Method for controlling an infrared laser source, infrared laser welding system and method for welding plastic parts

摘要

A method of controlling an infrared laser source located in a laser chamber of a laser welding system with a controller using closed loop feedback control with a feedback signal, the laser welding system comprising an optical sensor arranged to detect infrared radiation in the laser chamber The method comprises the following: before switching on the infrared laser source, the controller with the optical sensor detects an intensity of the infrared background radiation in the laser chamber; as soon as the laser source is on, the controller with the optical sensor detects an intensity of the infrared radiation in the laser chamber Calculating a corrected feedback signal with the controller by subtracting the detected intensity of the infrared background radiation in the laser chamber when the infrared laser source is switched off from the detected intensity of the infrared radiation when the laser source is switched on; andcontrolling an intensity of the infrared laser source with the controller when the infrared laser source is turned on with the closed-loop feedback control using the corrected feedback signal as the feedback signal for the closed-loop feedback control.