Fuzzy logic control for the Ti6A14V laser alloying process

It is well known that there are many process parameters which influence the results of the laser surface alloying process. Some parameters should be kept within certain tolerance limits to ensure the required quality of the surface alloying. Hence a closed loop control system is required during the alloying process for quality control. This system has multi-inputs and multi-outputs and nonlinear and time varying dynamic behaviour due to material properties and dimensional changes. It is very difficult to develop an accurate dynamic model for designing a model based control scheme. Hence a model-free fuzzy logic control method was employed in this study. Two fuzzy controllers were designed to adjust simultaneously the laser power and the traverse velocity, respectively, and for handling the absorptivity and geometrical variations of the work piece. Simulation results are used to evaluate the control performance of this control strategy.