Nanoline and Line Follower — the Simplest Way Into Robotics Competitions

If one league is the doorway into Iranian robotics competitions, this is it. Nanoline and line follower leagues run at IranOpen and nearly every domestic event, with the simplest rules of all: complete a line course in the shortest time.

The rule in one sentence

The robot is placed on the line, a button is pressed, and from that moment nobody may intervene. Fastest to the finish wins. Leaving the course incurs a penalty or a restart from a defined point, depending on that edition's rules.

What you need

A light chassis with two motors and wheels (plus a caster).
A reflectance sensor array (typically five to eight sensors) to see the line.
A microcontroller — an Arduino or equivalent is plenty.
Motor driver and battery.

All of it is available locally, which is exactly why the barrier is so low.

Three levels of skill

Level 1: just stay on the line

The simplest logic: if the left sensor sees the line, turn left. It works, but the robot wobbles and is slow.

Level 2: PID control

This is the real jump. Instead of all-or-nothing decisions, the robot measures how far off it is and corrects proportionally. The motion becomes smooth and far faster — usually several times faster than the naive version.

Level 3: anticipating the course

Elite robots accelerate on straights and brake before turns. That requires detecting the turn type early, or memorising the course on a first pass. This is where top-level races are won.

Calibration is failure cause number one: reflectance sensors are highly sensitive to ambient light. A robot that was flawless in the workshop may not see the line at all under competition lighting. Always build in a fast calibration routine — sweeping the robot across the line before the start, for instance.

Why this league is worth doing

It looks simple, and that is precisely its value: in a small league the student experiences the entire competition cycle — build, test, fail, fix, walk into the hall, face a referee. That experience pays off later in bigger leagues such as Rescue Line.

What comes next

A line-following robot is the natural prerequisite for RoboCupJunior Rescue Line. Many successful teams took exactly this path: Nanoline in year one, Rescue Line in year two. For the mechanics, read this article.

Frequently asked questions

What age is this league for?

One of the few that can start around age 8–9, because the logic is simple and tangible.

How much does the robot cost?

Very little compared with other leagues; it can be built from ordinary local parts, and educational kits exist.

How does Nanoline differ from a normal line follower?

Nanoline usually denotes a class with smaller robot dimensions and a narrower course. Exact details are set in each event’s call.

Ready for your first competition?

Novin Zehn competition teams train from zero to the world stage — in Tehran and live online.