robotic-finger

• RDS Speedster team
• Spring 2026

Description

This project controls a 3DOF robotic finger designed by the speedster team for Robot Design Studio 2026 at Northwestern University as the capstone for our undergraduate degrees in Mechanical Engineering.

This repository can run a set of benchmarking demos as well as whackamole demos in both simulation and on hardware.

Whackamole Hardware Demo

whack-1_github.mp4

Drake Simulation Demo

simulation_demo2.mp4

Installation Instructions

1. Create a new ros2 workspace named ~/rds_ws and a src folder

   cd ~/
   mkdir ~/rds_ws/src -p
   

2. Download the requirements.repos file and place it in the src of your workspace. Install all required repositories using this command:

    vcs import < requirements.repos
   

3. Build using colcon build

Drake ROS Installation

Drake must be installed on system as well as on drake_ros built locally in a overlay workspace.

1. Install drake on system drake installation tutorial

2. Source drake, add this to bashrc

    export PATH="/opt/drake/bin${PATH:+:${PATH}}"
    export PYTHONPATH="/opt/drake/lib/python$(python3 -c 'import sys; print("{0}.{1}".format(*sys.version_info))')/site-packages${PYTHONPATH:+:${PYTHONPATH}}"
   

3. Create overlay workspace with drakeros

    mkdir -p ~/drake_ws/src
    cd ~/drake_ws/src
    git clone https://github.com/RobotLocomotion/drake-ros.git
   

4. Build the drake overlay workspace. Build using gcc in ~/drake_ws.

    source /opt/ros/kilted/setup.bash
    export CC=gcc-13
    export CXX=g++-13
    colcon build --packages-select drake_ros \
    --cmake-args \
        -DCMAKE_PREFIX_PATH=/opt/drake \
        -Dpybind11_DIR=/opt/drake/lib/cmake/pybind11 \
        -DCMAKE_C_COMPILER=gcc-13 \
        -DCMAKE_CXX_COMPILER=g++-13 \
        -DBUILD_TESTING=OFF
   

5. Source overlay workspace, add this to bashrc

    source ~/drake_ws/install/setup.bash
   

Launchfiles

Simulation

1. ros2 launch finger_simulation 4barsim.launch.xml - Drake simulation with 4-bar linkage kinematics and Rviz2 visualization
2. ros2 launch finger_simulation basic_fingersim.launch.xml - Drake simulation with 4-bar linkage kinematics, Rviz2, and a fingertip tf frame

Visualization

3. ros2 launch finger_description fingerviz.launch.xml - URDF visualization in Rviz2 with interactive joint_state_publisher_gui for manual joint control

Control

4. ros2 launch finger_control demo.launch.xml - Full control stack running a selectable demo trajectory. Args:
   • bridge:=simulation|hardware (default: simulation)
   • demo:=force_step|sinusoidal|linear|ik|cartesian_ik|chirp|chirp_velocity|none (default: none)
   • use_rviz:=true|false (default: true)
   • record:=true|false (default: false)
5. ros2 launch finger_control 3d_waypoint_tracking.launch.xml - Full control stack with simulation vision for 3D waypoint tracking. Args:
   • bridge:=simulation|hardware (default: simulation)
   • use_rviz:=true|false (default: true)
   • record:=true|false (default: false)
6. ros2 launch finger_control pixel_whackamole.launch.xml - Whack-a-mole game using pixel-based vision and the whackamole server. Args:
   • bridge:=simulation|hardware (default: simulation)
   • use_rviz:=true|false (default: true)
   • record:=true|false (default: false)

Vision

7. ros2 launch finger_vision vision.launch.xml - RealSense camera + AprilTag detection + finger_vision node + Rviz2
8. ros2 launch finger_vision2 vision2.launch.xml - RealSense camera + AprilTag detection + finger_vision2 node + Rviz2