Chihiro Kobayashi

Signal Processing for Error Reduction of Automotive Hot-Wire Air Flow Sensor. Reducing Understimation-Error of Bobbin Type Hot-Wire under Pulsatile Flow.

The bobbin type hot-wire (H/W) element of an air flow sensor has a tend ency to underestimate the actual flow rate when subjected to large-amplitude pulsatile flow. We investigated the causes of this measurement error and propose a new dynamic model for the bobbin type H/W element, which dynamically combines its static nonlinear output characteristic and its dynamic response. By inverting our bobbin type H/W dynamic model, we have developed a signal processing method to correct the measurement error of the bobbin type H/W. Measurements using this signal processing method show that it reduces the bobbin type H/W measurement error.