Machine Learning Models for Road Surface and Friction Estimation using Front-Camera Images

Automotive active safety systems can significantly benefit from real-time road friction estimates (RFE) by adapting driving styles, specific to the road conditions. This work presents a 2-stage approach for indirect RFE estimation using front-view camera images captured from vehicles. In stage-1, convolutional neural network model architectures are implemented to learn region-specific features for road surface condition (RSC) classification. Texture-based features from the drivable surface, sky and surroundings are found to be separate regions of interest for dry, wet/water, slush and snow\ice RSC classification. In stage-2, a rule-based model that relies on domain-specific guidelines is implemented to segment the ego-lane drivable surface into [5×3] patches, followed by patch classification and quantization to separate images with high, medium and low RFE. The proposed method achieves average accuracy of 97% for RSC classification in stage-1 and 89% for RFE classification in stage-2, respectively. The 2-stage models are trained using publicly available data sets to enable benchmarking for future methodologies in the autonomous driving domain.