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Ma, H. (author), Zhao, Qile (author), Verhagen, S. (author), Psychas, D.V. (author), Dun, H. (author)This contribution implements the Kriging interpolation in predicting the tropospheric wet delays using global navigation satellite system networks. The predicted tropospheric delays can be used in strengthening the precise point positioning models and numerical weather prediction models. In order to evaluate the performances of the Kriging...journal article 2020
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Pang, Menglin (author), Tiberius, C.C.J.M. (author)This paper presents an approach to analyse the quality, in terms of precision and reliability, of a system which integrates-at the observation-level-landmark positions and GNSS measurements, obtained with a single camera and a digital map, and a single frequency GNSS receiver respectively. We illustrate the analysis by means of design...journal article 2020
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Wang, Kan (author), Teunissen, P.J.G. (author), El-Mowafy, Ahmed (author)Ambiguity dilution of precision (ADOP) and position dilution of precision (PDOP) are two popular scalar-diagnostics used in Global Navigation Satellite System (GNSS) positioning. Where the ADOP is a predictor for carrier-phase ambiguity resolution performance, the PDOP is meant to predict the receiver-satellite geometry's capability for...journal article 2020
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Psychas, D.V. (author), Verhagen, S. (author), Teunissen, P.J.G. (author)A single-receiver integer ambiguity resolution-enabled precise point positioning (PPP-RTK) user experiences a long convergence time when the rather weak single-constellation dual-frequency ionosphere-float model is used. Nowadays, the rapid development of Global Navigation Satellite Systems (GNSS) provides a multitude of available satellites...journal article 2020
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Mazouz, Rayan (author)Autonomously landing a spacecraft on the surface of a planetary body with a degree of precision in the order of meters is highly challenging. Over the course of time, the landing ellipse, defined as the region with a 99% likelihood of where a space vehicle will land, has improved steadily but currently still has dimensions in the order of...master thesis 2019
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Hu, Xin (author)The suspended microchannel resonator is one of the most reliable devices for the mass measurement of biological and chemical specimens. Since it works in vacuum, the energy dissipation is decreased to the minimum. In this case, the instability related to the thermoelastic coupling effect has become a major source of uncertainty and a main...master thesis 2019
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Nagda, Neel (author)Stringent control demands from the high-tech mechatronics industry have warranted the need to explore potentially advantageous non-linear controllers. Variable Fractional Order (VFO) calculus provides one such avenue to build non-linear PID-like controllers. VFO calculus is the generalization of integer order differentiation and integration,...master thesis 2019
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Cai, Chengwei (author)The PID controller is one of the most used controllers in the industry. However, fundamental limitations due to linearity restrict its performances when higher bandwidth, stability, and precision are required simultaneously in today’s high-tech industry. Reset control is a promising nonlinear control strategy which can overcome these limitations...master thesis 2019
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Mao, X. (author)Precise absolute and relative orbit determination, referred to as Precise Orbit Determination (POD) and Precise Baseline Determination (PBD), are a prerequisite for the success of many Low Earth Orbit (LEO) satellite missions. With the spaceborne, high-quality, multi-channel, dual-frequency Global Positioning System (GPS) receivers, typically a...doctoral thesis 2019
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Jutte, Wouter (author)The application of actively controlled micrometer precision positioning stages in products that are accessible to start-ups, individual consumers or third world countries is currently limited by their price and size. To solve this problem, the use of low-cost and compact components in stages is investigated. Earlier research done in the MSD...master thesis 2019
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Gurumoorthy, Ramanathan (author)CryoSat-2 is a European Space Agency (ESA) altimeter mission with an objective to study the connection between cryosphere melting and global sea level rise. The satellite carries a Doppler navigation system (DORIS) and a Satellite Laser Ranging system (SLR) to aid the precise computation of orbits down to centimetre level.<br/>CNES/IDS releases...master thesis 2019
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Ssenyunzi, Richard Cliffe (author), Oruru, Bosco (author), D'ujanga, Florence Mutonyi (author), Realini, Eugenio (author), Barindelli, Stefano (author), Tagliaferro, Giulio (author), van de Giesen, N.C. (author)The Global Navigation Satellite System (GNSS) can be used to derive accurately the Zenith Tropospheric Delay (ZTD) under all-weather conditions. The derived ZTDs play a vital role in climate studies, weather forecasting and are operationally assimilated into numerical weather prediction models. In this study, variations and statistical...journal article 2019
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Increasing the load capacity of planar ferrofluid bearings by the addition of ferromagnetic materialBoots, A. S.T. (author), Krijgsman, L. E. (author), de Ruiter, B. J.M. (author), Lampaert, S.G.E. (author), Spronck, J.W. (author)Ferrofluid pocket bearings are a type of bearing that are able to carry a load using an air pocket encapsulated by a ferrofluid seal. Previously designed ferrofluid bearings show the great potential of the stick-slip-free and low viscous friction bearings, however until now the load capacity is limited. In this article a method is presented...journal article 2019
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Schut, I.M. (author), Pasma, J.H. (author), De Veij Mestdagh, J.C. (author), van der Kooij, H. (author), Schouten, A.C. (author)To unravel the underlying mechanisms of human balance control, system identification techniques are applied in combination with dedicated perturbations, like support surface translations. However, it remains unclear what the optimal amplitude and number of repetitions of the perturbation signal are. In this study we investigated the effect of...journal article 2019
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Akyiiz, Erdi (author), Saikumar, N. (author), Hassan HosseinNia, S. (author)The high tech industry which requires fast stable motion with nanometer precision continues to mainly use PID which is limited by fundamental linear control limitations. Floor vibrations as disturbance significantly affect performance and their rejection is particularly affected by these limitations. Reset control has provided a promising...journal article 2019
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Saikumar, N. (author), Sinha, Rahul Kumar (author), Hassan HosseinNia, S. (author)This paper presents a novel nonlinear (reset) disturbance observer for dynamic compensation of bounded nonlinearities like hysteresis in piezoelectric actuators. Proposed Resetting Disturbance Observer (RDOB) utilizes a novel Constant-gain Lead-phase (CgLp) element based on the concept of reset control. The fundamental limitations of linear...journal article 2019
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Mao, X. (author), Visser, P.N.A.M. (author), van den IJssel, J.A.A. (author)Precise orbit determination was investigated for a satellite constellation comprised of two different missions, the CHAllenging Minisatellite Payload (CHAMP) satellite and the Gravity Recovery And Climate Experiment (GRACE) twin satellites. The orbital planes of these two missions aligned closely during March to May 2005, allowing precise...journal article 2019
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Mao, X. (author), Visser, P.N.A.M. (author), van den IJssel, J.A.A. (author)Baseline determination for the European Space Agency Swarm magnetic field mission is investigated. Swarm consists of three identical satellites -A, -B and -C. The Swarm-A and -C form a pendulum formation whose baseline length varies between about 30 and 180 km. Swarm-B flies in a higher orbit, causing its orbital plane to slowly rotate with...journal article 2019
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Mohammadi, Majid (author)Ontology alignment systems are evaluated by various performance scores, which are usually computed by a ratio related directly to the frequency of the true positives. However, such ratios provide little information regarding the uncertainty of the overall performance of the corresponding systems. The comparison is also drawn merely by the...journal article 2019
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Saikumar, N. (author), Sinha, Rahul Kumar (author), Hassan HosseinNia, S. (author)This paper presents a novel 'Constant in gain Lead in phase' (CgLp) element using nonlinear reset technique. PID is the industrial workhorse even to this day in high-tech precision positioning applications. However, Bode's gain phase relationship and waterbed effect fundamentally limit performance of PID and other linear controllers. This...journal article 2019