Vehicle System Control Software Validation for the Dual Drive Hybrid Powertrain (2009-01-0736)

Through the use of hybrid technology, Ford Motor Company continues to realize enhanced vehicle fuel economy while meeting customer performance and drivability targets. As is characteristic of all Ford Hybrid Electric Vehicles (HEVs), the basis for resolving these competing requirements resides with its Vehicle System Control (VSC) strategy. This strategy implements complex high-level executive controls to coordinate and optimize the desired operational state of the major HEV powertrain subsystems. To ensure that the VSC software meets its intended functionality, a software validation process developed at Research and Advanced Engineering has been integrated as part of the vehicle controls development process.
In this paper, this VSC software validation process implemented for a next generation hybrid powertrain is presented. First, an overview of the hybrid powertrain application and the VSC software architecture is introduced. Then the software validation process is described, which includes unit testing, model-in-the-loop testing, hardware-in-the-loop testing and vehicle testing. After that, issues observed with the current validation process are identified, and an open-loop simulation versus target testing procedure is proposed to enhance the validation process. Finally, conclusions and opportunities for further improvements are summarized.