基于新型模糊PID控制单元的LD精密温控研究

Research on precision temperature control of laser diode based on the novel fuzzy-PID control unit

为改善温度波动对光通信用半导体激光器性能的影响,设计了基于三维语言变量的高精度跟踪误差温度控制系统。为减小系统成本,利用运算放大器AD620和OP07等器件设计了温度采集系统,并采用最小二乘法拟合温度数据,从而建立温度—电阻关系模型,预测温度变化趋势;加入第三维模糊语言变量,结合窄域论以适当压缩E、EC、ECC的论域,采用模糊规则设定方法,建立新型三维模糊PID规则表并求解得出模糊查询表。结果表明:当预设温度为25℃时,温控系统超调量为0.97℃,最大下冲量出现在第17s,其值为0.69℃;工作51s后,LD系统进入稳定状态,温度保持为25±0.05℃;在第150~210s内,其温度值标准差为0.020 4℃。同时,该系统实现了对半导体激光器0~75℃的大范围精密温控,温控精度为±0.05℃。该系统能够实现对半导体的高效制冷、加热控制,具有响应时间快和系统开销小的优势,能对控制参数实现自整定。

To improve the impact of temperature fluctuation on performance of diode laser used for optical communication,a high-precision temperature control system by tracking error based on 3D linguistic variable was designed.To lower the system cost,at the same time,a temperature acquisition system was also designed under the help of operational amplifier AD620 and OP07,and least square method was used to fit the temperature data,thus establishing a temperature-resistance relationship model to predict the temperature variation trend;then a third-dimension fuzzy linguistic variable was added,and after properly compressing the domain of E,ECand ECCin accordance with the narrow field theory,a new-type fuzzy-PID rule table was created by adopting the method for fuzzy rule setting,thus working out the fuzzy query table.The results indicate that when the specified temperature is 25 ℃,overshoot of the temperature control system will be 0.97 ℃,with a maximum impulse of 0.69 ℃ occurring at 17 s;after 51 s,LD system enters into a stable state,with a temperature maintained at 25±0.05 ℃;during the time period of 150~210s,standard deviation of temperature value is kept at 0.020 4 ℃.The system,at the same time,achieves high precision temperature control over the diode laser within a large range of 0~75 ℃,with a temperature control precision of ±0.05℃.In addition,the system can achieve high-efficiency cooling and heating control over the diode laser,with such advantages as short response time,low cost and self-tuning parameters.