Study On High-speed Vibrating Mirror Swing-sweep Ultraviolet Laser Disinfection Equipment

Ultraviolet is widely used in the field of sterilization and disinfection.Its wide sterilization range,pollution-free,non-contact and other characteristics make it have a good broad-spectrum.Seen from the current form,epidemic prevention and control has become normal,and the disinfection and sterilization of bacteria or viruses on the surface of cold chain food and express delivery has also gradually attracted attention.Compared with traditional ultraviolet light,ultraviolet laser has the characteristics of fixed wavelength,high intensity,high power density,and can produce higher radiation dose in a short time.Its sterilization and disinfection ability is far higher than the disinfection and sterilization ability of traditional ultraviolet light.Because the light spot of the UV laser is small,and the range of sterilization is small,how to realize the wide range irradiation of the UV laser is of great significance.The traditional methods of ultraviolet laser beam expansion and spot shaping will reduce the intensity of the ultraviolet laser,and there is a problem that more energy is absorbed by the lens group,so that the irradiation intensity of the ultraviolet laser cannot reach the threshold of sterilization.In this paper,the scanning sterilization of ultraviolet laser is realized by galvanometer scanning technology,which can ensure that the laser beam has high intensity and power density.Based on the principle of ultraviolet laser sterilization and disinfection and the technical indicators of the scanning galvanometer,the galvanometer system can complete the ultraviolet laser sterilization and disinfection quickly and efficiently through the control strategy.First,based on the principle of ultraviolet laser sterilization,the relationship between optical power Q and object horizontal velocity v is obtained under the condition that the laser can completely cover the object surface,and the actual galvanometer scanning technical indicators are calculated according to the above conditions.Aiming at the scanning system of ultraviolet laser,the mathematical models of galvanometer motor,encoder,galvanometer lens and the whole system are established;The MATLAB simulation software is used to simulate and analyze the dynamic performance of the galvanometer system in frequency domain and time domain.The open-loop frequency domain characteristics of the system and the cutoff frequency of the galvanometer system in the presence of viscous friction are considered for analysis,and the key factors affecting the dynamic performance of the galvanometer are discussed to provide a theoretical basis for subsequent research.Secondly,the output response data of the galvanometer system under the square wave input signal is obtained on the basis of the experiment,which is taken as the state observation value of the system identification.The identification model of the galvanometer system is obtained by using the system identification method.The theoretical derivation mathematical model and the identification mathematical model are compared in the frequency domain and time domain by using the frequency domain analysis method.The frequency domain mainly focuses on the relationship between cut-off frequency,amplitude ratio and phase angle difference,and the time domain mainly conducts simulation analysis from two aspects of unit step signal and sinusoidal signal tracking to verify the accuracy of the identification system.Thirdly,the galvanometer system is corrected based on the actual application technical indicators,and a reasonable and effective controller is designed for the system to meet the technical requirements of ultraviolet laser scanning sterilization;The dynamic performance of the corrected system under different operating frequencies is discussed respectively.According to the step response of the system,the steady-state error is emphatically studied,which provides a powerful reference for further improving the ultraviolet laser sterilization technology.Finally,verify the actual dynamic and static performance of different control strategies,and based on the experimental study of high-speed galvanometer swing ultraviolet laser sterilization,verify the effect of ultraviolet laser sterilization and disinfection under different light power and different frequency of galvanometer swing through the single factor control variable experiment.