Raspberry Pi Robot Arm
Goal
I had an internship lined up for the summer of 2020, however, it got cancelled due to the COVID-19 pandemic. I'm the type of person that hates sitting around doing nothing so I decided to use the time to learn Robot Operating System (ROS) and some Python. Using the internet and some guides, I decided to learn by building a robot arm.
My Work
I designed an articulated robot arm with 3 joints. It had one joint at the base as the "shoulder", and two rotary joints on the arm as the "elbow" and "wrist". I didn't add an actuator because the purpose of this project was mainly for learning.
I used cardboard because it was a cheap material that I was able to readily obtain. I also chose to use 9g servos because they were cheap.
I created cardboard sensor housings that were able to hold the servo motors and attached them to the robot arm linkages so they could act as the joints.
To control the servos, I used a Raspberry Pi and a Servo Motor Controller. I used online guides to write a very simple Python code in Microsoft Visual Studio Code. My code made the servo motors rotate from 180 to -180 degrees in a loop.
Results
I tested my robot arm and learned that the motors were too weak to reliably control the joints. The motors would oscillate after a movement, signaling their inability to deal with the moment forces of the joints. I was planning to remedy this by shortening the links of the arm, however, at this point school started and I became busy with my ALTAIR Multi-Robot Search and Rescue System.