Energy networking in Light-based IoT: Design, implementation, and experimental validation

In this tutorial we highlight the optimal working methodology for discovering novel heterogeneous catalysts using modern tools. First, we give a structure to the discovery and optimisation process, explaining its iterative nature. Then, we focus in turn on each step of catalyst synthesis, catalysts testing, integrating low-level and high-level descriptor models into the workflow, and explorative data analysis. Finally, we explain the importance of experimental and model validation, and show how by combining experimental design, descriptor modelling, and experimental validation you can increase the chances of discovering and optimising good catalysts. The basic principles are illustrated with four concrete examples: oxidative methane coupling; catalytic hydrogenation of 5-ethoxymethylfurfural; optimising bimetallic catalysts in a continuous reactor system, and linking material properties to chemisorption energies for a variety of catalysts. Based on the above examples and principles, we then return to the general case, and discuss the application of data-driven workflows in catalyst discovery and optimisation.

Achieving uniform intensity distribution is essential for various laser applications such as material processing. This paper presents the design, simulation, and experimental validation of a segmented beam-shaping integrator mirror aimed at transforming an incident laser beam into a uniform line-shaped spot. The mirror surface is composed of multiple connected parabolic segments. A geometric optics computational method, implemented using Python code, was developed to determine the unique parameters and boundaries for each segment, based on input specifications including the working distance (f), the input aperture size (D), the target spot size (d), and the number of segments (s). For a design case with D=49.5mm, f=350mm, d=20mm, and s=7, the segment parameters were calculated. The calculated design was modeled in SolidWorks, and its performance was simulated using Zemax ray tracing, predicting a shaped spot closely matching the 20mm target size in the segmented direction and an expected size (approx. 1.4mm) in the orthogonal direction. Experimental validation was conducted using a 4kW fiber laser equipped with a fiber core diameter of 400µm and a numerical aperture of 0.15, along with a collimating lens with a 100mm focal length. The measured spot size at the target plane was 20.39mm×1.41mm (1/e2 width), showing excellent agreement with both the design specification and the simulation results. This work successfully demonstrates the effectiveness of the integrator mirror design method and fabrication process for creating high-performance beam-shaping integrator optics for high-power laser systems.

Vertical Take-Off and Landing Urban Aerial Mobility vehicle propulsion systems use rotors and blades to achieve lift, which results in heightened noise at the blade passing frequency. These frequencies must be attenuated to reduce cabin discomfort and comply with noise exposure limits. The design must absorb 350 Hz noise, be fire retardant to comply with aviation standards, and be maximally one inch thick. This paper outlines the design, computational simulation, and experimental validation of a novel aerospace-grade acoustic metamaterial. It contributes to the field of computational analysis of new metamaterial structures and experimental validation using prototype Helmholtz unit cells. Achieving maximum sound absorption with the aerospace requirements of minimal mass and fire safety led to the consideration of Nomex honeycomb Helmholtz resonator acoustic panels. Their sub-wavelength attenuation, tunability, lightweight and fire resistance make them an optimal fit for this application. A novel phenomenon was observed in experimental impedance tube testing where multiple Nomex honeycomb cells acted as one resonator cavity. This discovery allowed for samples of only one inch in thickness (cell depth) to achieve 83% sound absorption at 348 Hz. Experimental values match well with the calculated analytical solution using the Helmholtz equation and simulated sound absorption in COMSOL MultiPhysics. The acoustic metamaterial achieves tunable noise attenuation with minimal thickness, weight, and fire suppression using a novel design.

We present FAST-Hex, a micro aerial hexarotor platform that allows to seamlessly transit from an under-actuated to a fully-actuated configuration with only one additional control input, a motor that synchronously tilts all propellers. The FAST-Hex adapts its configuration between the more efficient but under-actuated, collinear multi-rotors and the less efficient, but full-pose-tracking, which is attained by non-collinear multi-rotors. On the basis of prior work on minimal input configurable micro aerial vehicle we mainly stress three aspects: mechanical design, motion control and experimental validation. Specifically, we present the lightweight mechanical structure of the FAST-Hex that allows it to only use one additional input to achieve configurability and full actuation in a vast state space. The motion controller receives as input any reference pose in $\mathbb{R}^3\times \mathrm{SO}(3)$ (3D position + 3D orientation). Full pose tracking is achieved if the reference pose is feasible with respect to actuator constraints. In case of unfeasibility a new feasible desired trajectory is generated online giving priority to the position tracking over the orientation tracking. Finally we present a large set of experimental results shading light on all aspects of the control and pose tracking of FAST-Hex.

Design and experimental validation of a disturbing force application unit for simulating spacecraft separation

Motivation: Synthetic biology studies how to design and construct biological systems with functions that do not exist in nature. Biochemical networks, although easier to control, have been used less frequently than genetic networks as a base to build a synthetic system. To date, no clear engineering principles exist to design such cell-free biochemical networks.Results: We describe a methodology for the construction of synthetic biochemical networks based on three main steps: design, simulation and experimental validation. We developed BioNetCAD to help users to go through these steps. BioNetCAD allows designing abstract networks that can be implemented thanks to CompuBioTicDB, a database of parts for synthetic biology. BioNetCAD enables also simulations with the HSim software and the classical Ordinary Differential Equations (ODE). We demonstrate with a case study that BioNetCAD can rationalize and reduce further experimental validation during the construction of a biochemical network.Availability and implementation: BioNetCAD is freely available at http://www.sysdiag.cnrs.fr/BioNetCAD. It is implemented in Java and supported on MS Windows. CompuBioTicDB is freely accessible at http://compubiotic.sysdiag.cnrs.fr/Contact: stephanie.rialle@sysdiag.cnrs.fr; franck.molina@sysdiag.cnrs.frSupplementary information: Supplementary data are available at Bioinformatics online.

This paper deals with the transfer of data by Power-Line Communication (PLC) on a Pulse Width Modulated (PWM) energy network. Target applications concern the adjustable speed drive for industrial infrastructures. In order to implement an efficient communication solution, it is necessary to have a model of the communication channel to determine certain parameters like bandwidth, carrier frequency and modulation formats. The originality of our work is the methodology used to determine the channel model. The first results of simulation and experimental validation are presented in this paper.

This paper presents a route-optimized drive mode switching control method for plug-in hybrid vehicles (PHVs) and its experimental validation. The research objective is to reduce fuel usage in situations where energy consumption along a route is probabilistically estimated from historical driving data. To address this, this study develops a driving-route model based on road grades and vehicle speed distributions with terrain maps and driving profiles. The driving-route model allows us to predict fuel and electricity demands on the planned route by applying energy consumption maps relating to drive modes of a PHV on the market. Moreover, the driving-route model can be shared among any PHVs, even if the powertrain properties differ. These models are leading to formulate an integer linear programming problem deciding the drive modes for reducing fuel consumption. In addition, this paper introduces an experimental system to show the proposed approach is applicable to the actual PHV. The experimental validation on the PHV indicates that this method can improve fuel efficiency compared with that of a conventional method.

In this paper, we present the functional design and experimental validation of network coding technology over hybrid networks including satellite links. We first describe our design framework based on a holistic modelling of (overlay) heterogeneous networking satellite scenarios. We then define different types of logical nodes depending on their encoding, re-encoding and decoding functionalities and whether or not the satellite (overlay) application designer has control over them. Nodes are assumed strategically chosen to recode, which may result in a small number of re-encoding nodes that suffice to optimize selected performance metrics. Our main contribution is a system-oriented functional design of network coding that enables flexible instantiation of different types of network codes via configurable network coding (C-NC) functions. Random or structured NC coefficients can be remotely or locally generated and a packet scheduler can forward packets according to different policies. The choice of coefficients and overall NC scheme depend on the SATCOM-specific performance target, namely delay or bandwidth constraints. Here, we present a preliminary design and experimental testebed validation for the case of delay constrained transmission. Our results show the practical benefits of re-encoding and performance tradeoffs of different network coding schemes. In particular, our results show the good structural properties and delay-reliability tradeoffs of our novel proposal of structured network codes using Pascal matrices due to the regenerative properties of the coding coefficients.

International audience

This paper provides, through both numerical analyses and physical tests, a validation of the optimality of structural designs obtained from a topology optimization process. Issues related to the manufacturability of the topology-optimized design are first addressed in order to develop structural specimens suitable for experimental validation. Multidomain and multistep topology optimization techniques are introduced that, by embedding the designer’s intuition and experience into the design process, allow for the simplification of the design layout and thus for a better manufacturability of the design. A boundary identification method is also proposed that is applied to produce a smooth boundary for the design. An STL (STereo Lithography) file is then generated and used as input to a rapid prototyping machine, and physical specimens are fabricated for the experiments. Finally, the experimental measurements are compared with the theoretical and numerical predictions. Results agree extremely well for the example problems considered, and thus the optimum designs pass both virtual and physical tests. It is also shown that the optimum design obtained from topology optimization can be independent of the material used and the dimensions assumed for the structural design problem. This important feature extends the applicability of a single optimum design to a range of different designs of various sizes, and it simplifies the prototyping and experimental validation since small, inexpensive prototypes can be utilized. This could result in significant cost savings when carrying out proof-of-concept in the product development process.

The automotive industry continually seeks innovative methods to reduce vehicle weight, enhance efficiency, and maintain structural integrity. This study presents a detailed framework that combines topology optimization (TO) and experimental validation, applied specifically to the design of a brake pedal for a Baja competition vehicle. The research involves a multi-step process, starting with finite element modeling, followed by TO using ANSYS Workbench to optimize the pedal's material distribution for weight reduction. Post-processing in Siemens NX is then performed to incorporate manufacturing constraints, ensuring the design is suitable for water jet cutting. The optimized brake pedal, constructed from 7075-T6 aluminum, weighs 42.6 g and demonstrates stress levels well below the yield strength of the material. Dimensions were determined based on the available space within the vehicle to ensure that the brake pedal would not interfere with any vehicle structure and would not impede the driver during operation. These considerations ensured that the pedal’s design maximized comfort and safety for the driver. Experimental validation is conducted through force and strain measurements, resulting in a 3.5% discrepancy between simulated and experimental stress values. Over 50 hours of track testing, including extensive on-road competition use, confirms the robustness and practical viability of the optimized design. This work underscores the potential of TO as a powerful tool for lightweight component design, demonstrating its integration with real-world testing and the ability to enhance the manufacturability of critical automotive components. The framework presented here not only validates the design process for brake pedals but also offers a versatile approach applicable to other vehicle components, contributing to the broader goal of optimizing automotive performance through lightweight designs.

Sector coupling and energy sharing are key elements in effectively decarbonising the thermal grid. 5th Generation District Heating and Cooling (5GDHC) provides a system for combining heating and cooling via an ambient temperature network. A main design challenge for 5GDHC is establishing a control regime that allows flow bidirectionality and energy synergies between heating and cooling. This work develops and experimentally validates a 5GDHC system wide hydraulic design and two fitting control strategies on a small scale. One has fixed grid return temperatures (TGridFix) while the other free floating grid temperatures (TGridFloat). Both feature decentralised variable speed pumping and a centralised passive balancing unit aimed at alleviating control instabilities arising from pump hunting. Experiments showed that TGridFix demonstrates slightly higher electrical consumption for the booster heat pump (Seasonal Coefficient of Performance of 3.84 compared to 4.16 for 20 h of operation) due to a mismatch between the evaporator and the grid temperature difference. Overall, TGridFix can lead to low prosumer interaction and better system wide predictability. Further considerations on generalisability of findings and full-scale implementations are highlighted. This works presents a set of detailed and experimentally validated control philosophies for 5GDHC systems, elucidating a key system implementation challenge.

We present experimental realization and validation of the six-port design of integrating sphere photometers for total luminous flux measurement, which significantly improves the uniformity of spatial response compared to the conventional single-port design. Construction, measurement procedure, and data acquisition of the realized instrument with a radius of 1m are described. Measurement of the spatial response distribution function confirms the expected effect of improving the uniformity by averaging the signals from the six detection ports. The related spatial mismatch error is determined to be less than 1.4% for all the realistic cases of beam angles and directions of a test lamp mounted in the vicinity of the sphere center. As a result, we confirm that the realized six-port instrument allows us to eliminate the complicated spatial mismatch correction procedure by adding a relative standard uncertainty of only 1.4/3%≈0.81%, which offers a great practical benefit for testing solid-state lighting products of various beam characteristics.

UD-WCMA: An energy estimation and forecast scheme for solar powered wireless sensor networks