Multi-Camera Main Platform Calibration

The dataset is collected onboard a compact handheld device that includes:

  • Intel NUC8i7BEH
  • Ouster OS-0 128 beam LIDAR with embedded IMU
  • SevenSense AlphaSense Development Kit multi-camera with embedded IMU
  • 8000 mAh battery pack and onboard power electronics

The sensor used for our experiments is the Alphasense multi-camera development kit from Sevensense Robotics AG. An onboard FPGA synchronizes the IMU and four grayscale fisheye cameras – a frontal stereo pair with an 11 cm baseline and two lateral cameras. Each camera has a FoV of 126° × 92.4° and a resolution of 720 × 540 px. This configuration also produced an overlapping FoV between the front and side cameras of about 36°. The cameras and the embedded cellphone-grade IMU were operated at 30 Hz and 200 Hz, respectively. The Ouster OS-0 LiDAR has 128 beams, which provides much denser data than many other LiDAR datasets. Both sensors are cutting edge devices in the mobile robotics community, that have been used in the DARPA Subterranean Challenge.

Sensor Type Rate [Hz] Characteristics
Ouster OS-0-128 LiDAR 10 128 beams, 50 m max range, 90° nominal vertical FoV
ICM-20948 IMU 100 Ouster embedded
Alphasense Multiple Cameras 30 Global shutter (IR), 720 × 540
Bosch BMI085 IMU 100, 200 or 400 synchronized with the cameras

The sensors are rigidly attached to a precisely 3D-printed base.

handheld_device

To distinguish the sensor frames, we use the following abbreviations:

  • Base : the bottom centre of the printed computer case
  • OS_I : The IMU coordinate system in the LiDAR.
  • OS_L : The LiDAR coordinate system where the point clouds are read
  • AS C0: The frontal right camera optical frame
  • AS C1: The frontal left camera optical frame
  • AS C3: The lateral right camera optical frame
  • AS C4: The lateral left camera optical frame
  • AS_I : The IMU coordinate system in the Alphasense.

Note: A URDF of the platform is publically available at https://github.com/ori-drs/halo_description Please note that we did not record the upwards facing camera shown in the URDF in these datasets.