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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Toward Deployable Origami Continuum Robot: Sensing, Planning, and Actuation

Santoso, Junius 14 November 2019 (has links)
Continuum manipulators which are robot limbs inspired by trunks, snakes, and tentacles, represent a promising field in robotic manipulation research. They are well known for their compliance, as they can conform to the shape of objects they interact with. Furthermore, they also benefit from improved dexterity and reduced weight compared to traditional rigid manipulators. The current state of the art continuum robots typically consists of a bulky pneumatic or tendon-driven actuation system at the base, hindering their scalability. Additionally, they tend to sag due to their own weight and are weak in the torsional direction, limiting their performance under external load. This work presents an origami-inspired cable-driven continuum manipulator module that offers low-cost, light-weight, and is inherently safe for human-robot interaction. This dissertation includes contributions in the design of the modular and torsionally strong continuum robot, the motion planning and control of the system, and finally the embedded sensing to close the loop providing robust feedback.
2

Toward Deployable Origami Continuum Robot: Sensing, Planning, and Actuation

Santoso, Junius 24 October 2019 (has links)
Continuum manipulators which are robot limbs inspired by trunks, snakes, and tentacles, represent a promising field in robotic manipulation research. They are well known for their compliance, as they can conform to the shape of objects they interact with. Furthermore, they also benefit from improved dexterity and reduced weight compared to traditional rigid manipulators. The current state of the art continuum robots typically consists of a bulky pneumatic or tendon-driven actuation system at the base, hindering their scalability. Additionally, they tend to sag due to their own weight and are weak in the torsional direction, limiting their performance under external load. This work presents an origami-inspired cable-driven continuum manipulator module that offers low-cost, light-weight, and is inherently safe for human-robot interaction. This dissertation includes contributions in the design of the modular and torsionally strong continuum robot, the motion planning and control of the system, and finally the embedded sensing to close the loop providing robust feedback.
3

STUDY AND IMPLEMENTATION OF 'FOLLOW THE LEADER'

CHANDAK, PRAVIN B. January 2002 (has links)
No description available.
4

High frequency CMOS integrated filters for computer hard disk drive and wireless communication systems

Zhu, Xi January 2008 (has links)
Operational transconductance amplifier and capacitor (OTA-C) filters have outstood among different types of filter due to high frequency and low power capabilities in the main stream digital CMOS technology. They have been widely used in computer hard disk drive (HDD) and wireless communication transceivers. OTA-C filters based on cascade and passive ladder simulation are well-known. However, multiple loop feedback (MLF) OTA-C filters which have certain advantages still have the scope for further research. So far there have been no explicit formulas for current-mode leapfrog (LF) filter design and performance evaluation of current-mode MLF OTA-C filters are still lacking. From application viewpoints, read channels for computer hard disk drives require very high frequency continuous-time filters. This automatically disqualifies active- RC/MOSFET-C filters and OTA-C filters become the only solution. In wireless communications, active-RC/MOSFET-C filters have been proved useful for mobile systems whose baseband frequency falls below a few MHz. However, for wireless LANs with the frequency of several tens of MHz, OTA-C filters are a strong candidate. Whilst in HDD read channels, cascaded OTA-C architectures have been most utilized and in wireless receivers, OTA-C structures based on ladder simulation have been popular, MLF OTA-C filters have not been practically used in either of the applications. This thesis describes some novel designs and applications of multiple loop feedback OTA-C filters with extensive CMOS simulations. Analogue filters for computer hard disk drive systems are first reviewed; the state of the art and design considerations are provided. Three VHF linear phase lowpass OTA-C filters are then designed, which include a seventh-order and a fifth-order current-mode filter based on the follow-the-leader-feedback (FLF) structure and a seventh-order voltage-mode filter using the inverse FLF (IFLF) configuration. These filters all have very low power consumption. The synthesis and design of general current-mode LF OTA-C filters are conducted next. Iterative design formulas for both all-pole and finite-zero functions are derived and explicit formulas for up to sixth-orders are given. These formulas are very easy to use for designing any type of characteristics. Subsequently, linear phase lowpass OTA-C filter design for HDD read channels using LF structures are investigated in details. A current-mode filter and a voltage-mode filter using the fifth-order LF structure are presented. The two filters can operate up to 800MHz and have very small passband phase ripple. Analogue filters for wireless communication baseband applications are also reviewed thoroughly in this thesis, where the design of a fourth-order current-mode FLF Butterworth lowpass OTA-C filter for multi-standard receivers is presented. Then two fifth-order current-mode elliptic lowpass OTA-C filters based on respective LF and FLF structures for wireless communication baseband are designed. Fifth-order voltage-mode IFLF and LF elliptic lowpass filters are also presented. All these MLF baseband filters designed can operate up to 40MHz to cover all important wireless and mobile standards. Simulations show that the LF structures have better dynamic range and stopband attenuation performances than the FLF and IFLF configurations.
5

Vícefunkční přeladitelný aktivní filtr. / Multifunctional tuned active filter

Šotner, Roman January 2008 (has links)
The diploma thesis deals about design of the ARC multifunctional filters using modern functional blocks. These active blocks are for example voltage feedback operational amplifiers (OAs), operational transconductance amplifiers (OTAs), current conveyors (CCIIs) or current mode analog multipliers, current feedback amplifiers (CFAs), integrated circuits with switched capacitors building blocks (SCs) and digital potentiometers. The filters are studied with ideal circuit models and models of third level (3) based on voltage controlled voltage sources, voltage controlled current sources etc. (analog behavioral modelling). The professional macromodels are used for example LT 1364 (Linear Technology), EL 2045 (Intersil), LT 1228 (Linear Technology), LM 13700 (National Semiconductor), EL 2082 (Intersil), AD 844 (Analog Devices) and others. The circuits of the designed filters are simulated in PSpice (OrCAD), parasite effects and effects of the real parts are studied. Tuning and electronic adjusting parameters these filters are discussed and controlled by simulation in PSpice. Properties some simulated circuits are compare with experimental results. In conclusion individual filters are discussed and compared their properties. The constructional details of the some filters are presented at the end of this work.
6

Conception de robots à tubes concentriques et application à l'inspection des cellules olfactives / Design of concentric tube robots and application to the inspection of the olfactory cells

Girerd, Cédric 30 January 2018 (has links)
Ces travaux de thèse s’inscrivent dans le cadre du projet ANR NEMRO, visant à étudier le lien entre déficience olfactive et maladies neurodégénératives. A cet effet, une biopsie optique de l’épithélium olfactif doit être réalisée. Son accès est cependant impossible, aujourd’hui, avec les outils conventionnels. Pour résoudre ce problème, nous proposons l’utilisation d’un robot à tubes concentriques (RTC). Sa synthèse est réalisée à partir d’images médicales. Elle prend en compte les critères de stabilité, la variabilité inter-sujet, et est associée à un déploiement ALFI (A La File Indienne). Le dispositif étant porté par le sujet, il doit être léger et compact. Une séquence de déploiement spécifique simplifie alors l’unité d’actionnement, et une implémentation est réalisée par fabrication additive multimatériaux. L’évaluation préliminaire d’un déploiement ALFI et des éléments de technologie clés a permis de valider l’approche retenue dans le projet NEMRO, ainsi que sa faisabilité. / This PhD thesis is part of the ANR NEMRO project, whose goal is to study the hypothetical correlation between olfactory deficiency and neurodegenerative diseases. For this purpose, an optical biopsy of the olfactory epithelium must be performed. However, this area is not accessible today with conventional tools. To go beyond this limitation, we propose to investigate the use a concentric tube robot (CTR). Its synthesis is performed from medical images. It takes into account the stability criteria, inter-subject variability, and is associated to a FTL (Follow-The-Leader) deployment. As the device is mounted on the subject, it has to be compact and lightweight. Thus, a specific deployment sequence simplifies the actuation unit, and an implementation is proposed using multimaterial additive manufacturing. Preliminary evaluations of the FTL deployment capabilities and the key components of the device allowed to validate the approach chosen for the NEMRO project, and its feasibility.
7

Elektronické filtrační obvody s obecnými kmitočtovými charakteristikami / Electronic Filtering Circuits with Arbitrary Frequency Characteristics

Klubus, Jan January 2020 (has links)
Master’s thesis deals with the issue of electronic filtering circuits with arbitrary frequency characteristics. First part of the thesis describes theoretical basis. Second part explores the possibilities of design procedures for filters with arbitrary frequency characteristics. Design procedures are demonstrated on examples accordingly to the presented methods, including their circuit implementation and computer simulation to verify the correctness of theoretical assumptions. Thesis also explores the possibilities of tuning circuit structures and electronic setting for characteristics using controllable active elements.

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