61 research outputs found

    マルチ スケール キノウ ヲ ユウスル コウソク ジドウ マイクロ マニピュレーション システム

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    Ebubekir Avci, Chanh-Nghiem Nguyen, Kenichi Ohara, Yasushi Mae, Tatsuo Arai, Analysis and suppression of residual vibration in microhand for high-speed single-cell manipulation, International Journal of Mechatronics and Automation, 2013-Vol.3, No.2, pp.110-11

    Workshop on "Robotic assembly of 3D MEMS".

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    Proceedings of a workshop proposed in IEEE IROS'2007.The increase of MEMS' functionalities often requires the integration of various technologies used for mechanical, optical and electronic subsystems in order to achieve a unique system. These different technologies have usually process incompatibilities and the whole microsystem can not be obtained monolithically and then requires microassembly steps. Microassembly of MEMS based on micrometric components is one of the most promising approaches to achieve high-performance MEMS. Moreover, microassembly also permits to develop suitable MEMS packaging as well as 3D components although microfabrication technologies are usually able to create 2D and "2.5D" components. The study of microassembly methods is consequently a high stake for MEMS technologies growth. Two approaches are currently developped for microassembly: self-assembly and robotic microassembly. In the first one, the assembly is highly parallel but the efficiency and the flexibility still stay low. The robotic approach has the potential to reach precise and reliable assembly with high flexibility. The proposed workshop focuses on this second approach and will take a bearing of the corresponding microrobotic issues. Beyond the microfabrication technologies, performing MEMS microassembly requires, micromanipulation strategies, microworld dynamics and attachment technologies. The design and the fabrication of the microrobot end-effectors as well as the assembled micro-parts require the use of microfabrication technologies. Moreover new micromanipulation strategies are necessary to handle and position micro-parts with sufficiently high accuracy during assembly. The dynamic behaviour of micrometric objects has also to be studied and controlled. Finally, after positioning the micro-part, attachment technologies are necessary

    Cooperative Manipulation using a Magnetically Navigated Microrobot and a Micromanipulator

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    The cooperative manipulation of a common object using two or more manipulators is a popular research field in both industry and institutions. Different types of manipulators are used in cooperative manipulation for carrying heavy loads and delicate operations. Their applications range from macro to micro. In this thesis, we are interested in the development of a novel cooperative manipulator for manipulation tasks in a small workspace. The resultant cooperative manipulation system consists of a magnetically navigated microrobot (MNM) and a motorized micromanipulator (MM). The MNM is a small cylinder permanent magnet with 10mm diameter and 10mm height. The MM model is MP-285 which is a commercialized product. Here, the MNM is remotely controlled by an external magnetic field. The property of non-contact manipulation makes it a suitable choice for manipulation in a confined space. The cooperative manipulation system in this thesis used a master/slave mechanism as the central control strategy. The MM is the master side. The MNM is the slave side. During the manipulation process, the master manipulator MM is always position controlled, and it leads the object translation according to the kinematic constraints of the cooperative manipulation task. The MNM is position controlled at the beginning of the manipulation. In the translation stage, the MNM is switched to force control to maintain a successful holding of the object, and at the same time to prevent damaging the object by large holding force. Under the force control mode, the motion command to the MNM is calculated from a position-based impedance controller that enforces a relationship between the position of the MNM and the force. In this research, the accurate motion control of both manipulators are firstly studied before the cooperative manipulation is conducted. For the magnetic navigation system, the magnetic field in its workspace is modeled using an experimental measurement data-driven technique. The developed model is then used to develop a motion controller for navigating of a small cylindrical permanent magnet. The accuracy of motion control is reached at 20 µm in three degrees of freedom. For the motorized micromanipulator, a standard PID controller is designed to control its motion stage. The accuracy of the MM navigation is 0.8 µm. Since the MNM is remotely manipulated by an external magnetic field in a small space, it is challenging to install an on-board force sensor to measure the contact force between the MNM and the object. Therefore, a dual-axial o_-board force determination mechanism is proposed. The force is determined according to the linear relation between the minimum magnetic potential energy point and the real position of the MNM in the workspace. For convenience, the minimum magnetic potential energy point is defined as the Bmax in the literature. In this thesis, the dual-axial Bmax position is determined by measuring the magnetic ux density passing through the workspace using four Hall-effect sensors installed at the bottom of an iron pole-piece. The force model is experimentally validated in a horizontal plane with an accuracy of 2 µN in the x- and y- direction of horizontal planes. The proposed cooperative manipulator is then used to translate a hard-shell small object in two directions of a vertical plane, while one direction is constrained with a desired holding force. During the manipulation process, a digital camera is used to capture the real-time position of the MNM, the MM end-effector, and the manipulated object. To improve the performance of force control on the MNM, the proposed dual-axial force model is used to examine the compliant force control of the MNM while it is navigated to contact with uncertain environments. Here, uncertain refers to unknown environmental stiffness. An adaptive position-based impedance controller is implemented to estimate the stiffness of the environment and the contact force. The controller is examined by navigating the MNM to push a thin aluminum beam whose stiffness is unknown. The studied cooperative manipulation system has potential applications in biomedical microsurgery and microinjection. It should be clarified that the current system setup with 10mm ×10 mm MNM is not proper for this micromanipulation. In order to conduct research on microinjection, the size of the MNM and the end-effector of the MNM should be down-scaled to micrometers. In addition, the navigation accuracy of the MNM should also be improved to adopt the micromanipulation tasks

    Automated Micromanipulation of Micro Objects

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    In recent years, research efforts in the development of Micro Electro Mechanical Systems, (MEMS) including microactuators and micromanipulators, have attracted a great deal of attention. The development of microfabrication techniques has resulted in substantial progress in the miniaturization of devices such as electronic circuits. However, the research in MEMS still lags behind in terms of the development of reliable tools for post-fabrication processes and the precise and dexterous manipulation of individual micro size objects. Current micromanipulation mechanisms are prone to high costs, a large footprint, and poor dexterity and are labour intensive. To overcome such, the research in this thesis is focused on the utilization of microactuators in micromanipulation. Microactuators are compliant structures. They undergo substantial deflection during micromanipulation due to the considerable surface micro forces. Their dominance in governing micromanipulation is so compelling that their effects should be considered in designing microactuators and microsensors. In this thesis, the characterization of the surface micro forces and automated micromanipulation are investigated. An inexpensive experimental setup is proposed as a platform to replace Atomic Force Microscopy (AFM) for analyzing the force characterization of micro scale components. The relationship between the magnitudes of the surface micro forces and the parameters such as the velocity of the pushing process, relative humidity, temperature, hydrophilicity of the substrate, and surface area are empirically examined. In addition, a precision automated micromanipulation system is realized. A class of artificial neural networks (NN) is devised to estimate the unmodelled micro forces during the controlled pushing of micro size object along a desired path. Then, a nonlinear controller is developed for the controlled pushing of the micro objects to guarantee the stability of the closed loop system in the Lyapunov sense. To validate the performance of the proposed controller, an experimental setup is designed. The application of the proposed controller is extended to precisely push several micro objects, each with different characteristics in terms of the surface micro forces governing the manipulation process. The proposed adaptive controller is capable of learning to adjust its weights effectively when the surface micro forces change under varying conditions. By using the controller, a fully automated sequential positioning of three micro objects on a flat substrate is performed. The results are compared with those of the identical sequential pushing by using a conventional linear controller. The results suggest that artificial NNs are a promising tool for the design of adaptive controllers to accurately perform the automated manipulation of multiple objects in the microscopic scale for microassembly

    Proceedings of the NASA Conference on Space Telerobotics, volume 1

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    The theme of the Conference was man-machine collaboration in space. Topics addressed include: redundant manipulators; man-machine systems; telerobot architecture; remote sensing and planning; navigation; neural networks; fundamental AI research; and reasoning under uncertainty

    International Workshop on MicroFactories (IWMF 2012): 17th-20th June 2012 Tampere Hall Tampere, Finland

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    This Workshop provides a forum for researchers and practitioners in industry working on the diverse issues of micro and desktop factories, as well as technologies and processes applicable for micro and desktop factories. Micro and desktop factories decrease the need of factory floor space, and reduce energy consumption and improve material and resource utilization thus strongly supporting the new sustainable manufacturing paradigm. They can be seen also as a proper solution to point-of-need manufacturing of customized and personalized products near the point of need

    Topology Optimization Design of Monolithic 3D Printed Compliant Mechanisms for Bio-Inspired Actuation Systems of FWMAVs

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    L'obiettivo principale della presente tesi è esplorare la capacità di un approccio di progettazione combinato che sfrutta contemporaneamente i vantaggi dell'analisi FEM, dei meccanismi flessibili, dell'ottimizzazione topologica e delle tecnologie di stampa 3D. Oggigiorno la continua ricerca di prodotti più leggeri e semplici è diffusa in ogni realtà industriale che mira a mantenere la competitività. Allo stesso tempo, sebbene la riduzione del numero di componenti di un prodotto sia un obiettivo auspicabile, anche la complessità dei design tende a crescere costantemente.In questo contesto, diventa significativa l'implementazione di un processo di progettazione atto a combinare diversi strumenti ingegneristici, al fine di soddisfare tutte le specifiche di prodotto richieste e di sviluppare prodotti innovativi con migliori prestazioni. In particolare, questa ricerca mira a evidenziare le criticità e le potenzialità dell'implementazione di meccanismi flessibili tramite ottimizzazione topologica nello sviluppo di strutture monocomponente stampabili in 3D per l'attuazione di Flapping Wing Micro Air Vehicles (FWMAV) bio-ispirati. Alla ricerca di un approccio moderno alla progettazione, i suddetti strumenti ingegneristici sono stati integrati con l’efficacia delle soluzioni offerte dalla natura, sfruttando l’idea di reingegnerizzare la flessibilità naturale insita nelle strutture biologiche.È stata presa in considerazione anche l'opportunità di personalizzare il design, in modo da fornire una potenziale fonte di ispirazione per una diversa gamma di applicazioni.The main focus of the present dissertation is to explore the capability of a combined design approach that exploits at once the advantages of FEM analysis, Compliant Mechanisms, Topology Optimization and 3D Printing Technologies. Nowadays the continuous pursuit of lighter and simpler products is widespread in any industrial company aiming to maintain competitivity. At the same time, while part-count reduction of an item is a desirable target, also the complexity of designs tends to be ever-growing.In this context, the implementation of a design process suitable to combine different engineering tools becomes significant, in order to fulfill all the required product specifications and to develop innovative products with increased performances. In particular, this research aims to highlight the critical issues and the potentialities of implementing topology optimized Compliant Mechanisms in the development of monolithic 3D printable structures for the actuation of bio-inspired Flapping Wing Micro Air Vehicles (FWMAVs). Seeking a modern approach to design, the aforementioned engineering design tools were integrated with the effectiveness of solutions offered by nature, exploiting the idea of re-engineering the natural flexibility inherent in biological structures.The opportunity of tailoring the design was taken into account too, in order to provide a potential source of inspiration for a different range of applications

    Bidirectional Neural Interface Circuits with On-Chip Stimulation Artifact Reduction Schemes

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    Bidirectional neural interfaces are tools designed to “communicate” with the brain via recording and modulation of neuronal activity. The bidirectional interface systems have been adopted for many applications. Neuroscientists employ them to map neuronal circuits through precise stimulation and recording. Medical doctors deploy them as adaptable medical devices which control therapeutic stimulation parameters based on monitoring real-time neural activity. Brain-machine-interface (BMI) researchers use neural interfaces to bypass the nervous system and directly control neuroprosthetics or brain-computer-interface (BCI) spellers. In bidirectional interfaces, the implantable transducers as well as the corresponding electronic circuits and systems face several challenges. A high channel count, low power consumption, and reduced system size are desirable for potential chronic deployment and wider applicability. Moreover, a neural interface designed for robust closed-loop operation requires the mitigation of stimulation artifacts which corrupt the recorded signals. This dissertation introduces several techniques targeting low power consumption, small size, and reduction of stimulation artifacts. These techniques are implemented for extracellular electrophysiological recording and two stimulation modalities: direct current stimulation for closed-loop control of seizure detection/quench and optical stimulation for optogenetic studies. While the two modalities differ in their mechanisms, hardware implementation, and applications, they share many crucial system-level challenges. The first method aims at solving the critical issue of stimulation artifacts saturating the preamplifier in the recording front-end. To prevent saturation, a novel mixed-signal stimulation artifact cancellation circuit is devised to subtract the artifact before amplification and maintain the standard input range of a power-hungry preamplifier. Additional novel techniques have been also implemented to lower the noise and power consumption. A common average referencing (CAR) front-end circuit eliminates the cross-channel common mode noise by averaging and subtracting it in analog domain. A range-adapting SAR ADC saves additional power by eliminating unnecessary conversion cycles when the input signal is small. Measurements of an integrated circuit (IC) prototype demonstrate the attenuation of stimulation artifacts by up to 42 dB and cross-channel noise suppression by up to 39.8 dB. The power consumption per channel is maintained at 330 nW, while the area per channel is only 0.17 mm2. The second system implements a compact headstage for closed-loop optogenetic stimulation and electrophysiological recording. This design targets a miniaturized form factor, high channel count, and high-precision stimulation control suitable for rodent in-vivo optogenetic studies. Monolithically integrated optoelectrodes (which include 12 µLEDs for optical stimulation and 12 electrical recording sites) are combined with an off-the-shelf recording IC and a custom-designed high-precision LED driver. 32 recording and 12 stimulation channels can be individually accessed and controlled on a small headstage with dimensions of 2.16 x 2.38 x 0.35 cm and mass of 1.9 g. A third system prototype improves the optogenetic headstage prototype by furthering system integration and improving power efficiency facilitating wireless operation. The custom application-specific integrated circuit (ASIC) combines recording and stimulation channels with a power management unit, allowing the system to be powered by an ultra-light Li-ion battery. Additionally, the µLED drivers include a high-resolution arbitrary waveform generation mode for shaping of µLED current pulses to preemptively reduce artifacts. A prototype IC occupies 7.66 mm2, consumes 3.04 mW under typical operating conditions, and the optical pulse shaping scheme can attenuate stimulation artifacts by up to 3x with a Gaussian-rise pulse rise time under 1 ms.PHDElectrical EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttps://deepblue.lib.umich.edu/bitstream/2027.42/147674/1/mendrela_1.pd
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