The past 12 months of the EcoCAR competition marked quite a turnaround for the Virginia Tech Hybrid Electric Vehicle Team (HEVT). After falling short of expectations at the Year 1 Finals in Toronto, the team returned to the garage with a new group of engineers and placed first among teams using National Instruments systems in the Hardware-in-the-Loop (HIL) presentation at Winter Workshop in January. How did they do it? Since the summer, mechanical engineers on the Controls subteam have spent countless hours becoming control system designers. In the video below, “Virginia Tech Gets in the Loop for EcoCAR,” the team explains the crucial points of its HIL system, as well as the benefits of using HIL for designing controllers.
The team points out that their success would not be possible without the gracious and patient support from National Instruments. They company donated powerful software, like LabVIEW and VeriStand, and hardware, like CompactRIO supervisory controller and simple-to-use USB-CAN interface, making it possible for HEVT to design and implement a safe, robust, control system. The team used their tools, in addition to the real-time vehicle model provided by GM and Argonne National Laboratory, to design its control strategy and implement it in both hardware and software. The ultimate goal is a refined and accurate real-time vehicle model running on the National Instruments PXI HIL Chassis. This model is important because it allows the team to test its controller against either the model or the real vehicle – and expect the same results. HEVT is using HIL to perfect its control code, so they can safely and simply take the controller from its HIL test stand and install it into the vehicle for further testing.
Safety is of utmost importance to HEVT and the safety-critical aspects of their control system is no exception. VeriStand’s “Stimulus Profile Editor” allows the team to simulate an infinite number of possible scenarios such as high temperatures, various vehicle speeds and communication errors, in order to ensure that the control code is robust and will not act unexpectedly under any circumstances. HEVT is confident that the amount of safety-critical testing they have done will allow them to put the controller in the vehicle in the coming weeks and compare real life to simulation! The Virginia Tech HEVT Controls team would like to thank National Instruments for their ongoing support.
Enjoy the video!