UNLV wins 1st place in Student Design Competition at ASME E-Fest West
At Pololu, I have spent the recent weeks developing new products, like the motor driver I announced on Wednesday, but at school (I am a mechanical engineering student at the University of Nevada, Las Vegas, UNLV) I have been managing an American Society of Mechanical Engineers (ASME) Student Design Competition (SDC) team. SDC teams create robotic devices to fulfill a problem statement that changes every year. They compete with their devices at one of ASME’s regional student conferences called E-Fests. Last year, I managed a three-member team that built The Rebel WIP and earned third place in the Robot Pentathalon at the E-Fest West. This year, my ten-member team made a squad of robots called The Rebel Bandits for the new SDC challenge, Robot Football. We overcame many technical challenges and 14 other teams to win first place at this year’s E-Fest West that competed this past Saturday!
The SDC’s Robot Football was loosely based on soccer, but with four robot teams competing to shoot eight tennis balls into four goals on a 5 m x 5 m field. Each team was assigned a goal to defend, and eight tennis balls were set in a square pattern at the center of the field for robots to score into the other goals. For this competition, teams could build multiple remote controlled robots, but the robots and controllers had to be able to fit inside a single 50 cm cube. Some teams built soccer squads with only two or three big robots, while other teams used up to six little robots for their squad (which made the matches super chaotic), but each team could only control one ball at a time. Robots controlling a ball needed to keep the ball on the ground when they moved around, but they could stop and lift the ball to shoot on a goal.
The Rebel Bandits.
I am really proud of the robots my team designed and built for this competition, so I want to share how my team made a first place robot squad! However, since we won the competition at E-Fest West, we were invited to compete again in the SDC Finals at ASME’s International Mechanical Engineering Congress and Exposition in Pittsburgh, Pennsylvania this November. We will be competing against the first and second place winners from the other student conferences: E-Fest East, E-Fest Asia Pacific, and E-Fest South America, as well as the SDC team from California State University, Northridge, who came in second place at E-Fest West. The teams will be more competitive, and the prize money increases significantly! So that makes me a little bit nervous about showing all the technical details for our robots right now, but I would still like to give a basic rundown.
Our strategy was to build three large robots: one defender, and two offensive robots. We call the defender robot The Outlaw. It is built on a U-shaped frame with 19 in (48.3 cm) long sides and has tall walls. Even though it cannot block from inside our penalty box and is not particularly fast, it can seriously impede the efforts of other teams to score on our goal just by being big and tall. The Outlaw uses three DC motors for its drive train at the base of the U-frame, and Pololu ball casters help support the far ends of the U-frame. One DC motor is driven by a G2 High-Power Motor Driver, and since we use an A-Star 32U4 SV for the Outlaw’s microcontroller, the other two DC motors are driven by a Dual G2 High-Power Motor Driver Shield for Arduino.
The Desperado and The Renegade.
The two offensive robots are named The Renegade and The Desperado (you should notice the Wild West theme by now). Other than the color schemes, these robots are almost complete duplicates. We decided to build only two offensive robots because it gave us sufficient space to build robust robots with high quality shooting mechanisms.
Each offensive robot uses four DC motors for the drive train. A standard size servo extends an arm with an intake belt, and a DC motor runs the intake belt to pull a ball into the robot’s reservoir. Another servo opens and closes a gate that keeps the ball in the reservoir or pushes the ball into the shooting mechanism. The reservoir allows the ball to roll on the ground as the robot moves without the intake belt constantly pushing down on the ball and impeding driving. The shooting device is a ramp and flywheel. When taking a shot on the goal, the operator stops the robot and the flywheel revs up to high speed. Then the gate servo pushes the ball into the ramp. The velocity of the wheel pulls the ball along the ramp structure and throws the ball at high velocity. Just beyond the outlet for the ball, a plate on a pivot controlled by a servo lets us control the ball’s trajectory. This allows us to shoot across long distances or over defender robots.
The offensive robots each use an Arduino Mega as their primary microcontroller. Most of the DC motors on The Renegade and The Desperado are controlled by either a Dual G2 High-Power Motor Driver Shield connected to the Arduino Mega or are driven by individual G2 High-Power Motor Drivers. On each robot, a Maestro servo controller is used as a slave controller that powers and controls the standard servos. Additionally we use the Maestros’ functionality as general I/O controllers to send logic signals to the individual 18v17 Motor Drivers. In our setups, we want the servos and the Maestros to be powered from 6 V, so we use a step-down voltage regulator to connect the Maestro power rails to main power supply on each robot, a 12 V lead-acid battery.
I am very fortunate to have worked with an awesome team this year for the SDC, and I am grateful for the parts and support we obtained from both Pololu and UNLV! It was also exciting to see different teams at the competition using other Pololu parts like our wheels, metal gearmotors, regulators, and brushed DC motor drivers. After our SDC Finals competition in November, I plan to write another blog post about more of the technical details of our robot. (Hopefully I will be able to brag a little about another first place trophy too!)
Patrick and 6 members of UNLV’s SDC team that traveled to competition in Pomona, California.
Until then, I want to know more about some of your projects! I hope you will share a little about your cool projects in the blog comments, or you can make a Pololu forum account and post in the Share Your Projects category!