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08 - VBOX 20SL Slip/Roll Angle Offsets

Slip Angle Offset

When using the VB20SL3 for measurement of Slip Angle, Pitch and/ or 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 Antennas A and B.

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 Pitch Angle and Slip Angle

To measure Pitch angle accurately at the same time as Slip angle with Antennas A and B will require the antennas to be
aligned as close as possible to a line parallel to the longitudinal line of the car.

Setting the Slip Offset

The VB20SL3 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 Setup Antenna configuration menu and select Slip offset ‘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 25 km/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 25 km/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 this procedure. Selecting the ‘Clear Offset’
option in the Configuration Screen will clear the current offset value.

https://racelogic.support//01VBOX_data_loggers/VBOX_II_Range/VBOX_II_User_Guide/08_-

_VBOX_20SL_Slip%2F%2FRoll_Angle_Offsets

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Summary of Contents for VB20SL3

Page 1: ...alculating and setting the offset With the antennas placed suitably and the antenna separation set correctly in the unit enter the Setup Antenna configuration menu and select Slip offset 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 25 km h Once this is achieved the unit will t...

Page 2: ...menu then select the Setup Antenna Menu and then select either the Pitch or Roll antenna setup menu From within either the Pitch or Roll antenna setup menu select either Pitch or Roll offset menu when the screen shows CALC OFFSET press the to calculate a PITCH or ROLL offset If required the Pitch or Roll angle offset can be re calculated at any time by repeating this procedure Selecting the Clear ...

Page 3: ...raight 0x7FB 05 03 00 00 00 00 00 00 Response Offset done value shown in Data bytes 2 5 0x7FB 05 01 3F 9D 70 A4 00 00 Response Offset failed 0x7FB 05 00 00 00 00 00 00 00 The Response message to indicate completion also contains the Offset value as a 32 bit IEEE float on Data bytes 2 5 In the example above Data bytes 2 5 3F 9D 70 A4 which equals a decimal value of 1 23o https racelogic support 01V...

Page 4: ...iciently and the Slip and Pitch channels are less likely to drop out If the expected angle between the antennas will be greater than 10o then the LEVEL option should be disabled set to NO Note When the antenna separation is 2 m the RTK lock is very resilient in most conditions and scenarios when the Level option is not enabled https racelogic support 01VBOX_data_loggers VBOX_II_Range VBOX_II_User_...

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