2019.1 Release Notes – Vehicle Dynamics Library 3.3

Vehicle Dynamics Library v3.3 is part of Modelon’s 2019.1 release.

New versions of Modelon libraries are sold and distributed directly from Modelon, as well as approved resellers.

New features

  • Pacejka 2012/MF 6.2 Models – VDL now has a native implementation of the Pacejka MF 6.2 tire model. This model can capture effects due to changed inflation pressure. The inclination dependency in force equations has also been changed, giving a more accurate response to larger camber angles.
  • Moment Method Experiment – A Moment Method chassis experiment has been added which can be used to sweep over a range of sideslip and steering wheel angles to generate yaw moment coefficient vs lateral acceleration diagrams. These diagrams, typically called moment method or yaw moment diagrams, are used to understand the vehicle’s stability and maneuvering performance.A representative diagram for the CompactLEKPacejka02 chassis is shown below.

Improvements

  • The base wheel templates have been modified to add summary variables for longitudinal slip (summary_kappa) and lateral slip (summary_alpha).
  • A simple rack-pinion steering model called RackLinear has been added. This model contains a linear ratio steering gear and a simplified steering column. This model is now referenced in the reduced fidelity front suspensions: LumpedMass, Polynomial, and SwingArm.
  • New analytic mechanisms have been added to eliminate non-linear equation systems in linkages where a rigid tie rod is used with a kinematic kingpin joint. The affected linkages are: DoubleWishboneRockerRTE2, DoubleWishboneRockerSRTE2, DoubleWishboneRockerSTTE2, DoubleWishboneRockerTTE2, DoubleWishboneSTTE2, DoubleWishboneTTE2.
  • Gearset models in Powertrains.Transmissions.Gearsets now have unified interfaces. In transmission models, gearsets can now be exchanged for different types depending on the needs to the model.

Minor Changes

  • Limits have been added in the brake, clutch and accelerator pedal robots to ensure that inappropriate values are not passed to the respective vehicle subsystems. The brake pedal will only output a positive pedal force. The clutch and accelerator pedal will only output a pedal position between from 0.0 and 1.0.
  • A bug has been fixed in Modelon.Mechanics.Rotational3D.Shaft that caused difference in results depending on how causality was set. This had an effect in steering models where the shaft is used. Causality can now be set in the shaft without changing the behavior.

Conversion of user libraries

  • User libraries will automatically be converted from version 3.2. These conversions are made using the included conversion script: VehicleDynamics/Resources/Scripts/Convert_to_3.3.mos.

Requirements

  • Vehicle Dynamics Library 3.3 is based on Modelon Base Library 3.3 and Modelica Standard Library 3.2.2.
Tags:
Release Notes, Vehicle Dynamics Library, Automotive