CTTC
Crane-Tip Trajectory Control
The forest-industry is a business where
you
always
seek
an
increase
in
productivity when it comes to the loading
and unloading of logs in the forest. The
project aims to aid the driver of a
forwarder in operating the crane. This
means that the driver should only have to
think about where to maneuver the cranetip, and then a computer will control the
actuators to make the tip move in a
corresponding way.
Technical solution
The operator will control the crane in a
cylindrical coordinate system. This means
that the operator steers the crane in three
directions, in-out(r), up-down (z) and around
the crane base (θ).
To accurately control the joints we always
have to know the current position of the
crane-tip. This information can be used to
create a software based safety perimeter
which the crane can’t move in to. By using
this information it may also be possible to
automatically move the crane-tip to different
positions.
Laboratory results
System Overview
The system consists of the components that is
seen above. The main control loop is running
on the CompactRIO and the user interface can
be accessed via the computer. The IQANmodule is simply used as a converter and
amplifier from control signal [V] to current [A]
to the valve.
The figures above shows how the crane-tip
follows a straight line both when doing steps
in radius and in height.
Project aim
The project aims to help beginners quickly
adapt to the steering of the crane and therefore
more quickly generate a profit. Studies has
showed that the psychological and physical
efforts can be decreased with CTTC since the
operator no longer has to focus on every joint
of the crane, it also decreases the number of
movements done by the operator.
Project members, from the left. Daniel Gunnarsson,
Mattias Nordin, Rickard Grundström