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Automated Robotic Deburring System
 Two problems are involved in the development of an automated tracking
system for robotic deburring of parts with unknown geometry: 1) the
design of an appropriate procedure for stable metal removal, and 2)
the development of a stable control method for tracking the edge of
a part with unknown geometry. The metal removal algorithm uses a set
of contact forces (cutting forces generated by the cutter) to develop
impedance control on the robot. The impedance control technique develops
compliancy in two orthogonal directions by feedback. The impedance
of the robot is modulated continuously to develop high and low stiffness
along the part edge. At any point in time during deburring, a large
impedance is required in the direction normal to the part, and a small
impedance is required in the direction tangent to the part. The small
impedance along the edge of the part causes the robot to slow down
when the cutter encounters a burr, while the large impedance in the
normal direction keeps the robot touching the part. These directions
do not necessarily coincide with the axes of the robot actuators;
their orientation is modulated by a supervisory program. The tracking
mechanism is a roller bearing mounted on a force sensor at the robot
endpoint. The tracking controller employs the force measured by this
force sensor to find the normal to the part surface. Using the part
contour information, the robot travels along the part edge using the
selected impedances.
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