6.3. Sensor Calibration

Estimate your intrinsic/extrinsic parameters on your sensor system using tier4/calibration_tools.

Note

Perform the following tasks on the x86-based ECU.

6.3.1. Calculate intrinsic parameters for cameras

First, launch calibration_intrinsic to estimate the intrinsic parameters of your cameras. See this document for detailed operation on the tool.

cd edge-auto
source install/setup.bash

ros2 launch edge_auto_launch calibration_intrinsic_sample.launch.xml

Intrinsic parameters for all cameras consisting of your system (e.g., camera0 and camera1 in this tutorial) should be stored on individual_params. After acquiring the files, put them in the appropriate folder on your Jetson-based ECU so that they are loaded and published as camera_info topics:

edge-auto-jetson/src/individual_params/individual_params/config/
└── default # <- this will be an identifier, which refered to as the value of `VEHICLE_ID` environment variable, of your system
    ├── camera0
    │   ├── camera_info.yaml  # <- replace this file with your calculated results
    │   ├── trigger.param.yaml
    │   └── v4l2_camera.param.yaml
    ├── camera1
    │   ├── camera_info.yaml  # <- replace this file with your calculated results
    │   ├── trigger.param.yaml
    │   └── v4l2_camera.param.yaml

6.3.2. (HESAI AT128 only) Get a correction file from LiDAR

HESAI AT128 have the capability to access their own correction file stored inside them. To get better results, you are encouraged to download the correction file from individual LiDAR, and store it in the appropriate folder on the x86-based ECU:

edge-auto/src/individual_params/individual_params/config/
└── default
    └── lidar
        └── at128_default.dat # <- replace this file with your downloaded dat file

6.3.3. Calculate extrinsic parameters between LiDAR and cameras

Finally, launch calibration_extrinsic that matches your LiDAR setup to estimate your extrinsic parameters between your lidar and cameras. See this document for detailed operation on the tool.

cd edge-auto
source install/setup.bash

ros2 launch edge_auto_launch calibration_extrinsic_at128_sample.launch.xml
## or
ros2 launch edge_auto_launch calibration_extrinsic_xt32_sample.launch.xml

To perform sensor fusion, pose relationships (i.e., extrinsic parameters) between all fused sensors need to be registered in TF, which is the ROS-fashion to represent the relationships.

Note

In these samples, there is the assumption that all sensors are fixed and their relative positions do not change.

After calculating extrinsic parameters, put the result in the appropriate files on the x86-based ECU:

edge-auto/src/individual_params/individual_params/config/
└── default
    ├── at128_to_camera0.json # <- replace this file with your calculated results
    └── at128_to_camera1.json # <- replace this file with your calculated results