Fiabilisation de la technologie courant porteur en ligne en vue de piloter des actionneurs d’aéronefs

Abstract : In the new aircrafts, hydraulic flight control systems are replaced by electric flight control systems. The main interests are a better flexibility of the aeronautical equipments and a decrease in maintenance costs and construction costs, but the major problem is the increasing of the wires length. In order to decrease this length, it has been proposed to use power line communications (PLC) technology for flight control systems. The decrease of wire will first decrease aircraft weight and therefore the consumption of kerosene and on the other hand will simplify maintenance and construction. The first part of this work is the measurement and the characterisation of the propagation channel on an aeronautic test bench (with HVDC supply and loads). This channel is composed of two couplers (inductive or capacitive) in order to connect the telecommunication system on the power wires with galvanic isolation and one twisted pair of 32 m longs. We have tested three architectures: the point-To-Point architecture with capacitive coupler, the point-To-Point architecture with inductive coupler and the point-To-Multipoint architecture with inductive coupler. The purpose of these measurements is to measured the transfer function on the [1 ; 100] MHz bandwidth. Then, we have computed the channel parameters like the coherence bandwidth and the delay spread. The second step was the design of the signal processing algorithm in order to satisfy the aeronautical specifications: a useful bite rate of 10 Mbit/s, a latency of 167- 334 μs, a BER of 10-12 and the respect of the DO-160 gauge in conducted emissions. For the transmissions, we have chosen the OFDM technology which has been use with success in other PLC systems. With the channel characterization, we have proposed a parametric study in order to define the OFDM parameters to satisfy the bite rate and the real time constraints. After, we compute digital simulations with Matlab to check the OFDM parameters. With these simulations, we have also defined the channel coding parameters (Reed-Solomon and convolutional coding) to satisfy the aeronautical specifications. The last part of this study was the design of the synchronisation system. Because of the channel stability, we considered a precise synchronisation after an initialisation period. Then, we focus on the estimation of the FFT shift, due to the sampling frequency shift, during a following-Up period. In order to avoid the decrease of the latency and the bitrate due to the pilot symbols or pilot sub-Carriers insertion, we proposed to correct the FFT shift with the receive data thanks to the maximal likelihood algorithm.
Complete list of metadatas

https://tel.archives-ouvertes.fr/tel-01123745
Contributor : Abes Star <>
Submitted on : Thursday, March 5, 2015 - 1:38:19 PM
Last modification on : Friday, November 16, 2018 - 1:28:14 AM
Long-term archiving on : Saturday, June 6, 2015 - 10:51:45 AM

File

2014ISAR0009.pdf
Version validated by the jury (STAR)

Identifiers

  • HAL Id : tel-01123745, version 1

Citation

Thomas Larhzaoui. Fiabilisation de la technologie courant porteur en ligne en vue de piloter des actionneurs d’aéronefs. Réseaux et télécommunications [cs.NI]. INSA de Rennes, 2014. Français. ⟨NNT : 2014ISAR0009⟩. ⟨tel-01123745⟩

Share

Metrics

Record views

701

Files downloads

1628