Automotive Power Line Communication: A New Wiring Topology for Powertrain Sensor Network : A pre-study on the technical feasibility of implementing power line communication for Volvo powertrain sensor network

Abstract: In motor vehicles the power and information are distributed by their own separate wiresand the amount of wires over the past decades has increased tremendously due to theever increasing electronics onboard. Solely the average weight of the wires has increasedfrom 4 to 91 kg over the last 50 years and it is therefore clear that a remedy to theever increasing wiring is needed. A possible solution to this could be to introducepower line communication (PLC) onboard a vehicle. The PLC aims at overlaying theinformation on top of the already existing power feed cables and thus eliminating theneed of dedicated wires for communication purposes. The PLC solution would thussimplify the wiring network to a bare minimum, since no additional wires besides thepower cables are needed.During this thesis work the PLC technology was studied as a possible cost and qualityreform of the powertrain sensor network, where it could be used to both reduce the costof wires and increase the system reliability.A theoretical background study was rst performed to investigate the limitations andpossibilities of the PLC implemented in a vehicle, and the PLC technology was alsotested upon the DC-lines of an e6 Volvo FMX truck, between the post catalytic NOxsensor and the ACM with two CAN protocol based PLC modems. The throughput, noiseand the scalar voltage gain was measured in this link with the ignition key at dierentpositions to test dierent modes of operations. It was shown that this particular link hada clear low pass characteristics with severe voltage attenuation without any signicantdierence caused by the dierent modes of operation. The severe characteristics of thelink did result into a fault connement mode of the CAN based PLC modems wheretheir communication capabilities were inhibited, which shows that at least with thisparticular link, reliable communication was not possible with the equipment at hand.Short EMC measurements were also carried out regarding the radiated emissions. Theresults showed that the PLC technology implemented in the existing wiring architecturecould be a possible cause of EMC problems if no counter actions are been taken intoaccount.Some of the economical aspects were also investigated, but most of the results were leftas hypothetical assumptions. A detailed cost saving analysis was nevertheless made onthe EATS-wire harness where the savings were estimated to be 1e. It is the hope thatthese calculations could be used as a sounding board for future PLC wire harness costanalysis.