An Automated Tachograph Chart Analysis System

This paper describes a new system that analyses tachograph charts. These circular charts are legal records of information on the different types of driver activity (driving, other duty, standby and rest) and vehicle data (speed and distance travelled). As each driver of each passenger and goods vehicle over a certain capacity must use a chart for every 24-hour period, there is a significant need for automated analysis (currently, tachograph charts are analysed manually). The system starts by determining the shape parameters of the chart (location of the centre and radius). The position of the start of the 24-hour period (radius from centre to 24 hour tick mark) is then estimated. Finally the driver activity trace (recorded in a circular manner) is extracted, converted into a linear representation and recognised. Results from the evaluation of the system against professionally prepared ground truth indicate at least 94% accuracy in reading the driving time even on difficult (with scratches and marks) charts.