A decade ago, “drive by wire” and “brake by wire” were the awe-inducing buzzwords emblematic of progress from mechanical to electronic systems. But as the number of sensors and other electronic gadgets under the hood and throughout the rest of the vehicle has increased engineers have found it more difficult to find space for all that wire. What’s more: wires cost money that car companies would rather not spend; add weight to the vehicles, affecting their performance and fuel economy; make assembly more challenging; and ratchet up the possibility of maintenance issues.
So, now the aim is to get rid of most of the wires snaking through a vehicle. And in a time when Wi-Fi, Bluetooth, and cellular communications are ubiquitous, it seems only natural that car companies would solve this problem by going wireless. But creating robust intra-vehicular wireless sensor networks is easier said than done. All that metal in the engine compartment and the vibration of those moving parts are a multipath nightmare. But researchers at Koc University, in Istanbul say they have worked out a theoretical map of nodes in what is essentially an engine-area wireless network featuring ultrawideband communications. Ultrawideband, wrote the researchers, is “resistant against multipath fading and signal power attenuation providing robust communication at low transmission power and high communication rate.”
They recently detailed their results of a real world tryout of their scheme in IEEE Transactions on Vehicular Technology. They put 19 sensors in the engine compartments of a Fiat Linea and a Peugeot Bipper. After running tests to analyze the validity of their theoretical engine channel model across a wide range of scenarios, the Koc researchers concluded that, “The small variations of the model parameters for different types and conditions of the vehicle demonstrate the reliability of the proposed simulation model built based on an extensive set of measurements.” In other words, the real-world tests proved out what they predicted with equations: sensors can reliably relay the data they collect without physical links.
The Koc University team says it will now turn its attention to other parts of the vehicle including the passenger cabin.
Willie Jones is an associate editor at IEEE Spectrum. In addition to editing and planning daily coverage, he manages several of Spectrum's newsletters and contributes regularly to the monthly Big Picture section that appears in the print edition.