Utilization of Turbocharger Speed Data to Increase Engine Power and Improve Air Path Control Strategy and Diagnostics

Turbocharging is significantly changing design and control strategies for Diesel and gasoline engines. This paper will review new advances in the turbocharger speed measurement. Until recently, the highly accurate and fast turbocharger speed data, based on the physical speed sensor signal, has been mainly used to safely decrease conservative safety margins for turbocharger speed and surge limits. In addition to significantly increasing power and low end torque, new generation sensor technology is providing new opportunities to utilize turbocharger speed data. New, state-of-the-art active eddy current based speed sensor technologies, including a configurable high temperature Application Specific Integrated Circuit (ASIC), and the extremely fast delivery of accurate turbocharger speed data, will not only benefit engine and turbocharger performance but also improve control, allow for advanced diagnostics and enable the possibility to virtualize other powertrain sensors (e.g. mass air flow and exhaust gas temperature sensors). The resulting optimized engine efficiency will equate with lower emissions, fuel savings and increased reliability.