MARVIN XI

In 2017, I learned an important lesson as a designer: having the entire machine depend on one system is a very bad idea. This lesson led to the design of what many called the most innovative component of MARVIN XI, the Rectangular Prism Expulsion Device (RPED). This system allows MARVIN XI to score even with almost every system onboard completely disabled. Using only this device and the robot's drive system, scoring objects could be loaded onto the backside of the machine and quickly deployed into scoring locations around the field. The system was completely self contained and relied only on separately powered motor controllers, so that if air pressure was lost on the machine scoring capability would not be reduced.

MARVIN XI's key scoring capability was found in its lift system, the design of which was deceptively simple. Making use of incredibly light C-channel components, the inner stages of the lift smoothly glided inside each other, pulled by two #25 chains driven by a single transmission at the base of the machine. The innermost carriage, containing the intake mechanism, was driven by a cascade lift system, enabling smooth, simultaneous motion of each lift component. The lift system was also robust enough to be used to lift the robot twelve inches into the air by way of hanging off a bar placed on the field. The hooks located at the top of the lift system are positioned there for this purpose. The design and placement of the hooks also allows the machine to hang alongside another robot, which was done successfully multiple times during competition.

MARVIN XI was designed with autonomous control in mind from the very beginning. Software control was simplified, allowing for easy, repeatable motions during autonomous. A special camera called a Limelight was integrated into the lift system, which allowed for autonomous tracking and capture of game elements. A built-in Inertial Measurement Unit (IMU) was used in conjunction with Grayhill Encoders to determine the robot's on-field position. By the end of the 2018 season, MARVIN XI was capable of placing two game pieces in up to two different scoring locations.

A surprisingly unique challenge introduced in 2018 was collecting and moving that year's game piece - large, weighted "Power Cubes". I took the lead on the design of the intake mechanism, seen to the left. Using a single custom-designed transmission, the intake spun two "intake" wheels in opposite directions, creating either a powerful "pull" motion or a somewhat-less-powerful "push" motion. As the cube is pulled in, the system "relaxes" by venting local air pressure. Once an IR detector determines that cube has been pulled in, the intake wheels shut off and the system "tenses" by re-filling the system with pressurized air. When scoring the cube, the cube could either be pushed out by the intake wheels or simply dropped by engaging a third pneumatic state which forced the intake "arms" apart to their maximum possible distance.

MARVIN XI is the most successful robot created by 2614. Ranking 4th in its division at Championships, it was also the third MARS robot to become a division finalist, narrowly missing a shot at the final elimination rounds, called Einstein Field. It is the only machine to have won two regular season events, and boasts the most event wins of any MARS machine. It also earned the largest number of design awards ever earned by the team in a single season, three consecutive Industrial Design awards and a Quality award at Championships. Final season record was 49-16-0.