Session: IMECE Undergraduate Research and Design Exposition

Paper Number: 120302

120302 - Development of 3d Printed Humanoid Robots 

In order to lower the barriers to entry for the use of “humanoid robots,” open source designs are appealing. Also, more affordable manufacturing techniques, such as 3d printing, will further aid this objective. This project focused on developing two open-source 3D-printed humanoid robots, as versatile lab assistants with a focus on lifting objects, pushing a cart, and walking. Two teams worked on achieving this; one team focused on making mechanical redesigns and the other worked on simulation and controls.
The design team carried out static and dynamic analyses to guide a series of redesigns to improve strength and integrate new components. The redesigns included a new grip mechanism to lift objects, sensors to aid the walking component (LiDAR TF Luna, Husky Lens Camera, and IMU), and component updates to integrate new lower cost motors. The grip was an under-actuated, 3-point finger grip with an electromagnet attached to the base of the forearm. A new spine was created, attached at the chest and pelvis, to assist with stability for standing and walking. The chest and feet were redesigned to include sensors to assist in walking.  To make the robots more cost effective, all of the Dynamixel motors were replaced with HerkuleX DRS motors allowing for uniformity in design and programming. The team performed torque analysis to determine the required torque for lifting specific lab tools, and used a motor decision matrix to choose HerkuleX brand motors. By replacing the original Dynamixel MX-64AT and AX-12 motors with HerkuleX DRS-0601 and DRS-0101, respectively, the cost was reduced by approximately $375. The smaller size of the new motors required adjustments to several parts, including the hip, thigh, shin, abdomen, neck, head, shoulder, and biceps.
The controls team’s first task involved updating the wiring of motors and electronics to improve performance and ensure consistent functionality. Kinematics and trajectory planning were implemented to replicate human movements and simplify motion control. This was followed by the integration of sensors such as TF Luna LiDAR, Husky Lens, and IMUs to provide data required for walking trajectories and feedback control. Additional batteries and power circuits were incorporated to account for new motors and sensors. These electrical updates included replacing the original solid core wires with higher quality threaded wires and resoldering weak connections and utilizing 11.1V LIPO batteries. In order to test all of these aspects, a simulation model was also developed in CoppeliaSim. Finally, a user-friendly interface was created to view all the sensor data and control the humanoid robots.

Presenting Author: James Van Milligen Worcester Polytechnic Institute

Presenting Author Biography: I am a masters mechanical engineering student at worcester polytechnic institute.

Authors:

James Van Milligen Worcester Polytechnic Institute
Emily Austin worcester polytechnic institute
Zenia Alarcon worcester polytechnic institute
Aashish Singh Alag worcester polytechnic institute
Tessa Lytle worcester polytechnic institute
Josh Fernandez worcester polytechnic institute
Finbarr O'sullivan worcester polytechnic institute
Erin Lee worcester polytechnic institute
Casey Snow worcester polytechnic institute
Pradeep Radhakrishnan worcester polytechnic institute
Kaveh Pahlavan worcester polytechnic institute