Build Blog Day 1 (1/06/2019)

Day 1: Kickoff

Here is the 2019 Deep Space Game Animation.

Game Analysis

General Strategic Goals

Our main goal is to achieve all 4 possible ranking points, similar to our matches with Lockdown in the 2018 Season. According to this year’s rules, the first ranking point can be earned by scoring all cargo balls into at least one rocket on the field, which means that we have to completely fill all cargo for at least one rocket on the field. The second ranking point can be earned if our alliance earns at least 15 points while climbing on the 3 levels of the habitat zone. This means that our robot should climb to level 3 for 12 points, and making sure one of our alliance partners gets to at least level 1. Another thought was possibly lifting another to level 3 for extra points, even if they cannot climb that high themselves. Though one more ranking point can be earned through a tied match, we are aiming for the other 2 ranking points by doing our best to win each match.

Strategy Discussion

Legend:
(s) = Sandstorm Period
(e) = Endgame

Must Haves Nice to Haves Ideas to Explore
Manipulate both game pieces Floor Intake for discs Exhaust cargo ball onto one side of rocket
Floor intake for cargo balls Steal game pieces from other side of field (e) How to get to level 3
Score both game pieces on all levels of the rocket Score on both sides of robot (e) lift one or two robots
Drivetrain w/ high acceleration Cannot be pushed around Human load balls
Score in Cargo bays Score at a distance (over a robot)
Score efficiently and accurately w/o driver control (s) Start on second level
Securely hold game pieces (e) Lift one robot
Low Center of Gravity
Score over bumper
(s) Drive down platform
(s) Score w/ Hatches
(s) Vision System → Manually-operated
(e) level 3

Discussion Notes

Sandstorm Period

During the Sandstorm period, we plan to start the robot from level 2 on the habitat zone. To achieve the 6 points, the robot will have to successfully cross the HAB line, which requires the robot to drop from level 2 to level 1 and drive down the platform. Since some bays in the cargo ship can be preloaded with hatch panels or cargo, we decided that it would to optimal to preload the bays with cargo to avoid the usage of null hatch panels. With this in mind, we decided that our robot must be able to score hatch panels during this period.

Tele-Op Period

Our main goal during the Tele-operated period is to achieve the two ranking points for completely filling the cargo on at least one rocket and receiving 15 points with our alliance partners by climbing on the habitat zone. To complete these tasks, our robot must have the ability to manipulate both game pieces. Since our robot should also be able to independently fill the cargo on a rocket, it will have to score on all 3 levels of the rocket. Due to fast cycle times (the time it takes the robot to pick up a game piece and score it), a drivetrain with high acceleration is a must. These fast cycles require efficient and accurate scoring without driver control, as well as the ability to securely store game pieces. Similar to our 2018 robot, Lockdown, we thought that it would be useful to have a way to score game pieces on both sides of the robot, but not mandatory. In the case that a robot on the opposing alliance parks itself right in front of a rocket, it would be nice if our robot could score at a distance.

End-Game

We decided to roughly allocate the last 30 seconds of a match to climbing onto the habitat zones. Since each robot earns 12 points by climbing to level 3 of the habitat zone, our robot must be able to climb to the third level. Additionally, it would be nice if our robot could lift 1 or 2 more robots on level 3.

Further Discussion

We also realized that we would need different strategies during our qualification and elimination matches. In our elimination matches, filling up an entire rocket matters less than in our qualification matches because there is RP bonus. We are considering lifting 2 robots in elims, since the points are unavailable anywhere else and it may be necessary to win in very high level matches where all game objects are scored.
Lifting a balanced load is easier than lifting an unbalanced load. (different robot designs)
Teleop cycle time is a bit less than 5 seconds per game object for perfect score. (assuming alliance partners don’t do anything)

Field CAD

We worked on constructing the field in CAD, focusing on designing a single level of a rocket. After designing this, we were able to laser cut the single layer rocket, allowing to test how cargo and hatch panels interact with the rocket when placed or scored. Looking forward, this also lets us test using different heights of the rocket.

Elevator CAD

Using two-dimensional CAD, we explored potential overall general robot design. We sketched different possible configurations for an elevator and arm. While testing these configurations, we were looking for designs such that the robot would have the abilities of stowing in max size and reaching the top rocket bay.

Drive Base CAD

We explored how different drive bases would beach coming off level 2 of the HAB zone. We experimented by changing wheel size, wheel spacement, and bumper alignment. 4” wheels with bottom of bumper flush with the bottom of drivebase beached horribly. 4” wheels with bumpers at maximum height scraped the belly pan but did not beach. However 6” wheels beached well. We then retested the 4” wheels to not beach such that the bumper completely surrounds the drive base perimeter. This lead to us testing whether the drivebase used for Lockdown (our 2018 robot) could successfully drive off level 2.

Lockdown Drivebase Compatibility Test

At our first build, we tested to see if Lockdown’s (our 2018 season robot) drivebase could drive off of the second level of the HAB Zone (6 inches higher than the first level) without trouble. So far, it seems that we will be able to drive off from the second level of the HAB Zone, proving that Lockdown’s dimensions and wheel spacing may be adequate for completing this “Must Have” task (from the Strategic Goals Chart Above). At the next build, we will work to build a better platform base, as we are low on large wood blocks to use as bases.

Disc Intake

At build, we were exploring ideas concerning how to pick up hatch panels from the floor using 2” flex wheels and angled 1×1 to emulate 2013 intake. After a few tests, we realized that this design worked in eventually directing the disc towards the robot and over a small knife edge. However, this was not nearly as effective as the design we would later prototype. We set out to use velcro to grip the disk from the top and feed it into the robot, but we ran the drill the wrong way and we realized the proficiency of a velcro kicker roller. With velcro, we were able to make kicker rollers that could be exceptionally large and far off the ground. We used a 2 in diameter roller coated in velcro about an eighth inch off of the floor as a kicker roller, and used a 1 inch diameter roller to sandwich the cube. This allowed us to hold the disk very securely during manipulation. We will follow up with a more precise prototype soon.

Cargo Ball Intake

After discovering that the cargo balls bounce away from the loading station, we decided to construct a prototype for a floor intake. By testing the intake by using a 1” diameter thunderhex axle, we decided the best compression offered to clear the cargo over the bumper was when the axle was placed 10.25” from the ground. Since we were moving towards the idea of an elevator on our robot to score at all levels of the rocket, we began looking at Lockdown’s (our 2018 seasonal robot) intake as a possible intake system for obtaining cargo.

Programming

Our programming team mainly worked on imaging RoboRIO & TalonSRX’s to the 2019 version of all the software so that we can start testing code on the 2018 Programming bot drivebase. We built a 1:1 model of the vision targets on the Destination: Deep Space Field so that we could start testing the vision pipeline. With the Limelight V1, we were having trouble determining skew (the angle between the Limelight plane and the vision target board plane). We ordered Limelight V2’s today, so we are going to see if that works better.

Field Construction

At build, a group of students cut the laid out carpet and used seamed the ends of each carpet, in order to prepare the area for field construction for this year’s challenge. At the next build, we plan on taking the necessary measurements and adding the borders of the field.