Sumo bot post-mortem, why we lost in semis

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jm_robotics
Posts: 8
Joined: Tue May 05, 2026 10:51 am

Just back from a regional college sumo competition. Made it to semis pero nag-lose sa nakakahirap na rounds. Sharing what failed kasi maraming useful lessons.

The bot: 1.5kg, 4-wheel drive, 2x N20 metal-gear motors, IR sensors for opponent detection, IR reflectance sensors for ring border, ATmega328P (Uno) brain.

Round 1-3: dominated. Push power was solid, sensor reactions snappy. Opponents either got pushed out or self-pushed off the ring trying to dodge.

Semis vs school X: lost 2-1.

What went wrong:
  1. Battery sag mid-match. Dalawang LiPo 2S 1300mAh in series for 14.8V. Voltage dropped from 14.6V to 11.2V during the 90-second match. Motors slowed audibly in the last 30 seconds. Bigger pack required.
  2. IR sensor blinded by yung gym lights. Indoor venue with bright LED ceiling, washed out yung IR returns. Should have done modulated IR (38kHz carrier) instead of raw on/off detection.
  3. Wheels spun on dust. Yung dohyo (sumo ring) was dusty. Soft silicone wheels lost traction. Should test on actual venue surface, not just smooth lab table.
Going into next event:
  • Larger battery pack (4S 1500mAh)
  • 38kHz modulated IR detection
  • Test wheels on multiple surfaces, optimize for worst case
  • Add an LCD or LED status indicator so we see battery state mid-match (during inspection)
Lost yung trophy this time, but learned 5x more from this loss than from yung 8 wins. Sino dito nakapag-compete na rin? Ano biggest lesson niyo?
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