Search Results

This paper investigates classifications of road type and driving style based on on-board diagnostic data, which is commonly accessible in modern vehicles. The outcomes of these classifications can be utilized in, for example, supporting the advanced driver assistance systems (ADAS) for enhancing safety and drivability, and online adaptation of engine controller for improving performance and fuel consumption. Furthermore, the classifications offer valuable information for fleet operators to consider when making decision on procurement plans, maintenance schedules and assisting fleet drivers in choosing suitable vehicles. To this end, a velocity-based road type classification method is evaluated on measurements collected from real driving conditions and compared to an open-sourced map. To produce representative results, two most commonly adopted driving style classification methods, i.e. acceleration and jerk-based methods are evaluated and compared on the same set of measurements.

In recent years the need for testing, calibration and certification of automotive components and powertrains have increased, partly due to the development of new hybrid concepts. At the same time, the development within electrical drives enables more versatile chassis dynamometer setups with better accuracy at a reduced cost. We are developing a new chassis dynamometer laboratory for vehicle research, aiming at extending a recently commercially available dynamometer, building a new laboratory around it, and applying the resulting facility to some new challenging vehicle research problems. The projects are enabled on one hand by collaboration with the dynamometer manufacturer, and on the other hand on collaboration with automotive industry allowing access to relevant internal information and equipment. The test modes of the chassis dynamometer are under development in a joint collaboration with the manufacturer.

To evaluate driver perception of a vehicle powertrain a moving base simulator is a well-established technique. We are connecting the moving base simulator Sim III, at the Swedish National Road and Transport Research Institute with a newly built chassis dynamometer at Vehicular Systems, Linköping University. The purpose of the effort is to enhance fidelity of moving base simulators by letting drivers experience an actual powertrain. At the same time technicians are given a new tool for evaluating powertrain solutions in a controlled environment. As a first step the vehicle model from the chassis dynamometer system has been implemented in Sim III. Interfacing software was developed and an optical fiber covering the physical distance of 500 m between the facilities is used to connect the systems. Further, a pedal robot has been developed that uses two linear actuators pressing the accelerator and brake pedals.

Variable cam timing engines pose new questions for engine control system designers. The cam timing directly influences cylinder air charge and residual mass fraction. Three models that predict residual mass fraction are investigated for a turbocharged dual independent Variable Cam Timing (VCT) engine. The three models (Fox et. al. 1993, Ponti et. al. 2002, and Mladek et. al. 2000) that all have real time capabilities are evaluated and validated against data from a crank angle based reference model. None of these models have previously been validated to cover this engine type. It is shown that all three models can be extended to dual independent VCT engines and that they also give a good description of the residual gas fraction. However, it is shown that the two most advanced models, based on a thermodynamic energy balance, are very sensitive to the model inputs and proper care must therefore be taken when these models are used.