System-of-Systems development based on deterministic Ethernet

Lead Research Organisation: CRANFIELD UNIVERSITY
Department Name: Sch of Aerospace, Transport & Manufact

Abstract

Deterministic Ethernet, which has been originally designed as avionics communication platform with focus on in-vehicle communications provides inherent features that allow to tightly couple multiple vehicles. Thus, individual Deterministic Ethernet -based systems can connect to each other to form a Deterministic Ethernet -based System-of-Systems (SoS). While the inherent Deterministic Ethernet features require a wired connection between the individual systems, there is a need to explore the possibilities to construct Deterministic Ethernet -based SoS that leverage wireless connections to each other and/or to a common navigation reference such as the Global Navigation Satellite System (GNSS).
Therefore, the focus of this PhD will be on construction of System-of-Systems using Deterministic Ethernet based on individual Deterministic Ethernet systems that coordinate their actions by means of a GNSS reference with a possibility of a wireless implementation. The benefits of this development should identified and quantified for the relevant use cases, e.g. commanding the swarms of UAVs or UAV to ground station coordination.
The PhD thesis will explore the research hypothesis, both by analytical means (potentially based on simulations) as well as by means of practical evaluation on a Deterministic Ethernet Development System.

Publications

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Description In the literature, the importance of distributed system is quite significant where several methodologies and approaches have been looked at to improve the latency in time distributed networks.TTE network to improve overall QoS of the network. Some methods have been proposedto improve the overall QoS of all three types of traffic in the network; such algorithms and methods are proposed. Similarly, other researchers focus on optimisation of the overall traffic in the TTE network with various approaches. The studies indicate and point to how researchers utilize methods to enhance QoS in disturbed or mixed critical systems. Some of these time-dependent networks are Zig bee, Profibus, and CAN, where these networks rely on internal time to perform tasks to send the critical messages in the networks [10]. However, TT messages utilising external clocks such as a GNSS in a TTE network are not very well-investigated and remain undeveloped to date.
In the TTE network, all required protocol mechanisms and network capabilities have to be provided, enabling the definition of deterministic dataflows with defined latency and jitter. In addition, the Ethernet switch will be required to implement all mechanisms to prevent unintended interactions among different critical dataflows[4].


For safety-critical systems, it is necessary to have procedures that can handle congestion-free paths for fault-tolerant messages. No frame is lost, and all the frames sent are transferred to desired end stations (ES) with predefined bounded latency and jitter.

• Support a deterministic fault-tolerant network for safety-critical systems. The traffic congestions should be prevented for TT messages and clocks synchronised to one master clock.
• We investigate the end-to-end delay of TT traffic having external clock scheduling, which is achieved by applying network calculus and design models for analysis and results from the TTE network.
• By developing the idea of unicast/multicast virtual links (VLs) and robust bandwidth partitioning, which mandates every-stream of TT traffic monitoring and determining mechanisms.
• I am investigating methods and techniques for utilising the ISO model's MAC layer to integrate the TT traffic in the TTE network.
• Implement simulation configuration, which is verified and validated, is correct and can be traced to system integration and application communication requirements for the fault-tolerant network.
Exploitation Route The outcomes from the research are useful many Aerospace and automotive industries where the proposed novel approaches can be used to improve Time triggered messages in the network with external clock to synchronise multiple system of systems.

The objective is to present a general perspective on total system design, focusing on networking aspects, especially the integration of external clock synchronisation in a TTE network and system of systems (SoS).


The following objectives are identified after carefully reviewing the literature study:
1. To carry out an intensive literature review for identifying gaps in the area of TTE networks.
2. Investigate and develop the technique for synchronising the clock from a GNSS to the master clock of the TTE network and study the effects of external clock synchronisation in a fault-tolerant TTE network and develop simulations to calculate the performance of the network.
3. Using the concept of virtual links (VLs) in a TTE network to create multiple networks as well as identifying techniques to be able to control multiple TTE networks (System of Systems SoS) from one primary external timing source (GNSS).
4. To identify the scalability of dataflows supporting Virtual links (VLs) in the TTE network and introduce the VLs with defined latency and jitter in the TTE switch for a fault-tolerant system of systems (SoS).
5. Investigate methods and techniques to introduce TT traffic in a wireless network standard (IEEE 802.11) supporting external clock synchronisation to control systems like Unmanned Aerial Vehicles (UAVs) communicating with ground stations forming a system of systems (SoS).
6. Implement the network design, tools, and algorithm model to calculate maximum latencies in the TTE network for synchronising with an external clock. Also, verify and validate the results against implemented techniques.

These are some of the critical points highlighted that have not been explored TTE network to calculate the latency with an external time source. There is no specific algorithm that calculates multiple delays
Sectors Aerospace, Defence and Marine,Digital/Communication/Information Technologies (including Software),Electronics,Transport
 
Description Determnistic Time Triggered Ethernet communication 
Organisation TTTech Computertechnik
Country Austria 
Sector Private 
PI Contribution Currently I am working on methods investigate how external timing source can be used with Time triggered messages for creating multiple system of systems The system provided by TTTech has helped In this regard for simulations and improving the QoS in a TT network.
Collaborator Contribution Partnets have not made any contribution apart from providing the development system.
Impact TTTech has been kind enough to provide a development system as part of my PhD. the purpose of this development system is to utilise the time Triggered messages in the network with exytrnal clock synchronisation for testing and simulations.
Start Year 2018