ABSTRACT

In robotic assembly, each step of operations is required to be simple
so that even a crude robot can perform the operation. In this paper,
we analyze what conditions should be satisfied in order to make the
operations to be performed in a simple yet reliable manner. First,
forces applied by a robot are analyzed, and conditions for
quasi-static equilibrium are investigated. It is found that, under
certain conditions of part geometry and motion trajectories,
quasi-statically unbalanced situations occur, which prevent the robot
to control the object motion reliably. Assembly operations are
analyzed to find conditions under which the robot can manipulate the
object stably, robustly and reliably without requiring complex control
actions to the robot manipulator. Next, an efficient mathematical tool
is developed to analyze each step of assembly operations and to
automatically evaluate the quasi-static unbalance conditions. The
method is applied to task planning in robotic assembly.