VB20SL User Guide
Page 13 of 30
Slip Angle Offset
When using the VB20SL for measurement of Slip Angle, Pitch / Roll Angle, True Heading, Lateral Velocity or Yaw Rate, it is essential that the Slip Angle
offset is determined before conducting tests. This then compensates for any misalignment in the placement of the two antennas.
There are also many occasions when the antennas cannot be placed directly in line with the car, such as when an ‘off-vehicle’ antenna is used to measure
the Slip angle over a particular wheel.
Measuring Roll angle and Slip Angle
To measure Roll angle at the same time as slip angle
will require the antennas to be mounted at 90 degrees to the body of the car, in this case it is vital that
the offset is calculated.
Setting the Offset
The VB20SL includes a built-in facility for calculating and setting the offset. With the antennas placed suitably and the antenna separation set correctly in the
unit, enter the Configuration Screen and select ‘Calc. Offset’. The unit will give instructions on its display screen to allow it to determine the offset.
First, the unit will instruct you to drive at a speed greater than 25km/h. Once this is achieved, the unit will tell you to drive straight,
and will begin calculating the Slip Angle offset automatically. During the 5 second process, it is very important that you keep the
vehicle in a straight line and above 25km/h. The Slip angle sensor beeps during this calculation and then stops beeping when it
has finished calculating the offset.
If required, the Slip Angle offset can be re-calculated at any time by repeating thi
s procedure. Selecting the ‘Clear Offset’ option in the Configuration Screen
will clear the current offset value.
Please note that the unit will need to have a full RTK lock to perform this procedure
– if the orange ‘RTK’ light is flashing, the procedure cannot be initiated.
