The simplest type of turn your mouse can make is an in-place turn where
both wheels rotate in opposite directions. Once you have your motors calibrated
you can peform accurate in-place turns through 90 or 180 degrees. The
180 degree turns are, of course, needed to get out of dead ends. Reversing
direction like this should only be needed during searching and can be
eliminated with some cunning if your mouse is bidirectional.

A turn in-place will want velocity profiles for each wheel. The rotational
inertia of the mouse will now become important to you. Keep as much mass
as possible near the centre of the mouse and keep the mass as small as
you can. Wall sensors on booms can contribute surprisingly large amounts
to the moment of inertia due to the distance-squared term in the equations.

A wide track helps to get good accuracy in the turns. Narrow tires will
help give better repeatability.

You might want to consider turning about one wheel. Since the single
whhel that does turn has to travel twice as far, there is probably little
to be gained in terms of speed. Also, the inertia problems will be worse
for this type of turn than for an in-place turn.

Positional accuracy is, as ever, important. If you begin a turn with
a heading error, you will finish it with the same heading error. However,
start with an offset error and you turn it into a forward error ande vice
versa. The forward error may be the hardest to detect as it may be several
cells before you get a good reference point to recalibrate from.

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