Bachelor and Master Theses

Title: Resource based analysis of Ethernet communication between software partitions
Subject: Computer Science
Level: Advanced
Description: A common computational model used in industrial control systems is to have multiple networked computer nodes that cooperate in performing some desired task. A single feature in the system is typically composed by several software components that are allocated to different nodes in the system. These components exchange information, e.g., about the movement of a robot axis represented by a sensor value. The information sent between two individual components could be small, for an axis sensor we may need to send a 32 bit integer, but the total amount of information sent in the system might by high though.
When sending some piece of information (hereafter called signal) from one component to another you can adopt different strategies. A straightforward approach is to treat each connection between components as a separate communication channel and send a network frame with the signal each time there is information available. The drawback with such an approach is that sending a small signal, e.g., the 32 bit value, in an Ethernet frame will render very poor utilization (a few percent only). On the other hand, if a maximum Ethernet frame is completely filled with data the utilization is very high (maybe 97%). Hence, there is good potential for optimization.
In control systems, many activities are cyclic, i.e., they are repeated with a given period time, e.g., reading a sensor, making a calculation and updating the state of the controlled process. Therefore different components will execute cyclically with different period times, sending signals to local and remote components. Moreover, there will be requirements on the latency of different activities, i.e., the time from reading a sensor, sending the corresponding signal over the network, making a computation and setting an actuator state will have to be within specific bounds.
A possible method for optimizing the network load would be to put several signals from different components in one single network frame. The most straightforward use would be to put signals that should be sent with the same period time in one frame. Depending on the different period times and signals to be transferred, it may in some cases be less expensive to let a signal piggy back in an existing frame that is sent with a shorter period time than needed, than to create a new frame with the appropriate period time. Thus, we have an optimization problem to solve that involve component cycle times, signal sizes, latency requirements, and network load.

To facilitate the above network optimization, two things are needed:
1. A software framework that support definition of frames that are sent periodically, and the allocation of signals to frames.
2. A method for calculating the appropriate set of frames and their period times, based on the available signals and their timing requirements.

The context for the thesis work is industrial control systems. These systems have high requirements on reliability, availability, and safety. The control systems are real-time systems with strict requirements on timeliness with respect to latencies and jitter. It is important that the work is based on solid scientific foundation; hence part of the thesis involves studying the state-of-the-art in the field. For real-time network technologies such as CAN, related work can be found in e.g., [1][2]. Using real-time theory in conjunction with Ethernet and the quality-of-service (QoS) for Ethernet in order to provide methods for predicting worst case behavior is in this context a bit more novel. The complete thesis work should study state-of-the-art, propose a method based on existing literature, develop a concept implementation, perform experiments that verify the theories, and document the work in a report and optionally a conference paper.
The basic framework and analysis for one application scenario has been set-up and developed as part of thesis work in 2013. This thesis work will build upon and extend that work.

Scope: Master Thesis for one student.
Location: At ABB Corporate Research.
When: January 2014.



[1] K. Sandstrom, C. Norstom, and M. Ahlmark. 2000. Frame packing in real-time communication. In Proceedings of the Seventh International Conference on Real-Time Systems and Applications(RTCSA '00). IEEE Computer Society, Washington, DC, USA.
[2] Polzlbauer, F.; Bate, I.; Brenner, E., "Optimized Frame Packing for Embedded Systems," Embedded Systems Letters, IEEE , vol.4, no.3, pp.65,68, Sept. 2012
Company: ABB Corporate Research, kontaktperson: Kristian Sandström
Prel. end date: 2014-06-15
Presentation date: 2014-06-13
Student: Cezar Chiru ccu12001@student.mdh.se
IDT supervisor: Meng Liu
meng.liu@mdh.se, +46-21-107353
Examinator: Moris Behnam
Moris Behnam
moris.behnam@mdh.se, 021-107094
Misc: Abstract: Nowadays, Industrial Control Systems (ICSs) are becoming larger and implement more complex functions. Therefore technologies that are currently used to implement these functions, like hardware platforms and communication protocols might soon be

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