Provided is an arm structure for a robot which can favorably carry out jobs
which are typically performed by humans. By determining the length of the arm and
the height of the axis of rotation of the arm in such a manner that a range of
rotational motion of the arm in accessing the region can be covered by a range
in which the fore-and-aft distance to the tip of the arm can be linearly approximated,
even though the trajectory of the arm is approximated by a line, the error in the
distance to the object can be limited within a prescribed range, and the practicality
and economy of computation can be achieved at the same time.
