Kinematics analysis of 6-DOF parallel micro-manipulators with offset u-joints : a case study

This paper analyses the kinematics of a special 6-DOF parallel micro-manipulator with offset RR-joint configuration. Kinematics equations are derived and numerical methodologies to solve the inverse and forward kinematics are presented. The inverse and forward kinematics of such robots compared with those of 6-UCU parallel robots are more complicated due to the existence of offsets between joints of RR-pairs. The characteristics of RR-pairs used in this manipulator are investigated and kinematics constraints of these offset U-joints are mathematically explained in order to find the best initial guesses for the numerical solution. Both inverse and forward kinematics of the case study 6-DOF parallel micro-manipulator are modelled and computational analyses are performed to numerically verify accuracy and effectiveness of the proposed methodologies

Peptides, DNA and MIPs in gas sensing. From the realization of the sensors to sample analysis

Detection and monitoring of volatiles is a challenging and fascinating issue in environmental analysis, agriculture and food quality, process control in industry, as well as in ‘point of care’ diagnostics. Gas chromatographic approaches remain the reference method for the analysis of volatile organic compounds (VOCs); however, gas sensors (GSs), with their advantages of low cost and no or very little sample preparation, have become a reality. Gas sensors can be used singularly or in array format (e.g., e-noses); coupling data output with multivariate statical treatment allows un-target analysis of samples headspace. Within this frame, the use of new binding elements as recognition/interaction elements in gas sensing is a challenging hot-topic that allowed unexpected advancement. In this review, the latest development of gas sensors and gas sensor arrays, realized using peptides, molecularly imprinted polymers and DNA is reported. This work is focused on the description of the strategies used for the GSs development, the sensing elements function, the sensors array set-up, and the application in real cases

Soft eSkin:distributed touch sensing with harmonized energy and computing

Inspired by biology, significant advances have been made in the field of electronic skin (eSkin) or tactile skin. Many of these advances have come through mimicking the morphology of human skin and by distributing few touch sensors in an area. However, the complexity of human skin goes beyond mimicking few morphological features or using few sensors. For example, embedded computing (e.g. processing of tactile data at the point of contact) is centric to the human skin as some neuroscience studies show. Likewise, distributed cell or molecular energy is a key feature of human skin. The eSkin with such features, along with distributed and embedded sensors/electronics on soft substrates, is an interesting topic to explore. These features also make eSkin significantly different from conventional computing. For example, unlike conventional centralized computing enabled by miniaturized chips, the eSkin could be seen as a flexible and wearable large area computer with distributed sensors and harmonized energy. This paper discusses these advanced features in eSkin, particularly the distributed sensing harmoniously integrated with energy harvesters, storage devices and distributed computing to read and locally process the tactile sensory data. Rapid advances in neuromorphic hardware, flexible energy generation, energy-conscious electronics, flexible and printed electronics are also discussed. This article is part of the theme issue ‘Harmonizing energy-autonomous computing and intelligence’

Appropriate Design of Parallel Manipulators

International audienceAlthough parallel structures have found a niche market in many applications such as machine tools, telescope positioning or food packaging, they are not as successful as expected. The main reason of this relative lack of success is that the study and hardware of parallel structures have clearly not reached the same level of completeness than the one of serial structures. Among the main issues that have to be addressed, the design problem is crucial. Indeed, the performances that can be expected from a parallel robot are heavily dependent upon the choice of the mechanical structure and even more from its dimensioning. In this chapter, we show that classical design methodologies are not appropriate for such closed-loop mechanism and examine what alternatives are possible

Mechatronic development and dynamic control of a 3-DOF parallel manipulator

This is an Author's Accepted Manuscript of an article published in Mechanics Based Design of Structures and Machines: An International Journal, 40:4, 434-452 [September 2012] [copyright Taylor & Francis], available online at: http://www.tandfonline.com/10.1080/15397734.2012.687292The aim of this article is to develop, from the mechatronic point of view, a low-cost parallel manipulator (PM) with 3-degrees of freedom (DOF). The robot has to be able to generate and control one translational motion (heave) and two rotary motions (rolling and pitching). Applications for this kind of parallel manipulator can be found at least in driving-motion simulation and in the biomechanical field. An open control architecture has been developed for this manipulator, which allows implementing and testing different dynamic control schemes for a PM with 3-DOF. Thus, the robot developed can be used as a test bench where control schemes can be tested. In this article, several control schemes are proposed and the tracking control responses are compared. The schemes considered are based on passivity-based control and inverse dynamic control. The control algorithm considers point-to-point control or tracking control. When the controller considers the system dynamics, an identified model has been used. The control schemes have been tested on a virtual robot and on the actual prototype. © 2012 Taylor & Francis Group, LLC.The authors wish to express their gratitude to the Plan Nacional de I+D, Comision Interministerial de Ciencia y Tecnologia (FEDER-CICYT) for the partial financing of this study under the projects DPI2009-13830-C02-01 and DPI2010-20814-C02-(01, 02). This work was also supported in part by the CDCHT-ULA Grant I-1286-11-02-B.Vallés Miquel, M.; Díaz-Rodríguez, M.; Valera Fernández, Á.; Mata Amela, V.; Page Del Pozo, AF. (2012). Mechatronic development and dynamic control of a 3-DOF parallel manipulator. Mechanics Based Design of Structures and Machines: An International Journal. 40(4):434-452. https://doi.org/10.1080/15397734.2012.687292S434452404Awtar, S., Bernard, C., Boklund, N., Master, A., Ueda, D., & Craig, K. (2002). Mechatronic design of a ball-on-plate balancing system. Mechatronics, 12(2), 217-228. doi:10.1016/s0957-4158(01)00062-9Carretero, J. A., Podhorodeski, R. P., Nahon, M. A., & Gosselin, C. M. (1999). Kinematic Analysis and Optimization of a New Three Degree-of-Freedom Spatial Parallel Manipulator. Journal of Mechanical Design, 122(1), 17-24. doi:10.1115/1.533542Castelli, G., Ottaviano, E., & Ceccarelli, M. (2008). A Fairly General Algorithm to Evaluate Workspace Characteristics of Serial and Parallel Manipulators#. Mechanics Based Design of Structures and Machines, 36(1), 14-33. doi:10.1080/15397730701729478Chablat, D., & Wenger, P. (2003). Architecture optimization of a 3-DOF translational parallel mechanism for machining applications, the orthoglide. IEEE Transactions on Robotics and Automation, 19(3), 403-410. doi:10.1109/tra.2003.810242Clavel , R. ( 1988 ). DELTA, a fast robot with parallel geometry.Proceedings of 18th International Symposium on Industrial Robot.Switzerland: Lausanne, April, pp. 91–100 .Díaz-Rodríguez, M., Mata, V., Farhat, N., & Provenzano, S. (2008). Identifiability of the Dynamic Parameters of a Class of Parallel Robots in the Presence of Measurement Noise and Modeling Discrepancy#. Mechanics Based Design of Structures and Machines, 36(4), 478-498. doi:10.1080/15397730802446501Díaz-Rodríguez, M., Mata, V., Valera, Á., & Page, Á. (2010). A methodology for dynamic parameters identification of 3-DOF parallel robots in terms of relevant parameters. Mechanism and Machine Theory, 45(9), 1337-1356. doi:10.1016/j.mechmachtheory.2010.04.007García de Jalón, J., & Bayo, E. (1994). Kinematic and Dynamic Simulation of Multibody Systems. Mechanical Engineering Series. doi:10.1007/978-1-4612-2600-0Gough , V. E. , Whitehall , S. G. ( 1962 ). Universal tire test machine.Proceedings of 9th International Technical Congress FISITA, London, pp. 117–137 .Sung Kim, H., & Tsai, L.-W. (2003). Kinematic Synthesis of a Spatial 3-RPS Parallel Manipulator. Journal of Mechanical Design, 125(1), 92-97. doi:10.1115/1.1539505Lee, K.-M., & Shah, D. K. (1988). Kinematic analysis of a three-degrees-of-freedom in-parallel actuated manipulator. IEEE Journal on Robotics and Automation, 4(3), 354-360. doi:10.1109/56.796Li, Y., & Xu, Q. (2007). Design and Development of a Medical Parallel Robot for Cardiopulmonary Resuscitation. IEEE/ASME Transactions on Mechatronics, 12(3), 265-273. doi:10.1109/tmech.2007.897257Merlet, J.-P. (2000). Parallel Robots. Solid Mechanics and Its Applications. doi:10.1007/978-94-010-9587-7Merlet , J. P. ( 2002 ). Optimal design for the micro parallel robot MIPS.Proceedings IEEE International Conference on Robotics and Automation, Washington, DC, pp. 1149–1154 .Ortega, R., & Spong, M. W. (1989). Adaptive motion control of rigid robots: A tutorial. Automatica, 25(6), 877-888. doi:10.1016/0005-1098(89)90054-xPaccot, F., Andreff, N., & Martinet, P. (2009). A Review on the Dynamic Control of Parallel Kinematic Machines: Theory and Experiments. The International Journal of Robotics Research, 28(3), 395-416. doi:10.1177/0278364908096236Rosillo, N., Valera, A., Benimeli, F., Mata, V., & Valero, F. (2011). Real‐time solving of dynamic problem in industrial robots. Industrial Robot: An International Journal, 38(2), 119-129. doi:10.1108/01439911111106336Stewart , D. A. ( 1965 ). A platform with 6 degree of freedom.Proceedings of the Institution of Mechanical Engineers.Part 1 15:371–386 .Syrseloudis , C. E. , Emiris , I. Z. ( 2008 ). A parallel robot for ankle rehabilitation-evaluation and its design specifications.Proceeding of 8th IEEE International Conference on BioInformatics and BioEngineering, Athens, October 1–6

NSSDC Conference on Mass Storage Systems and Technologies for Space and Earth Science Applications, volume 1

Papers and viewgraphs from the conference are presented. This conference served as a broad forum for the discussion of a number of important issues in the field of mass storage systems. Topics include magnetic disk and tape technologies, optical disks and tape, software storage and file management systems, and experiences with the use of a large, distributed storage system. The technical presentations describe, among other things, integrated mass storage systems that are expected to be available commercially. Also included is a series of presentations from Federal Government organizations and research institutions covering their mass storage requirements for the 1990's

NASA Tech Briefs, July 1991

Topics include: New Product Ideas; NASA TU Services; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Machinery; Fabrication Technology; Mathematics and Information Sciences; Life Sciences