Version 4.0

Vehicle Dynamics Library 4.0 is part of Modelon’s 2022.1 release.

New Features

Example Models Restructured

The vehicle and chassis example models have been restructured to be easier to find and use. At the vehicle level, each example vehicle ( Compact, Coupe, Sedan and Pickup) has a set of pre-parameterized powertrain and brake models and the corresponding vehicle variants that use these. Similarly, each chassis example has a package in ( Chassis.Examples) containing pre-parameterized suspension models of varying fidelity. The Compact and Sedan chassis examples have been updated w.r.t. suspension kinematics and compliance to better reflect common vehicles of these types.

Consistent Vehicle/Chassis Mass

Powertrains and brakes used in example vehicles have been updated to have mass properties turned off. This provides consistent mass and inertia between chassis and vehicle simulations without adjustments. For applications where mass is needed, for example if the engine is mounted on bushings, the mass properties can easily be turned on with the enable_mass_properties flag in each component.

Brake Model Examples

All vehicle examples now use the Basic brake system. In previous releases, this example brake system was called Lumped. The example brake systems have been resized based on the mass properties of each vehicle to ensure better stability under braking.

Engine Model Examples

The Engines.Examples have been expanded and regrouped based on the engine size (number of cylinders) with appropriate torque maps and engine rotational inertias. Each engine size now has properly parameterized examples of the tabular, polynomial, cycle-resolved pressure and cycle-resolved engine torque models.

InputPlanes and InputPlanes2 Ground Models

Two new ground models have been added: InputPlanes and InputPlanes2. These ground models allow external inputs for ground contact information with an individual ground plane for each wheel. The pivot position and inclination of each ground plane is controlled individually. For the InputPlanes2 model, the surface friction of each ground plane is also defined individually.


Compatibility with MSL 4.0.0

This release of VDL is now compatible with MSL 4.0.0. MSL 4.0.0 is not backward compatible to previous versions. Therefore, VDL is no longer compatible with previous versions of MSL and must be used with MSL 4.0.0 or higher. Please see the release notes for information about the exact difference between version 4.0.0 and version 3.2.3, as well as information about compatibility with other Modelica packages.

Minor Improvements

  • The OpenCRG ground model was updated to use OpenCRG 1.2.0. ASAM OpenCRG 1.2.0 is backward compatible to OpenCRG 1.1.2. This is the first release of OpenCRG since it was taken over by ASAM (Association for Standardization of Automation and Measuring Systems)
  • The base wheel templates and sensors have been modified to add tire surface friction (mu) to the signal bus as VDL_whl_mu.
  • A kingpin_longitudinal_offset parameter is available in the LumpedMass, Polynomial, and SwingArm reduced fidelity front suspensions to allow a longitudinal offset of the steering joint at the wheel center.
  • The kinematic joints of the coupling components in Chassis.Couplings have been moved to the trailing component. This eliminates the need to change the fix_coupling parameter in the towing coupling when a trailer is connected thus this parameter is removed.

Minor Changes

  • The Examples.Simulink models have been removed as the Functional Mock-up Interface (FMI) is a better approach for deploying models. Please see Examples.FMI for equivalent models using the FMI standard.
  • The Compact Planar chassis has been deprecated and will be removed in a future release. The Compact reduced fidelity models: Compact LumpedMass, and Compact Polynomial chassis provide a better alternative.
  • A bug has been fixed in the ComplianceAnalysis controller which caused the left wheel camber to be written with the opposite sign in the compliance matrix in a file generated using a compliance analysis experiment e.g. SteerableSuspensionComplianceAnalysis.
  • The ComplianceInput model used in elastokinematic tabular linkages (e.g. TabularSTTE1) has been updated to use the {3,1,2} rotation sequence by default instead of {1,2,3}. This is consistent with the kinematics model used in these linkages and the hub angle sensors used to generate the compliance matrix in a ComplianceAnalysis experiment.
  • The effect of the k_rpm and k_thr scaling parameters on the CycleResolvedTorque (e.g. I2) engines has been made consistent with the Tabular engines as they use the same torque map (rpm_thr_table_tau table). Previously, these scaling parameters had the opposite behavior in the CycleResolvedTorque engines compared to the Tabular.

Conversion of User Libraries

User libraries will automatically be converted from version 3.7. These conversions are made using the included conversion script: VehicleDynamics/Resources/Scripts/Convert_to_4.0.mos.