Knowledge Bank

As the regulations for fuel efficiency and vehicle emissions increase, the demand for more innovative fuel efficient vehicles grows. The term hybrid electric vehicle has become an everyday term, however; only 3.8% of cars sold in 2013 were hybrid or electric vehicles. A newer category of hybrids is the plug in hybrid electric vehicle, which is generally capable of driving in an all-electric mode and as a hybrid. A prominent challenge with plug-in hybrids is maintaining expected vehicle performance while achieving maximum energy efficiency. The goal of this research project was to develop an acceleration mode to meet performance and consumer acceptability targets for the Ohio State EcoCAR 2 plug-in hybrid electric vehicle. When defining the acceleration mode, it was necessary to evaluate the team determined acceleration targets. These targets were to accelerate the vehicle in both all-electric and hybrid modes from 0-60 MPH in 11.5 seconds and from 50-70 MPH in 10 seconds. The acceleration modes in both all-electric and hybrid modes were also expected to meet acceptable consumer standards for everyday driving. Based on the requirements, the acceleration modes were developed to meet all performance targets. Each mode operates similarly, but has different entrance and exit conditions. In developing the performance modes, it was necessary to evaluate the maximum component operating conditions to avoid causing any possible vehicle faults. The initial mode operation and algorithm development was done using in a Software-in-the-Loop simulator, where the impact of each modification could be easily tracked. Fault testing and timing was done using a real time Hardware-in-the-Loop simulator. The final validation and calibration will be done in the vehicle. Initial development has shown that the vehicle, in simulation, is able to enter and exit each acceleration mode and that the 0-60 MPH acceleration mode is able to achieve the acceleration target of 11.5 seconds. In taking the time to focus on hybrid vehicle performance the hope is that in the future consumers will consider plug-in hybrid electric vehicles both efficient and enjoyable to drive. This will increase the number of fuel efficient and low emissions vehicles on the road.