The Hydraulic Robotic Arm (Finished)
This is my project for the Society of Astronautics and Rocketry. As part of the special projects team, I have been assigned as the lead on the design of a hydraulic robotic arm for a rover which will go on to compete in NASA’s University Rover Challenge at the Mars Desert Research Station in Utah.
The Idea
The idea for a hydraulic robotic arm was born from a research project that I did in my senior year of high school. For my research project, I had designed a prosthetic arm using 3D printed parts in addition to soft actuators (Pictured Below).
However, unlike traditional prosthetics, this prosthetic arm did not use mechanical linkages to curl the fingers on the hand. Rather, it used air and King Actuators developed by the Haverford School to actuate the fingers. If you want to learn more about this project, follow the link below.
Link: https://docs.google.com/document/d/1_1rrXU5s6YOW_qrYkyfdZjtCwcDZWVHSwGtssVa3Nog/edit?usp=sharing
Improvements
The prosthetic hand above however, was janky to say the least. While the hand worked, it underperformed compared to other prosthetics on the market. It was a proof of concept and could be improved upon. An idea that I had come across while doing the research for the above hand was a pneumatic hand developed by researchers at the Delft University of Technology. They had used pneumatic cylinders as the fingers. We wanted to implement these into our design and based off of their research, we were able to develop this first prototype.
We were able to test this prototype and found that the hand was not curling as far as we had hoped. Check out the test below:
After looking at the footage as well as the mechanism itself, we were able to determine that the clevice in addition to our 3D-printed piece was causing the finger to not curl properly. After making some changes, we were able to make the hand curl approximately 90 degrees as seen in the video below:
After this test, we knew that we had a proof of concept and that we could start working towards our first full version of the hand. We decided to have three fingers and develop it as a claw from an arcade claw machine. This would allow for us to do many of the challenges necessary for the NASA Rover challenge. Here is the CAD image of our concept.
Since we only had the parts to be able to build one finger for now, we built and tested it. The test was a success and we were on our way to build the full thing and thus ordered the parts that we needed.
