Durability and performance development for transmissions using a primemover to replace the combustion engine

Transmission Test System

The increasing complexity of modern powertrains is placing increasing demands on the Instrumentation and Test Systems. Parallel development activities of key powertrain components (combustion engine, hybrid engine, transmission, etc.) require transmission testing activities at the earliest possible stage. Validating the transmission in an early development phase requires test methods where as much system functions as possible can be tested without the combustion engine and without proving ground tests. Therefore it is mandatory to test available components as soon as possible to improve durability, functionality and performance. The Test System must be flexible to develop various transmission types:

  • Manual Transmission (MT)
  • Automatic Transmissions (AT)
  • CVT-Transmission
  • Automated Manual Transmissions (AMT)
  • Double Clutch Transmissions (DCT)
  • Transmissions for Hybrid Electrical Vehicles (HEV) 

AVL Approach

The success of testing modern and complex powertrains is clearly determined by the "Road to Rig" approach. AVL's Transmission Test System covers the requirements for durability and performance validation of modern transmissions for a Front-Engine – Rear Drive powertrain configuration without rear differential gearbox. Increased and enhanced rig testing is the way to reduce vehicle development times.

AVL's Test System involves four major modules:

  • The primepover (AVL DynoPrime) has a comparable inertia to the combustion engine which will be emulated. This ensures realistic torque reactions during gear-shifts and realistic acceleration.
  • The engine simulation module covers the engine stationary map and the torque rise time. Thus the transmission feels to difference to the replaced combustion engine.
  • The vehicle mass simulation is calculating the load to the powertrain based on the road load equation using aerodynamical drag and rolling resistance.
  • The load dynamometers (AVL DynoTrain) do have an optimized inertia to ensure a proper vehicle mass simulation.

Benefits at a Glance

  • Evaluation of specified strain limits of the transmission case and rotating parts
  • Evaluation of specified lifetime of gear teeth and bearings
  • Determination of lifetime of transmission clutch pack and brake lifetimes
  • Evaluation and optimization of the component dimensioning
  • Driving Performance and strategy
  • Upgrade to Maneuver Based Testing possible