Robot

ROBOT

Introducing TAG 4.0, a robot on a quest to complete all 15 missions on the Unearthed mat. With its drop-in hub, multiple sensors, and 4 different shells, it's ready for the challenge.

Each year FLL Challenge teams are tasked with building and coding an autonomous robot to compete in a robot game completing missions for points on a mat. At competitions we share our robot design process in our judging session, and we also get to compete in the robot game. You can learn more about our robot, TAG (which stands for Team Alpha Geek) below.

Identify

We tested many different ideas such as a drop-in hub, drop-on attachments, and Tacobot, a 3-sensored robot from Carnegie Mellon. A lot of these ideas didn't get chosen, but testing them helped us identify what to incorporate into our robot! We also tested lots of different wheel options to figure out which ones would be best for our robot.

Design

We built our robot as a team going through many, many versions and iterations. Our robot has a flat black, gear outputs on three sides and the robot's brain (which has the hub, sensors and motors) is removable making for quick transitions and less time in the home area. It was a long process getting the robot to be balanced and figuring out how to have the robot's brain removable.

Create

We created two identical removable hubs - allowing both home areas to be coding at once & 5 identical shells - allowing our 4 different clusters to each have their own shell (and have an extra). Finally, we made a CAD (Computer Automated Design) version of our shell to have something to look back on if needed.

Iterate

Our robot and mechanisms have gone through many iterations this season. For example, on cluster four, we made a scissor lift inspired by the Isogawa books. It was difficult getting the gears strong enough for our scissor lift to work. We tested gears, worm gears, rubber bands, treads, and finally found a small rack and pinion was strong enough!

Communication

With four coding groups, we have to make sure we all are communicating. We achieved this by creating a robot log that we filled out after every meeting, taking note of what each coding side did. We also created a GANTT chart based on the Engineering Design Process (Identify, Design, Create, Iterate, Communicate) to have a plan to follow for our season.

Our team's GANTT chart.

Gear Ratios

Throughout our TAG's journey we have continued to iterate our mechanisms. An example of this is gear ratio's. We use gear ratios to increase the torque of our mechanisms. For shell 2 on our ultimate hammer we use a 1:6 gear ratio with the driver gear being 8 teeth and the driven gear being 48 teeth. By using a small to a big gear, we increase the torque, making it more powerful. On shell 3's rack and pinion we use a 3:1 gear ratio where our driver gear is larger than our driven gear. This increases the speed, cutting our run time in half.

Code Innovation

Team Alpha Geek robot isn't just mechanically sound. It has innovative code too! An example of this is our use of broadcasting blocks to do 2 things at once. Like in run 3, when we extend our rack and pinion while driving forward. Another example of efficient code is when we use arc turns by moving both wheels in the same direction, with one going faster than the other. This creates a smooth, curved turn to get around the mission mat. Also, our robot corrects itself while driving straight. To do this, we use the hub's internal gyroscopic sensor to measure the yaw angle, making our runs more accurate.

Watch a video of TAG 4.0 from Unearthed (25-26)

Watch a video of TAG 3.0 from Submerged (24-25)

Watch a video of TAG 2.0 from Masterpiece (23-24)

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