Non-linear dynamic modeling of hot-film/wire MAF sensors with two-stage identification based on Hammerstein model

The hot-film/wire MAF sensors are widely used in automotive engines to measure the intake mass air flow for controlling the air fuel ratio due to their quick response, wide range and high reliability. However their non-linear dynamic characteristics influence the measurement accuracy of the hot-film/wire MAF sensors. In order to describe the sensor characteristics, this paper proposes a two-stage identification method based on the Hammerstein model and the experimental data of multi-amplitude step response. The modeling results show that the non-linear dynamic models of hot-film/wire MAF sensors are more accurate than the linear dynamic models, and convenient for sensor non-linear dynamic correction. This modeling method can also be applied to other sensors.