Autonomous Consistency
Where your autonomous really ends up, run after run: how far the group sits from the mark, how widely it scatters, and the circle that holds half the runs.
Inputs
Put a tape mark where the routine should end, measured to one fixed point on the robot (the center of the drive is easiest). After each run, measure from the mark to that point: across the field (right is plus) and along it (past the mark, away from your starting wall, is plus). A run that stops dead on the mark is 0, 0.
Results
Half the runs end within
—in
Measured from the group’s own center.
The group sits this far off the mark
—in
The group sits
—
Spread around the group
—in
Root-mean-square distance from the group’s center.
Worst run, from the mark
—in
Runs recorded
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How this is calculated
A routine can miss in two separate ways. It can stop in the same wrong place every time, which is bias. Or it can stop somewhere different every time, which is spread. The page finds the group’s center first, then measures each run from that center, so the two don’t get mixed up.
group center = (average across, average along) bias = distance from the mark to the group center spread = √( average of (distance from the group center)² ) half-circle radius = the middle distance from the group centerWith your numbers
Why the half circle
The half circle is the median: half the runs stop inside it and half outside. It isn’t pulled around by one strange run the way an average is, so it’s a fair single number for “how close does it usually stop”.
What this doesn’t cover
Only where the robot stopped, not which way it faced. A small heading error at the end can matter more than an inch of position, so measure it separately if the next move depends on it. The runs are only comparable if the start was set up the same way each time.
Make a notebook page
Turns this calculation into a dated engineering notebook page: the setup, data, results, figures, working and sources, numbered and cited. You add the goal, the decision and the reflection in your own words, plus photos and sketches. Print it, paste it into Google Docs, or download a Word file or slides.
Save this run, and compare
Keeps what is on screen so you can change something and see both sides of the change. Saved in this browser only, never uploaded.
Sources & assumptions
No VEX figures are used. Every number comes from your runs, and the statistics are derived from them with the formulas above.
Where this goes next
Explore further on the full mapWhere the answers on this page can be used, and which tools could have given you the numbers it asks for.
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Autonomous Consistency
Where your answer goes
Odometry Error Simulatorfind which tracking error could explain the scatter you measureduses your position error againCompare Test Versionstest whether a change to the routine really tightened the groupuses your trial results againIMU Driftcheck how much of the miss is the heading wanderinga number carries across the next question it raises