Angular Velocity Calibration

1. Course Content

• Verify the rotation accuracy of the chassis wheel odometry (calculated from motor encoder data) and calibrate the angular velocity

[!IMPORTANT]

The car is calibrated at the factory, so no re-calibration is needed on first use. If you find that the odometry rotation error is large during subsequent use, refer to this tutorial for calibration.

2. Preparation

ros2 launch microros_v2_bringup car_base.launch.py use_camera:=false

3. Calibration Demonstration

Note: If the odometry data is wrong, you can press the reset button to restart the car.

• Run the command in the terminal

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ros2 run common_demo calibrate_angular_z --ros-args -p test_angle_deg:=360.0

• The tested angle test_angle_deg here is 360 degrees. After the car stops moving, measure the actual rotation angle and enter the measured actual rotation angle into the terminal; the terminal will automatically calculate the calibration coefficient.

[!TIP]

test_angle_deg:=360° is a demonstration example; you can adjust the tested angle as needed.

4. Write the Calibration Coefficient to the MicroRos Control Board

• Close the microros_v2_bringup and calibrate_linear terminals started earlier, and double-click the RobotManager application icon on the virtual machine desktop
• On the control board page, enter the calibration coefficient calculated in the previous step into the angular velocity coefficient, and click Apply Configuration.

5. Verification Test

• Repeat the test again ros2 run common_demo calibrate_angular_z --ros-args -p test_angle_deg:=360.0; the rotation error will now be smaller than before calibration.