Self-tuning fuzzy PI control for laser power stabilization

This paper proposes a self-tuning fuzzy PI controller to stabilize the laser power. The laser system is a nonlinear system due to its complexity and easily affected by environment conditions. However, traditional PI controller cannot cope with this nonlinear and time varying system since the parameters of PI controller are fixed. This paper utilizes the fuzzy reasoning engine (FRE) to adjust the parameters of PI controller in order to overcome the above drawbacks. This control algorithm is implemented in Microchip dsPIC33FJ64GS606 microprocessor. The experimental results verify our proposed control algorithm can dramatically stabilize the laser output power and further improve the tracking performance when laser desired power command is changed.