drive_ti.png

System Integration as early as possible

Powertrain in the Loop Test System

The increasing complexity of modern powertrains is placing increasing demands on System Integration in an early development stage. Development engineers need Test Systems to test powertrains in a virtual environment without having a prototype vehicle. System Integration in the virtual environment has to consider typical functional aspects from road tests where system operation

  • effects how driver interacts with vehicle (powertrain)
  • effects how drive cycles activate, operate and stress the system
  • reacts on changes in environmental conditions
  • changes the load profiles for components, especially in HEV
  • can prevent/reduce component damage and provides additional limp home capabilities
  • causes unforeseen interactions which result in undefined operation conditions. 

AVL Approach

The success of testing modern and complex powertrains is clearly determined by the interactions of mechanical components, electrical components, and Control Units and Control strategies. These interactions can only be figured out during virtual driving maneuvers. A virtual vehicle-driver-road-infrastructure-traffic environment system generates real-world testing loads to the powertrain. This testing-method is known as "maneuver based testing". AVL's Powertrain in the Loop Test System involves two major modules:

  • The vehicle simulation is calculating the traction force of each wheel to mimic vehicle loads during proving ground tests. A vehicle dynamics model with 6 Degrees of Freedom (6DoF) is mandatory to describe the vehicle's motion in space. These 6DoF are the accelerations in X, Y and Z direction (Jerk, Side Shift and Lift) as well as the rotations around these axles (Roll, Pitch and Yaw).
  • The load dynamometers (AVL DynoWheel) are replacing the wheel and do have an inertia comparable to the wheel. Thus the dominant vibration modes, e.g. during a Tip-In, are on the Powertrain in the Loop Test System similar as on road tests.

Benefits at a Glance

  • Maneuver Based Testing on a virtual proving ground with vehicle like loads
  • Automated Calibration Transmission in an early development stage
  • Drivability Assessment without the need for a prototype vehicle