CoBot — ROS 2 Robotic Platform

ROS 2 Jazzy · Ubuntu 24.04

A distributed ROS 2 system split across two workspaces: a lightweight edge node running on a Raspberry Pi, and a compute-heavy brain running on a CUDA-enabled laptop. Together they drive a 4WD mobile base with a 6-DOF xArm manipulator, 3D LiDAR, and RGB-D vision.

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The Robot

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Demo Video

https://youtu.be/pPVNTSV94Bw?si=5ImayjD9v3hi-nGu

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System Architecture

Four ROS2 nodes communicating over well-defined topics and message types:

Node	Role
Perception Node	ZED Mini interface, object detection, depth filtering
TF Broadcaster Node	Converts detections to TF frames, maintains ROS2 TF tree
IK & Control Node	Analytical IK solver + trajectory generation
Arm Controller	Joint position controller → xArm 1s hardware interface

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Object Detection to Robotic Picking Workflow

End-to-end pipeline from camera input to physical pick execution:

Pipeline Steps:

1. ZED Mini Camera captures RGB + depth frames
2. Object Detection Node identifies target, extracts 3D (x, y, z) in camera frame
3. Hand-Eye Calibration (ArUco markers, AX = XB) resolves zed_camera_link → base_link
4. TF Broadcasting publishes target_link into the ROS2 TF tree
5. Custom Processing Node computes joint angles via IK
6. Joint Trajectory Command sends angles to the xArm controller
7. xArm Motion Execution picks the object

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ZED Mini Point Cloud

Raw stereo point cloud used for depth-aware object localization:

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2D Mapping (SLAM)

Occupancy grid generated during navigation for path planning on the mobile base:

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Current Status

Module	Status
4WD Mobile Base	✅ Operational
xArm Driver (Serial Bridge)	✅ Operational
2D LiDAR (RPLidar)	✅ Operational
3D LiDAR Integration	✅ Added to system
3D Mapping (FAST-LIO)	✅ 3D map successfully generated
Autonomous Navigation (Nav2)	🔧 In Progress
cobot_perception (ZED Mini + IK)	🔧 In Development

Latest: Added a 3D LiDAR to the system and successfully created a 3D map using FAST-LIO. Currently working on full autonomous navigation with Nav2.

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Repository Structure

CoBot-ROS2/
├── CoBot-ROS2/               # Edge Node workspace (Raspberry Pi)
│   ├── src/
│   │   ├── bumperbot_*       # Core robot packages
│   │   ├── xarm_driver/      # Serial bridge to xArm servos
│   │   ├── cobot_perception/ # ZED Mini vision + ikpy IK solver
│   │   └── my_robot_bringup/ # Launch files for the Pi
│   └── README.md
│
├── cobot_compute_ws/         # Compute Brain workspace (Laptop / CUDA)
│   ├── src/
│   │   ├── bumperbot_*       # Shared packages built on laptop side
│   │   └── my_robot_bringup/ # SLAM, Nav2, EKF launch files
│   └── README.md
│
├── docs/images/              # Project images for documentation
└── README.md                 # You are here

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Quick Start

Edge Node (Raspberry Pi)

cd CoBot-ROS2
source install/setup.bash
ros2 launch my_robot_bringup edge_node.launch.py

Compute Brain (Laptop)

cd cobot_compute_ws
source install/setup.bash
ros2 launch my_robot_bringup compute_brain.launch.py

Both machines must share the same ROS_DOMAIN_ID:

export ROS_DOMAIN_ID=42
export ROS_LOCALHOST_ONLY=0

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Workspace READMEs

• CoBot-ROS2 — Edge Node
• cobot_compute_ws — Compute Brain