Development and Correlation of Co-Simulated Plant Models for Propulsion Systems 2020-01-1416

Model-based system simulations play a critical role in the development process of the automotive industry. They are highly instrumental in developing embedded control systems during conception, design, validation, and deployment stages. Whether for model-in-the-loop (MiL), software-in-the-loop (SiL) or hardware-in-the-loop (HiL) scenarios, high-fidelity plant models are particularly valuable for generating realistic simulation results that can parallel or substitute for costly and time-consuming vehicle field tests.

In this paper, the development of a powertrain plant model and its correlation performance are presented. The focus is on the following modules of the propulsion systems: transmission, driveline, and vehicle. The physics and modeling approach of the modules is discussed, and the implementation is illustrated in Amesim software. The developed model shows good correlation performance against test data in dynamic events such as launch, tip-in, tip-out, and gearshifts. To quantify the correlation accuracy, metrics are defined to provide a numerical assessment of plant model behavior and accuracy.

In this study the engine is treated as a torque source, to concentrate on transmission, driveline, and vehicle dynamics. If necessary, a full-fledged engine model based on GT-Power can be connected through co-simulation interface. Co-simulation of software from different vendors greatly expands the plant modeling capability and the flexibility of coupling with controllers. Co-simulated models for both SiL and HiL purposes are discussed, with the focus on the interface options, cosim running configurations, model reduction, and bench validation. Although the vehicle modeled here has a conventional powertrain with an automatic transmission, the modeling architecture and correlation methodology can be readily applied to alternative propulsion systems.