• Sajiv Shah

FRC 2021 Infinite Recharge @ Home Strategy Part 2 (Ball Pickup continued)

Updated: Dec 19, 2020

When looking at specific robot paths, we realized that the positioning of our intake is very important. During autonomous, which will discuss more in a later post, it makes sense for balls to be intaked on the other side that they are shot from (shown below).

In this scenario, the robot would be driving and intaking balls, then directly moving to the shooting location and shooting without having to turn at all. Turning does not take a long time but it does require more calculation and creates a more difficult driving path, especially with a Westcoast drivetrain. Although this appears to work for in gameplay and autonomous, there are also many robot paths where an intake on the same side where the shooter is.

In the image above, one case where a dual-sided intake is useful is exemplified. While in one of our identified shooting zones which is in the defense-protected triangle (where the robot initially starts in the image), the easiest place to pick up balls would be from the blue loading station area. As long as we (the red team) are scoring enough balls, the blue team would be forced to dump some out at the blue loading station, giving our alliance the chance to make a very short trip, pick those balls up, and score them. In that case, we would want the intake to be on the front of the robot, so we can make short turns and pick the balls up. However, there is a likely case where we must travel under the trench or through the truss onto our side and pick balls up from our loading station, where it would be best for our intake to be on the back of our robot. There is also a chance that we are only able to pick 2 or 3 balls up from the blue loading station, and then would either have to shoot those balls or travel back to the red side to get more balls to shoot.

The problem is not the location of the intake in relation to the shooting direction, but rather the overall robot orientation. If our robot could intake from any side, it would need to rotate far less than if it had to turn around to intake balls. Having a shooter on a turret system where the shooter rotates would not solve our intaking problems, and it appears that the only design which allows us to achieve easy drive paths is a dual-sided intake.

A dual-sided intake system is far easier said than done and requires additional design to the shooter and feeder. The feeder will need to allow balls to be entered from both sides and have a central way to insert it into the shooter without bias to a certain side in order to ensure an accurate and consistent shot. Furthermore, rotating the robot is not a large driving issue (as the driver I have experience and feel it is fairly simple) and is inevitable in many cases, making the dual-sided intake obsolete. The additional complexity and weight most likely do not make this dual-sided intake worth it, but it would be interesting to prototype a feeder system that allows for it considering that a system that can get balls from the loading station can probably also intake balls from both sides.