ICT in road vehicles — Reliable vehicle sensor information from OBD versus CAN

The focus of the research and development activities in Intelligent Transportation Systems is to increase road traffic safety and improve transport efficiency. Telematics Systems can provide values on both fields, by providing real-time reliable vehicle specific information [1]. Road vehicle related information can be categorized into several types, but technical information provided through the electronic network of today´s vehicles is becoming an increasingly important segment. Using the standard onboard diagnostics (OBD) is a popular solution nowadays for getting out technical data from the vehicle, but it has its limitations [2]. Professional systems rather use direct access to the vehicles CAN network to extract more detailed technical data out from the ECU communication [3]. Even automatic vehicle location (AVL) service providers have difficulties in differentiating between the possibilities and potentials of CAN bus and OBD. This article clearly identifies the differences between the solutions available on the market, by means of comparing the FMS CAN standard, the OBD standard and the Proprietary Vehicle CAN protocol. The comparison is not only theoretical, but it is based on different measurements and analysis. The measurement results demonstrate the benefits and limitations of these information sources. For the measurement we have used our VehicleICT [4] framework that provided the platform for storing and analyzing the data. Based on the provided comparison, the identified advantages and disadvantages of certain source types, we can select the proper solution for a specific requirement. One objective of this research activity is to clarify confusions about the relation of OBD and CAN from the Telematics Systems providers point of view. Besides that this research can be also considered as a pioneer work that demonstrates the capabilities of our VehicleICT framework.