For the FIRST Recycle Rush challenge, the team endeavored to design, build, program, and operate a robot that would pick up totes and stack them on the scoring platforms. It could lift three totes at a time, even more if they were picked up from the short side, two at a time. The robot also featured fingers that could pick up the recycling bin from the handle, and our human player was able to throw the pool noodles like javelins into the opposing side of the field.
In this game, the robot focused on picking up the totes and stacking them. The robot was also equipped with fingers to pick up a recycling bin. The manipulators were designed using rapid prototyping with 3D printing and then fabricated from aluminum by our partner, NASA.
Aluminum “fingers” were designed to grip the lip of the totes. Sprung into place, the fingers could be pressed out of the way and spring back to lock in to the tote.
The robot used a gyro and accelerometer to “know” its position on the field. Drivers could alternate between field centric and robot centric control. Though the mecanum wheels were driven directly from their gearboxes, the chain from the lift system made for a heavy robot.
The funky layout of the field required maneuverability and traction. Combined with the shifting center of balance, these conditions warraned using mecanum.
This was our first year using the Talon SRX motor controllers and their daisy-chain CAN system. Using the integrted CAN with Powerpole connectors greatly increased the reliability of the signal and reduced errors from disconnected motor controllers.
As the robot picked up totes, it’s center of balance would progressively move forward until the robot was in danger of tipping. Using a worm screw and Igus rails, we placed the battery on a sliding platform that would project the battery backwards to help balance the robot.
Programmed in LabView, the robot utilized a gyro was placed on top of the RoboRio, which was not at the exact center of the robot, so the code needed to accommodate the difference.
The source code can be found here.
With a combination of filtering driver inputs, integration of a new digital gyroscope, and using the built-in accelerometer of the new RoboRIO controller, we achieved better robot control than we ever had before.