Advanced shifting control of a two speed gearbox for an electric vehicle

The apparition of electric vehicles on the market generates new challenges. Within them, one of the most important is related to the vehicle autonomy. In this paper an advanced shifting control system for a two speed gearbox is presented. It combines driving conditions and driving style inference techniques in conjunction with an expert decision control system for selecting the most suitable gear for energy saving. The expert control system is offline-tuned using a set of pre-specified simulation trips which characterize different scenarios. These pre-specific trips are recognized in real time to apply the expert control rules. The strategy is combined with an automatic shifting sequence with speed synchronization which reduces shifting times and torque transitions. Compared to a single-geared vehicle, an energy saving up to 10% can be achieved keeping the driver sensations while driving. An ad-hoc HIL mechatronic test bed has been developed for the complete system testing purposes.