Photo credit Peter NybergThe four wheel vehicle dynamometer was funded by the Moviii-project and the laboratory is developed and extended together with Rototest and VTI.
Drive cycles in vehicle optimization
Drive cycles are used for vehicle testing and certification, but also as an engineering tool during development. In the latter application an important question is what test cycle to use to be able to excite and examine a certain component or function under study. In general terms the aim is to establish the correspondence between drive cycle and test object. Two projects that have been performed so far are a study of co-surge in a twin turbo V-engine car, and a study of a split axle hybrid where a diesel drives the front axle and an electrical motor drives the rear axle.
Vehicle behavior models
The vehicle behavior part of the project combines the propulsion laboratory with the informatics laboratory in order to find efficient descriptions. The picture below shows one of our cars equipped with additional modern sensing equipment on the race track we collaborate with to obtain measurements.
Projects so far has been about powertrain oscillation analysis aiming at tire pressure analysis, and models for at-the-limit maneuvers. The latter models have been used for calculations of time-optimal behavior.
Hardware In The Loop Co-Simulation
I an attempt to increase the fidelity of moving base simulators while at the same time developing a new tool for evaluating powertrain solutions the VTI moving base simulator SimIII has been connected with the chassis dynamometer in the Vehicle Propulsion Laboratory. The physical distance between the facilities is about 500m.
The setup lets the driver of the SimIII simulator experience an actual powertrain while technicians are given a new tool to evaluate powertrains solutions in a controlled environment.
For this purpose a pedal robot was constructed that actuates the throttle and brake requested by the driver in the moving base simulator over at the VTI facility. The vehicle response is then measured and sent to the VTI facility where it is actuated in the moving base simulator.
Results from running the complete setup showed expected functionality and we are successful in performing a driving mission based on real road topography data. Vehicle acceleration and general driving feel was perceived as realistic by the test subjects.