DONG Liang-xiong1，XIAO Jin-he2，ZHU Fa-xin1

（1. Maritime School of Zhejiang Ocean University，Zhoushan 316022，China；

2. Wuhan Branch of China Classification Society，Wuhan 430022，China）

Abstract：Aiming at less original design and the problems that the analog circuit design are not applicable to hot-film air flow meter（AFM）of duel fuel marine engine in China. A kind of hot-film air flow meter based on MC9S08QD4 microcontroller was designed by studying the nonlinearity error of AFM and defects of analog circuit. On the basis of fully utilizing hardware resources，the microcontroller acts as the central controller and performs the signal processing and control of the meter. In allusion to the cross-sensitivity of ambient

temperature，a error compensation method of air flow meter based on polynomial regression analysis was presented and automatic calibration based on Look- up Table for nonlinearity were introduced. The performance comparative tests were done within engine different working conditions. The test result indicate that the design can reduces nonlinearity error and the influence of the change of engine operation points，that is helpful to realize automation and intelligent of air flow meter.

Key words：hot-film air flow meter（AFM）；nonlinearity error；automatic calibration；error compensation