Abstract
It is important to grasp the road surface condition in real time to prevent slipping accidents caused by ice road surface. Particularly in autonomous driving technology, its importance increases. We focused on QEF (Quasi-Electrostatic Field) sensing technology as one of the methods of road surface condition sensing technology. QEF has a characteristic that it is distributed like a static electricity in a dielectric such as a human body or a vehicle body. QEF sensing is to sense electrical changes occurring between the tire and the road surface with a sensor on the vehicle body. Therefore, the tire itself is a sensor and there is no need to attach a sensor device directly to the tire. In this research, we developed a QEF sensor unit and conducted comparative experiments on dry road, wet road, snow road and ice road using experimental vehicles. As a result, it was found that a difference of 10 dB or more was obtained as the amplitude value average of the voltage of the frozen road compared with other road surface conditions. Based on this, we proposed and verified the road surface estimation method with the amplitude value as the feature quantity, and it was confirmed that the road surface condition excluding the snow road is consistent.
