DSpace Repository

Welcome to the NLR Reports Repository

Royal NLR conducts research, which is published in reports. Only a minor part of these reports is made public. This repository holds these public, so called Technical Publications (TP), mainly produced from 1996 up till now.

Technical publications published before 1996 may be obtained using the request-form. Other types of NLR-reports are Contract Reports (CR) and Technical Reports (TR), which in general are not public. You may however request a copy by using the request-form. In some cases permission may be granted, depending on specific properties and contractor of the report. Reports will be supplied as pdf-file.

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Recent Submissions

Delivery from the sky : investigating visual cues to communicate robot intentions in simulated public spaces
(Nature, 2026) Lingam, S.N.; Petermeijer, S.M.; Obaid, M.; Martens, M.H.
As robots such as drones begin delivering packages from the sky in public spaces, humans will interact as recipients. Clear communication of a drone’s vertical motion and delivery intentions is essential to reduce feelings of uncertainty and build trust among the public. This study investigates how visual cues, including delivery methods and interfaces, communicate a drone’s drop-off and take-off intentions and affect recipients’ uncertainty in a simulated public environment. Through a video-based online questionnaire, 150 participants viewed scenarios where a drone delivered a package either by landing or via a cable-drop mechanism, each presented with or without visual interfaces such as onboard lights, a display, or ground projection. Participants rated the scenarios for uncertainty, understandability, predictability, trust, and convincingness, and provided qualitative feedback. Results show that visual interfaces improved participants’ ability to predict drone actions, increased certainty in approaching the drop-off spot, and improved trust. While lights posed challenges with visual clarity, both display and projection interfaces conveyed vertical motion and delivery intentions effectively. Projection was particularly recommended, as it marked the drop-off spot on the ground and a safety boundary. We discuss the implications of our findings beyond delivery scenarios, considering broader public space interactions with robots operating in vertical planes, and highlight the need for validation through real-world experiments.
Integrating Urban Air Mobility into smart cities : A proposal for relevant use cases in the next decades
(Emerald, 2024) Di Vito, V.; Dziugiel, B.; Melo, S.; Thije, J.T. ten; Duca, G.; Liberacki, A.; Hesselink, H.H.; Giannuzzi, M.; Menichino, A.; Montaquila, G.; Cerasuolo, G.; Witkowska-Koniecz, A.
Purpose Urban air mobility (UAM) development and deployment into future cities is gaining increasing and relevant interest in the past years. This study, a conceptual paper, aims to report the high-level description of the most relevant UAM application use cases (UCs) emerging from the research activities carried out in the ASSURED UAM project. Design/methodology/approach The UAM application UCs have been obtained from the ASSURED UAM project dedicated activities that have been carried out to, first, develop suitable operational concepts for UAM deployment in the next decades and, then, to further refine and design the most relevant UCs for UAM deployment in the next decades, leading to the public issue of dedicated overall document. Findings The ASSURED UAM UCs for UAM deployment in the next decades encompass both public (point-to-point, point-to-everywhere, direct medical transport of people) and private (direct last-mile delivery, advanced last-mile delivery, automatic personal aerial transportation) services applications, evolving in incremental way over time according to three considered time horizons (2025, 2030 and 2035), toward progressive integration into metropolitan transport system. Originality/value This paper provides final outline of the ASSURED UAM UCs, starting from the analysis of overall identified possible UAM applications, focusing on the description of the six main UCs considered as relevant for the application under the wider societal benefits point of view. The UCs are described in terms of expected operational environment, needed technological enablers and envisaged regulatory implications. Keywords Acknowledgements ASSURED UAM project has received funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 101006696. Citation Di Vito, V., Dziugiel, B., Melo, S., Ten Thije, J.T., Duca, G., Liberacki, A., Hesselink, H., Giannuzzi, M., Menichino, A., Montaquila, R.V., Cerasuolo, G. and Witkowska-Konieczny, A. (2024), "Integrating urban air mobility into smart cities: a proposal for relevant use cases in the next decades", Aircraft Engineering and Aerospace Technology, Vol. ahead-of-print No. ahead-of-print. https://doi.org/10.1108/AEAT-03-2024-0081
Fully thermoplastic honeycomb sandwich composites produced by fusion bonding
(Sage Journals, 2026) Vos, C.J. de; Erartsin, O.
A new method is proposed to create fully thermoplastic sandwich panels by fusing a cellular Polyetherimide (PEI) core with a polyaryletherketone (PAEK) facing through infrared heating of the skin followed by rapid pressing. The process eliminates the need for adhesives, reducing weight and cycle times while enhancing recyclability. The effects of processing temperature on core erosion, skin-core adhesion, and crystallinity of the PAEK matrix were investigated. Results show that higher temperatures lead to increased core erosion but also improve skin-core adhesion up to a certain point. The optimal processing temperature range was found to be around 310–320°C, where a balance between minimal core erosion and maximal adhesion strength is achieved. Flatwise tensile testing demonstrated that samples processed at 310–320°C exhibit both adhesive and core tensile failure modes, with higher strengths achieved at these temperatures. The method requires optimal tuning of the processing parameters and core geometry to achieve reliable and strong bonds between the core and skin. This research contributes to the development of sustainable manufacturing methods for thermoplastic sandwich structures, offering potential applications in aerospace and other industries where lightweight, high-performance materials are critical. Future work will focus on scaling up this technology and exploring its applicability to more complex geometries and material combinations.
Context-Aware Human Performance Measurement for Simulation-based Tactical Training
(NTSA, 2025) Oijen, J. van; Bellucci, T.; Oldenbeek, M. van
Modern military forces increasingly introduce simulation-based training to develop and sustain critical skills through procedure, tactical, or mission training in realistic threat environments. However, effectively assessing trainee performance remains a challenge. Most simulation systems include data recording, monitoring, or debrief/after-action review (AAR) tools to support trainee performance measurement and assessment. While these tools capture relevant data required for performance measurement, they often do not utilize this data for objective, actionable insights for human assessors, such as instructors. The usage of captured data is usually limited to basic visualizations or communication replays, leaving contextual interpretation and analysis concerning trainee task performance to the human assessor. In this paper, we present a lightweight measurement framework for real-time context-based performance analytics to support trainee assessment in simulation-based training. The framework supports three key features. First, it is based on the chaining of individual measures to create a network of progressively rich information, ranging from (1) ground-truth data to (2) task-specific performance metrics and (3) objective assessments. Second, it supports the contextual activation of measures such that measurements can be delivered in real-time at the right time, relevant to the current task, situation, or mission phase. Finally, we show how AI techniques, such as Deep Learning for behavioral recognition, Natural Language Processing for communication analysis, and rule-based methods for procedural evaluation, can enhance performance assessment. The outcome of measures can be visualized and delivered to human assessors by means of a dashboard, or fed into instructional systems for learner profile management. We evaluate the framework in a case study for fighter pilot training. Based on a use case scenario, we demonstrate how our framework enhances instructor capabilities by providing real-time, data-driven insights into pilot performance across key skill areas, including communication, tactical decision-making, and maneuvering.
Comparative Investigation of Radiation-Driven Failure Mechanisms in Photonic–Electronic Optical Communication Terminals Across Earth Orbits
(IEEE, 2026) Dijks, J.H.C.; Jong, S. de; Menicucci, A.; Akay, I.; Donkers, N.
Optical Communication Terminals (OCTs) integrate photonic and electronic technologies to enable high-speed, secure, and interference-free space communication. Deployment across multiple orbital regimes exposes these heterogeneous systems to diverse radiation environments, each presenting distinct failure mechanisms that challenge conventional Radiation Hardness Assurance (RHA) approaches, particularly for cost-constrained Small Satellite (SmallSat)-class missions where economic feasibility must be balanced against radiation hardness requirements. This paper presents a multi-orbit radiation effects investigation for photonic-electronic architectures by characterizing environment-specificvulnerabilities and failure modesacrossSun-SynchronousOrbit(SSO),LowEarthOrbit(LEO),andMiddleEarthOrbit(MEO). SPENVISbased environment analysis shows that SSO presents a mild radiation environment with Total Ionizing Dose (TID) below 1 krad(Silicon (Si)) per year at 4 mm Aluminium (Al) shielding and low charged particle flux. LEO is dominated by proton-induced Single Event Effects (SEEs) with moderate TID, and MEOexhibits TIDexceeding 30krad(Si) per year at the same shielding level, together with relatively higher heavy-ion fluxes that drive SEE rates. Technology-level analysis reveals fundamental differences between photonic and electronic subsystems. Photonics exhibits predominantly parametric degradation that can be mitigated through margin allocation, whereas electronics remains susceptible to discrete, stochastic failure modes requiring active mitigation. These findings motivate reconfigurable architectures leveraging Field Programmable Gate Arrays (FPGAs), radiation-tolerant photonic subsystems,Wide-Bandgap (WBG) power semiconductors, and emerging Non-Volatile Memories (NVMs) to enable component-level commonality across orbital regimes. Additionally, photonic devices require parametric end-of-life characterization with explicit translation to link budget margins, while electronic systems require mission-tailored mitigation strategies and system-level testing.