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2020 Tech Binder
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Table of Contents

Table of Contents        2

Analysis        3

Kickoff        3

Autonomous Period        4

Teleoperated Period        4

Endgame        4

Priority List        5

Design        6

Chassis        7

Intake        8

The Gut        9

Shooter        10

Climber        11

Buddy Climb        12

Shifting Gearbox        13

Programming        14

Kotlin Programming Language        14

Autonomous        15

Teleoperated        16

State Space Vendor Dependency -- WPILibStateSpace        17

Vision        18

Analysis

Kickoff

During kickoff, the whole team worked together to determine the strategy for the season. After reading through the game manual and taking a Kahoot rules quiz, the team split up into smaller groups and discussed different strategies and analyzed point values, then decided on the following priorities for the coming season.

The team’s 2020 kickoff strove to involve as many students as possible in determining the strategy for the season. After learning the rules of the game by means of a group read-through of the game manual and a Kahoot quiz, the team split up into small groups — balanced by subteam and grade — to conduct point analysis and discuss potential season strategies. The following season priorities were then decided by a consensus of the team:

  1. Climber
  2. Trench travel capability
  3. Power cell capacity
  4. Accurate shooter
  5. Control wheel mechanism

Autonomous

Obi Non’s minimum autonomous period goal was to score at least three preloaded power cells and move off the line. However, through extensive effort and tuning, the team has achieved a eight-cell routine.

Teleoperated

In the teleoperated period, running fast cycles and reliably scoring power cells in the inner/outer power port was the decided to be most important, which influenced the team’s decision to pursue a swerve drivetrain. In addition, a swerve drivetrain allows for better defense avoidance, another major priority. The control panel was made a low priority due to the difficulty of the associated ranking point and large quantity of power cells required.

Endgame

Due in part to the team’s underestimation of the importance of endgame points in the 2019 game, a high priority was put on climbing in the 2020 season. Analysis suggested that almost half of all scoring could occur during the endgame. Additionally, the endgame ranking point appeared to be the most achievable. On top of earning the alliance a ranking point, a double level climb would also greatly increase points scored, improving the probability of a win. This inspired the team to invest in a buddy climber capable of leveling the generator switch.

Priority List

  1. Climbing

Climbing with a buddy was chosen as the first priority due to the massive amount of points scored in the endgame as well as the potential ranking point.

  1. Fitting under the trench

Under-trench motion was a priority to enable rapid cross-field motion.

  1. Scoring power cells in the high goal

Reliable scoring in the high (inner and outer) goal is the most efficient method to collect points outside of the endgame period.

  1. Carrying as many power cells as possible

A large carry capacity maximizes points-per-second and decreases the need for cross-field travel.

  1. Intaking from the floor

A floor intake expedites power cell collection and allows cells to be collected in the opposing alliance’s sector, minimizing driving time between cycles.

  1. Manipulating the control panel

Control panel manipulation occurs a maximum of twice per match, and relies heavily on power cell scoring. For this reason, the team elected to not allocate resources to such a manipulator until climbing and power cell scoring mechanisms had been completed.

Design

Chassis

A swerve drive’s high maneuverability and modularity outweighed the potential risk of attempting a relatively new drive train. The team started testing out a swerve drive in the 2019 offseason, and by the 2020 season was comfortable enough with its programming and controls to utilize it in competition.

Drivetrain

Wide Base

Intake

Obi Non’s intake aims to follow the design philosophy of “touch it, own it”. After experimenting with many designs, we found an effective design which optimized efficiency and reliability.

The Gut

Using a combination of belts, kickwheels, and gravity, the gut stores 5 power cells and funnels them to the shooter. After testing long belt run designs, an open top gravity assisted hopper indexed power cells more reliably and with reduced degrees of freedom.

Shooter

The shooter is designed to maintain consistent accuracy from anywhere on the near side of the field. We achieved this using an adjustable rack and pinion hood and a livecam for computer aided vision.

Rack and Pinion Hood

Dual Flywheels

Climber

Mounted high and on the edge of the robot, the arm allows for balanced buddy or single climbs. In order to fit under the trench, space had to be optimized. A 3-stage telescoping arm with raised superstructure allowed the buddy climber to fit below while still remaining within the design constraints.

        Telescoping Arm

        Bistable over center linkage

Buddy Climb

Designed to be compact and reliable, the buddy climber makes use of a ratchet strap attached to a second robot to apply leverage and lift an alliance partner.

Shifting Gearbox

To power all of Obi Non’s mechanisms without exceeding the PDP slot limit, the team opted to use a shifting gearbox to power the climber and the shooter. Designed for speed, compactness and versatility, the shifting gearbox provides the power to spin the flywheel at over 5000rpm and lift over 300lbs.

Programming

Kotlin Programming Language

Autonomous

Teleoperated

State Space Vendor Dependency -- WPILibStateSpace

Vision