Department of Computer Science and Electrical Engineering
AUTHOR: DAVID O'ROURKE
STUDENT NUMBER 341594961
Abstract
:Multiplex Wiring in automobiles is a technique used to reduce the quantity of wires in the automobile. This technology is utilised because it enables the reduction of the overall cost of the vehicle and because it enables intelligence t o be incorporated into the automobile. Figure 1 is a graphical depiction of an in-vehicle network. Multiplex Wiring Systems generally utilise a twisted pair wire for signal and power transmission but this thesis has successfully created a reliable n etwork utilising a single wire with signal and power integration. This has been demonstrated in this thesis with the creation of a master module and two slave modules to form the network.
Figure 1: A Standard Multiplex Wiring System. Picture obtained from http://design-net.com/automotive/multiplex.html
This thesis is a continuation of Chik’s (1998) thesis and has successfully created a faster more reliable network using Chik’s (1998) work as a basis. The network baud rate has been successfully doubled to 19,200 baud, the software has been completely re-written in C, hamming error coding techniques have been introduced to the system and extensive documentation of the performance of the system has been carried out.
The hardware of the system has been largely unchanged from the previous design, due to the overall success of the previous design. A new microcontroller has been researched and is anticipated to increase the overall efficiency and speed of the system by a factor of 10.
The network has been successfully demonstrated in a 1995 Toyota Camry and operated reliably in all modes of operation. This is attributed to the interference shielding of the system. This is accomplished by digital amplitude modulation and error correction software. The latency of the system was measured as being approximately 50ms in most operating conditions and will become stable at this value with the introduction of multi-tasking to the software.
The thesis was a successful continuation of Chik’s (1998) work and has accomplished its aims of solidifying his work and improving the overall system. If you are interested in further details please feel free to contact me at the below email address or if you would like you can download the completed sections of my thesis directly.
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