The Game: Power Up
This year's challenge is called FIRST Power Up. We are limited to designing a 120lb 33x28x55” robot that scores points in a 27’x54’ playing field.
In this year’s challenge, our robot needs to pick up yellow milk crates and place them on a number of different scoring platforms. There are 3 different structures with scoring platforms. The “scale” is located in the middle of the field and contains 2 scoring platforms. There are also 2 “switches” on either end of the field. The switches are lower scoring platforms 18” off the ground located at the two ends of the field.
Each of the scoring structures has 2 scoring platforms. The red team scores on one side of the structure and the blue team scores on the other side. One of the unique aspects of this game is the randomness of the scoring plates. Before the match starts, we don’t know if we will have the scoring platform on the left or right side of each structure.
As per usual with FIRST Competitions, each round begins with a 15 second autonomous period where the robots can only used sensor inputs and pre-programmed instructions to navigate and score points. After the end of the autonomous period the tele-op period begins where our human drivers can operate the robot. This year’s autonomous will be especially difficult because of the randomized scoring platforms. At the end of the match, robots can climb on a pull-up bar 7’ off the floor to receive additional points.
We are building a robot that will be able to score in any of the 3 scoring structures. Since the robot has a maximum height at the beginning of the match, we need to build a robot that expands and reaches upwards to platform 5’ above the ground. We plan to use the same mechanism to reach the pull-up bar and lift ourselves off the ground at the end of the match. Since the milkcrates we are scoring are asymmetrical and are readily available on the floor, we’re designing a mechanism that will attach to our lift and be able to pick up the milkcrate in any orientation from the ground.
This is the top of our 2 stage elevator. We designed a linear slide system so the robot can expand upwards to reach up to the 5’ high platform. The lift is nearing completion. We still need to drive it with a chain system, but the system is sliding smoothly and not binding. We prototyped this using our stratasys 3d printers and will be milling and turning the bearing supports in the next two weeks.
We’ve also been working on a gripper prototype for the crates. This one uses 2 jaws mounted on a linear slide which is controlled by a pneumatic piston. This week we’re going to refine this design more and then test it on a driving robot to see how well it can pick up the crates. Once we verify that it works well and make the necessary changes we’ll mount it onto the lift.
We’re also finalizing our electronics for our robot. During the Fall we designed and laser cut this box to house all of the electrical components. The design is a huge improvement over last year because now it’s easier to trace wires, view indicator lights, and replace components. We’re making use of our sponsor TE Connectivity’s connectors for our CAN Bus for better reliability.