Sequence of Actions Performed for a Defined Event

This section describes the sequence of actions performed by MotionView and MotionSolve when you run the event.

MotionView

  • In the event dialog, if the Path profile is set to road centerline, the driver demand file (ddf) is written using the centerline path that is created using the Road tools functionality. If the Path profile is set to curve, the ddf is created using the points from the MotionView curve entity.
  • The altair driver file (adf) is written out taking the event parameters from the dialog.
  • If the ‘Calculate on export’ check box visible in the Altair Driver panel is checked, the driver evaluates the vehicle parameters.
  • The road property file mentioned in the event dialog is paired along with all the auto tire entities.
  • The solver input file is then exported in the XML format.
  • After the solver input file has been exported, the road property files for all auto tires are reset to the previous value.

MotionSolve

  • A static simulation is performed on the vehicle during which the vehicle yaw and vehicle XY plane constraints are acting on the vehicle. The steering wheel motion is set to zero and the wheels are locked.
  • After the static solution is successfully completed the wheels are unlocked and the initial conditions for the vehicle are set. This includes component velocities and angular velocities of the wheels.
  • The steer ratio for the vehicle is then calculated as follows. The steering wheel is rotated by a known value and the corresponding wheel movement is recorded. The procedure is performed using two static simulations and the measured wheel movements are used to find the steer ratio.
  • Lastly, the vehicle constraints are deactivated, and the transient simulation is started as defined in the adf.