Design Of High Precision Gas Bath Temperature Control System Based On ARM

Spatial heterodyne interference spectroscopy is a new technology developed and applied in recent years.It is especially suitable for atmospheric remote sensing detection.The Doppler asymmetrical spatial heterodyne(DASH)interferometer,as a typical device for the application of spatial heterodyne interference spectroscopy,is widely used in the field of atmospheric optical fine detection.DASH interferometers as precision optical instruments are significantly affected by changes in the ambient temperature.In order to ensure the accuracy and stability of the DASH interferometer measurement,high-precision temperature control systems must be developed.Aiming at the defects that the existing home-made constant-temperature control equipment has poor temperature uniformity and poor temperature control stability,this paper presents a design scheme of a high-precision air-bath incubator system.Based on the theoretical derivation and simulation analysis,this program designs a constant-temperature air processing module,an air bath thermostat box,and a temperature measurement and control circuit,and builds an experimental platform for verification.The main work done in the paper is as follows:Theoretical analysis of the influence of the temperature field on the optical system demonstrates that temperature change is the most important factor affecting the performance of the optical instrument.Comparison of temperature adjustment methods explains the reasons for the use of air bath temperature regulation.Determine the temperature control strategy based on actual needs.The overall design of the air bath incubator system was proposed.Analyze the heat demand,select the temperature adjustment unit,and design the air temperature processing module.Based on the theoretical analysis and combined with ANSYS fluid simulation results,a thermostatic chamber containing an equal-air supply system was designed.Proposed temperature measurement and control system hardware solutions.Specific design: ARM-based core control circuit;temperature acquisition circuit based on PT1000 platinum resistance and ADS1247 A/D converter;temperature regulator drive circuit based on DRV8303 driver chip.Analyze PID temperature control strategy and its software implementation method.The overall design of the temperature control system software is proposed,and theprogram design of the main program,temperature data acquisition,PID control algorithm,and PWM driver are described in detail.An experimental platform was set up for temperature control stability and bath temperature uniformity experiments.By processing and analyzing the experimental data,the designed air bath incubator system was verified,and high-precision temperature control with an accuracy of ±0.1? can be basically achieved.