Abstract
Keywords - Fogging prevention, climate control, mean radiant temperature sensor, sensors number reduction, safety.
Abstract- To improve driving safety it is of outmost importance to be able to guarantee that the windshield never starts fogging by means of an automatic and reliable procedure. This in order to have the least interaction between the driver and the air conditioning system so to improve the safety and reduce the mental workload.
To reach this goal, a fogging condition estimation algorithm has been developed. It requires just a Mean Radiant Temperature (MRT) sensor and a Relative Humidity Sensor (RH). The MRT sensor is placed on the roof pointing towards the dashboard and a windshield with a suitable field of view. The MRT sensor application and the related control system have already been developed and patented by Centro Ricerche Fiat.
This work is therefore a further development of this activity. The MRT sensor allows the estimation of both cabin internal temperature and inner windshield surface temperature. Combining this measurement with cabin relative humidity coming from the RH sensor, the estimation algorithm forecasts fogging conditions so that the automatic thermal control system can take actions before to prevent them. The fogging prevention control function is safer, more robust and energy effective, with respect standard operation way.
Moreover, this approach allows also cost savings because makes redundant the Solar sensor and the Fog optical sensor, and the presence of the R.H. sensor makes possible the cabin humidity control.