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van Meer, M. (author), Deniz, E. (author), Witvoet, G. (author), Oomen, T. (author)Sensors in high-precision mechatronic systems require accurate calibration, which is achieved using test beds that, in turn, require even more accurate calibration. The aim of this paper is to develop a cascaded calibration method for position sensors of mechatronic systems while taking into account the variance of the calibration model of the...conference paper 2023
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van Dael, M. (author), Witvoet, G. (author), Swinkels, B. (author), Pinto, M. (author), Casanueva, J. (author), Bersanetti, D. (author), Mantovani, M. (author), Vardaro, M. (author), Oomen, T. (author)Gravitational Wave detectors require feedback control to control the length between the sensitive components of the detector. The degrees of freedom in the control system are inherently coupled and the level of interaction furthermore varies over time. A systematic control design approach for the feedback controllers is presented which provides...article 2022
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van Meer, M. (author), Witvoet, G. (author), Oomen, T. (author)Switched reluctance motors are appealing because they are inexpensive in both construction and maintenance. The aim of this paper is to develop a commutation function that linearizes the nonlinear motor dynamics in such a way that the torque ripple is reduced. To this end, a convex optimization problem is posed that directly penalizes torque...article 2022
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Mooren, N. (author), Witvoet, G. (author), Oomen, T. (author)Repetitive control enables the exact compensation of periodic disturbances if the internal model is appropriately selected. The aim of this paper is to develop a novel synthesis technique for repetitive control (RC) based on a new more general internal model. By employing a Gaussian process internal model, asymptotic rejection is obtained for a...article 2022
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Kuiper, S. (author), Bos, A. (author), de Vreugd, J. (author), Witvoet, G. (author), Dekker, A. (author), Kamphues, F.G. (author), Slegtenhorst, G.F. (author), Jonker, W.A. (author), Maniscalco, M.P. (author), Femenía-Castella, B. (author), Núñez Cagigal, M. (author), Bienes Pérez, J. (author), Cózar-Castellano, J. (author), González-Cava, J.M. (author), Mato, A. (author), Soler Trujillo, A.M. (author), Vega Reyes, N. (author)This paper describes the preliminary design of the Adaptive Secondary Mirror (ASM) for the European Solar Telescope (EST), as designed by TNO. This ASM will contain 1950 actuators over an optical aperture of Ø80cm. The mirror-shell of this ASM is concave with a radius of 2.156m and has a thickness of 2.5mm. To cope with the high optical heat...conference paper 2022
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Dirks, B.P.F. (author), Ferrario, I. (author), Le Pera, A. (author), Vito Finocchiaro, D. (author), Desmons, M. (author), de Lange, T.J. (author), de Man, H. (author), Meskers, A.J.H. (author), Morits, J.P.J. (author), Neumann, N.M.P. (author), Saathof, R. (author), Witvoet, G. (author)Due to the distance limitation of quantum communication via ground-based fibre networks, space-based quantum key distribution (QKD) is a viable solution to extend such networks over continental and, ultimately, over global distances. Compared to Low Earth Orbits (LEO), QKD from a Geostationary Orbit (GEO) offers substantial advantages, such as...conference paper 2021
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Saathof, R. (author), Meskers, A.J.H. (author), van Kempen, F.C.M. (author), Witvoet, G. (author), Korevaar, C.W. (author), de Lange, T.J. (author), Crowcombe, E.E. (author), Fritz, E.C. (author), van de Pol, M. (author)Optical satellite communications is a maturing technology to enable word-wide access to high throughput internet. In the past years a lot of effort has been taken to increase the applicability and the TRL of this technology. In collaboration with industry, TNO initiated several developments for space and ground technologies. Many of these...conference paper 2021
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Herfst, R.W. (author), van Es, M.H (author), Kuiper, S. (author), Witvoet, G. (author), Peters, J. (author), Willekers, R.W. (author)In semiconductor manufacturing, the shrink following Moore's law requires ever tighter overlay and registration between the different (material) layers. For accurately characterising this overlay and registration, TNO has developed a large dynamic range atomic force microscope demonstrator; the LDR-AFM can measure marker-to-feature distances...article 2020
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Kramer, L. (author), Peters, J. (author), Voorhoeve, R.J. (author), Witvoet, G. (author), Kuiper, S. (author)The demand for higher data transfer between satellites and ground stations is ever increasing. To address this, (free-space) optical communication (OC) technology is emerging. Pointing mechanisms with low size, weight and power (SWaP), high accuracy and low recurring costs are key enablers for constellations of OC systems. In this paper, TNO...conference paper 2020
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Mooren, N. (author), Witvoet, G. (author), Oomen, T. (author)Feedforward control is essential in highperformance motion control. The aim of this paper is to develop a unified framework for automatic feedforward optimization from both batch-wise data sets as well as real-time data. A statistical analysis is employed to analyze the effect of noise, i.e., an iteration varying disturbance, on feedforward...conference paper 2019
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de Lange, T.J. (author), de Man, H. (author), de Bruijn, D. (author), Hazelebach, R.L.M. (author), Rijnbeek, R.A. (author), Baeten, M.J.J. (author), Silvestri, F. (author), Human, J.D. (author), Witvoet, G. (author), Crowcombe, W.E. (author)LEOCAT is an optical head for intersatellite communication currently under development by TNO (ESA ARTES contract). The objective of LEOCAT is to develop a low recurring cost low SWAP (Size Weight and Power) optical head for the optical satellite communication constellation market. The aim of LEOCAT is to achieve a data-rate of 10Gbit/s over a...other 2019
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Kuiper, S. (author), Kramer, L. (author), Dekker, B. (author), Nieuwkoop, E. (author), Witvoet, G. (author), Human, J.D. (author), Lemmen, M.H.J. (author), Crowcombe, W.E. (author)TNO’s FSM technology is based on a unique electromagnetic actuator. The key benefits of this technology for are: Large range; ±2˚ optical range (both axis) - High band width: Closed loop bandwidth > 1kHz - Highly compact; ø27x30mm with ø20mm mirror - Reliable; Redundant windings, no wear, Passed life-time testing.other 2019
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Witvoet, G. (author), Peters, J. (author), Kuiper, S. (author), Oomen, T. (author)The overlay performance between different layers of semiconductor devices is a key parameter for correct functionality of such devices. With device features getting increasingly smaller, there is a need for novel and more accurate overlay metrology tools. This paper aims to increase the positioning accuracy of such a novel metrology machine...conference paper 2019
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Witvoet, G. (author), Peters, J. (author), Kuiper, S. (author), Keyvani, S. (author), Willekers, R.W. (author)TNO is developing a novel Large Dynamic Range Atomic Force Microscope (LDR-AFM), primarily but not exclusively designed for sub-nm accurate overlay metrology. The LDR-AFM combines an AFM with a 6 degrees- of-freedom interferometric positioning stage, thereby enabling measurements of sub-nm features on a wafer over multiple millimeters marker-to...conference paper 2019
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Fritz, E.C. (author), van der Valk, N.C.J. (author), Witvoet, G. (author), Bos, A. (author), de Man, H. (author), Crowcombe, W.E. (author), van der Heijden, N. (author), Kerkhof, P.J. (author)Cube satellite (cubesat) is a specific realization of a smallsat that is characterized by its volume changing in increments of 1dm3, or 1U. A (popular) 3U format cubesat is furthermore classified as a Nano satellite, as it typically has a mass between 1 and 10 kg. Within CubeSATs expanding the downlink data bandwidth is one of the central...other 2019
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Kramer, L. (author), van den Dool, T.C. (author), Witvoet, G. (author)Abstract: High throughput qualification of semiconductor devices is needed to improve cost efficiency. This paper describes a nano-precision capable, multi-agent, flexible positioning platform, which can be used to increase (metrology) throughput in semiconductor industry by parallelization of measurements. It is based on magnetic levitation and...conference paper 2019
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Dresscher, M. (author), Human, J.D. (author), Witvoet, G. (author), van der Heiden, N. (author), den Breeje, R. (author), Kuiper, S. (author), Fritz, E.C. (author), Korevaar, C.W. (author), van der Valk, N.C.J. (author), de Lange, T.J. (author), Saathof, R. (author), Doelman, N.J. (author), Crowcombe, W.E. (author), Duque, C.M. (author), de Man, H. (author)The anticipated capacity benefit of optical satellite communications has triggered a cascade of technology developments. In this paper, we present three such technologies, namely; i). A cube satellite laser terminal (CubeCAT), ii). A lower Earth orbit satellite optical head (LEOCAT) and iii). A calibration and verification test bench for coarse...conference paper 2019
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Peters, J. (author), Herfst, R.W. (author), Witvoet, G. (author), Kuiper, S. (author), van Es, M.H. (author), Willekers, R.W. (author)TNO developed a novel Large Dynamic Range Atomic Force Microscope (LDRAFM), designed for sub-nm accurate metrology. The current work provides an overview of recent developments and presents the results obtained after final integration of the complete system. Results indicate impressive stability over long range, enabling subnm metrology...other 2019
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Kramer, L. (author), van den Dool, T.C. (author), Witvoet, G. (author)A nano-precision-capable, multi-agent, flexible positioning platform can be used to increase (metrology) throughput in semiconductor industry by parallelisation of measurements. It is based on magnetic levitation (MagLev) and 6-DoF control, combining large x- and y-motions with sub-nanometer scanning resolution in a single stage. The system...article 2019
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Witvoet, G. (author), Kuiper, S. (author), Meskers, A.J.H. (author)This paper presents the first test results of a novel Fine Steering Mirror (FSM) for optical communication terminals. The FSM utilizes efficient variable reluctance actuators, tailored for the specific application, making it highly compact and power efficient. The test results demonstrate a high dynamical performance of <1.7kHz closed-loop...conference paper 2018