Software Overview

OMY is a 6-DOF robotic manipulator designed for real-world Physical AI research.
It supports teleoperation, trajectory learning, and deployment of AI policies through a unified ROS 2 control architecture.

The platform runs on ROS 2 Jazzy and uses the ros2_control framework for real-time joint-level control.
The arm is driven by DYNAMIXEL-Y series actuators connected over RS-485 using the Dynamixel SDK.

This system is designed for:

• Collecting motion data through teleoperation
• Training and testing trajectory-based AI models
• Running learned or predefined trajectories on real hardware

OMY provides an efficient and compact platform for Physical AI research in both academic and industrial environments.

System Architecture

INFO

The diagram below illustrates the overall control structure of OMY. Teleoperation or AI-generated commands are processed through ros2_control, translated by the hardware interface, and executed by DYNAMIXEL actuators via RS‑485.

Layer	Component	Description
Compute	Raspberry Pi5	ROS 2 Jazzy
Motion Control	ros2_control	Real-time joint control at 400Hz
Actuators	DYNAMIXEL-Y series	High-torque servo via RS-485
Communication	RS‑485	Dynamixel Protocol 2.0
Networking	Ethernet	Remote access
Sensors (optional)	Intel RealSense D405	Mounted on wrist (F3M only)

Why ros2_control?

OMY uses ros2_control for modular, real-time control of its joints.

• Clean separation between hardware and control logic
• Supports multiple controller types (trajectory, GPIO, command)
• Integrates easily with teleop, GUI, and AI-based trajectory sources

This makes it easy to switch between manual, scripted, or learned motion strategies.

Motion Execution Pipeline

Input Source (Teleoperation / AI Policy)
      ↓
ROS 2 JointTrajectory / Command Topics
      ↓
controller_manager (400Hz loop)
      ↓
OMY Controllers
      ↓
DynamixelHardwareInterface
      ↓
RS‑485 Bus
      ↓
DYNAMIXEL-Y Actuators

Controller Configuration & Joint Mapping

Controller	Segment	DOF	Input Topic
arm_controller	6-DOF Arm	6(7)	/leader/arm_controller/joint_trajectory
gpio_command_controller	Gripper (GPIO pin)	1	/gpio_command_controller/commands
joint_command_broadcaster	All joints (read-only)	–	Publishes to /joint_states

INFO

In AI TELEOPERATION mode, the number of joints in the Arm Controller becomes 7.

• All actuators operate in position mode by default.

---

Controller YAML Example (link)

/**:
  controller_manager:
    ros__parameters:
      use_sim_time: False
      update_rate: 400  # Hz
      thread_priority: 40
      cpu_affinity: [1, 2, 3]

      joint_state_broadcaster:
        type: joint_state_broadcaster/JointStateBroadcaster

      arm_controller:
        type: joint_trajectory_controller/JointTrajectoryController

      gpio_command_controller:
        type: gpio_controllers/GpioCommandController

/**:
  arm_controller:
    ros__parameters:
      joints:
        - joint1
        - joint2
        - joint3
        - joint4
        - joint5
        - joint6
        - rh_r1_joint

      interface_name: position

      command_interfaces:
        - position

      state_interfaces:
        - position
        - velocity

      allow_partial_joints_goal: true

/**:
  gpio_command_controller:
    ros__parameters:
      type: gpio_controllers/GpioCommandController
      gpios:
        - omy_end
      command_interfaces:
        omy_end:
          - interfaces:
            - R LED
            - G LED
            - B LED
      state_interfaces:
        omy_end:
          - interfaces:
            - Button Status

Debugging & Visualization Tools

Tool / Topic	Description
ros2 control list_controllers	Check controller status
ros2 topic echo /joint_states	Monitor joint position/velocity
Rviz2	3D view of robot model (URDF), TF, and movement

Safety & Limits

• Joint limits are defined in the URDF and enforced at the controller layer
• Velocity/position clamping can be configured per joint
• Communication errors are detected by the Dynamixel hardware interface