Fiber Bragg grating optical sensors for fast dynamic strain measurements in a gasoline direct injector

Control systems for automotive applications have rapidly evolved introducing intelligence to address the increasing demand for pollution and oil consumption reduction. Fiber Bragg Grating (FBG) sensors are used in this work for monitoring Gasoline Direct Injectors (GDI) in order to optimize the engine performance and reduce the emissions. Several fast-Acting solenoid injectors have been instrumented with FBG sensors and mounted in a test bench at the testing department of CPT Italy S.r.l to simulate the injector's behavior during the actuation phase. The FBG sensors, installed on the stem of the GDI, provide dynamic measurement of the strain variation during the injection process, pointing out the unwanted effects of the reopening, leading to injector tip wetting and consequent increased polluting emissions. The acquired data allows one to fully understand the GDI process and to optimize the injector design in order to reduce emissions, as required by recent European directives for the emission standards.