Project 03 of 06 / Competition robotics

VEX Over Under

Seven years of competition robotics, ending with a robot that had to score, cross a barrier and climb, and a team that had to do it twice on the same day.

Role: Captain and lead programmer
Team: 41103A NextGen, seven people
Period: 2018 to 2024
Result: Two time national champion

The 41103A competition robot on its case in the pit, showing the intake rollers, the drivetrain and the folding wings, with the team number plate mounted on the frame. — **41103A in the pit**The competition robot between matches. The intake sits at the front, the pneumatic wings fold along each side, and the number plate rides on the frame.

The challenge

Build one robot that scores, traverses and climbs, and does it the same way every match.

Over Under asked for triball handling, movement across a central barrier and an end game elevation climb. Any one of those is a mechanism. All three at once is a packaging argument, and the autonomous routine only works if the robot ends up in the same place it did in practice.

The build

The pit, the seven people who ran it, and the trophies.

Photographs from the 2023/24 Over Under season, at the Australian national championship and at the world championship in Dallas.

The seven person team seated around a table with the robot and two VEX Robotics Competition trophies, in front of a national championship banner. — **The seven**The full team with the robot and the national championship trophies. Everyone here owned a part of the build.

The seven team members in suits standing in a row on a beachfront path, Hiranya in the centre in a checked jacket. — **The seven, off the field**Same seven people, no robot. Six years of building things together does that.

Team members in the pit area at the VEX World Championship in Dallas, standing beside the 41103A pit banner among hundreds of other team stands. — **Pit floor, Dallas**The world championship pit. Roughly 820 teams from more than 70 countries, and every one of them within walking distance of your bench.

Control stack

Fuse several imperfect sensors into one repeatable field position.

No single sensor on a VEX robot is trustworthy on its own. Encoders drift when a wheel slips, the inertial sensor drifts over a match, and neither of them knows where the field is. Combining them is what makes an autonomous routine survive contact.

Inertial sensorHeading feedback for turns and orientation.
EncodersDrivetrain and mechanism movement feedback.
Colour sensorField state input the odometry cannot infer.
C++ controlAutonomous routines and driver control behaviour.

My contribution

Own the code, shape the mechanisms, run the team.

Program the full control stack. Wrote the autonomous and driver control code in C++, including the sensor fusion the routines depend on.
Design the pneumatic mechanisms. Developed the intake, scoring and elevation climb systems and the packaging that let all three coexist.
Lead competition execution. Ran strategy, driver training and event preparation for a seven person team.
Build capability around the team. Mentored junior teams and helped organise the 2022 Australian National VEX Championship.

National result: Back to back Australian titles
International result: Two world championship qualifications
2023-24 season: World Championship Sportsmanship Award
Venue: Dallas, Texas

Previous builds

Over Under was the last robot, not the first.

Six seasons came before it. Each game changed the scoring objects and the field, so each year the mechanisms were designed again from nothing, and each year the code and the drivetrain carried a little more of what the last one taught us. These two are earlier season robots from the same programme.

An earlier season robot lit with coloured light, showing the flywheel, the gear train, the drive motors and a NextGen name plate across the front of the chassis. — **Earlier season robot**A previous year's build. Flywheel and gear train on the upper deck, drive motors underneath, and the team plate across the front.

An earlier robot beside a home practice field, with pneumatic cylinders and a folding arm visible and scoring discs stacked on the floor nearby. — **Home practice field**An earlier build next to the practice field it was tuned on. Most of the driving hours happened here rather than at events.

Coverage

What other people wrote about it.

Team 41103A, competing as NextGen out of Pedare Christian College, was the only South Australian team to qualify for the 2024 world championship. Two pieces of coverage from that season:

Press

SA VEX robotics team makes history at the World Championship in Texas
Glam Adelaide, 5 May 2024. The event drew roughly 117,000 competitors from more than 70 countries.

Radio

The Pedare robot, Adelaide Mornings
ABC Radio Adelaide. The team on air about the robot we took to Dallas.