CONTROLLING A ROBOT'S MOTION SPEED BY A FORCE-TORQUE-SENSOR FOR DEBURRING PROBLEMS

The paper describes how a commercial ASEA-robot IRB 60 working in a cast iron manufactory was provided with a force-torque-sensor and a control system to improve its deburring performance. Former work where the sensor developed at DFVLR was used for teach-in improvements and off-line path corrections due to grindstone wear was extended now to burr dependent path velocity control. The paper outlines our parallel interface between the robot's microprocessor and the supervisory microprocessor that is charged with sensor data processing and control algorithm. A simplified dynamic model of the deburring process including the robot's elasticity is derived. It allows to arrive at a digital control algorithm based on the design goal to keep a certain contact force between grindstone and burr. Essential improvements in robot deburring are achieved.