Altair MotionView 2025.1 Release Notes

Real-time Simulation Using Code Generation for Vehicle Models (MotionSolve)

MotionSolve 2024 introduced real-time simulation for car models created from the Vehicle Tool Extension > Assembly Wizard using a variable step integrator. The newly enhanced MotionSolve real-time simulation now uses code generation, a superior approach, and runs at a constant step and constant cost integrator.

• When Real-Time Compliant is selected, MotionSolve builds the FMU of the vehicle and solves it in real time.
• When Code generation is selected, the C code for the MotionSolve vehicle model, excluding the driver and tire, is generated. Use this code to compile and build an FMU, which can be used with any FMU-compatible software.
• The Car/Small Truck and Heavy Truck libraries, created by MotionView wizard, are supported in the Real-Time Compliant and Code generation options.

In vehicle models created with the Car/Small Truck and Heavy Truck libraries, the Code generation option is available in the Entity Editor for supported events, alongside the Real-time Compliant option. Use this option to generate the C code. Refer to the Readme.txt file, generated by MotionSolve, for details to build the C code.

Support for Generalized Damping for Flexible Bodies (MotionSolve)

MotionSolve now supports generalized damping for flexible bodies exported from a CMS analysis. Specify the generalized damping using the GenDamp block in Reference_FlexData. In OptiStruct, PARAM,MBDDAMP,YES specifies the inclusion of the generalized damping matrix in the Flex h3d_file. If Body_Flexible contains both a GenDamp block and modal damping, the cumulative damping will be applied.

Mass/Inertia Setup Event for Vehicle Models

The Vehicle Tools Extension introduces a new event that can be used for achieving a model’s target mass and inertia properties. This event’s primary use is in vehicle models for achieving the required front axle/rear axle mass distribution by tuning the mass (and optionally, moment of inertias) of a specific body using an automated program.

This reduces the manual effort that is required to run the model iterations for different mass and inertia values. The output from this event is a text file, which reports the mass and inertia to be used for the subject body to achieve the overall mass and inertia targets of the assembly.

To access the Mass/Inertia Setup event, go to the Entity Browser: Vehicle Tools > Events > General.

Visualization of Tire Deformation for Altair Fiala and Siemens Simcenter MF-Tyre/MF-Swift

The Vehicle Tools Extension now includes the option to visualize tire deformations for Altair Fiala and Simcenter MF-Tyre/MF-Swift. You can turn on the toggle to view the tire deformations in a HyperView animation. These deformations enhance the visual appeal of the animations and provide an approximate estimate of contact patch sizes.

User Spline Support for CSV/RPC/DAC Input Formats

In MotionSolve, an in-built subroutine is now available and can be used to read CSV, RPC/RSP, and DAC formats. This is implemented as a SPLINE_READ user-subroutine and is used to create a Reference_Spline element in the XML/Python solver deck. You can use this subroutine to read 2D and/or 3D spline data into your MotionSolve models. For 3D splines, only CSV formats are supported.

Functional Mockup Unit 3.0 Export

MotionView now supports exporting the model to the Functional Mockup Unit (FMU) version 3.0 format. An additional choice of the format is available in the Export dialog.

MotionSolve Results in H3D, Version 24

MotionSolve H3D results have been upgraded and will be written in H3D version 24, which can be read from HyperView 2024.1 or later.

Static and Assembly Analysis

MotionSolve automatically enables static_hold for a constant expression in an explicit control_diff during static/assembly to avoid convergence failure.

MotionSolve Linear Analysis

In MotionSolve, linear analysis has been improved for enhanced performance, which may lead to differences in the linear results.

Edit Variable Names in Wizard Models

It is now possible to change the variable names of entities in models built using the wizards. Caution is recommended, however, when changing the variable names, as it could affect tasks or events that might depend on entities whose variable names have been changed.

Pre-evaluation of User-defined Templates

The user-defined template now has a Boolean attribute called pre_evaluate. This option is useful during the model export when the template needs to be evaluated before other entities. This option is now available in the template’s Entity Editor, labeled as Evaluate early on export.

Turn Off Static in Full Vehicle Driver Events

The AltairDriver Events in the Vehicle Tools now contain an option to skip the static simulation that precedes the transient simulation. This option supports the vehicle models that do not achieve static equilibrium easily. A model may not achieve static equilibrium if it is on a road surface this is not flat, or if the model has residual forces at the beginning. Turn off the Run initial static option from the Driver Event's Entity Editor.

In addition to the first static, the AltairDriver performs two additional static simulations to estimate steer ratio. These can also be skipped. For example, if you have a rear-axle steered, or all-axle steered vehicle, skipping the steer estimation and manually entering the steer ratio is recommended (steer ratio is used by AltairDriver’s Feed Forward steer controller). Turn off the Compute steering ratio option from the Entity Editor if it is not necessary.

Version Upgrade for Cosin FTire

The Vehicle Tools Extension has upgraded the support for Cosin FTire to 2024-4. The new version is backward compatible with tire and road input files from previous versions.

Going forward, MotionSolve will support the FTire interface v2024-4 and earlier versions. Future versions of MotionSolve will maintain the interface, but cannot guarantee its compatibility.

Version Upgrade for Simcenter MF-Swift/MF-Tyre

The Vehicle Tools Extension has upgraded the support for Siemens Simcenter MF-Tyre/MF-Swift to v2412. The new version is backward compatible with tire and road input files from previous versions.

nPost Event for Models Without Tires

An n-Post event from the Vehicle Tools Extension can be now added to a model that does not have tires. In the early stages of the product development, when the model does not have fully detailed tire data and property files, the nPost event can be used to run a spindle-coupled analyses that can produce meaningful results.

Anti-squat/dive, Motion-ratio, and CG Location Subroutines Using C++

The subroutines that calculate the anti-squat/dive, motion-ratio, and CG location have been migrated to use a C++ DLL instead of a Python script. This provides some performance improvement and better compatibility with MotionSolve real time. Models that use the Python subroutines will continue to work in newer versions of MotionSolve.

Expression Builder for File Data Members

It is now possible to define parametric expressions for any field that takes a file name as input or output through the Entity Editor. Every file field has the option Build Expression, which gives access to the Expression Builder.

This feature supports linking entities to file name datasets or a file path location, such as the solver file location.

Improvements to Pre-loading an NLFE Body

Previously, to provide pre-loads to an NLFE, a Python script was needed to convert the preloaded state XML file to a CSV file. You then had to use the CSV file in the Positions and Gradients dialog of the NLFE Entity Editor. The conversion from XML to CSV is no longer necessary. You can now use the state XML file in the Positions and Gradients dialog. Also, pre-loading more than one NLFE body in a model is now supported using the same XML file.

• MotionView crashes while editing multiple compliant joints.
• Spline3D does not expand when selecting Use local file and function name.
• Respond if option does not get the correct value in sensors.
• MotionSolve license is not returned if you interrupt a live run in MotionView.
• Replacing an assembly crashes MotionView.
• In Frequency Response Analysis, you cannot assign number of steps > 10.
• MotionView, with the Vehicle Tools Extension, fails to load a standard include file in certain cases.
• FLX crashes HyperView on Linux when plotting Nodal Strain or Stress.
• For the Move tool, the Tool orient mode (orange handles) is not reset when using the Shift button 'UP'.
• MotionView crashes when trying to clear the existing session using the Ctrl+N keyboard shortcut.
• Reload error for a saved XML model when the Python, Compose, or Matlab scripts are not in the working directory.
• MRF not written during a forced assembly in a reloaded model with flexible bodies.
• Drum road models are not solving when exported as a Python deck.
• In Electronic Power Assisted Steering (EPAS), the torque sensor expression has an error.
• Scooter models with CVT, built using the Assembly Wizard, have errors.
• SDF reports are not created for models with rear-steered axles or with more than two axles.
• Input signal files from nPost models are missing in the archived folder.

The following known issues will be addressed in a future release:

Vehicle Tools > Jupyter reports

There are limited usability options and modified workflows compared to previous versions. Select the Run All Cells option to view the plots.

In Edit mode, use Refresh to apply and display your changes.