Virtual Testing and Simulation Environment [Micro-HiL] for Engine and Aftertreatment Calibration and Development -Part 2

The growing complexity of powertrain control strategies, software, and hardware is proving to be a significant challenge to the engineering community with regard to managing effective optimization to meet the desired performance. With an increased emphasis on shorter development time and the use of additional sensors and actuators becoming common, the increased dependence on physical models and use of complex interdependent control systems demands a thorough system understanding. This also encourages the use of process improvement tools to assist in an effective engineering process. In this paper, such a tool is discussed in its second phase of development. The Micro-HiL system will be discussed over a wide scope that focuses on the interests of the calibration and development community. The purpose of this paper is to provide an update on the Phase 2 activity of Micro-HiL development; Phase 1 was discussed in-depth at the 2011 SAE World Congress [2011-01-0703]. Beginning with a detailed discussion on new components that were incorporated into the Micro-HiL, the latter part of the paper will focus on several new functional areas that were introduced. The major component discussion will involve idle governing, aftertreatment modeling, engine model extension, and how a complete desktop test cell environment was realized. Finally, the reader will be shown how a virtual testing environment can be applied by harnessing known tools, and how this approach can play a crucial role in supporting the development and calibration community in their daily activity. INTRODUCTION The concept of Micro-HiL, where the virtual engine model is connected to a real time processing ECU through a series of sophisticated software and hardware interfaces, was conceived to develop a desktop test environment. Understanding the complex interaction between the various control strategies is becoming very crucial with increasing demand on sophisticated controls and refined calibration. The conventional approach used in most cases involves utilizing the test cell or vehicle for understanding these complex interactions. Very often the cost associated to study these interactions far out-ways the conceived advantages or the time required in test cell setup and testing does not fit within the current product development timeline. Thus a virtual environment where test execution can be made with full flexibility to alter the boundary conditions proves to be a great tool for calibration and strategy development. As discussed in the previous publication (2011-01-0703), the initial steps involved in developing the Phase 1 Micro-HiL were further enhanced to meet some of the new demands from calibration and development engineers. The key element addressed in this follow up effort is the creation of a Virtual Test Cell (VTC) environment. Features such as engine starting and idle control were implemented within the new setup to mirror processes that are associated with actual engine testing. Additional features such as component interchangeability were implemented to give the user the advantage of testing new components within the existing setup along with closed loop aftertreatment thermal management controls to expand the capabilities of the VTC to the aftertreatment field. Virtual Testing and Simulation Environment [Micro-HiL] for Engine and Aftertreatment Calibration and Development -Part 2 2012-01-0928 Published 04/16/2012 Harsha K. Nanjundaswamy, Mufaddel Dahodwala, Mitesh Farsodia, Dean Tomazic and Erik Koehler