Presentation, Force Estimation and Control of an instrumented platform dedicated to automated micromanipulation tasks.

International audienceThis paper presents a platform used to measure micromanipulation forces. The main interest of the proposed platform is that it uses classical force sensors with limited range and adapts these sensors to that of micromanipulation forces. The proposed platform, and an additional micropositioning device, are afterwards used to develop a micromanipulation system. To automate this system, we design two control levels. First, an internal loop with a PID controller is employed to improve the micropositioning device's performances. Then, an external loop based on an incremental control law is implemented to control the force. The automated system is finally used for the micromanipulation task on rigid and non-rigid microobjects

Microrobotique et Micromécatronique pour la Réalisation de Tâches de Micro-Assemblage Complexes et Précises.

Ce document présente une synthèse de mes contributions scientifiques aux domaines de la microrobotique et de la micromécatronique ainsi que des transferts effectués, tant à destination de l’industrie que de l’enseignement. Les travaux conduits sont orientés vers la réalisation de tâches de micro-assemblage complexes, précises et automatisées par approche microrobotique et sont plus particulièrement appliqués aux MOEMS.L’échelle micrométrique considérée induit de nombreuses spécificités qui se traduisent par un déficit notable de connaissances du comportement des systèmes à cette échelle. Pour cela, une première partie des travaux est dédiée à l’étude et à la modélisation multiphysique des systèmes microrobotiques et micromécatroniques. Cette connaissance a conduit, dans une seconde partie des travaux, à la proposition de nouveaux principes de mesure et d’actionnement mais également au développement de microsystèmes complexes, instrumentés et intégrés (micro-banc-optique, micropince, plateformes compliantes). Enfin, des lois de commandes et des stratégies d’assemblage originales ont été proposées notamment une commande dynamique hybride force-position combinant une commande hybride externe et une commande en impédance. Celle-ci permet de maîtriser la dynamique des transitions contact/non-contact critique à l’échelle micrométrique mais également d’automatiser des processus de micro-assemblage complexes. L’ensemble de ces travaux ont fait l’objet de validations expérimentales permettant de quantifier précisément les performances obtenues (exactitude de positionnement, temps de cycle, robustesse…). Les perspectives de ces travaux portent sur la proposition de systèmes microrobotiques et micromécatroniques compacts et intégrés utiles au micro-assemblage haute dynamique ainsi qu’à l’assemblage de composants nanophotoniques

Affordable flexible hybrid manipulator for miniaturised product assembly

Miniaturised assembly systems are capable of assembling parts of a few millimetres in size with an accuracy of a few micrometres. Reducing the size and the cost of such a system while increasing its flexibility and accuracy is a challenging issue. The introduction of hybrid manipulation, also called coarse/fine manipulation, within an assembly system is the solution investigated in this thesis. A micro-motion stage (MMS) is designed to be used as the fine positioning mechanism of the hybrid assembly system. MMSs often integrate compliant micro-motion stages (CMMSs) to achieve higher performances than the conventional MMSs. CMMSs are mechanisms that transmit an output force and displacement through the deformation of their structure. Although widely studied, the design and modelling techniques of these mechanisms still need to be improved and simplified. Firstly, the linear modelling of CMMSs is evaluated and two polymer prototypes are fabricated and characterised. It is found that polymer based designs have a low fabrication cost but not suitable for construction of a micro-assembly system. A simplified nonlinear model is then derived and integrated within an analytical model, allowing for the full characterisation of the CMMS in terms of stiffness and range of motion. An aluminium CMMS is fabricated based on the optimisation results from the analytical model and is integrated within an MMS. The MMS is controlled using dual-range positioning to achieve a low-cost positioning accuracy better than 2µm within a workspace of 4.4×4.4mm2. Finally, a hybrid manipulator is designed to assemble mobile-phone cameras and sensors automatically. A conventional robot manipulator is used to pick and place the parts in coarse mode while the aluminium CMMS based MMS is used for fine alignment of the parts. A high-resolution vision system is used to locate the parts on the substrate and to measure the relative position of the manipulator above MMS using a calibration grid with square patterns. The overall placement accuracy of the assembly system is ±24µm at 3σ and can reach 2µm, for a total cost of less than £50k, thus demonstrating the suitability of hybrid manipulation for desktop-size miniaturised assembly systems. The precision of the existing system could be significantly improved by making the manipulator stiffer (i.e. preloaded bearings…) and adjustable to compensate for misalignment. Further improvement could also be made on the calibration of the vision system. The system could be either scaled up or down using the same architecture while adapting the controllers to the scale.Engineering and Physical Sciences Research Council (EPSRC

Space Station Freedom Utilization Conference

The topics addressed in Space Station Freedom Utilization Conference are: (1) space station freedom overview and research capabilities; (2) space station freedom research plans and opportunities; (3) life sciences research on space station freedom; (4) technology research on space station freedom; (5) microgravity research and biotechnology on space station freedom; and (6) closing plenary

Medical Robotics

The first generation of surgical robots are already being installed in a number of operating rooms around the world. Robotics is being introduced to medicine because it allows for unprecedented control and precision of surgical instruments in minimally invasive procedures. So far, robots have been used to position an endoscope, perform gallbladder surgery and correct gastroesophogeal reflux and heartburn. The ultimate goal of the robotic surgery field is to design a robot that can be used to perform closed-chest, beating-heart surgery. The use of robotics in surgery will expand over the next decades without any doubt. Minimally Invasive Surgery (MIS) is a revolutionary approach in surgery. In MIS, the operation is performed with instruments and viewing equipment inserted into the body through small incisions created by the surgeon, in contrast to open surgery with large incisions. This minimizes surgical trauma and damage to healthy tissue, resulting in shorter patient recovery time. The aim of this book is to provide an overview of the state-of-art, to present new ideas, original results and practical experiences in this expanding area. Nevertheless, many chapters in the book concern advanced research on this growing area. The book provides critical analysis of clinical trials, assessment of the benefits and risks of the application of these technologies. This book is certainly a small sample of the research activity on Medical Robotics going on around the globe as you read it, but it surely covers a good deal of what has been done in the field recently, and as such it works as a valuable source for researchers interested in the involved subjects, whether they are currently “medical roboticists” or not

Parallel Manipulators

In recent years, parallel kinematics mechanisms have attracted a lot of attention from the academic and industrial communities due to potential applications not only as robot manipulators but also as machine tools. Generally, the criteria used to compare the performance of traditional serial robots and parallel robots are the workspace, the ratio between the payload and the robot mass, accuracy, and dynamic behaviour. In addition to the reduced coupling effect between joints, parallel robots bring the benefits of much higher payload-robot mass ratios, superior accuracy and greater stiffness; qualities which lead to better dynamic performance. The main drawback with parallel robots is the relatively small workspace. A great deal of research on parallel robots has been carried out worldwide, and a large number of parallel mechanism systems have been built for various applications, such as remote handling, machine tools, medical robots, simulators, micro-robots, and humanoid robots. This book opens a window to exceptional research and development work on parallel mechanisms contributed by authors from around the world. Through this window the reader can get a good view of current parallel robot research and applications

Life Sciences Program Tasks and Bibliography for FY 1997

This document includes information on all peer reviewed projects funded by the Office of Life and Microgravity Sciences and Applications, Life Sciences Division during fiscal year 1997. This document will be published annually and made available to scientists in the space life sciences field both as a hard copy and as an interactive internet web page