WaitForWaitpoint precission

You are completely right about the distances being an approximation.
They are based on some calculations using the motor speeds and the position data from the camera.

The calculation is in the imageProcessor.py script in the ControlLoop class.
The function is called IncreaseDistance and it attempts to work out distance based on:

• How fast the YetiBorg is travelling
• What angle the track appears to be at
• How far the YetiBorg is from the center of the track

We did find that the estimate of speed for this calculation was a bit inaccurate in the simulation.
In Settings.py there are two versions of the estimated max speed:

1. yetiSpeed - this version is used when running an actual race
2. simulationYetiSpeed - this version is used in the simulation

It may be that the values here are not quite right.

The best thing to do is assume the waypoints will not be perfect during an actual race, it may be worth trying WaitForDistance and figuring out what distances best match the place you wish to make changes.
Alternatively you can adjust the exact positions used for the waypoints by changing the distanceBetweenWaypoints values in Settings.py.

As for the calculation itself it is not perfect, there are some parts which can be improved:

1. The offset from center used is not where the robot is, but a couple of robot lengths ahead
2. It assumes the inside line is always shorter than the outside line, this is not true for the whole track
3. The distance is assumed to be in a straight line, the actual robot curves when steering

Improvements to this calculation will likely give more accurate distance reporting.