Experimental study on wind-based vehicle speedometer applying the whistle principle

It is important to consider the effect of wind when driving a vehicle at high speeds since the rate of fuel consumption may change according to wind direction in relation to vehicle driving direction. In order to minimize fuel consumption when driving at high speeds, it is necessary to control the relative vehicle speed against the wind. This paper proposes a new type of speedometer that is based on wind speed instead of conventional ground speed. For the detection of wind speed, we focus on the whistle principle where the frequency of the whistle sound is proportional to the airflow rate. To measure the wind speed as airflow rate, we developed a special whistle suitable for a wind-based vehicle speedometer by using CAD software for three-dimensional modeling. Characteristics of the developed wind-based vehicle speedometer were tested in both indoor experiments and actual-vehicle outdoor experiments. The validity of the proposed method was confirmed by the experiments.