Mechanical Concepts for Beginners/Individuals interested in robotics using our 2021-2022 robot!!!

Hey there! If you are here you are probably interested in the mechanical, electrical, and programming concepts used in our robot this year. This will teach any member of the team, or potential community member interested in robotics, the process that goes along with building a competitive robot. Attached below is a picture of our robot.

First off, let's take a brief overview at the challenge in the 2021-2022 Rapid React Season. A short description of the challenge is that robots have to navigate the field, pick up cargo balls, and shoot them into two circular hoops at the center of the field. In the first 15 seconds, robots are autonomous meaning a human does not control them. For the rest of the match, robots are controlled by human drivers that try to accomplish the tasks of the game using the robot. At the end of the match, in a period called endgame, robots traversed a series of climbing bars(like inclined monkey bars) to try reaching the highest rung. So, with that information let's get into the mechanical/programming/electrical ideas that helped us achieve a functional robot.

Mechanical Concepts

First, let's touch on one of the most basic concepts that we had to figure out how to accomplish. In order for the robot to be able to shoot the ball, we needed to figure out how to intake the ball. We also had to account for the fact that the game this year was restricted by the rule the robot could not extend out of its frame perimeter prior to the match. After designing, we determined that we could use the power of gravity to drop our intake, which uses a motor to run a bar with rubber wheels. This allows for the balls to be taken in at a rapid rate. Even though we faced a few problems with the intake during the competition, the intake design was simple and efficient for a rookie team new to the build process.

Second, we had to determine how our shooter would work. The high goal in the FRC challenge this year was 8 feet 8 inches, while the low goal was around 3 and a half feet. Thus, when designing our robot we had to consider whether we would like to shoot high or low goal. The design we finished on is having a transport wheel and a shooter wheel that compress a ball against a ramp, which allows the ball to shoot with enough velocity and height to go in the upper hub. In order to have a reliable amount of compression we used a spring that held the wood ramp so that the ball could compress the right amount and shoot properly. After only being able to shoot low hub in our first competition, we made adjustments to the gear ratios of our motors to shoot into the upper hub at our second competition. This growth between competitions helped us learn a lot about the design process!

Third, perhaps the most difficult part of this years game was attempting to figure out how to traverse the "inclined monkey bars" during the endgame period. Right from the bat we made several CAD models for a fully functional traversal climb, however, that didn't work out. Thus we aimed to go for a ball screw climb using an arm from a medical bed, however we were unable to use this arm due to FIRST rules. So, with limited time before our first competition we switched to the passive climb idea that a different teams secondary robot used, Robonauts EveryBot. This climb hits the first bar, raises an arm that reaches the mid bar and hangs on the mid bar. This brings us to the main idea that you, the reader, should take from this article. If you ever join robotics, keep asking questions and taking the advice of more knowledgeable teams/mentors/peers. This will allow for the continuous growth of ideas. During this build season, we used the ideas of many more knowledgeable teams such as FRC Team 7503 Radicubs and used ideas from teams such as FRC Team 118 Robonauts. This allowed us to be succesful and learn so much!

Electrical Concepts

Secondly, our robot would not be able to work without electronics. So, here is a quick overview into the key components. The power of the robot comes from the 12V battery. This voltage then goes to the PDP where the power is spread to the various components of the robot such as Roborio(robots brain), motors/Spark Maxes(robots lungs), and robot signal light(gives robot status). Without the usage of these parts, the parts are hard to understand, which is why, if you are interested should look at the FRC Electronics guide linked here

Programming Concepts

The movement and functionality of our robot would not be possible without the usage of programming. Due to the familiarity of many of our members with Java, our primary coding language for FRC 2022-2023 season Rapid React is Java. Once again there are many parts in FRC programming, which is why this will only give you a brief idea of what we accomplished this year. First, the code helped us successfully complete all of our tasks: intake, transport, and shoot. However, what is more fascinating is what we tried to accomplish that we were not able to achieve, but will continue to try next year. This is that we actually attempted to use vision processing to find the balls, make our robot move towards the balls, align ourselves to the hub using a gyroscope, and finally score. Even though we were not successful, our goal to do this as a rookie team was incredible!

Takeaways

From this brief overview of our design process this season, the audience should have a small understanding on how the FRC Build Season goes and what kinds of things members work on during this time frame. Keep in mind, that throughout this process there is still extraneous activities such as seeking finances and outreach still occurring, so if you weren't intrigued by the concepts described in this blog, there is still a place for you! Additionally, readers should take away that none of our success would have been possible without us continuing to learn by asking questions and not being afraid to put ourselves out there. So, we suggest to anyone reading this: keep following your goals and we hope to see you on a successful robotic team soon!!!