This article presents the realization of a tensegrity-based robot composed of a three-bar symmetric prismlike minimal tensegrity configuration. Statics and kinematics are studied presenting the workspace for the designed robot. After a detailed implementation description of the physical robot, some trajectories within its workspace are analyzed. Although our long-term objective is to provide mobile tensegrity-based robots to the community, this work studies a case in which the robot is anchored to the ground. This provides us with a first insight of how these structures should be actuated and sensed to produce movement. ; This work has been supported by project PROFIT CIT-020400-2007-78 financed by the Education and Science Ministry of the Spanish Government. ; Peer Reviewed
The main objective of this paper is twofold. First, to conclude the overview about tensegrity frameworks, started by the same authors in a previous work, covering the most important dynamic aspects of such structures. Here, the most common approaches to tensegrity dynamic modeling used so far are presented, giving the most important results about their dynamic behavior under external action. Also, the main underlying problems are identified which allow the authors to give a clear picture of the main research lines currently open, as well as the most relevant contributions in each of them, which is in fact the second main objective of this paper. From the extensive literature available on the subject, four main areas have been identified: design and form-finding methods which deal with the problem of finding stable configurations, shape changing algorithms which deal with the problem of finding stable trajectories between them and, also control algorithms which take into account the dynamic model of the tensegrity structure and possible external perturbations to achieve the desired goal and performance. Finally, some applications of such structures are presented emphasizing the increasing interest of the scientific community on tensegrity structures. ; This work was supported by projects: 'Estudio de estructuras tensegrity para el desarrollo de sensores manipuladores y robots móviles' (4798), 'Estudio y diseño de manipulador mecánico sobreactuado basado en estructuras tensigrity' (4801/Ref.CIT-020400-2007-78). This work has been partially supported by the projects CICyT DPI2006-14001 and PROFIT CIT-020400-2007-78 both financed by the Education and Science Ministry of the Spanish Government. ; Peer Reviewed
This paper hands in a review of the basic issues about the statics of tensegrity structures. Definitions and notation for the most important concepts, borrowed from the vast existing literature, are summarized. All of these concepts and definitions provide a complete mathematical framework to analyze the rigidity and stability properties of tensegrity structures from three different, but related, points of view: motions, forces and energy approaches. Several rigidity and stability definitions are presented in this paper and hierarchically ordered, from the strongest condition of infinitesimal rigidity to the more wide concept of simple rigidity, so extending some previous classifications already available. Important theorems regarding the relationship between these definitions are also put together to complete the static overview of tensegrity structures. Examples of different tensegrity structures belonging to each of the rigidity and stability ca\-tegories presented are described and analyzed. Concluding the static analysis of tensegrity structures, a review of existing form-finding methods is presented. ; This work was supported by projects: 'Estudio de estructuras tensegrity para el desarrollo de sensores manipuladores y robots móviles' (4798), 'Estudio y diseño de manipulador mecánico sobreactuado basado en estructuras tensigrity' (4801/Ref.CIT-020400-2007-78). This work has been partially supported by the projects CICyT DPI2006-14001 and PROFIT CIT-020400-2007-78 both financied by the Education and Science Ministry of the Spanish Government. ; Peer Reviewed
Behavioural modelling of physical systems from observations of their input/output behaviour is an important task in engineering. Such models are needed for fault monitoring as well as intelligent control of these systems. The paper addresses one subtask of behavioural modelling, namely the selection of input variables to be used in predicting the behaviour of an output variable. A technique that is well suited for qualitative behavioural modelling and simulation of physical systems is Fuzzy Inductive Reasoning (FIR), a methodology based on General System Theory. Yet, the FIR modelling methodology is of exponential computational complexity, and therefore, it may be useful to consider other approaches as booster techniques for FIR. Different variable selection algorithms: the method of the unreconstructed variance for the best reconstruction, methods based on regression coefficients (OLS, PCR and PLS) and other methods as Multiple Correlation Coefficients (MCC), Principal Components Analysis (PCA) and Cluster analysis are discussed and compared to each other for use in predicting the behaviour of a steam generator. The different variable selection algorithms previously named are then used as booster techniques for FIR. Some of the used linear techniques have been found to be non-effective in the task of selecting variables in order to compute a posterior FIR model. Methods based on clustering seem particularly well suited for pre-selecting subsets of variables to be used in a FIR modelling and simulation effort. ; The research reported in this article was made possible, thanks to a Ph.D. fellowship of the Ministry for Education and Culture from the Spanish Government funded within the frame of the TAP96-0882 project. ; Peer Reviewed
This article is an open-access article distributed under the terms and conditions of the Creative Commons Attribution license.-- et al. ; In this article we explain the architecture for the environment and sensors that has been built for the European project URUS (Ubiquitous Networking Robotics in Urban Sites), a project whose objective is to develop an adaptable network robot architecture for cooperation between network robots and human beings and/or the environment in urban areas. The project goal is to deploy a team of robots in an urban area to give a set of services to a user community. This paper addresses the sensor architecture devised for URUS and the type of robots and sensors used, including environment sensors and sensors onboard the robots. Furthermore, we also explain how sensor fusion takes place to achieve urban outdoor execution of robotic services. Finally some results of the project related to the sensor network are highlighted. ; This work has been supported by URUS, the Ubiquitous Robotics in Urban Settings project, funded by the European Commission (FP6-IST-045062), by CONET, the Cooperating Objects Network of Excellence (FP7-2007-2-224053), by the Spanish National projects UbRob, Ubiqitous Robotics in Urban Settings (DPI2007-61452) and PAU, Perception and Action under Uncertainty (DPI2008-06022) of the DPI program; and MIPRCV, Multimodal Interaction in Pattern Recognition and Computer Vision of the Consolider Ingenio 2010 program (CSD2007-00018); and by the project SIRE, funded by the Andalusian Government (P06-TEP-01494). ; Peer Reviewed
