Altair MotionView 2021 Release Notes


The Altair MotionView 2021 release provides several enhancements and bug fixes to the MotionView:
  • MotionView Python API
  • MotionView-EDEM Interface Updates
  • Track Builder
  • New Leaning Three-Wheel Example Models
  • New 1D Anti-Lock Braking and Electric Powertrain Models
  • Full-Vehicle Event Updates
  • DELFT-TYRE (MF-Tyre/MF-SWIFT) Version Update
  • Other Enhancements
  • Resolved Issues

MotionView Python API

MotionView now has a Python interface for creating a model. Using the API, MotionView models can be created, queried, and modified through Python. This functionality opens avenues for modeling and customization, leveraging the power and flexibility of the Python language.

The API documentation for each entity with examples is available in the MotionView Python Reference Guide.

MotionView-EDEM Interface Updates

Flexible body coupling with Altair EDEM is now supported. It is possible to transfer a flexible body to EDEM as well as add it to the EDEM system for interaction.

MotionView now uses obj files in the background to transfer geometry to EDEM. This change significantly speeds up the transfer process. In addition, the EDEM system panel has been enhanced with an option to pick either a Body or a Graphic. This change enables the selection of all graphics belonging to a body at once. For more details, please refer to the Bulk Material Interaction topic.

Track Builder

A new utility is now available for building track systems. This utility assists in building the track linkage along with other components in the track system such as sprockets, rollers, and idlers. The tool is available under the Model menu.

Figure 1.

Refer to the Track Model topic in the MotionSolve User Guide for additional details.

New Leaning Three-Wheel Example Models

MotionAuto adds leaning three-wheel example models in two configurations: two (2) front wheels and one rear wheel and one front wheel and two rear wheels. To access the models, load the MBD Vehicle Dynamics Tools preference file and then select the “Vehicle Tools” menu from the MotionView menu bar and then select “Example Models” and choose the desired model to open. The leaning three-wheel example models may be used with all full vehicle events.

Figure 2. 1+2 and 2+1 Three-Wheel Leaning Vehicles

New 1D Anti-Lock Braking and Electrict Powertrain Models

MotionAuto adds new 1D Anti-Lock Braking and Electric Powertrain models. These 1D models are FMUs exported from Altair Activate and wrapped by MDL systems for use with MotionView and MotionSolve. The 1D models are offered as assembly wizard options in the two-wheeler and passenger car libraries. The Altair Activate models (.scm files) are included so you can view and edit the models to produce new FMUs as needed. Specific features of the 1D models are described below.
Anti-Lock Braking

Anti-lock braking systems sense impending wheel lock-up under braking and modulate hydraulic brake pressure to individual brake calipers to prevent wheel lock. The 1D Anti-Lock Brake system takes wheel speeds, vehicle longitudinal acceleration, and front and rear master cylinder hydraulic pressures as feedback from the vehicle model and outputs hydraulic pressures for the brake calipers. The Anti-Lock Brake system consists of a control block and hydraulic block. The control block employs the wheel speeds and the vehicle longitudinal acceleration to estimate the tire longitudinal slips and the modulates the hydraulic control valves to reduce hydraulic pressures to specific wheels as need to limit slip.

Electric Powertrain

The Two-Wheeler and Car/Light Truck libraries now include electric powertrain systems for Battery Electric Vehicles (BEVs). The electric powertrain system maps throttle and brake inputs from the driver to demanded torque (either for traction or regeneration). The demanded torque and the motor shaft rotational speed are input to the 1D motor, inverter, and battery models encapsulated within an FMU. Output from the FMU is the actual torque produced or absorbed by the motor which may differ from the demanded torque due to current or power limits. The actual torque is applied to the driveline to accelerate or decelerate the vehicle.

The MDL system wrapping the FMU 1D motor, inverter, and battery models includes the motor’s stationary and rotating mass and inertia, and also the battery mass and inertia which is a significant portion BEVs total mass and inertia. Finally, the electric motors’ torque-speed characteristic is read from an external file for use in Altair Driver’s feedforward speed and acceleration control.

Full-Vehicle Event Updates

You can now select the road for an event and set Altair Driver PID grains for the event from the event editors.
Road Selection
All event editors now contain a Road Parameters section with an option menu for selecting the road. You can choose to run the event on a flat road, run the event on a road file you select in the event editor, or run the event on the road files specified from the AutoTires.

Figure 3.
Road Graphics
In addition, when you select to run on a flat road the event editor offers you the option to create road and path graphics. A road settings dialog give you control over the size and colors of the graphics.

Figure 4. Single Lane Change Event with Road and Path Graphics
Driver PID Gains
All event editors now offer the ability to set Driver gains. The gains available depend on the vehicle type. For leaning vehicles (for example, motorcycles and scooters) you can set the lean angle and lateral path PID gains. For all vehicles you add and set the gains for a longitudinal PID controller to improve speed and acceleration control.

MDL Library Enhancements

Two-Wheeler Library
  • A classic telescopic front fork system sized for scooters is a new option available in the two-wheeler assembly wizard.
  • The stiffness and damping values in scooter front and rear suspensions systems are updated provide more realistic ride-frequencies and eliminate overdamping.
Truck Library
The Truck Library adds an option for Electric Power Assisted System (EPAS) to the pitman arm steering system. The assist torque acts on the input shaft to the steering gear in parallel to the torque that comes from the driver.

DELFT-TYRE (MF-Tyre/MF-SWIFT) Version-up to 2020.1.1

DELFT-TYRE from Siemens distributed with Altair HyperWorks is updated to Simcenter Tire version 2020.1.1 from version 6.2.2. Simcenter Tire is Siemen’s rebranding of TASS/TNO’s DELFT-TYRE. DELFT-TYRE version 2020.1.1 is thread-safe and available for real-time operating systems, MotionSolve models employing DELFT-TYRE version 2020.1.1 typically run faster than those employing DELFT-TYRE 6.2.2 while producing the similar results. Most users of DELFT-TYRE with MotionSolve should only notice faster execution. However, there are some differences that long time users of DELFT-TYRE need to be aware of: these are described the “Differences” section below.

To ease potential problems users may have transitioning to DELFT-TYRE 2020.1.1, Altair is continuing support DELFT-TYRE 6.2.2 through the HyperWorks 2021 release. NOTE: Altair will discontinue support of DELFT-TYRE 6.2.2 with the HyperWorks 2022 release. To revert to DELFT-TYRE 6.2.2 in HyperWorks 2021, set the environment variable MS_DELFTTYRE_6 to 1.
DELFT-TYRE Version 2020.1.1 shows the following differences with respect to MF-Tyre/MF-Swift 6.2.
Un-Supported Fit Types
DELFT_TYRE 2020.1.1 drops support for the following versions of the Magic Formula equations (fit types):
FITTYP = 21 MF-Tyre 5.2 Magic Formula equations
FITTYP = 50 MF-Tyre 6.0 Magic Formula equations

Further, the tire property parser is stricter than in previous versions of DELFT-TYRE, so it is typically not possible to change the FITTYP in a file from an old version to a new version. If you have tire property files using these un-supported fit types, please consider using the newer example tire property files from the HyperWorks installation (see ..Altair\2021.0\hwdesktop\hw\mdl\autoentities\properties\Tires\MF_SWIFT), or contact Siemens to have your older tire property files refitted.

Property File Header Block
DELFT-TYRE 2020.1.1 requires using the block name [MDI_HEADER] as the first block in the tire property file. Some example tire property files in older versions of HyperWorks use [ALTAIR_HEADER] as the first block and DELFT-TYRE 2020.1.1 reports an error reading these files. Replacing ‘ALTAIR_HEADER’ with ‘MDI_HEADER’ corrects the error.
Property File Units
Only SI units are allowed as input in the tire property file. Automatic conversion of non-SI units to SI units is not supported.
2D Enveloping Contact
The 2D enveloping contact method is deprecated (USEMOD = 4xx).
Motorcycle Contact Mode
In DELFT-TYRE 2020.1.1 the values of the parameters MC_CONTOUR_A and MC_CONTOUR_B determine if a tire is a motorcycle tire and enable motorcycle behavior. The motorcycle contact mode is deprecated (USEMOD = 2xx) and it is no longer possible to treat car tires as motorcycle tires or vice versa.
TNO Roads
DELFT_TYRE 2020.1.1 drops support of 2D ’TNO Roads’ in rdf format (for example PlankRoad, PolylineRoad, and SineRoad) and USEMOD = 3xx for employing a tire’s distance travelled as an ordinate for 2D roads. Where possible 2D ‘TNO Roads’ are replaced by Altair’s 2D roads.
Known Issues
Setting the road friction multiplier MU in TNO flat road has no effect in DELFT-TYRE version 2020.1.1. DELFT-TYRE version assumes MU = 1.0 ignoring user input.

CDTire Version Up to v4.2.11

With HyperWorks 2021 CDTire is updated from version 4.2.2 to 4.2.11. See the CDTire documentation for additional information.

CDTire for MotionSolve Now Employs Altair Licensing

With the HyperWorks 2021 release, CDTire now uses Altair Licensing. If you previously purchased CDTire for MotionSolve or CDTire for MotionSolve with resizing and your maintenance is paid, your HyperWorks 2021 license will enable use of CDTire with MotionSolve. Going forward this means you no longer need to run the CDTire license server and install a separate CDTire license. Note there is no unit draw for CDTire. If you purchased CDTire for MotionSolve, and you Altair License does not enable usage of CDTire, please contact your Altair Account Representative.

Known Issues

  • Linux Road Tools Issues: 3D Spline Road used for Event path has problems, which affects closed loop events.
  • Have to set ENVVAR to access electric powertrain.
  • Road mu not effective with DELFT-TYRE 2020.1.

Other Enhancements

Updates to Multi-Disciplinary Tools
  • The old "points2mesh" macro is replaced by NEW "points2nodes" and "points2fpoints" macros
  • Replacement of old "roller2Dcam_*" systems by NEW "roller2cam" macro
  • New Seal feature
  • Updates to geometry features in HyperMesh
    • simplification of "apply2displayed" and "apply2marked" macros management
    • improved "line2motion" macro management in "apply2marked" mode
FMU Updates
FMU panel and the Edit dialogs have been updated. Reload FMU is now available in the FMU entity panel. A Reset to defaults button is available to reset the inputs and parameters individually.

The MDL statements for FMU have been revamped. Input and Parameter array arguments have been removed from *FMU while new data statements *SetFMUInputs and *SetFMUParameters are provided. MotionView maintains backward compatibility. Support for older usage of statements is continued. MotionView automatically saves with the newer syntax and statements.

Virtualization of Joints
MotionView supports the virtualization of joints functionality of MotionSolve, where the joint is represented as a soft constraint instead of a rigid constraint. This is particularly useful in models which may have redundant constraints.
Geometry Import
Import geometry process has been simplified. The geometry is imported directly into MotionView without the need for additional inputs. Material assignment can be made through right click context in the graphics area upon selection of graphics.
Hiding Implicit Graphics in Systems
An attribute draw_graphic is available at the system entity level to show/hide the implicit graphics of entities within the system. Usage: *Set(sys.draw_graphic, false), where sys is the variable name of the system. If set to false, all implicit graphics within the system including child systems are hidden.
Missing Graphic Files
File Graphics with missing reference file when not used in contacts will not prevent export of the solver deck. A warning is now issued instead of an error.
User Defined Solver String
User defined solver string is now supported.

Resolved Issues

  • Compliant joint body data-members referred to old reference in some cases after the body is merged.
  • First entry in the Parametric points table is empty on invoke.
  • Parametric Points will not use loc_rel_to function if the points are being defined in Global Frame.
  • Graphics defined using a reference marker is shown with respect to Global Frame when changing the file through dataset.
  • FMU located in a read-only folder was not accessible.
  • Copying auto-entity within the same parent caused error due to definition name.
  • App error on clicking contact properties macros when selected entity is not a contact.
  • Cratio Vector damping on flex bodies had display issues.
  • Flexbody when used with milli-second as time unit fails to solve.
  • Copying a Graphic system from a vehicle model crashes MotionView.
  • An app error appears when CPU core field is changed under Simulation Settings in Run panel.
  • An app error is encountered when editing an entity data through the Forms dialog.
  • MODLOAD matrix in the MTX file had a formatting issue.
  • Several other entity export issues to Msolve Python has been resolved.
  • Importing of Hypermesh FE model using Import CAD/FE using Hypermesh tool fails to bring mass and inertias.
  • Cut and paste of entities from system containing *if statements gives errors.
  • Cut/copy/paste of bodies having graphics in graphic system causes crash of application.
  • ADF file driven Vehicle models fails to solve when used as an FMU.
  • App error in data summary after selecting a curve with filters on for entities and changing to a different tab.
  • App errors in CG inertia summary when entering incorrect value or expressions.
  • Symmetric properties check box on the Beam pair panel does not work.
  • Damping in PLINE elements within the NLFE Belt Pulley and NLFE spring has been changed to 0.001.
  • Application error during Assembly-Save As after creating a new session.
  • Issues with export to MotionSolve Python.
    • Location based functions are incorrectly exported to MSolve Python when used in upper or sentence case.
    • Failure to export to MotionSolve py format when deformable surface is present.
    • Force outputs on non-compliant joints creates request for compliant part of the joint.