Adaptive laser focusing head design for the 3D free surface in parallel kinematic machining

An adaptive laser head was designed for microscale patterning and welding applications. An optical design for laser head was performed by using ray tracing technique with commercial software. Setting the focal length of the lens at 100 mm the calculated focus beam diameter was offset to be 10 μm for the CFRP welding applications. To perform an auto-focusing calibration an LRF (Laser Range Finder) distance sensor was used to measure the distance to the target surface. Using a DC Motor with PID control loop, the distance was kept at constant between the laser head and the target material. In this paper, we propose an algorithm for auto-focusing calibration function and detail schematics of laser head design.. (paper)