE Volume 25 Pagination 2741–2754 ISSN 0953-816X Keywords Bioengineering

#### New biomedical devices with selective peptide recognition properties. Part 1: Characterization and cytotoxicity of molecularly imprinted polymers

 Title New biomedical devices with selective peptide recognition properties. Part 1: Characterization and cytotoxicity of molecularly imprinted polymers Publication Type Journal Article Year of Publication 2007 Authors Rechichi, A, Cristallini, C, VITALE, U, Ciardelli, G, Barbani, N, Vozzi, G, Giusti, P Journal JOURNAL OF CELLULAR AND MOLECULAR MEDICINE Pagination – ISSN 1582-1838 Keywords Bioengineering

#### Microfabrication for tissue engineering: rethinking the cells-on-a scaffold approach

 Title Microfabrication for tissue engineering: rethinking the cells-on-a scaffold approach Publication Type Journal Article Year of Publication 2007 Authors Vozzi, G, Ahluwalia, A Journal JOURNAL OF MATERIALS CHEMISTRY Pagination – ISSN 0959-9428 Keywords Bioengineering

#### La rigenerazione nervosa negli innesti a polarità  invertita: dati a confronto tra applicazione sull'uomo e analisi sperimentale su modello animale

 Title La rigenerazione nervosa negli innesti a polarità  invertita: dati a confronto tra applicazione sull'uomo e analisi sperimentale su modello animale Publication Type Journal Article Year of Publication 2007 Authors POGGI, DS, Massarella, M, Cerulli, G, Caraffa, A, Burchielli, S, Modenato, M, Cantile, C, Vozzi, G, De Maria, C, Lisanti, M, Bonicoli, E, Cantini, G Journal RIVISTA DI CHIRURGIA DELLA MANO Pagination – Keywords Bioengineering

#### An Artificial Neural Network approach for Haptic Discrimination in Minimally Invasive Surgery

 Title An Artificial Neural Network approach for Haptic Discrimination in Minimally Invasive Surgery Publication Type Conference Paper Year of Publication 2007 Conference Name Robot and Human interactive Communication, 2007. RO-MAN 2007. The 16th IEEE International Symposium on Pagination 25–30 Publication Language eng Authors Sgambelluri, N, Valenza, G, Ferro, M, Pioggia, G, Scilingo, EP, De Rossi, D, Bicchi, A Publisher IEEE Keywords Haptics

#### Adaptive on-line planning of environmental sampling missions with a team of cooperating autonomous underwater vehicles

 Title Adaptive on-line planning of environmental sampling missions with a team of cooperating autonomous underwater vehicles Publication Type Journal Article Year of Publication 2007 Authors Caiti, A, Munafò, A, Viviani, R Journal INTERNATIONAL JOURNAL OF CONTROL Volume 80 Pagination 1151–1168 ISSN 0020-7179 Keywords Robotics URL http://dx.medra.org/10.1080/00207170701230973 DOI 10.1080/00207170701230973

#### Working towards autonomous distributed systems

 Title Working towards autonomous distributed systems Publication Type Journal Article Year of Publication 2007 Authors Caiti, A Journal SEA TECHNOLOGY Volume 48 Pagination 7–7 ISSN 0093-3651 Keywords Robotics Notes Editorial

#### Design and realisation of drop-free trocar for ophthalmic applications

 Title Design and realisation of drop-free trocar for ophthalmic applications Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. IEEE Int. Symp. Industrial Electronics ISIE 2007 Pagination 2810–2814 Publication Language eng Authors Guerrini, P, Vozzi, G, Ahluwalia, A, Mazzei, D, Palla, M, Rizzo, S Keywords Bioengineering DOI 10.1109/ISIE.2007.4375056

#### Development of a high-throughput bioreactor system for biomedical applications

 Title Development of a high-throughput bioreactor system for biomedical applications Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. IEEE Int. Symp. Industrial Electronics ISIE 2007 Pagination 2788–2792 Publication Language eng Authors Mazzei, D, Vozzi, G, Ahluwalia, A, Cisternino, A Keywords Bioengineering DOI 10.1109/ISIE.2007.4375051

#### Decentralized Intrusion Detection in Cooperative Multi-Agent Systems

 Title Decentralized Intrusion Detection in Cooperative Multi-Agent Systems Publication Type Miscellaneous Year of Publication 2007 Authors Fagiolini, A, Pallottino, L, Dini, G Keywords Embedded Control, Robotics Abstract We address the problem of detecting faulty behaviors of robots belonging to a multi-agent system. Our objective is to develop a scalable architecture that can be adopted to realize a completely decentralized intrusion detector monitoring the agents' behavior. We want the solution to be independent from the set of rules'' describing the interaction among the agents, and from their dynamics; (non-invasive) mainly based on HW/SW components that are already present on-board of each agent. We focus on systems with decentralized cooperation schemes where cooperation is obtained by sharing a set of rules'' by which each agent plans its next action'' and where some of the agents may act not according to the rules due to spontaneous failure, tampering, or malicious introduction. Notes Poster Presentation

#### Uniform stabilization for linear systems with persistency of excitation. The neutrally stable and the double integrator cases

 Title Uniform stabilization for linear systems with persistency of excitation. The neutrally stable and the double integrator cases Publication Type Miscellaneous Year of Publication 2007 Authors Chaillet, A, Chitour, Y, Lor, A, Sigalotti, M Keywords Robotics Abstract Consider the controlled system $dx/dt = Ax + \alpha(t)Bu$ where the pair $(A,B)$ is stabilizable and $\alpha(t)$ takes values in $[0,1]$ and is persistently exciting. In particular, when $\alpha(t)$ becomes zero the system dynamics switches to an uncontrollable system. In this paper, we address the following question: is it possible to find a linear time-invariant state-feedback, only depending on $(A,B)$ and the parameters of the persistent excitation, which globally asymptotically stabilizes the system? We give a positive answer to this question for two cases: when $A$ is neutrally stable and when the system is the double integrator.

#### Towards uniform linear time-invariant stabilization of systems with persistency of excitation

 Title Towards uniform linear time-invariant stabilization of systems with persistency of excitation Publication Type Miscellaneous Year of Publication 2007 Authors Chaillet, A, Chitour, Y, Lor, A, Sigalotti, M Keywords Robotics Abstract Consider the controlled system $dx/dt = Ax + \alpha(t)Bu$ where the pair $(A,B)$ is stabilizableand $\alpha(t)$ takes values in $[0,1]$ and is persistently exciting. In particular, when $\alpha(t)$ becomes zero the system dynamics switches to an uncontrollable system. In this paper, we address the following question: is it possible to find a linear time-invariant state-feedback, only depending on $(A,B)$ and the parameters of the persistent excitation, which globally exponentially stabilizes the system? We give a positive answer to this question for two cases: when $A$ is neutrally stable and when the system is the double integrator.

#### An MRI Compatibility Study of a Fabric Sensing Glove for Sensory-Motor Brain Activity Exploration

 Title An MRI Compatibility Study of a Fabric Sensing Glove for Sensory-Motor Brain Activity Exploration Publication Type Conference Paper Year of Publication 2007 Conference Name The 10th Annual International Workshop on Presence Pagination 79-83 Publication Language eng Authors Vanello, N, Hartwig, V, Tesconi, M, Zupone, G, Sgambelluri, N, Tognetti, A, Ricciardi, E, Scilingo, EP, Bicchi, A, Pietrini, P, De Rossi, D, Landini, L Editor Laura Moreno, Starlab Barcelona, SL Keywords Haptics

#### Integrating Two Haptic devices for Performance Enhancement

 Title Integrating Two Haptic devices for Performance Enhancement Publication Type Conference Paper Year of Publication 2007 Conference Name World Haptics Conference 2007 Pagination 139-144 Publication Language eng Authors Scilingo, EP, Sgambelluri, N, Tonietti, G, Bicchi, A Keywords Haptics Abstract This paper deals with a new configuration for a haptic system, which is able to simultaneously replicate independent force/displacement and force/area behaviors of a given material. Being force/area information a relevant additional haptic cue for improving softness discrimination, this system allows to extend the range of materials whose rheology can be carefully mimicked. Moreover, according to the Hertz theory, two objects with different curvature radius having the same force/displacement behavior can respond with different contact area to the same applied force. These behaviors can be effectively replicated by the integrated haptic system here proposed enabling and independent control of force/displacement and force/area. The system is comprised of a commercial device (Delta Haptic Device) serially coupled with a Contact Area Spread Rate (CASR) device. Two specimens of a material and two of another one, all with different curvature radii, were identified and modeled in terms of force/area and force/displacement. These behaviors were successfully tracked by the integrated haptic system here proposed.

#### Distributed intrusion detection for secure consensus computations

 Title Distributed intrusion detection for secure consensus computations Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. IEEE Int. Conf. on Decision and Control Pagination 5594-5599 Date Published December Publication Language eng Authors Pasqualetti, F, Bicchi, A, Bullo, F Keywords Embedded Control, Robotics Abstract This paper focuses on trustworthy computation systems and proposes a novel intrusion detection scheme for averaging networks with misbehaving nodes. This prototypical control problem is relevant in network security applications. The objective is for each node to detect and isolate the misbehaving nodes using only the information flow adopted by standard averaging protocols. We focus on the single misbehaving node problem. Our technical approach is based on the theory of Unknown Input Observability. First, we give necessary and sufficient conditions for the misbehavior to be observable and for the identity of the faulty node to be detectable. Second, we design a distributed unknown input estimator, and we characterize its convergence rate in the

#### Probabilistic verification of decentralized multi-agent control strategies: a case study in conflict avoidance

 Title Probabilistic verification of decentralized multi-agent control strategies: a case study in conflict avoidance Publication Type Conference Paper Year of Publication 2007 Conference Name American Control Conference (ACC) Pagination 170-175 Publication Language eng Authors Pallottino, L, Bicchi, A, Frazzoli, E Keywords Embedded Control, Robotics Abstract Many challenging verification problems arise from complex hybrid automata that model decentralized control systems. As an example, we will consider decentralized policies that steer multiple vehicles in a shared environment: properties of safety and liveness, such as collision avoidance and ultimate convergence of all vehicles to their goals, must be verified. To formally verify the behavior of proposed policies, it is desired to identify the broadest class of start and goal configurations, such that safety and liveness would be guaranteed. Simple conditions are proposed to identify such a class: ideally, a formal proof that such conditions are necessary and sufficient for safety and liveness is requested. Unfortunately, in decentralized control frameworks classical approaches are difficult to apply. Hence, probabilistic verification method can be applied to quantify the accuracy and the confidence of the veridicity of the desired predicate. The probabilistic verification method is applied to a recently proposed cooperative and completely decentralized collision avoidance policy for non-holonomic vehicles.

#### A Dynamic Programming Approach to Optimal Planning for Vehicles with Trailers

 Title A Dynamic Programming Approach to Optimal Planning for Vehicles with Trailers Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. IEEE Int. Conf. on Robotics and Automation Pagination 3098 - 3103 Publication Language eng Authors Pallottino, L, Bicchi, A Keywords Embedded Control, Robotics Abstract In this paper we deal with the optimal feedback synthesis problem for robotic vehicles with trailers which can be modeled by differential equations in chained-form. With respect to classical methods for numerical evolution of optimal feedback synthesis via Dynamic Programming which are based on both input and state discretization, our method exploits the lattice structure naturally imposed on the reachable set by input quantization. A generalized Dijkstra algorithm can be used to obtain optimal feedback control laws, for chained-form vehicles with n-trailers, in an effective way.

#### A Component-Based Approach to Localization and Collision Avoidance for Mobile Multi-Agent Systems

 Title A Component-Based Approach to Localization and Collision Avoidance for Mobile Multi-Agent Systems Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. European Control Conference (ECC) Pagination 4285-4292 Date Published July Publication Language eng Authors Alriksson, P, Nordh, J, Arzén, K-E, Bicchi, A, Danesi, A, Schiavi, R, Pallottino, L Keywords Embedded Control, Robotics Abstract In the RUNES project a disaster relief tunnel scenario is being developed in which mobile robots are used to restore the radio network connectivity in a stationary sensor network. A component-based software development approach has been adopted. Two components are described in this paper. A localization component that uses ultrasound and dead reckoning to decide the robot positions and a collision avoidance component that ensures that the robots do not collide with each other.

#### Higher order method for non linear equations resolution: application to mobile robot control

 Title Higher order method for non linear equations resolution: application to mobile robot control Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. European Control Conference Pagination 3628-3634 Publication Language eng Authors Balestrino, A, Pallottino, L Keywords Autonomous Vehicles, Navigation and Planning Abstract In this paper a novel higher order method for the resolution of non linear equations is proposed. The particular application to the mobile robot navigation in an environment with obstacles is considered. The proposed method is based on the {\em embedded-relaxed} approach in which the dimension of the resolution space is augmented and a different and faster direction toward the root is computed. The method is proved to converge with higher order for the augmented resolution space of dimension 2 and 3. Finally, the method is applied to the problem of mobile robot navigation between obstacles considered as repulsive potentials.

#### Hybrid Multi-rate Control of the Common-Rail

 Title Hybrid Multi-rate Control of the Common-Rail Publication Type Conference Paper Year of Publication 2007 Conference Name European Control Conference Pagination 54-61 Publication Language eng Authors Balluchi, A, Bicchi, A, Mazzi, E, Sangiovanni-Vincentelli, A, Serra, G Keywords Embedded Control, Robotics Abstract We present an industrial case study in automotive control of significant complexity: the new common-rail fuel- injection system for Diesel engines developed by Magneti Marelli Powertrain. In this system, an inlet metering valve, inserted before the High Pressure (HP) pump, regulates the fuel flow that supplies the common rail according to the engine operating point (e.g. engine speed and torque). The standard approach to controller design adopted in the automotive in- dustry is based on mean-value models of the plant. However, the fuel injection system exhibits complex discrete-continuous interactions, due to the slow time-varying frequency of the HP pump cycles and the fast sampling frequency of sensing and actuation. Hence, a hybrid approach to controller design is very promising. In this paper, we present the synthesis of a hybrid multi-rate controller for a Magneti Marelli Powertrain common-rail fuel- injection system for four-cylinder multi-jet engines. Controller design is based on a hybrid model of the injection system. The resulting hybrid controller performs significantly better then previous controllers developed in the company on the basis of mean-value models of the plant.

#### Decentralized Intrusion Detection for Secure Cooperative Multi-Agent Systems

 Title Decentralized Intrusion Detection for Secure Cooperative Multi-Agent Systems Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. IEEE Int. Conf. on Decision and Control Pagination 1553-1558 Publication Language eng Authors Fagiolini, A, Valenti, G, Pallottino, L, Dini, G, Bicchi, A Keywords Embedded Control, Robotics Abstract In this paper we address the problem of detecting faulty behaviors of cooperative mobile agents. A novel decentralized and scalable architecture that can be adopted to realize a monitor of the agents

#### Local Monitor Implementation for Decentralized Intrusion Detection in Secure Multi-Agent Systems

 Title Local Monitor Implementation for Decentralized Intrusion Detection in Secure Multi-Agent Systems Publication Type Conference Paper Year of Publication 2007 Conference Name 3rd IEEE Conference on Automation Science and Engineering Pagination 454–459 Publication Language eng Authors Fagiolini, A, Valenti, G, Pallottino, L, Dini, G, Bicchi, A Keywords Embedded Control, Robotics Abstract This paper focuses on the detection of misbehaving agents within a group of mobile robots. A novel approach to automatically synthesize a decentralized Intrusion Detection System (IDS) as well as an efficient implementation of local monitors are presented. In our scenario, agents perform possibly different independent tasks, but cooperate to guarantee the entire system

#### Variable Impedance Actuations for Physical Human Cooperating Robots: a Comparative Analysis of Performance, Safety and Dependability

 Title Variable Impedance Actuations for Physical Human Cooperating Robots: a Comparative Analysis of Performance, Safety and Dependability Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. IARP-IEEE/RAS-EURON Workshop on Technical Challenges for Dependable Robots in Human Environments. Date Published April Publication Language eng Authors Filippini, R, Sen, S, Bicchi, A Keywords Robotics Abstract An antagonistic actuation with variable stiffness is proposed for ensuring safety and performance in human friendly robotic applications. Various arrangements are analysed with respect to performance, safety and dependability. The results are expected to provide useful guidelines for choosing an actuation mechanism and its implementation for human-robot interactive applications.

#### A Comparative Dependability Analysis of Antagonistic Actuation Arrangements for Enhanced Robotic Safety

 Title A Comparative Dependability Analysis of Antagonistic Actuation Arrangements for Enhanced Robotic Safety Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. IEEE Int. Conf. on Robotics and Automation Pagination 4349–4354 Publication Language eng Authors Filippini, R, Sen, S, Tonietti, G, Bicchi, A Keywords Robotics Abstract In this paper we introduce an analysis of dependability of an elementary yet critical component of robotic systems designed to operate in environments shared with humans, i.e. the joint-level actuation system. We consider robot joints that implement the Variable Impedance Actuation (VIA) paradigm. The VIA has been demonstrated to be an effective mean to achieve high performance while constantly keeping injury risks to humans by accidental impacts below a given threshold. The paper describe possible implementations of the VIA concept which use the Antagonistic Actuation (AA) in three different arrangements. This study follows a previously reported paper dealing with safety. Here a detailed comparative dependability and performability analysis in front of possible specific failure modes is conducted, whose results provide additional and useful guidelines for design of safe and dependable actuation systems for physical human-robot interaction.

#### A Fast RANSAC–Based Registration Algorithm for Accurate Localization in Unknown Environments using LIDAR Measurements

 Title A Fast RANSAC–Based Registration Algorithm for Accurate Localization in Unknown Environments using LIDAR Measurements Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. IEEE Int. Conf. on Automation Science and Engineering Date Published September Publication Language eng Authors Fontanelli, D, Ricciato, L, Soatto, S Conference Location Scottsdale, AZ, USA Keywords Embedded Control, Robotics Abstract The problem of accurate localization using only measurements from a LIDAR sensor is analyzed in this paper. The sensor is rigidly fixed on a generic moving platform, which moves on a plane. Practical on–line applications of localization algorithms impose constraints on the execution time, problem that is addressed in this paper and compared with other existing solutions. Due to the nature of the sensor adopted, the localization algorithm is based on a fast and accurate {\em registration} algorithm, which is able to deal with noisy measurements, outliers and dynamic environments. The proposed solution relies on the RANSAC algorithm in combination with a Huber kernel in order to cope with typical nuisances in LIDAR measurements. The robust registration is successively used in combination with an Extended Kalman Filter to track the trajectory of the LIDAR over time, hence to solve the localization problem. Simulations and experimental results are reported to show the feasibility of the proposed approach.

#### Steering Dynamical Systems with Finite Plans and Limited Path Length

 Title Steering Dynamical Systems with Finite Plans and Limited Path Length Publication Type Conference Paper Year of Publication 2007 Conference Name European Control Conference Pagination 4686-4690 Publication Language eng Authors Greco, L, Fagiolini, A, Bicchi, A, Piccoli, B Keywords Embedded Control, Robotics Abstract Complex dynamical systems can be steered by using symbolic input plans. These plans must have a finite descriptive length, and can be expressed by means of words chosen in an alphabet of symbols. In this way, such plans can be sent through a limited capacity channel to a remote system, where they are decoded in suitable control actions. The choice of this symbols is essential to efficiently encode steering plans. To this aim, in this paper, we state the problem of finding symbols maximizing the interval of points reachable by the system along paths with constrained length. We focus on the problem with two symbols, and compare the results with those produced by plans not accounting for the length constraint. Moreover, the behavior of a simple helicopter, steered by both kinds of plans, has been simulated, in order to illustrate the power of the overall control system, and to emphasize the improvements introduced by the new plans.

#### Almost Sure Stability of Anytime Controllers via Stochastic Scheduling

 Title Almost Sure Stability of Anytime Controllers via Stochastic Scheduling Publication Type Conference Paper Year of Publication 2007 Conference Name Proc. IEEE Int. Conf. on Decision and Control Pagination 5640-5645 Date Published December Publication Language eng Authors Greco, L, Fontanelli, D, Bicchi, A Keywords Embedded Control, Robotics Abstract In this paper we consider scheduling the execution of a number of different software tasks implementing a hierarchy of real-time controllers for a given plant. Controllers are considered to be given and ordered according to a measure of the performance they provide. Software tasks implementing higher-performance controllers are assumed to require a larger worst-case execution time. Control tasks are to be scheduled within given availability limits on execution time, which change stochastically in time. The ensuing switching system is prone to instability, unless a very conservative policy is enforced of always using the simplest, least performant controller. The presented method allows to condition the stochastic scheduling of control tasks so as to obtain a better exploitation of computing capabilities, while guaranteeing almost sure stability of the resulting switching system.

#### An experimental study of exploiting multipath fading for robot communications

 Title An experimental study of exploiting multipath fading for robot communications Publication Type Conference Paper Year of Publication 2007 Conference Name Proceedings of Robotics: Science and Systems Date Published June Publication Language eng Authors Lindhè, M, Johansson, KH, Bicchi, A Conference Location Atlanta, GA, USA Keywords Robotics Abstract A simple approach for mobile robots to exploit multipath fading in order to improve received radio signal strength (RSS), is presented. The strategy is to sample the RSS at discrete points, without deviating too far from the desired position. We first solve the problem of how many samples are needed for given communications performance and how they should be spaced. Second, we propose a circular and a grid trajectory for sampling and give lower bounds on how many samples they will yield. Third, we estimate the parameters of our strategy from measurements. Finally we demonstrate the validity of our analysis through experiments.