Real time control of automated adhesive dispensing

In order to ensure the process integrity for reliable structural adhesive joints and due to the change of adhesive viscosity with environmental variation, strict control for the dispensing process is needed. The authors present a real time control method for dispensing adhesive by using a vision sensor as a feedback controller. The system comprises a six axes robot which carries a digital controlled dispensing gun, a camera and a laser line of light to monitor the bead parameters. The bead parameters can be optimised through online process control to ensure that the bead stays in the desired bandwidth. The control process is done by continuous communication between the robot controller, dispensing controller and microcomputer which hosts vision and control algorithms. The implementation and software issues are addressed. The software performance and results are also discussed