We formed 3 teams to represent King’s at Unibots UK 2025, an autonomous robotics competition hosted by Cambridge University Robotics Society (CURS) in collaboration with Heriot-Watt Robotics Society.
The competition challenged university teams to build autonomous robots capable of collecting various types of balls - including a remote-controlled ‘snitch’ - in a dynamic, fast-paced arena.
About Unibots
Unibots is an inter-university robotics competition founded in 2022 by CURS, aiming to bridge the gap between beginner and advanced robotics with a hands-on, competitive platform. This year, teams were tasked with designing autonomous robots to collect table tennis balls, mini rugby balls, and a snitch—an unpredictable remote-controlled ball—while navigating a shared arena with up to four competing bots at once.
Meet our teams
Team A – "Just Put the Balls in the Bag"
Comprising all first-year students, Team A focused on simplicity and reliability. Their design featured a laser-cut frame with a revolving sweeper that directed balls up a ramp into the collection area. The robot used a top-mounted camera feeding live video to an onboard mini-PC. There, a team developed AI model trained via supervised learning identified and tracked the balls, enabling the bot to navigate autonomously.
Unfortunately, on competition day, a soldering error (not made by the team) led to a battery short-circuit, preventing the robot from fully competing. Despite this, the team earned points when balls accidentally rolled into their idle bot.
📸 Team A’s robot. Photo by Abyan Memon.
Team B – "Team Pikachu"
Team B’s approach emphasized software over hardware. The robot had a simple mechanical design—a basic ramp for pushing balls—but featured a highly sophisticated AI system developed from scratch by Oguzhan.
The AI resembled the YOLO object detection framework but was fully custom-built and fine-tuned over several months. It included a priority-based path planning module that selected targets based on proximity and size, offering temporal stability to “hallucinate” ball positions when briefly obscured.
Running at 16–17 FPS on a Raspberry Pi (an impressive leap over the typical 4–6 FPS) the system sent commands to an ESP32 via PySerial for responsive motion control. The robot was capable of backing up, centering, and ramming balls into its ramp with precision. It could also be remotely operated and viewed globally via a phone and cloud-based system.
📸 Team B’s robot. Photo by Abyan Memon.
Team C – "Ice Cream Society"
Team C’s bot stood out for its unique front-mounted three-wing spinning collector and mecanum wheels that enabled strafing in all directions—ideal for dodging collisions and maneuvering around obstacles. The drivetrain used chain-linked mecanum wheels, and the team relied on a combination of a Raspberry Pi and laptop for live streaming and vision processing.
In a surprising twist, the loss of their front collection wheel in the first match allowed them to more easily collect larger rugby balls—turning a setback into an advantage. Team C ultimately performed the best among KCL teams, winning Accu’s “Favourite Bot Design” award for their creativity—including a rubber duck mounted on the bot.
📸 Team C’s bot and rubber duck. Photo by Abyan Memon.
Powered by Innovation
Behind two teams was custom hardware developed by KCL Electronics President Dimitri, who also runs a power electronics start-up. He provided a custom ESP32 development board with an integrated power supply and a compact H-bridge motor driver, capable of handling 25A, far beyond standard 5–10A off-the-shelf options.
Competition Day Highlights & Challenges
Held on March 30th at the University of Cambridge, the event was filled with both breakthroughs and setbacks:
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Team A, hindered by the last-minute battery failure, couldn’t fully compete but remained in good spirits.
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Team B’s AI worked seamlessly, though hardware issues required quick fixes—including duct-taping a new ramp. A disputed match reset by another team caused them to lose the snitch, resulting in a replay.
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Team C capitalized on their robot’s agility and recovered well from mechanical damage. Though they didn’t make the knockout rounds, their design stood out for both performance and creativity.
However, the competition wasn’t without controversy. The league-style scoring system, which awarded points based on performance against randomly matched bots, led to inconsistencies. Some bots advanced with lower scores simply due to favourable matchups. KCL teams were particularly frustrated by repeated matchups against the same competitors—especially Cambridge’s heavily fortified “box robot.”
Looking Ahead
Despite the hurdles, Unibots UK 2025 was an incredible learning opportunity for all involved. Our teams demonstrated innovation, adaptability, and resilience—and left with new ideas, stronger collaboration, and national recognition for design excellence.
We’re proud of Team A, Team B, and Team C, and look forward to next year’s competition with even more ambition—and hopefully, a bit more soldering luck.
Credits
This article is based off Bots, Brains and Broken Circuits: King’s Teams Battle It Out at Unibots UK by Abyan Memon for Roar News. Edited by Dylan Kainth.