ILK-02: Interlock stop distance - a fast part brakes before its zone

high prioritySimulator or real robotabout 30 minInterlock rules (two parts that must not collide)

• Your robot needs: Lift or arm with an encoder or Turret.
• Starter bots that fit: none (it needs parts the starter bots do not have).
• Library version: v0.17.0 or newer.
• The docs it tests: Two parts that must not collide (interlocks), Tunables.java: every number, part by part.

Why

A motor does not stop the moment it is told to: the robot only decides once per loop, and a braking motor still coasts. The rule works out each part's stop distance from its speed and the slowest recent loops, and slows it down in time. We tested it in the simulator (a turret at about 680 degrees a second); real lifts and turrets are heavier and slower to stop.

Safety

• ILK-01 passed first, on this robot, with slow powers.
• Real robot: raise the power in steps (0.3, 0.6, then full). Stop at once if a part ends inside its zone.
• Fingers away from both parts. A hand on STOP.

Setup

• An interlock rule that works at low power (ILK-01).
• The part that moves fast toward its zone (usually the turret or the lift) at its normal maxPower.
• Simulator: the V2 example robot as in ILK-01 (its turret is fast).
• Optional: <part>StopSec in the rule's Tunables section (for example turretStopSec = 0.15, the default).

Steps

1. INIT, START. Put the other part in its zone (V2: wrist folded).
2. Push the fast part's stick fully toward its zone and hold it. Watch where it stops. Read its angle or counts on the Driver Station.
3. Write how far outside its zone it stopped. It should slow down near its waiting point, then stop there (two margins outside the zone).
4. Do it 5 times, from different starting places (near the zone and far from it).
5. Make the loops slow on purpose: turn on a camera, or run the simulator with other programs busy. Repeat step 2 three times.
6. If it ever ended inside the zone, or past its waiting point: raise <part>StopSec (say 0.25), INIT again, and repeat.

Pass rule

In all 8 tries (steps 4 and 5) the part stops outside its zone (0 times inside), within about one margin of its waiting point.

Record

Write these down while you test. The report form has them as a list to fill in.

• the fast part, its motor and gear ratio, its maxPower
• the zone edge, its waiting point, and where it stopped each time
• the StopSec you ended with (and the margin, if you set one)
• simulator or real robot; slow loops: how you made them

If your robot is different

A servo part needs no stop distance (it is never sent past its fence): test a motor part. A lift that moves fast downward with gravity is a good test: say which way it moved. If your part has no motor id in Robot.java (.part(...) or a motor id), the rule learns its top speed from the fastest it has seen: say if the first runs stopped later than the later ones.

Report your result

Pass, fail, or could not run: every result helps. The form opens on GitHub with this test filled in (a free GitHub account is needed). No student names, please.

Report result

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All tests · Next: MEC-01 A lift or arm on two motors - same power, same moment