Study Of Laser Diode Temperature Control System Based On Paremeter Auto-Tuning Fuzzy-PID Control Technique

Now, laser diode (LD) is extensively applied in science and research, national defense, industry fields etc. The principle of laser diode determine its inevitable heat.When it is on work,it produces the caloric which greatly influences the characteristics of LD (for example, with LD temperature changed, the wavelength of the LD output light drifts), and so influences the accuracy and lifetime of the instrument. In order to ensure the normal work of the laser diode, its wavelength must maintain a high degree of stability.Therefore, we need to strictly control the change of the LD temperature.In this paper,I designed a temperature control system which is based on MCU Microprocessor.and also designed Data Acquisition, Data protection, LCD etc. in the part of implementation of devices ,I use TEC (LD) technology which is developing very fast. In Process Control, Incremental PID formula is taken. Firstly, the method of critical proportional band is used to get the parameters of digital PID control at certain temperature. Secondly with PID control algorithms and fuzzy control theory finalized Fuzzy - PID control algorithm for system tuning parameters, Finally the MATLAB simulation toolkit is used for system simulation.Practice has proven that compared with the conditional PID,the Fuzzy-PID can do better,and it has low overshoot,faster response etc. By the control of the LD temperature,we greatly improved laser performance and product quality.