Sensors move into virtual world
It is usually been the rule that monitoring another parameter meant adding another sensor. The advent of virtual sensing has changed that clever engineers are increasingly using input from a couple of sensors to monitor a third parameter. That saves component costs and complexity, adding only the code needed to determine the additional parameter. The technique is already seeing use in production. The majority of E85 vehicles have virtual ethanol sensors,” said Ken Krider, Engine management system manager at GM. “We look at the air/fuel mix and defect it based on the oxygen sensor.
Many virtual- sensing applications are in critical aspects of vehicle operation. Ethanol sensing impacts both fuel consumption and emissions. Other sensors are being used to virtually monitor other aspects of emission controls. Increasingly exhaust stream components such as NOx (oxides of nitrogen) and CO (Carbon monoxide) may be predicted using sensors in other parts of the system.