specific requirements of bmep, emissions and fuel consumption, as well as helping to minimise knock by improved control of residuals and the effective compression ratio. To achieve this, says Stone, the VCU has to be significantly faster than any other controller currently in use on an engine. “It’s extremely important to get the controlling algorithms right. The power consumption depends on the quality of that algorithm and that’s an area we’re particularly active in at the moment. By automotive standards, it needs to be significantly faster than an ignition or fuelling ECU, because we’ve got to be looking at where the valve is multiple times per event – over 100 times per event –, whereas an ignition ECU only has to do its sums per cylinder once every other revolution. We’ve got a lot of computing to do; we’re talking about probably 10 times faster – a 100 microsecond computing cycle.”
Fast forward Asked if there are no downsides to this technology, Stone smiles and laughs briefly. “It’s going to be embarrassing for the injector suppliers, because the great thing about having only tiny lift is that there’s a very small amount of energy used - it’s practically silent at idle and, even at full engine speed, it’s noticeably quieter than standard valve trains.” Now working towards its third
generation of development rig, Camcon is seriously courting interest from the industry. “We do have interest from OEMs, but ultimately we’re looking for a tier one to take on the industrialisation. We need a very serious level of interest from an engine producer, in order to encourage a tier one that there will be a market for it. “It would be nice to think that we
could move it forward quickly enough to be in service, with some reasonable experience, before the 2020 regulations come in; maybe 2018. It all depends on what happens from here.”
May/June 2013
www.automotivedesign.eu.com 15
“The £1,000 would be at the top end of the range. If you only spend half that, you don’t quite get half the system, as the VCU will be a significant investment.”
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