Allston | Robot Dog I

Project Overview

Designed and built a custom quadruped robot integrating mechanical design, electronics, control systems, and robotics simulation. Each leg uses three servo motors and a custom four-bar linkage to control hip rotation, leg pitch, and knee motion. The project was developed from the ground up, beginning with mechanical design and 3D-printed prototypes before progressing to servo control, inverse kinematics, gait development, and ROS 2/Gazebo simulation. The long-term goal is to develop stable walking and more advanced locomotion, including navigating uneven terrain and stairs.

What I Worked On

• Designed the body, articulated legs, and four-bar knee linkage in SolidWorks for 3D-printing
• Developed inverse kinematics to convert desired foot positions into required joint angles and derived four-bar linkage geometry to relate knee position to servo motion.
• BProgrammed 12 servo motors using an Arduino Mega and PCA9685 PWM controller.
• Developed coordinated leg trajectories for controlled foot movement and gait development.
• Designed the robot's power distribution and servo control electronics.
• Created a ROS 2 model of the robot using URDF/Xacro.
• Integrated CAD geometry, joint constraints, mass properties, and centers of mass into the simulation.
• Used RViz and Gazebo to visualize and test robot motion before implementing it on the physical system.