4. Sensors Architecture: Top-carrier Robot#

4.1. Introduction#

Sensors Architecture Description

The sensor architecture adopts a modular approach to accommodate diverse use cases. In this configuration designed for flat-bed (top-carrier) AMR/AGVs, all stereo cameras support robust perception, while mono cameras facilitate teleoperation and sensor-to-sensor calibration.

This architecture comprises of four stereo and four mono cameras.

https://gitlab-master.nvidia.com/isaac/isaac/-/raw/release-4.3/docs/nvidia-isaac-ros//resources/isaac_ros_docs/robots/nova_sensor_mounting_guide/sensor_arch_top_carrier_1.png/

Acronym	Camera Designation
FS	Front stereo
BS	Back stereo
RS	Right stereo
LS	Left stereo
FC	Front camera
BC	Back camera
RC	Right camera
LC	Left camera

4.2. Stereo-vision Cameras Coverage Requirements#

4.2.1. Surround Coverage Requirements#

Req ID:

Ground Visibility

27461095

Stereo cameras arrangement shall be able to see the ground plane from a distance of < 1m from the foremost and the back-most AMR surfaces across the AMR width.

Stereo cameras arrangement shall be able to see the ground plane from a distance of < 1m from the leftmost and the rightmost AMR surfaces across the AMR length.

https://gitlab-master.nvidia.com/isaac/isaac/-/raw/release-4.3/docs/nvidia-isaac-ros//resources/isaac_ros_docs/robots/nova_sensor_mounting_guide/stereo_surround_coverage_ground_visibility.png/

Req ID:	Combined HFOV
27461115	Stereo cameras arrangement shall provide 360 degrees coverage around the AMR.

4.2.2. Mounting Requirements#

Req ID:	Pitch Range
27461119	Any stereo camera pitch angle shall be between -10 and 5 degrees.

Req ID:	Z-range
27461136	Any stereo camera Z vertex shall be < 0.5m height.

4.3. Mono Cameras Coverage Requirements#

4.3.1. Surround Coverage Requirements#

Req ID:

Ground Visibility

27461145

Cameras arrangement shall be able to see the ground plane from a distance if < 0.2m from the foremost and the back-most AMR surfaces across the AMR width.

Cameras arrangement shall be able to see the ground plane from a distance < 0.2m from the leftmost and the rightmost AMR surfaces across the AMR length.

https://gitlab-master.nvidia.com/isaac/isaac/-/raw/release-4.3/docs/nvidia-isaac-ros//resources/isaac_ros_docs/robots/nova_sensor_mounting_guide/mono_surround_coverage_ground_visibility.png/

Req ID:	Combined HFOV
27461155	Cameras arrangement shall provide 360 degrees coverage around the AMR.

4.3.2. Mounting Requirements#

Req ID:	Pitch Range
27461163	Any camera pitch angle shall be between -10 and 5 degrees.

Req ID:	Z-range
27461167	Any camera Z vertex shall be < 0.5m in height.

Sensors Mounting Example

Below is an implementation example for the camera belt.

The stereo cameras’ coverage is depicted in the images below:

https://gitlab-master.nvidia.com/isaac/isaac/-/raw/release-4.3/docs/nvidia-isaac-ros//resources/isaac_ros_docs/robots/nova_sensor_mounting_guide/top_carrier_sensors_mounting_ex_1.png/

The sensors mounting locations and angles are summarized in the following table:

Stereo cameras’ (Hawks) mounting locations and angles.#
	X [m]	Y [m]	Z [m]	Pitch [deg]	Yaw [deg]	Roll [deg]
FS	-0.017	0.075	0.344	0	0	0
BS	-0.681	-0.075	0.344	0	180	0
RS	-0.398	-0.15	0.344	0	-90	0
LS	-0.548	0.15	0.344	0	90	0

Note

Hawk vertex, aligned with the left lens center, was chosen for representation of Hawk locations. Refer to the Hawk datasheet for more information.

The mono cameras’ coverage is depicted in the images below:

The sensors mounting locations and angles are summarized in the following table:

Mono cameras’ mounting locations and angles.#
	X [m]	Y [m]	Z [m]	Pitch [deg]	Yaw [deg]	Roll [deg]
FC	-0.01	0	0.374	0	0	0
BC	-0.688	0	0.374	0	180	0
RC	-0.349	-0.157	0.344	0	-90	0
LC	-0.349	0.157	0.344	0	90	0

Note

Owl vertex was chosen for representation of Owl locations. Refer to Owl datasheet for more information.

For reference, the AMR used in this example is shown on a 10cm x 10cm grid: