Load modeling and emulation for an earthmoving vehicle powertrain

Previously an earthmoving vehicle powertrain simulator (EVPS) was built at the University of Illinois to investigate generic power optimization of multi-load hydrostatic transmissions. In the current work, nonlinear load models for an earthmoving vehicle powertrain are developed for a wheel loader and emulated using the EVPS. The load models are to be utilized in the overall development and evaluation of controllers for multi-load powertrains. The three load models include steering, drive, and implement systems. The hardware-in-the-loop setup of the EVPS allows for two-stage pressure relief valves to be used in coordination with the real-time simulations of the load models to emulate powertrain loads. Simulation and emulation results from the load models are presented for a 180-degree loading cycle. Although this was done for earthmoving vehicles, it is felt that this hardware-in-the-loop approach with load emulation could be used in many automotive or other transportation applications.