The IMU calibration tool calibrates the orientation of IMU with respect to the car ("Rig") coordinate system.

To use the tool, you must first capture IMU data with the car performing the special calibration sequence:

1. Find a level surface. It is important for the surface to have no significant incline.
2. Start recording the IMU data with the car stopped. (To obtain the IMU data, you can use recorder application that DriveWorks provides.)
3. With recording on, wait for at least 5 seconds before driving. This is needed for the tool to find the gravity vector.
4. Rapidly accelerate and rapidly stop multiple times (try to avoid skidding). This is needed for the calibration utility to find forward and backward vectors.
5. Stop the recording.

Once you have the IMU data file, you can run the tool providing --params=file= and --rig= arguments. For example,

calibration_imu –params=file=imu.bin –rig=rig.xml

This command finds the orientation of the IMU, with respect to the car and creates a new file called calibrated-imu-rig.xml that has an IMU node with the orientation written in a quaternion form.