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Bourges, France

Pop-Stefanov B.,Georgia Institute of Technology | Menec S.L.,MBDA
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2013

During the mid-course phase of an air-to-air missile, choosing the optimal Guidance Point (GP) so as to maximize lock-on success and minimize intercept time is critical. Given low computational resources available on board and a very constrained maneuvering time frame, GP-based algorithms must be efficient. We suggest an innovative approach using Reinforcement Learning (RL) to produce finite state controllers that can be executed efficiently - using table lookup - to meet the strict time limits of a target engagement. Instead of hand-crafting a GP-picking algorithm for every combination of sensor and aircraft configuration, one promising alternative models a missile-target engagement as a Partially Observable Markov Decision Process (POMDP) and automatically generates a controller for picking the best GP by solving the POMDP model. Using a recently developed offline algorithm called Monte Carlo Value Iteration (MCVI) we constructed continuous-state POMDP models and solved them directly, without discretizing the entire state space. © IFAC. Source

Morales R.M.,University of Leicester | Turner M.C.,University of Leicester | Court P.,Finmeccanica | Hilditch R.,MBDA | Postlethwaite I.,Northumbria University
IET Control Theory and Applications | Year: 2014

This study considers the design of a closed-loop force-tracking system for a semi-active damper, designed to be used to reduce in-plane vibrations caused by helicopter rotor blades during steady-state forward flight conditions. The study describes the development of the control law and includes details of (i) how the initial mathematical model of the system is adapted for controller design; (ii) how a non-linear dynamic inversion (NDI) control law is modified into a form suitable for implementation; and (iii) how the free parameters in the NDI controller can be optimised for various different operational modes. The success of the approach is demonstrated through both force-tracking simulations and also more comprehensive tests in which the controller is incorporated into a large-scale vibration simulation of the AgustaWestland 101 helicopter. The results show that the NDI-based controller can provide a satisfactory level of performance and hence greatly assist in the reduction of unwanted vibrations. © The Institution of Engineering and Technology 2014. Source

Najmi H.,INSA Val de Loire | El-Tabach E.,University of Orleans | Chetehouna K.,INSA Val de Loire | Gascoin N.,INSA Val de Loire | Falempin F.,MBDA
International Journal of Hydrogen Energy | Year: 2016

Using Fuel Cell on board of aircraft imposes to extract light species (such as Hydrogen and light hydrocarbons) from the liquid fuel which is stored and used, possibly at temperatures where a fuel pyrolysis occurs. Natural porosity of composite material could be used to filtrate the selected species. Hence the permeability of the porous media becomes one of the key parameter to be accurately measured. It is often determined experimentally in laboratory with disc samples (outlet of the flow is achieved through the porous material) and normal flow. However, this configuration is far from the realistic one consisting of tubes (a main flow is found additionally to the one through the material, tangential permeability). Therefore, the effect of a second outlet on the Darcy's and Forchheimer's permeabilities characterization should be studied (despite the permeability is an intrinsic property of the material itself and it should not be dependent on the test apparatus). This paper focuses on a new way of using an existing test bench for the determination of Darcy's and Forchheimer's permeabilities of C/SiC porous composite tube by taking two outlets into account. Operating parameters (temperature, pressure and mass flow rate) are measured for three different configurations: i) primary outlet (P.O) is 0% open ii) P.O is 50% open and iii) P.O is 100% open. Then Darcy's and Forchheimer's permeabilities are computed by ISO and P2 methods using a direct search algorithm. Obtained results from different methods are compared and discussed. They are in agreement with the literature data which guarantees the reliability of the test bench and of related measures. © 2015 Hydrogen Energy Publications, LLC. Source

Jacquemod G.,CNRS Laboratory of Electronics, Antennas and Telecommunications | Nowak M.,CNRS Laboratory of Electronics, Antennas and Telecommunications | Nowak M.,CEA Grenoble | Colinet E.,CEA Grenoble | And 2 more authors.
Sensors and Actuators, A: Physical | Year: 2010

This paper presents an inductive telemetry platform system for the continuous, real-time and simultaneous remote measurement in harsh environment. First, a SOL (self-oscillating loop) topology for the remote interrogation of wireless battery-less passive sensors is described. This system uses a capacitive sensor configured as an LC-tank whose resonant frequency shifts with the physical measurement. Such a system is generally based on an impedance analyzer in order to measure this frequency shift. In fact, if you increase the distance between the sensor and the reader, the sensibility is not sufficient to use the SOL technique. To overcome this issue, an anti-resonance cancellation, realized with a simple RC cell, is implemented. However, this architecture is dedicated only for a single capacitive sensor. Second, based on an efficient algorithm used for system identification purpose, a readout unit for multiple sensors is proposed. The overall performances of these architectures are analyzed with respect to coupling factor and sensor parameters. Using these two approaches, tests show promising results at mutual coil distances up to 5 cm. © 2010 Elsevier B.V. All rights reserved. Source

Tancredi N.,MBDA | Alunni S.,Capgemini | Bruno P.,University of Rome La Sapienza
Communications in Computer and Information Science | Year: 2016

The developed methodology aims to study and define a platform for “Rapid Prototyping,” in a full “Model-Based Design” approach, providing a significant reduction in the development time. The described approach allows us to test algorithm models, realized by the designer in Simulink™, directly on a real platform (prototype On Board Computer), in real time, to evaluate the performance in terms of computational load. The main advantages of this innovative approach with respect to the traditional one are an increased robustness of the algorithms before the integration (reduction of development time) and the ability to quickly evaluate different design solutions in terms of performance and reliability. With the implementation of the described design logic is possible to put the On Board Computer in the loop simulation starting from the early stages of development (CIL—computers in the loop). The proposed methodology enables us to automatically generate, through the Simulink™platform, embedded code with its makefile realized models; to send the generated files via Ethernet to a remote device (On Board Computer, etc.) with operating system “Linux,” Real-Time Linux, etc.; to compile the project through makefile directly on a remote system; and to run it, all in a fully automatic and user-friendly way. © Springer International Publishing Switzerland 2016. Source

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