Supplementary Material to: Road profile computation using smartphone-measured acceleration
Description
Data sets consists of data acquired by five smartphones: four serving as acceleration sensors and one controlling device. The master device collects the localization data from global navigation satellite systems (GNSS) and communicates over Bluetooth with the the sensor smartphones. They collect acceleration data at ca 250 Hz. At this stage the sensors (smartphones) were installed to the car body over the front wheels of the vehicle (sensor 1 & 2 over left, sensor 3 & 4 over right wheel). They were aligned along the front car axle as shown in Figure 1 so the z-axis of accelerometer covered the gravity vector. The instrumented vehicle was Alfa Romeo Giulietta. Measurements were repeated seven times with different driving speeds on a route with new asphalt pavement and four rubber speed bump illustrated in Figure 2. The bumps' cross-sections along the road axis were 0.88 m long and 0.06 m high. The registered acceleration signals were used in model calibration and evaluation procedures. The dataset, attached in Acceleration.Signal.csv, consists of six columns: - rideId - individual number of the single ride over four speed bumps, - smartphoneId - individual number of the smartphone mounted in the car, - bumpNo - individual number of the speed bump, - chainage - chainage [m] calculated on the basis of speed measurement and sampling frequancy, - az - raw acceleration signal [m/s2 ], - speed - car speed calculated on the basis of GNNS measurement [km/h ], Data in table is resampled to exact frequency of 250 Hz. Chainage is calculated on the basis of GNSS-acquired speed. Chainage was shifted, so the zero approximately covers the middle of the speed bump. Acknowledgments The authors would like to thank the employees of Heller Consult sp. z o. o. for their work in preparing, conducting, and processing measurements, in particular Arkadiusz Dyczkowki, Emil Łopata, Piotr Pasiński, Andrzej Nadowski, andMarta Mączko. The work was carried out under a programme of, and co-funded by, the European Space Agency. The views expressed in this work are those of the authors and can in no way be taken to reflect the offcial opinion of the European Space Agency.