Bend Sequence Planner
The bend sequence planner (a.k.a. Planning) implements an A* search
strategy to find the best sequence of bending operations and repositionings of the
part in the robot gripper to make a bent sheet metal part. Input consists of a
3D model of the part to be manufactured and several databases describing the
manufacturing facilities available. The program outputs instructions for
setting up and controlling several robots, sensing devices, and a bending
machine to automatically make the part. Key components of Planning include:
A* Search: The A* search strategy looks for a least cost solution in the
space of all possible bend sequences. The cost of doing a particular bend or repo
in the sequence is determined by consulting several expert programs. A Tooling
expert evaluates a potential bend sequence by how many tooling stages it
requires. A Grasping expert determines how to hold the part in the robot
gripper for each bend and seeks to minimize the number of repositionings
required. A Moving expert determines the motion plan required to transport the
part through the various stages of manufacture and seeks to minimize the amount
of movement required.
Final Plan Generation: When the A* search has determined the best
sequence of bends and repositionings to make the part, Planning combines
information from Grasping, Tooling, and Moving to produce the final plan for
making the part, including a robot motion plan, a backgage plan (to accurately
position the part for bending), instructions for setting up the required
punches and dies, and information for use by a graphical human interface to
display a simulation of the plan.
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Copyright © 1997 Duane T. Williams. All rights reserved.
Last updated 27 February 1997.