Angry Orangutan
3D Printed Prismatic Mechanism
Course: SCI 6478 Informal Robotics / New Paradigms for Design & Construction
Instructor: Chuck Hoberman
Collaborator: June Yoo
Date: Mar.-May., 2022
New fabrication techniques are transforming the field of robotics. Rather than rigid parts connected by mechanical connectors, robots can now be made of folded paper, carbon laminates or soft gels. They can be formed fully integrated from a 3D printer rather than assembled from individual components. Informal Robotics draws on cutting-edge research from leading labs, in particular, Harvard’s Micro Robotics Laboratory which has created unique designs for ambulatory and flying robots, end-effectors, medical instruments and other applications.
Angry Orangutan is a bio-inspired Informal Robotics project. It is driven by the curious walking movements and behaviors of wild Orangutans, through which they exude incredibly high similarity to human beings. They walk with 4 limbs, moving the diagonal limbs at the same time. It is a quite adaptable motion that could adjust to different surface kinds.
KEYWORDS:
Origami, 3D Printing, Informal Robotic, Bio-inspired Design, Adaptable Motion
OBJECTIVES
– Kinematics: design techniques for pop-ups, origami, and soft mechanisms.
– Fabrication: methods: for composite materials, laminated assembly, self-folding, and integrated flexures – the kit of parts will allow for hands-on exploration.
– Controls: how to actuate movement and program desired behavior. Topics include servos, linear actuators, and use of Arduino actuator control.
– Applications: takes us beyond purely technological concerns, contextualizing Informal Robotics within larger trends where materials, manufacturing and computation are starting to merge.
01 Knematic Design through Prismatic Mechanism
02 Knematic Design Development
03 Prismatic Mechnism by Laminate Technique
04 Final Project Development
​Angry Orangutan is a bio-inspired Informal Robotics project. It is driven by the curious walking movements and behaviors of wild Orangutans, through which they exude incredibly high similarity to human beings. They walk with 4 limbs, moving the diagonal limbs at the same time. It is a quite adaptable motion that could adjust to different surface kinds.
To realize the form and structure of the robotics, we utilize a system of 3D-printed components that could be snapped onto each other and maintain their freedom to rotate at each joint. The assembly of these pieces produces a composite robotic that has two degrees of freedom and could be actuated with two servo motors at its core to move its limbs. The transformable component system is inspired by origami, which could transform its overall shape through an increment of states when being folded.
Angry Orangutan could be remotely controlled by an infrared controller. The motions of the two motors are programmed with Arduino onto a breadboard circuit. The breadboard is integrated onto the robot as one part of the torso. Through the step by step increments of motor angles, the Orangutan is able to carry out a variety of movements, including shoving arms front and back, wiggling left and right, and dancing. It could also, with the combination of commands, steer front, back, left, and right, or in a circular motion – much like a lively Orangutan!
Discussions
In the previous iterations, we first defined the movement with two symmetrical arm structures, and explored three different movements (moving each motor, and moving two motors at the same time) of the strong arms actuate forward and backward, left and right, and rotate. We then tried to place it on the ground with a backpack torso, extending the two arms to allow for a wider trajectory, trying to bring the two arms to the center.
We also tried placing it on a frictionless car with wheels and customized the scratch parts with flexible length, to offer supports to move forward. Lastly, after another close analysis of the orangutan video, we observed that all four limbs of the orangutan are key parts for it to walk, so we added the hind legs.
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Some of the key modifications include the arm and torso modifications. The arm length was shortened to guarantee smooth actuation. We settled down with 3 as the maximum number of joints - more joints would cause too much friction and displacement that prohibits the arms from actuating properly. The torso was modified from a car to a real torso. By getting rid of the car, we integrated the torso as part of the whole system, rather than a separate piece, and made sure that the torso is constructed with the same kind of component system.
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We customized the pieces from solid to hollow centers to lighten up the weight. We also utilized the end pieces that Prof. Chuck and Joon developed, which have truncated edges to indicate the end conditions of the limb where it terminates. The final geometry is an assembly of triangle and square pieces.