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RACELOGIC Support Centre

How to Mount VB3iS

Mounting

VB3iS can be either fixed rigidly to a vehicle through the fixing holes, or secured using a telescopic mounting arm.


Try to position the unit as close as possible to the centre of the vehicle, making sure that it is level with the ground. If VB3iS is using its internal IMU, the unit should be ideally mounted in the direction of travel - as shown in the image below. However, if this is not possible, the internal IMU orientation can be changed using the VBOX Setup Softwarethe Front Panel of the unit or using the VBOX Manager.

For best results, mount the VB3iS and GNSS antenna as close to each other as possible. For example, bolt VB3iS to the seat rails and place the GNSS antenna on the roof directly above.

Note: VB3iS and the antenna should be mounted on the same rigid body to provide a relative reference. So for a vehicle such as a truck cabin, both the VB3iS and the antenna should be fitted to the cabin body (if cabin is air-sprung) or to the vehicle chassis.
 

VB3iS Mounting Fixed.png

Fixed Mounting

VB3iS can be mounted rigidly to the vehicle via the fixing holes, ideally mid-way along the wheelbase.

Using a Mounting Arm

A flexible way to fix the VB3iS rigidly within the vehicle is by using the Racelogic Mounting Arm. The three-part telescopic handle is fully adjustable to any length between 70 – 150 cm, another 20 cm can be added by extending a third section using the compression lever.

Both ends are fixed to an 8 x 13 cm plate which sits on a joint to accommodate for uneven surfaces. The VB3iS can then be pressed against the floor and the vehicle's ceiling, ensuring that the VB3iS is fixed tightly. Another option is to use a bracket that attaches to the mounting arm, meaning that the VB3iS can be fixed to the mounting arm before being installed within the vehicle. If using the bracket, it is recommended that the VB3iS is mounted vertically towards the bottom of the pole for greater stability.
 

VB3iS Mounting Arm Bracket.jpg
 

Please contact vbox@racelogic.co.uk for more information or to order a mounting arm (RLACS212-V2) and/or mounting bracket (RLACS291).

Measuring Antenna OffsetsVB3iS Antenna Offsets.jpg

If you are using IMU Integration, once VB3iS has been mounted securely, the relative position of the antenna must be measured to at least within ±5 cm.
 

This will be either the x,y,z offset values from the VB3iS to the antenna if using the internal IMU, or the IMU04 to the antenna if using an External IMU.

These distances must then be entered into the VB3iS via inputting directly using the VBOX Setup Softwarethe Front Panel of the unit or using the VBOX Manager.

VBOX Setup Software

  1. Ensure VB3iS is powered.
  2. Connect VB3iS to a computer using the supplied loom, connect an RLCAB001 cable to the 'CONFIG' lead and connect the serial plug to the computers serial port – this can be done via a serial > USB convertor if required.
  3. Open VBOX Setup and connect to VB3iS by selecting the correct COM Port.
  4. Select the 'IMU' menu and then the 'Settings' tab.
 
  1. Enter the measured ahead/behind, right/left and above/below offset values within the 'Antenna to IMU offset' options.
    Note: The options will be labelled 'Antenna to reference offset' if an External IMU is being used in conjunction with a Roof mount.
     

VB3iS Antenna Offset VBS.png
 

  1. Select 'Write to unit' to save the settings.

Front Panel

  1. Press the 'OK' button to enter the menu, navigate to 'IMU' using the 'Up' and 'Down' arrows and the press the 'OK' button.
VB3iS IMU Front Panel.png  
 
  1. Ensure IMU Integration is 'Enabled' and then navigate to 'Ant to IMU Offset' using the 'Down' arrow, press the 'OK' button to enter the menu.
    Note: This menu is labelled 'Ant to Ref. Offset' if an External IMU is being used in conjunction with a Roof mount.

VB3iS IMU Offset Front Panel1.png

VB3iS IMU Offset Front Panel2.png

  1. Use a combination of the 'Up' and 'Down' arrows and the 'OK' button to enter the measured ahead/behind, right/left and above/below offset values.
    Note: This menu is labelled 'The IMU is' if an External IMU is being used or 'The reference point is' if an External IMU is being used in conjunction with a Roof mount.
VB3iS IMU Offset Front Panel3.png VB3iS IMU Offset Front Panel4.png
  1. Selecting the 'OK' button will move along digits and selecting past the final digit will store the value.
VB3iS IMU Offset Front Panel5.png  
 

Pitch/Roll Offset

If VB3iS is placed on a non-flat surface, the 'Pitch/Roll Offset' action within the Front Panel of the unit or the VBOX Manager should be used to compensate the IMU attitude angle channels (pitch angle, roll angle). If using an External IMU, these offsets will apply to the external module.

  1. Press the 'OK' button on the front panel to enter the menu, navigate to 'IMU' using the 'Up' and 'Down' arrows and the press the 'OK' button.
VB3iS IMU Front Panel.png  
  1. Ensure IMU Integration is 'Enabled' and Location is set to 'Internal' if you are using the internal IMU or 'External' if you are using an External IMU.

VB3iS IMU Enabled.png

VB3iS IMU Internal.png

  1. Navigate to 'Pitch/Roll Offset' using the 'Down' arrow, press the 'OK' button to enter the menu.
VB3iS IMU Internal2.png VB3iS IMU Offset Front Panel6.png
 
  1. Press the 'OK' button again to auto level the pitch and roll offset.
VB3iS IMU Offset Front Panel7.png  

Be aware that when mounting the VB3iS on an angle, the raw accelerometer and gyro data will be incorrect as the channels are not pitch compensated.