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,
  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.