dARM ROS2 Package

A containerized ROS2 control package for the dARM 6DOF robotic arm, supporting both Gazebo simulation and physical hardware control through ODrive controllers.

Overview

This repository provides the ROS2 implementation for the dARM robot, featuring:

• Dual-container architecture (simulation on x86, robot on ARM)
• PS5 controller teleop support
• Gazebo simulation with physics
• Hardware interface for ODrive communication (in development)

Architecture

Joint Configuration

• link_1_joint: Base rotation
• link_2_joint: Dual-motor differential drive (2x ODrive nodes)
• link_3_joint: Single motor
• forearm_joint: Single motor
• Forearm differential (bend/twist via 2 motors):
  • differential_joint: Bend axis (motors oppose)
  • gripper_joint: Twist axis (motors together)
• Gripper fingers: Prismatic joints with coupled motion

Container Strategy

• Simulation Container: x86, Ubuntu 24.04, ROS2 Jazzy, Gazebo Sim
• Robot Container: arm64, Ubuntu 24.04, ROS2 Jazzy, Bluetooth support

Current Status

Implemented ✅

• Complete URDF/Xacro robot description with accurate inertial properties
• Containerized build system with multi-architecture support
• Gazebo simulation environment with physics
• PS5 controller teleop with:
  • Joint position control
  • Predefined poses (home, vert, left, right)
  • Dead-man switch safety
  • Real-time joint state display
• ROS2 control framework with joint trajectory controller
• Launch files for both simulation and hardware
• Transmissions properly configured for differential joints

In Development 🚧

• ODrive hardware interface plugin (odrive_ros2_control_plugin/ODriveHardwareInterface)
• Hardware bring-up procedures

Planned 📋

• MoveIt2 integration for motion planning
• Computer vision integration

Prerequisites

Development Environment

• Docker Engine (Linux) or Docker Desktop (Windows/Mac)
• Git

For Simulation (Windows WSL2)

• WSL2 with Ubuntu 24.04
• VcXsrv or similar X server

Usage

Simulation Mode

# Using docker-compose
docker-compose -f docker/compose.sim.yml up

Robot Mode

# Using docker-compose
docker-compose -f docker/compose.robot.yml up

PS5 Controller Mapping

Dead-man Switch: Hold L2 to enable any motion

Joint Control Modes:

• No Bumpers: Base rotation (left stick Y), Joint 2 (right stick X)
• L1 Held: Joint 3 (left stick Y), Forearm (right stick X)
• R1 Held: Differential bend (right stick X), Gripper twist (left stick Y)

Gripper Control: D-Pad Left/Right to open/close fingers

Quick Poses:

• X Button: Home position (all zeros)
• Triangle: Vertical pose (arm straight up)
• Square: Left preset position
• Circle: Right preset position

Development Notes

Container Hardware Passthrough

• WSL2 GPU: Uses /dev/dxg device mounting
• USB Controllers: Requires usbipd-win on Windows host

Differential Joint Implementation

The forearm differential is implemented using coupled transmissions:

• Both motors contribute to each axis of motion
• Bend motion: motors oppose (different signs in transmission)
• Twist motion: motors work together (same signs)
• Effective gear ratio approaches 13:1 when both motors active

Troubleshooting

Controller Not Detected

# Check device exists
ls -la /dev/input/js0

# In container, test with:
ros2 run joy joy_node
ros2 topic echo /joy

Roadmap

Phase 1: Hardware Integration (Current)

• Complete ODrive hardware interface

Phase 2: Motion Planning

• MoveIt2 configuration
• Collision geometry setup
• Path planning integration

Phase 3: Advanced Features

• Vision system integration