nVIZ Ergonomics Plugin

Installation

Autodesk VRED provides two paths for maintaining plugins. Please identify the directory where you want to keep the nVIZ Ergonomics Plugin. The paths are displayed in the VRED terminal window after launching VRED:

Download and execute the nVIZ Ergonomics Plugin installer. After the installer has completed, you need to copy the two following files to your VRED plugins directory:

  • C:\Program Files\nVIZ\Ergonomics\nVIZ Ergonomics.py
  • C:\Program Files\nVIZ\Ergonomics\nVIZ Ergonomics.ui

License File and Config File

The plugin supports the import of ergonomics data from an Excel file. The definition of which data to read from the Excel file is defined in the config file. nVIZ will provide you with a custom Excel file parser and with a config file to meet the specific ergonomics process in your organization. Please contact nVIZ to receive your license file and config file.

The license and config files need to be copied to the directory:

  • C:\Program Files\nVIZ\Ergonomics\

After installation, the nVIZ Ergonomics Plugin can be launched from the context menu like any other VRED module – right mouse click on the Main Tool Bar or on the Quick Access Bar:

Ergonomics Review Preparation

Scene Graph Nodes

For the full functionality of the Ergonomics Plugin to be available for both the HTC and the ART tracking systems, also in combination with the nVIZ Motion Plugin for driving simulation, we require a special scene graph structure at the top level nodes as depicted below:

The naming of the nodes is arbitrary but they must be correctly referenced in the vehicle rig tab (see below “Vehicle Rig”) and the nodes need to be correctly referenced in the VRPN Tracking module (see below “Tracking System ART”) . Also, the structure, i.e., the parent-child relations and the order are mandatory.

  • Rigged_Camera – is required for the active camera.
    • ActiveVehiclePosition – is required for the alignment of the view points to the seat reference points across multiple vehicle types with different vehicle positions.
      • Ergo_Camera – needs to be the active camera for the ergonomics review.
  • CarMakerFR1 – is required for the driving simulation data in reference frame FR1 from CarMaker when using the nVIZ Motion Plugin for driving simulations.
    • nVIZErgoSeatReferencePoint – needs to be referenced to the VRPN tracking cart node (see below) and is required for transformations of the seat reference points and view points
    • nVIZErgoSeatBuck – needs to be referenced to the seating buck target in the VRPN tracking (see below) and is required for recording the position of the seating buck.
    • nVIZErgoViewPoint – needs to be referenced to the glasses target in the VRPN tracking (see below) and is required for recording the position of the glasses.
    • Vehicles_Switch – is required for storing multiple vehicles to be reviewed.
      • <vehicle name>_VehiclePosition – is required for the alignment of the vehicle position across multiple vehicle types.
        • <vehicle name> – this needs to be the top level node of your vehicle.

Tracking System HTC

The Ergonomics Plugin supports both the tracking system from HTC (OpenVR) for ergonomics reviews with the HTC Vive as well as the tracking system from ART for ergonomics reviews in a CAVE.

Ergonomics reviews with the HTC Vive require an extra HTC tracker to be positioned in the z-coordinate of the seat reference point. The “Reset HMD Pose” function (see “Ergonomics Review” below) will position the driver’s view in the scene at the x, y coordinates of the seat reference point and the z coordinate calculated from the vertical distance between the HMD and the tracker. The orientation will be aligned to the longitudinal vehicle axis.

Tracking System ART

Ergonomics reviews with the ART tracking system in a CAVE rely on the tracking of the seating buck by a VRED cart node. The imported ergonomics data needs to include the correct offsets for the seating buck targets.

The VRED scene graph nodes (see “Scene Graph Nodes” above) need to be correctly referenced to ART sensors in the VRPN Tracking module as depicted below. The “ViewPoint” node needs to be attached to the same sensor as the “Glasses” and the “SeatBuck” node needs to be attached to the same sensor as the “SeatReferencePoint”.

Ergonomics Review

Ergonomics Project

All the settings defined in an Ergonomics review can be saved to a project file and reloaded from there. The file format is *.egb

  • Open Project: Opens an existing Ergonomics project. The Windows Explorer will be launched when clicking the button.
  • Save Project: Saves all the Ergonomics Plugin settings to a binary project file.
  • Read Ergonomics Data File: Imports ergonomics data from an Excel file (see below “Ergonomics Data Import”)

Ergonomics Data Import

The starting point for an ergonomics review is the import of the ergonomics data stored in an Excel file. Typically this data includes the seat references points of multiple vehicles as well as seating buck dimensions, view point coordinates, seat and steering wheel adjustment ranges etc.

  • Read Ergonomics Data File: This function will launch the Windows Explorer, allow you to select the Excel file and then start an external process to extract the relevant ergonomics data from the Excel file according to the ‘xlsximport.config’ file.  By default, the config file created by the installer will be used:
  • C:\Program Files\nVIZ\Ergonomics\xlsximport.config

The results of the data import is displayed in a Windows terminal window. Additionally the results are written to a log file in the same directory as the imported Excel file:

  • C:\…\…\Ergonomics_<Time Stamp><Excel File Name>.log

After successful data import, the combo boxes and the list fields on the different tabs of the plugin will be filled in.

The color of the “Check Active Vehicle” button indicates the completeness and consistency of the imported data per selected vehicle.

  • Check Active Vehicle: This function performs a check on the data of the vehicle selected in the “Vehicle” combo box to make sure the required scene graph structure is correct ( see “Scene Graph Nodes” above). See the VRED terminal window for the results of the check as depicted below. The color of the button will also change according to the result:
    • Green: Indicates that the data of the active vehicle is complete and consistent, i.e., all paths to mandatory and optional nodes in the vehicle rig have been found.
    • Yellow: Indicates that the data is consistent, i.e., all paths to mandatory nodes in the vehicle rig have been found but some optional nodes could not be found.
    • Red: Indicates that the data is inconsistent or incomplete.

Tracking System

Make sure that you have selected the correct tracking system.

  • Tracking System: Select the tracking system you are using from the combo box.
  • Reset HMD Pose: This function is applicable to the HTC tracking system (OpenVR) only. It will calibrate the current position and orientation of the HMD to be seated in the driver seat looking straight ahead (see “Tracking System” above).
  • Seat Reference Point Tracking: This function is applicable only for reviews in a CAVE with the ART Tracking and in combination with the nVIZ Motion Plugin for Virtual Test Driving . Use it to deactivate the sensor which sets the seat reference point to get a smooth vehicle motion. Otherwise the motion will be juddering at the refresh rate of the sensor.
    • Sensor ID: The sensor ID assigned in the VRED VRPN tracking dialog.
    • Body Name: The body name assigned in the VRED VRPN tracking dialog.

The tracking data is recorded from the sensors and will be shown in the LCD displays if the “Display Listener” is checked.

  • Vehicle Reference: If the radio button “Vehicle Reference” is selected, the seat reference point and view point coordinates will be displayed in the vehicle reference coordinate system.
  • DTrack Reference: If the radio button “DTrack Reference” is selected, the seating buck target and glasses target coordinates will be displayed in the DTrack reference coordinate system (depicted below).

Seating Position and View Point Simulation

The Ergonomics Plugin simulates different seating positions in the virtual scene based on the imported seat reference point coordinates as well as different view points based on the view point coordinates.

  • Seat Reference Point: Select a seat reference point (driver, front passenger etc.) from the combo box to simulate the seating position.
  • View Point: Select a view point (95th percentile male, 5th percentile female etc.) from the combo box to simulate the view point. The seat reference point Z value will be offset by the delta Z between view point and glasses target at the moment the combo box gets switched. Select “Head Tracking” to reset the seat reference point Z value to the original value.

Seat, Steering, etc. Adjustments

The Ergonomics Plugin simulates the adjustment of the vehicle items relevant for ergonomics (seat, steering column and mirrors) within the defined ranges and based on the defined pivot points (see below “Adjustment Items”).

  • Adjustment: Selects the item to be adjusted, seat, steering column, interior mirror, etc.
  • Forward-Backward: Moves the item within the defined ranges along the defined vector ( see tab “Adjustment Items”).
  • Left-Right: Moves the item within the defined ranges along the defined vector ( see tab “Adjustment Items”).
  • Down-Up: Moves the item within the defined ranges along the defined vector ( see tab “Adjustment Items”).
  • Reset Adjustment: Resets the currently selected adjustment item.
  • Reset All Adjustments: Resets all adjustment items for the active vehicle.
  • Copy Adjustment Settings: Copies adjustment ranges and settings for all adjustment items from the vehicle selected in the “From” combo box to the active vehicle.

Ergonomics Data

Seat Reference Points

The imported seat reference points per vehicle are listed in the list field.

  • Update Seat Reference Point: Updates the selected seat reference point coordinates to the spin box values.
  • Copy Seat Reference Point: Copies the seat reference point values from the vehicle and seating buck selected in the combo boxes to the active vehicle and seating buck.

View Points

The imported view points (95th percentile male, 5th percentile female etc.) per vehicle are listed in the list field.

  • Add View Point: Adds a view point to the list.
  • Update View Point: Updates the selected view point to the spin box values.
  • Delete View Point: Deletes the selected view point

Vehicle Position

The imported vehicle positions per vehicle are listed in the list field.

  • Update Vehicle Position: Updates the selected vehicle to the position entered in the spin boxes. The active vehicle is transformed to that position.
  • Design CSYS: The active vehicle will be positioned in the design reference frame (typically located in the center of the front axle with the X-axis pointing backwards).
  • CarMaker FR1: The active vehicle will be positioned in the CarMaker FR1 reference frame (located at the vehicle’s rear most point on the ground with the X-axis pointing forward). This is required if the plugin is used together with the nVIZ Motion Plugin for driving simulations.

Vehicle Rig

The imported vehicle rig per vehicle is listed in the list field. At import of the Excel file with the ergonomics data, the plugin will check for vehicle rig files <name>.txt in the directory:

  • C:\Users\Public\Documents\nVIZ\Ergonomics\UserData\VehicleRigs

If a text file with a name identical to the vehicle name from the Excel sheet is found, the rig file will be imported for that vehicle. Otherwise, the default vehicle rig file will be imported from the directory:

  • C:\Program Files\nVIZ\Ergonomics\UserData\VehicleRigs

After import, the plugin will search for the node paths specified in the rig file and indicated found or missing node paths in color.

  • Green Line: Node path was found.
  • Red Line: Node path was not found and node is mandatory.
  • Yellow Line: Node path was not found but node is not mandatory.

Adjustment Items

The adjustment item ranges and pivots are listed in the two list fields.

  • Update Adjustment Ranges: Updates the adjustment ranges of the selected item to the values of the spin boxes.
  • Update Adjustment Pivot: Updates the adjustment items pivot point of the selected item to the values of the spin boxes.
  • Pivot Position and Orientation: The pivot point position will be taken from the three coordinate values and the orientation will be taken from the three angles.
  • 2 Points => Direction Vector: The pivot point position will be taken from the coordinates of the first point and the pivot orientation will be calculated from the direction vector P1-P2 such that the X-axis is aligned to the vector with the Z-axis upwards.

Options

  • Print Information: Prints debug information to the VRED terminal window.