Towards speed-independent road-type classification

The knowledge of terrain types is not only useful for improving passenger´s safety and comfort, but also for bounding safe navigation routes for autonomous vehicles. Most of the work in the literature is limited to rover operations at slower speeds or rovers with rigid wheels. This paper discusses and presents a critical analysis of speed independency of classifiers for passenger vehicles with tyres at road operating speeds. The suitability of using different features calculated based on vertically mounted accelerometer data as well as road profile data were analyzed. The experimental results agree with the literature, where speed independency could be achieved by using the Fast Fourier Transform (FFT) features extracted from the estimated road profiles. However, we also show that it is possible to achieve comparable results by extracting different features directly from acceleration data. This eliminates the requirement of accurate knowledge of the vehicle model parameters or speed of the vehicle.