DASH FREE uses a
simple algorithm for line-following. Each sensor selects
which of two trimmers will set the speed for the
corresponding motor. The outer sensor controls the speed
of the outer motor. The inner sensor controls the speed
of the inner motor. The speeds can be set independently
to the desired value. Speeds can be adjusted to
compensate for the layout of the various heavy items and
There are three conditions that the
mouse will find in normal operation. It it finds the
fourth condition it is "lost".
In this condition the motors should be
set so that the outer motor is slightly faster than the
inner motor. This will gradually bring the outer sensor
onto the line.
In this condition the outer motor
should be slightly slower than the inner motor. This will
gradually bring the outer sensor off the line. These two
conditions will make the mouse run along the outside edge
of a straight line using the outer sensor to speed up and
slow down the outer motor to keep the mouse close to the
When the mouse reaches the corner, the
inner sensor will come off the line. Under these
conditions the inner motor should stop altogether to make
the mouse spin round as quickly as possible.
This is the algorithm described in the
manual that comes with DASH FREE. It may be
possible to get good results with slightly different
algorithms. For example, it may not be necessary to stop
the inner motor completely at a corner. It may be quicker
to take a wider line and avoid drastic accelerations.