DriveWorks SDK Reference
3.5.78 Release
For Test and Development only

IMU Calibration Sample
Note
SW Release Applicability: This sample is available in both NVIDIA DriveWorks and NVIDIA DRIVE Software releases.

Description

This sample demonstrates estimating IMU extrinsics with the NVIDIA® DriveWorks Calibration Engine.

Running the Sample

The IMU calibration sample, sample_calibration_imu, accepts the following optional parameters. If none are specified, the IMU extrinsics are estimated on a default dataset.

./sample_calibration_imu --rig=[path/to/rig/configuration/file]
                         --imu-sensor=[integer/sensor-name]
                         --can-sensor=[integer/sensor-name]
                         --camera-sensor=[integer/sensor-name]

where

--rig=[path/to/rig/configuration/file]
    Path to the rig configuration file.
    Default value: path/to/data/samples/recordings/suburb0/imu_offset_rig.json

--imu-sensor=[integer]
    The index or name of the IMU sensor in the rig configuration file to calibrate
    Default value: 0

--can-sensor=[integer]
    The index or name of the CAN sensor in the rig configuration file
    Default value: 0

--camera-sensor=[integer]
    The index or name of the camera sensor in the rig configuration file (used for visualization only)
    Default value: 0

Output

The sample does the following:

  • Creates a window.
  • Displays a video. The speed at which the video is displayed differs, depending on convergence:
    • Before convergence, the sample does not limit the video playback. As a result, the visualization appears to be sped up.
    • After convergence, the sample slows the video playback to the usual 30-frames per second.
  • Displays nominal calibration indicators (blue) and, after convergence, a corrected calibration indicator (green). The indicator shows the estimated rig horizon as seen in the camera's frame. The rig horizon shows the estimated IMU roll and pitch.

After convergence, the sample runs the sample data in a loop, during which the calibration is further refined.

sample_calibration_imu.png
IMU Calibration

Additional information

For more information on IMU calibration, see IMU Self-Calibration .