Folding Cartons with Fixtures: A Motion Planning Approach
Submitted to the IEEE Transactions on Robotics and Automation, December 1998
Liang Lu and Srinivas Akella
Abstract
Packaging products such as telephones and two-way radios after
assembly is a common manufacturing task. Carton folding is a
packaging operation typically performed by human operators or with
fixed automation. We present a flexible method to fold cardboard
cartons using fixtures; a carton blank is folded by moving it through
a fixture with a robot. This method enables rapid changeovers between
product models by interchanging fixtures. We outline a procedure to
design a fixture given a carton and a folding sequence. We present an
implemented motion planning algorithm that generates all folding
sequences for a carton by modeling it kinematically as a robot
manipulator with revolute joints and branching links. A fixture
constrains the carton to move along paths consisting of line segments
in its configuration space. We characterize the set of valid paths
for these carton robots with many degrees of freedom and generate them
using the motion planner. To illustrate the method, we selected a
folding sequence for an example carton, designed a fixture, and
demonstrated folding of the carton from blanks with an industrial
robot.