Design and Control of a Rotary Inverted Pendulum; Cannabis and Racial Disparity in the United States

Wermter, Charles, School of Engineering and Applied Science, University of Virginia
Momot, Michael, University of Virginia
Wylie, Caitlin, University of Virginia

There is no connection between the issues investigated by my technical project and STS research paper.
Racial disparity in the United States cannabis industry is more than just a relic of the past; it’s a contemporary social justice issue with deeply rooted implications. My STS research paper discusses the historical context of racial disparity in the United States in an attempt to better understand the persistent inequalities faced by marginalized communities today. I describe how cannabis has been used as a tool by those in positions of political and/or economic power to control and oppress minorities, namely those of Mexican and African descent.
My specific STS problem was racial disparity in the United States cannabis industry. Two books were paramount to my research as a whole, Marihuana, the First Twelve Thousand Years by Ernest Abel and The African Roots of Marijuana by Chris Duvall. I used Google Scholar to find articles detailing specific instances of racial discrimination such as government sponsored media campaigns with the aim of associating cannabis with race and selective enforcement of laws criminalizing cannabis. I started with the ancient global history of cannabis and proceeded to the arrival of cannabis and its spread and history within the United States. Lastly, I found specific evidence for racial disparity in the United States. I found, most importantly, that cannabis has been used directly by the United States government to control and oppress minority populations through discriminatory legislation, racial stereotypes, and selective enforcement.
If not properly controlled unstable systems can lead to catastrophic failure such as an airplane crash or the complete meltdown of a nuclear reactor. An unstable system is a system that after being disturbed will not return to its equilibrium position without some sort of external influence. In the case of an aircraft, if the control system fails to properly stabilize the plane it could stall, enter a dive, or enter a spin which could all result in a crash. My technical project is a rotary inverted pendulum, a classic controls problem that attempts to hold a pendulum balanced on its tip upright through rotary mechanical movement.
The group started by researching existing rotary inverted pendulums, poring over YouTube videos, online forums, and project websites from other university programs. The group concluded that a proportional-derivative controller would be sufficient to control the inverted pendulum arm. A proportional-derivative controller is a type of control loop that changes the output based on the feedback of the system. If the group wanted to expand the capabilities of the device, a proportional-integral-derivative controller would have to be implemented, which would add more control and the ability to hold the pendulum arm stable at an angle.
I was successful in revealing the historic account of racial disparity in the United States cannabis industry, though I did not achieve all I set out to do. I would have liked to have been able to discuss how this extends to the modern day cannabis industry. Racial inequalities still exist in the contemporary cannabis industry and I wanted to use my historical research as a stepping stone to discuss and make suggestions for approaching this issue. Future researchers should do exactly that. Discuss how patterns of economic inequality and barriers to entry hinder minority participation in the industry, how traffic stops, arrests, and incarceration rates show a disproportionate targeting of minorities for cannabis related offenses, and how discriminatory lending practices and regulatory barriers prevent those with criminal records from obtaining licenses to become a player in the industry.
The group was successful in solving our general problem. We successfully created and stabilized our rotary inverted pendulum using a proportional-derivative feedback loop. The group did not achieve all that we set out to do. The group wanted the device to be able to flip the arm up and stabilize it, rather than having it start from a stable position and requiring input to keep it that way. Future researchers should investigate a proportional-integral-derivative controller and implement it to achieve more advanced control and a higher range of desired outcomes.
I would like to extend my deepest thanks to those who assisted me during my time as an undergraduate. Although I have missed many, I would like to name a few people who I would not have made it here without: Michael Momot, Gavin Garner, Travis Elliott, Caitlin Wylie, Robert Vinson, Muhammed Nazeer, Angel Herndon-Scott, Ellen and Garth Wermter, Brendan Riley, Jimmy Garza, Aaron Seymour.

BS (Bachelor of Science)
pendulum, racial disparity, cannabis, controls

School of Engineering and Applied Science

Bachelor of Science in Mechanical Engineering

Technical Advisor: Michael Momot

STS Advisor: Caitlin Wylie

Technical Team Members: Aaron Seymour, Jimmy Garza

Issued Date: