150 research outputs found
Performance optimization of a UWB-based network for safety-critical avionics
To reduce the aircraft weight and maintenance costs while guaranteeing system performance and reliability, an alternative avionic communication architecture based on Ultra Wide Band (UWB) and TDMA protocol is proposed to replace the back-up part of safety-critical avionics network. The analysis and performance optimization of such a proposal is tackled as follows. First, appropriate system modeling and timing analysis, using Network Calculus and Integer Linear Programing (ILP) approach, are provided to evaluate the end-to-end delays and verify system predictability. Then, an optimization approach to find the optimal TDMA cycle duration, which minimizes the end-to-end delays, is proposed. Finally, the efficiency of our proposal to enhance the system performance is validated through a realistic avionic case study
Performance analysis of TDMA-based Wireless Network for Safety-critical Avionics
The opportunities and challenges for using wireless interconnects for safety-critical avionics have been discussed in our previous work.A Wireless Avionics Network (WAN)has been proposed based on hybrid architecture UWB and Switched Ethernet with adequate reliability and security mechanisms to increase scalability and reduce electromagnetic susceptibility. Furthermore, a TDMA-based protocol was considered to guarantee a contention free access and enhance communication predictability. However, the use of wireless technologies may increase the communication latencies due to transmission errors, and real time constraints have to be verified. In order to deal with the worst case performance analysis of such network, an appropriate schedulability analysis based on Network Calculus formalism is presented in this paper and obtained results for a realistic case study are discussed herein
Lessons Learned in ATCO2: 5000 hours of Air Traffic Control Communications for Robust Automatic Speech Recognition and Understanding
Voice communication between air traffic controllers (ATCos) and pilots is
critical for ensuring safe and efficient air traffic control (ATC). This task
requires high levels of awareness from ATCos and can be tedious and
error-prone. Recent attempts have been made to integrate artificial
intelligence (AI) into ATC in order to reduce the workload of ATCos. However,
the development of data-driven AI systems for ATC demands large-scale annotated
datasets, which are currently lacking in the field. This paper explores the
lessons learned from the ATCO2 project, a project that aimed to develop a
unique platform to collect and preprocess large amounts of ATC data from
airspace in real time. Audio and surveillance data were collected from publicly
accessible radio frequency channels with VHF receivers owned by a community of
volunteers and later uploaded to Opensky Network servers, which can be
considered an "unlimited source" of data. In addition, this paper reviews
previous work from ATCO2 partners, including (i) robust automatic speech
recognition, (ii) natural language processing, (iii) English language
identification of ATC communications, and (iv) the integration of surveillance
data such as ADS-B. We believe that the pipeline developed during the ATCO2
project, along with the open-sourcing of its data, will encourage research in
the ATC field. A sample of the ATCO2 corpus is available on the following
website: https://www.atco2.org/data, while the full corpus can be purchased
through ELDA at http://catalog.elra.info/en-us/repository/browse/ELRA-S0484. We
demonstrated that ATCO2 is an appropriate dataset to develop ASR engines when
little or near to no ATC in-domain data is available. For instance, with the
CNN-TDNNf kaldi model, we reached the performance of as low as 17.9% and 24.9%
WER on public ATC datasets which is 6.6/7.6% better than "out-of-domain" but
supervised CNN-TDNNf model.Comment: Manuscript under revie
A Survey of Air-to-Ground Propagation Channel Modeling for Unmanned Aerial Vehicles
In recent years, there has been a dramatic increase in the use of unmanned
aerial vehicles (UAVs), particularly for small UAVs, due to their affordable
prices, ease of availability, and ease of operability. Existing and future
applications of UAVs include remote surveillance and monitoring, relief
operations, package delivery, and communication backhaul infrastructure.
Additionally, UAVs are envisioned as an important component of 5G wireless
technology and beyond. The unique application scenarios for UAVs necessitate
accurate air-to-ground (AG) propagation channel models for designing and
evaluating UAV communication links for control/non-payload as well as payload
data transmissions. These AG propagation models have not been investigated in
detail when compared to terrestrial propagation models. In this paper, a
comprehensive survey is provided on available AG channel measurement campaigns,
large and small scale fading channel models, their limitations, and future
research directions for UAV communication scenarios
Specification and Performance Indicators of AeroRing—A Multiple-Ring Ethernet Network for Avionics Embedded Systems
The complexity and costs of the avionics communication architecture are increasing exponentially with the increasing number of embedded computers over the last few decades. To limit the cabling complexity and the deployment costs of such a communication architecture, we specify a new Gigabit multiple-ring Ethernet network, called AeroRing, while meeting the avionics requirements. First, we describe the current Aircraft Data Communication Network (ADCN) to highlight the main characteristics and requirements that have to be fulfilled by our solution. Then, we give an overview of the most relevant solutions to improve ADCN performance and relate them to AeroRing. Afterwards, we detail the specifications and the main Performance Indicators (PIs) of AeroRing. Finally, sensitivity and validation analyses of AeroRing are conducted through a realistic avionics application, regarding the various PIs, in comparison to the backbone network of the ADCN, the Avionics Full DupleX Switched Ethernet (AFDX). The computed AeroRing performance metrics show its ability to guarantee the avionics requirements
The latest advances in wireless communication in aviation, wind turbines and bridges
Present-day technologies used in SHM (Structural Health Monitoring) systems in many implementations are based on wireless sensor networks (WSN). In the context of the continuous development of these systems, the costs of the elements that form the monitoring system are decreasing. In this situation, the challenge is to select the optimal number of sensors and the network architecture, depending on the wireless system’s other parameters and requirements. It is a challenging task for WSN to provide scalability to cover a large area, fault tolerance, transmission reliability, and energy efficiency when no events are detected. In this article, fundamental issues concerning wireless communication in structural health monitoring systems (SHM) in the context of non-destructive testing sensors (NDT) were presented. Wireless technology developments in several crucial areas were also presented, and these include engineering facilities such as aviation and wind turbine systems as well as bridges and associated engineering facilities
- …