Development of adaptive laser head for compensating error of beam waist position during processing materials using laser beam spot detection method

Abstract

The purpose of this research is to develop a device capable of compensating for laser beam positioning error during processing of workpieces. This research is relevant, since several errors occur when processing workpieces with a laser beam, which lead to decrease in the level of accuracy. Two factors lead to these errors, such as the presence of vibrations and unstable beam waist position of the laser beam. It is known that one of the main reasons of unstable beam waist position of the laser beam is uneven surface of the workpiece. When processing a workpiece with a laser beam, the uneven surface of the workpiece causes the beam waist position to change. The position of the beam waist is important because it affects the accuracy of the workpiece. In order to reduce errors in the positioning of the beam waist, a system or mechanism is needed that can compensate for these errors. To achieve this, the system or mechanism must have ability to adapt to the surface of the workpiece. Thus, the development of the device in this study is a solution to the problem that arises during laser processing. In this research, an adaptive laser beam head device is designed which has adaptive capabilities to the surface of the workpiece so that it can compensate for position errors, stabilize the beam waist position, and reduce internal vibrations during workpiece processing. The laser beam head in this research can move in 3 degrees of freedom. With this ability, the laser beam head can move to follow the surface shape and adjust the beam waist position to the workpieces. During operation, to be able to track the position of the laser beam on the workpiece, the device is equipped with a camera. In this research, an experiment with mockup of this device was conducted to determine the level of its capabilities. From the experiment, it can be concluded that device is performing its objectives successfully. It can maintain the position of the laser beam waist on the surface of workpiece with a relatively high level of accuracy. This is evidence by the relatively low error rate. In general, this device can be used and implemented as a system for compensating the positioning error of the laser beam during workpiece processing and also can be implemented to improve the technology of workpiece processing with a high level of accuracy.