Camera based feedback control of the laser cladding process

A camera based feedback controller has been designed and implemented to optimize the energy input during the cladding process. This controller eliminates the need and e ort to experimentally optimize the process. Moreover this controller automatically determines the required energy input to meet a well-de ned criterion for a wide range of speeds, powder mass rates and material combinations. Also, it corrects the energy input for changes in geometry, absorptivity and heat accumulation in the product during the process. An important quality aspect of the cladding process is the meltpool depth, which can not be measured directly during process. However, the meltpool width is directly related to the meltpool depth and is therefore used as feedback signal to adjust the laser power. The width, but also the length and area of the meltpool are extracted from camera images of the process. The controller has been proven successful for a wide range of cladding speeds and powder mass rates.