5.4.1 Sensor Interfaces

The sensor interfaces provide data access and control for the robot’s various sensors, including cameras, IMUs, LiDAR, and touch sensors.

Core Features

Vision Sensors

• RGB Camera: Captures color images

• Depth Camera: Provides depth information

• Camera Intrinsics: Retrieves calibration parameters

Pose Sensors

• IMU Data: Acceleration, angular velocity, and attitude angles

• Gyroscope: Measures angular velocity

• Accelerometer: Measures acceleration

Environmental Perception Sensors

• LiDAR: Provides point cloud data

• Touch Sensors: Tactile feedback

Standard Sensor Messages

Most sensor interfaces use the standard message types defined in ROS sensor_msgs:

Sensor Data Type	Message Definition
Camera intrinsics	CameraInfo
Raw image	Image
Compressed image	CompressedImage
IMU data	Imu
LiDAR point cloud	PointCloud2

IMU Topics

Includes chest IMU and torso IMU, both located on the development compute unit (PC2).
You can also use the IMUs integrated in LiDAR and the RGB-D camera.

Topic Name	Data Type	Description	QoS	Frequency
/aima/hal/imu/chest/state	Imu	Chest IMU data	TRANSIENT_LOCAL	500Hz
/aima/hal/imu/torso/state	Imu	Torso IMU data	TRANSIENT_LOCAL	500Hz
/aima/hal/sensor/lidar_chest_front/imu	Imu	LiDAR IMU data	TRANSIENT_LOCAL	200Hz
/aima/hal/sensor/rgbd_head_front/imu	Imu	RGB-D camera IMU data	RELIABLE	200Hz

Head Touch Status Topic

Supported features:

• Access low-level touch events and raw samples

• Disable the built-in “head pat” skill (to be enabled)

Topic Name	Data Type	Description	QoS	Frequency
/aima/hal/sensor/touch_head	TouchState	Head touch status	TRANSIENT_LOCAL	100Hz

• TouchState ros2-msg @ hal/msg/TouchState.msg

  # Head touch status
  # Topic: /aima/hal/sensor/touch_head
  
  MessageHeader header             # Message header
  uint8 event_type                 # Touch event (0-unknown, 1-idle, 2-touch, 3-slide, 4-single tap, 5-double tap, 6-triple tap)
  uint32[8] data                   # Raw sensor values for 8 channels
  uint32[8] threshold              # Touch thresholds for 8 channels
  bool[8] is_touched               # Touch state of 8 channels
  

Rear RGB Camera Topics

The rear RGB camera is on the development compute unit (PC2) and can be used for visual localization assistance and semantic scene understanding.
Raw image bandwidth is about 90 MB/s — use only on the same compute unit, do not subscribe across units.

Topic Name	Data Type	Description	QoS	Frequency
/aima/hal/sensor/rgb_head_rear/camera_info	CameraInfo	Camera intrinsics	RELIABLE+TRANSIENT_LOCAL	N/A
/aima/hal/sensor/rgb_head_rear/rgb_image	Image	Raw image	TRANSIENT_LOCAL	10Hz
/aima/hal/sensor/rgb_head_rear/rgb_image/compressed	CompressedImage	Compressed image	TRANSIENT_LOCAL	10Hz

Stereo Camera Topics

The stereo camera is on the development compute unit (PC2) and can be used for stereo vision, teleoperation, obstacle perception, object recognition, VIO SLAM, VLA and more.
Raw image bandwidth is about 90 MB/s per eye — use only on the same compute unit, do not subscribe across units.

Topic Name	Data Type	Description	QoS	Frequency
/aima/hal/sensor/stereo_head_front_left/camera_info	CameraInfo	Left camera intrinsics	RELIABLE+TRANSIENT_LOCAL	N/A
/aima/hal/sensor/stereo_head_front_left/rgb_image	Image	Left raw image	TRANSIENT_LOCAL	10Hz
/aima/hal/sensor/stereo_head_front_left/rgb_image/compressed	CompressedImage	Left compressed image	TRANSIENT_LOCAL	10Hz
/aima/hal/sensor/stereo_head_front_right/camera_info	CameraInfo	Right camera intrinsics	RELIABLE+TRANSIENT_LOCAL	N/A
/aima/hal/sensor/stereo_head_front_right/rgb_image	Image	Right raw image	TRANSIENT_LOCAL	10Hz
/aima/hal/sensor/stereo_head_front_right/rgb_image/compressed	CompressedImage	Right compressed image	TRANSIENT_LOCAL	10Hz

RGB-D Camera Topics

The RGB-D camera is on the development compute unit (PC2) and can be used for object detection, spatial obstacle avoidance, and semantic environment understanding.
Raw image bandwidth is about 25 MB/s per stream — use only on the same compute unit, do not subscribe across units.

Topic Name	Data Type	Description	QoS	Frequency
/aima/hal/sensor/rgbd_head_front/rgb_camera_info	CameraInfo	RGB intrinsics	RELIABLE	10Hz
/aima/hal/sensor/rgbd_head_front/rgb_image	Image	Raw image	RELIABLE	10Hz
/aima/hal/sensor/rgbd_head_front/rgb_image/compressed	CompressedImage	Compressed image	RELIABLE	10Hz
/aima/hal/sensor/rgbd_head_front/depth_camera_info	CameraInfo	Depth intrinsics	RELIABLE	10Hz
/aima/hal/sensor/rgbd_head_front/depth_image	Image	Depth image	RELIABLE	10Hz
/aima/hal/sensor/rgbd_head_front/depth_pointcloud	PointCloud2	Depth point cloud	RELIABLE	10Hz
/aima/hal/sensor/rgbd_head_front/imu	Imu	IMU data	RELIABLE	200Hz

LiDAR Topics

Provides LiDAR point clouds and LiDAR-integrated IMU data for obstacle avoidance and SLAM/localization.
The LiDAR is on the development compute unit (PC2) with data bandwidth on the order of 10 MB/s — cross-unit subscriptions are not recommended.

Topic Name	Data Type	Description	QoS	Frequency
/aima/hal/sensor/lidar_chest_front/lidar_pointcloud	PointCloud2	LiDAR point cloud	TRANSIENT_LOCAL	10Hz
/aima/hal/sensor/lidar_chest_front/imu	Imu	LiDAR IMU data	TRANSIENT_LOCAL	200Hz

Code Examples

For detailed code samples and explanations, see:

• C++ Examples: Code samples, sensor interface section

• Python Examples: Code samples, sensor interface section

Safety Notes

Attention

• For high-bandwidth raw camera streams, do not subscribe across compute units; this may destabilize the system and create safety risks.