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International audience; As the number of actors in the electricity market increases, peer to peer decentralized markets gain interest despite facing two challenges. First, the amount of exchanged messages increase significantly, which makes the resolution dependent on communication delays, as well as computation delays. Second, the physical limitations of the power network are not taken into account. An asynchronous implementation of an endogenous peerto-peer market is here introduced to address these difficulties. The proposed algorithm is tested on a 31 agents testcase and a study of the influence of the various algorithm parameters on the convergence time is performed.

Multi-energy networks are becoming a leading research subject in the last years, particularly, with the accelerating emergence of renewable resources into the energetic system. Decoupling this problem into several single-vector networks results in a sub-optimal solution. However, this approach comes up against a great technological complexity, from the design of each of the components necessary for such a hybrid network to their modeling and the global management of the whole. In this work, we propose coupled electrical and thermal networks, with an energy hub integrating electrochemical and thermal storage systems, and conversion systems: Heat To Power and Power To Heat. To achieve this, a modeling of the different physical subsystems and a management of the whole system using Model Predictive Control (MPC) are investigated. Finally, a comparison of the two configurations without and with coupling is conducted to evaluate the impact of such a multi-energy network.

The long term goal of the Autonomous Robot Evolution (ARE) project is to create populations of physical robots, in which both the controllers and body plans are evolved. The transition of evolutionary designs from purely simulation environments into the real world creates the possibility for new types of system able to adapt to unknown and changing environments. In this paper, a system for creating robots is introduced in order to allow for their body plans to be designed algorithmically and physically instantiated using the previously introduced Robot Fabricator. This system consists of two types of components. Firstly, skeleton parts are created bespoke for each design by 3D printing, allowing the overall shape of the robot to include almost infinite variety. To allow for the shortcomings of 3D printing, the second type of component are organs which contain components such as motors and sensors, and can be attached to the skeleton to provide particular functions. Specific organ designs are presented, with discussion of the design challenges for evolutionary robotics in hardware. The Robot Fabricator is extended to allow for robots with joints, and some example body plans shown to demonstrate the diversity possible using this system of robot generation.

Advances in rapid prototyping have opened up new avenues of research within Evolutionary Robotics in which not only controllers but also the body plans (morphologies) of robots can evolve in real-time and real-space. However, this also introduces new challenges, in that robot models that can be instantiated from an encoding in simulation might not be manufacturable in practice (due to constraints associated with the 3D printing and/or automated assembly processes). We introduce a representation for evolving (wheeled) robots with a printed plastic skeleton, and evaluate three variants of a novelty-search algorithm in terms of their ability to produce populations of manufacturable but diverse robots. While the set of manufacturable robots discovered represent only a small fraction of the overall search space of all robots, all methods are shown to be capable of generating a diverse population of manufacturable robots that we conjecture is large enough to seed an evolving robotic ecosystem.

International audience; Peer-to-peer markets are a promising approach for integrating decentralized generation and prosumers into electricity markets. However, these markets require a very large number of messages to be exchanged in order to find a solution that respects the constraint of power balance in power systems. This study first establishes the shape of the compromise between communication costs and residual power imbalance resulting from a P2P market. Secondly alternative stopping criteria are proposed in order to reduce the cost of communication. The most effective approach is to ratify each trade independently using a threshold on its primary and dual residues, while continuing to negotiate the other trades. With the same residual imbalance, this stopping criterion results in a tenfold reduction of the number of messages exchanged on the basis of a Monte Carlo simulation. This reduction factor seems independent of the number of market participants.

A highly flexible and conformal 2×2 antenna array on room temperature vulcanized (RTV) silicone is presented. The patches are realized in the top layer consisting of copper clad polyimide. Three different ground planes (copper clad polyimide, copper mesh, and conductive polymer) were realized to determine their flexibility, conformability, and impact on RF performance. The reflection coefficient, boresight antenna gain, and radiation pattern are presented and compared with a reference antenna array on RTV silicone with copper clad polyimide for the top layer and ground plane. To prove its flexibility and conformability, a flat case and two curved cases are considered. The reflection coefficient, radiation pattern, and antenna gain are not very significantly affected when the antenna arrays are conformed.

Conformal antenna arrays are of significant interest for automotive and aerospace applications. Such arrays can be conformed to the surface of vehicles and aircraft while providing minimum impact on aerodynamics. However, the design and analysis of such antenna systems differs from the planar case. Also, beamforming and nulling for curved antenna arrays with directional elements requires modification of the beamforming and nulling algorithms. Here, a linear array of four elements is considered on a curved surface. Instead of using traditional beamforming with phase shifters, software defined radio (SDR) is used. A method is proposed to achieve adaptive beamforming and nulling of the flexible array, by using a SDR platform to feed the antenna array, in various conformed configurations. Minimum Variance Distortionless Response (MVDR) beamforming is used and adapted to the conformal antenna. Experimental results show good agreement with simulations.

Over the past two decades, nongovernmental organisations (NGOs) have grown at an exponential rate yet many of these NGOs find themselves fluctuating between states of being financially stable, to barely surviving the following year as funding and resources have been diminished. With most of these NGOs relying on product surplus or in-kind donations, a mismatch in the supply of resources and the actual need of the NGO arises. This not only has an impact on the NGOs but also the recipients of the services provided by the NGOs. Managing the donated resources and reducing product waste can aid in meeting sustainability development goals as well as empowering the community through social inclusion. The aim of this research paper is to identify frameworks that can aid in the management of donated products and resources in NGOs.

A flexible and conformal antenna for 2.4 GHz applications, using a commercial off-the-shelf (COTS) room temperature vulcanized (RTV) silicone rubber substrate and flexible polyimide printed circuit board (PCB) technology, is presented. Three different solutions for the ground plane are investigated. Antennas are tested on a flat surface and conformed to a cylindrical surface as well. The presented antennas greatly simplify the fabrication of highly conformal antennas and enable the practical implementation of flexible antennas with minimal performance degradation and at a relatively low cost.

A conformal and lightweight patch antenna on commercial off-the-shelf (COTS) silicone sponge rubber (SSR) for the 2.4 GHz ISM band, is presented. Three different options for the ground plane are investigated: copper-cladded polyimide, copper wire mesh, and DuPont PE873 stretchable silver conductor. For these three options, the antenna is measured on a flat surface and conformed to cylindrical surfaces with radius R= 160 mm, R =80 mm, and R =40 mm.

A conformal 2x2 active patch array on a low-cost commercial off-the-shelf (COTS) silicone sponge rubber (SSR) flexible substrate, combined with flexible PCB technology, is presented. The active array consists of a passive 2x2 patch array integrated with a low noise amplifier (LNA). The passive array is designed and characterized first. Its measured performance on a flat surface is found to agree well with simulations. The simulated boresight gain is 13 dB and the measured gain is 11.8 dB. Subsequently, the LNA is designed and tested on the flexible substrate. Compared to the vendor’s LNA evaluation board, a reduction in gain of 3.2 dB is measured. Finally, the passive array and the LNA are integrated together. The performance of the active array is measured on a flat surface, and when conformed to cylindrical surfaces. The gain of the active array on a flat surface agrees well with the summed performance of the constituting passive array and the LNA. When conformed to cylindrical surfaces, the gain of the active array reduces and the beamwidth increases.

A highly flexible and conformable polymer-based patch antenna, based on commercial off-the-shelf (COTS) room temperature vulcanized silicone (RTV) silicone rubber substrate combined with a stretchable silver conductor, is presented. The measured performance of the antenna is compared with a reference antenna, which uses the same RTV silicone rubber as substrate and polyimide with copper cladding for the top layer and the ground plane. The measured gain of the polymer-based antenna is $\sim$ 4 dB lower compared to the reference antenna. This is also predicted by simulations and is due to the lower conductivity of the conductive polymer compared to copper in the reference antenna. The radiation pattern and gain of the polymer-based antenna remain mostly unaffected when the antenna is conformed to cylindrical surfaces of various radiuses.