Technologies for Flexible Fixturing and Higher Speed Part Handling in Automated Automotive Sheet Metal Assembly

Abstract

A lack of fixturing flexibility and of high speed handling of non-rigid parts are two important problems in automotive sheet metal assembly operations. This paper describes the development of two unique grippers for flexible fixturing of automotive sheet metal parts, and of two methods for the vibration control needed for high speed handling of non-rigid parts. Each gripper is designed to execute a 3-D fixturing strategy which does not require accurate initial part placement, and provides a large number of valid fixturing solutions. Both grippers are tested on several automotive parts. With the first design, the average standard deviation of the parts’ location before fixturing of 0.5 mm was reduced to 0.01 mm after fixturing. The methods of vibration control may be used with most of the industrial robots used for part handling. At a speed of 1 m/s the LEC method reduced the vibration amplitude by 33% after four learning trials. At 0.5 m/s the ICS method reduced the vibration amplitude by 60% and the settling time by 67%.