Research On Active Disturbance Rejection Control In High Precision Temperature Control System For Immersion Liquid

As the non-optical lens in the whole system of projection optics,the immersion liquid lens play the role of expanding the range of refractive index.The stability of temperature of liquid lens is the key factor effecting the resolution.In order to fulfill the goal,it is necessary to design corresponding structure and algorithm.What the paper has done is as follow:First,the three-level temperature control technical solution has been proposed to meet the corresponding design goals.The multistage temperature control system enable to improve the precision step by step and it also contributes to split the influence of disturbance from different area to the difficulty of the whole system.The main body of multistage high-precision temperature control is the second stage and the third stage is to make up for the difference of two different injection channel.Secondly,as the most critical stage,the second stage endure the dynamic disturbance of load,the nonlinear and huge time delay which make the general PID is hard to achieve excellent performance.Therefore,improved the cascade structure has been adopted to suppress inner disturbance from flow and cooling water's variation.In addition,the active disturbance rejection control(ADRC)algorithm based on cascade structure has been introduced which can make up the uncertainty from the model or the outer environment.It is obvious that the algorithm of ADRC-PID are more able to defend the outer disturbance and take more advantage over PID-PID in robustness by the result of simulation.At last,the experiment in temperature experiment platform for the second stage manifested that the multistage ADRC-PID algorithm has been proved to be very effective in precision,stability,traceability and robustness.It can meet the short term requirement of <0.01?@5min and the long time requirement of less than 0.05?.