Powertrain Dynamics Library

The Powertrain Dynamics library is a Modelica library for modelling rotating MultiBody systems like automotive powertrains. It has been designed to provide a convenient modelling methodology and deliver efficient simulation of these complex systems.

The models support the full design cycle using simple 1D representations for concept evaluation that easily evolve into detailed MultiBody models for detailed analysis. Animation is included in all the parts to aid understanding of the system dynamics. The library uses standard Modelica connectors and is compatible with all the other Automotive libraries available for Dymola.

Key Features

  • Detailed powertrain modelling with efficient simulation as a mulitbody system.
  • Includes engine, transmission, driveline and chassis models for complete vehicle simulation.
  • Build complex mechanical systems from individual elements such as bearings, shafts, gears, clutches, joints and mounting systems.
  • Evaluate 3D gear mesh forces, bearing loads and losses.
  • Shafts with a large number of linear and nonlinear compliance characteristics.
  • Longitudinal chassis models with Pacejka tyre slip and simple suspension with pitch and bounce.
  • Compatible with Vehicle Dynamics library, Engines, Powertrain and SmartElectricDrives libraries.
  • 3D Effects (torque reactions, gyroscopic effects etc.).
  • Faster simulation performance than Standard multibody library.
  • Flexible implementation.
  • Highly configurable with wide range of component fidelity.

Applications

The library is applied in many different applications as follows:

  1. Vehicle performance, fuel economy and drivability assessment capturing the full motion of the powertrain
  2. Hardware specification – complete torsional characteristic of transmission and driveline
  3. Conceptual architecture design – efficiency studies
  4. Control system optimisation using detailed physical models of the complete vehicle
  5. Modal analysis of the powertrain* for predicting torsional excitation modes i.e. shuffle
  6. Shift quality and feel – detailed components for capturing the dynamics of the gear shifting system
  7. Powertrain-chassis interaction – PTDynamics is fully compatible with the Vehicle Dynamics library allowing the interaction between the chassis and powertrain to be analysed

Library Contents

Engines

Mapped based engine model for torque generation, emissions and fuel consumption calculation. Simple engine controllers also included for idle speed and fuelling control.

Transmission

Torque converts, Retarders, shift mechanisms including synchronizers, detents and shift barrels. Powertrain mounts are included with various DOF’s and compliance characteristics.

Drivelines

Collection of examples and experiments assembled from examples models from the shafts, joints and differentials packages.

Chassis

Simple chassis with pitch, and roll Degrees of freedom as well as linear and pacejka tyre models are included for longitudinal dynamics. Various road definitions are also included.

Clutches

Numerous components for modelling torque transfer in a wide range of coupling elements. Wet and dry Multi-plate, Cone, Band and dog elements are all included ranging from simple to complex geometry defined responses.

Differentials

Templates and examples of gear bearing and shaft arrangements for a wide variety of differential arrangements (open and torsen) including slip control devices.

Gears

Gear mesh models with 3D force calculations with optional backlash, mesh stiffness and efficiency for spur and helical gears. Numerous planetary configurations are also included configurable for different levels of fidelity. Simple chain drive models are also included.

Joints

Multibody models of a wide range of joints found within power transmission systems including constant velocity, universal and plunging joints.

Shafts

Numerous options for uniform and composite shafts are included with a wide variety of torsional characteristics from rigid and simple linear to non-linear plastically deformable characteristics are included using a computationally efficient MultiBody approach.

Linearization

Linear systems analysis package with functions for natural frequency analysis and plotting.

Brakes

Simple disc brake models are included.

Drivers

Open and closed loop drivers available for drive cycle and simple source manoeuvres as well as specific TipIn and idiot start tests.

Resources

Technical Papers