Workspace Overview

The Giraffe ROS 2 workspace is composed of four primary packages—giraffe_description, giraffe_moveit_config, giraffe_control, and giraffe_hardware—that together enable simulation, motion planning, and hardware control of the Giraffe 5-DoF robotic arm. The giraffe_description package provides the robot model, control configuration, and launch files for visualization, simulation, and real hardware use. giraffe_moveit_config supplies the MoveIt 2 configuration for kinematics, planning, and RViz integration. giraffe_control implements a custom driver for communicating with the Feetech servos, while giraffe_hardware defines a ros2_control hardware interface for seamless integration with ROS 2 controllers and real-time execution.

giraffe_description

This package contains URDF for giraffe robotic manipulator along with ros2 control xacro, ros2 controller config files, and the launch files for the entire workspace.

• display.launch.py: This launch file visualizes the giraffe robot model in ROS 2. It includes:

  1. Robot State Publisher: Publishes the robot's state using the URDF.
  2. Joint State Publisher GUI: Enables interactive joint control.
  3. RViz Visualization: Displays the robot in a pre-configured RViz environment.

  Usage:

  ros2 launch giraffe_description display.launch.py

• simulation.launch.py: This launch file sets up the simulation environment for the giraffe robot in Gazebo and RViz. It includes:

  1. Gazebo Simulation: Starts Gazebo server and client with the giraffe robot model.
  2. Robot Description and State Publisher: Publishes the robot's URDF and joint states.
  3. Controllers: Spawns and activates controllers for joint trajectory and gripper control.
  4. RViz Visualization: Displays the robot model and state in RViz.

  Usage:

  ros2 launch giraffe_description simulation.launch.py

• moveit_sim.launch.py: This launch file integrates the giraffe robot with Gazebo, MoveIt! 2, and RViz for advanced motion planning and control. Key features:

  1. Gazebo Integration:
     • Spawns the giraffe robot in Gazebo.
     • Configures ros2_control and joint controllers.
  2. MoveIt! 2 Motion Planning:
     • Loads MoveIt! 2 configurations (SRDF, kinematics, OMPL planning).
     • Starts the move_group node for motion planning and execution.
  3. RViz Visualization:
     • Launches RViz preconfigured for MoveIt! 2 to visualize and interact with the robot.

  Usage:

  ros2 launch giraffe_description moveit_sim.launch.py

• moveit_interface.launch.py_: This launch file configures and launches the giraffe robot hardware, MoveIt! 2, and a hardware interface for motion control. Key features:

  1. MoveIt! 2 Motion Planning:
     • Loads MoveIt! 2 configurations (SRDF, kinematics, and OMPL planning).
     • Starts the move_group node for motion planning and trajectory execution.
  2. RViz Visualization:
     • Displays the robot's state and motion planning visualization using a preconfigured RViz setup.
  3. Hardware Interface:
     • Includes a node for the giraffe robot's hardware interface for integration with controllers.

  Usage:

  ros2 launch giraffe_description moveit_interface.launch.py

giraffe_moveit_config

The giraffe_moveit_config package provides the MoveIt! 2 configuration for the 5-DoF robotic arm named "Giraffe," designed for use with ROS 2 Humble. It includes essential files for motion planning and execution, such as:

• URDF and SRDF: Defines the robot's kinematic structure and semantic description.
• Kinematics Configuration: Specifies IK solvers for planning.
• OMPL Planning Configuration: Configures planning pipelines for trajectory generation.
• Controller Configuration: Integrates with ros2_control for real-time trajectory execution.
• RViz Configuration: Pre-configured visualization setup for MoveIt! 2.

This package is utilized by the giraffe_description package's launch file to enable simulation and motion planning for the Giraffe arm in Gazebo and MoveIt! 2 environments.

giraffe_control

The giraffe_control package provides hardware-level control for the 5-DoF Giraffe robotic arm. It includes a ROS 2 node, giraffe_driver, and a corresponding launch file to facilitate communication between ROS 2 and the physical hardware.

Features

1. Giraffe Servo Driver (giraffe_driver):

   • Implements direct communication with the Giraffe arm's servos using the Feetech motor bus.
   • Processes incoming command messages to set motor positions.
   • Read motor position feedback from the servos to publish feedback.
   • Supports homing offsets, acceleration settings, and position conversion from radians to motor steps.
   • Subscribes to /command for joint commands and publishes feedback to /feedback topic.
   • Interfaces with six motors:
     • base_link_shoulder_pan_joint
     • shoulder_pan_shoulder_lift_joint
     • shoulder_lift_elbow_joint
     • elbow_wrist_1_joint
     • wrist_1_wrist_2_joint
     • wrist_2_gripper_joint

2. Launch File:

   • Starts the giraffe_driver node.
   • Configures parameters for easy integration with other ROS 2 packages.

Usage:

The giraffe_control package is used by the giraffe_description package's launch file to provide hardware control during simulations and real-world operation. It ensures seamless integration of the Giraffe robotic arm into ROS 2 for both motion execution and feedback.

giraffe_hardware

The giraffe_hardware package provides a ros2_control hardware interface for the Giraffe 5-DoF robotic arm plus a gripper joint. This interface lets you control and monitor the arm through standard ROS 2 controllers and topics, simplifying integration with motion planning frameworks like MoveIt.

Features:

1. Giraffe Hardware Interface (GiraffeInterface):
   • Implements a hardware_interface::SystemInterface plugin.
   • Subscribes to feedback (sensor_msgs/msg/JointState) for joint position updates.
   • Publishes to command (sensor_msgs/msg/JointState) to send joint commands.
   • Handles all six joints of the arm.

Usage:

• Integrate with controller_manager and standard controllers (e.g., joint_trajectory_controller).
• Place giraffe_interface in your ros2_control configuration.
• Commands and feedback are exchanged via standard ROS topics, enabling easy simulation or real hardware operation.