8.3 IMU

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8.3.1 IMU Sensor Data Format 1 — Standard Format

Description: Retrieve IMU sensor data, including acceleration, angular velocity, orientation quaternion, and Euler angles. Applicable to all Walker Tienkung models.

• Communication type: topic

• Topic name: /imu

• Message definition: sensor_msgs::msg::Imu

• Message format:

  std_msgs/Header header
  geometry_msgs/Quaternion orientation
  float64[9] orientation_covariance
  geometry_msgs/Vector3 angular_velocity
  float64[9] angular_velocity_covariance
  geometry_msgs/Vector3 linear_acceleration
  float64[9] linear_acceleration_covariance

• Example command:

  # View topic messages
  ros2 topic echo /imu

8.3.2 IMU Sensor Data Format 2 — Custom Format

Description: Retrieve IMU sensor data, including acceleration, angular velocity, orientation quaternion, Euler angles, and error alarms. Applicable to all Walker Tienkung models.

• Communication type: topic

• Topic name: /imu/status

• Message definition: bodyctrl_msgs::msg::Imu

• Message format:

  std_msgs/Header header
  geometry_msgs/Quaternion orientation
  geometry_msgs/Vector3 angular_velocity
  geometry_msgs/Vector3 linear_acceleration
  bodyctrl_msgs/Euler euler
  uint32 error
  
  float64[3] angular_velocity_covariance
  float64[3] orientation_covariance
  float64[3] linear_acceleration_covariance

  error field definition:

  error = 33072    # Device offline

• Example command:

  # View topic messages
  ros2 topic echo /imu/status