| From the imagination of "Chang’e flying to the moon" to the practice of "lunar exploration project",the Chinese people’s curiosity and exploration of the moon have never stopped.But in lunar exploration missions,lunar dust has become the main "troublemaker",so we must quantitatively evaluate the characteristics of lunar dust to solve the safety hazards it brings.Therefore,it is of great and far-reaching scientific significance to fully understand the lunar dust and explore the movement speed of the dust on the moon surface.It can help to provide strong data support for the protection of the lunar dust.Due to the uniqueness of lunar dust and its environment,current velocimetry techniques are not suitable for directly measurement.In this paper,a lunar dust particle velocity measurement technology is proposed.And a measurement system for lunar dust motion characteristics is built.Due to the limitation of experimental conditions,it is impossible to simulate the lunar dust motion field,and the dust in the air has a certain similarity with the lunar dust.Experiments are carried out to evaluate the performance of the system to achieve lunar dust velocity measurement.The main research contents of this paper are as follows.By fully investigating the principles and advantages of each flow field velocimetry technology,it is determined that the particle image velocimetry system is used as the carrier to conduct research on the lunar dust velocity measurement.The development status and measurement principle of the particle image velocimetry system were explored and analyzed,and the parameter requirements of the hardware system composed of the tracer particle scattering system,the lighting system and the imaging system were analyzed in depth.The matching methods of the correlation measurement technology and particle tracking technology have been explored.It provides a solid foundation for the construction of the moon dust speed measurement system.The research on the characteristics of menstrual dust and the environment on the lunar surface led to the principle of lunar dust velocity measurement technology;based on the requirements of "visible" and "measured" lunar dust,an imaging system for the motion characteristics of lunar dust was designed and built,which was verified by data The detection ability of the system was evaluated,and the minimum measurable particle diameter was better than 0.5μm;in order to measure the speed of the lunar dust,a lunar dust motion characteristic inversion system was constructed based on a computer platform.The background noise removal and image enhancement preprocessing operations were carried out on the collected images,which increased the signal-to-noise ratio of the images;the algorithm program for particle identification and centroid extraction was written,and the particles in the image were accurately identified and centroid calculation was achieved,which is the construction of the subsequent speed measurement algorithm model will be a strong data support.In order to evaluate the performance of the system for measuring the speed of lunar dust,the system is used to measure the speed of airborne dust particles similar to the lunar dust.Through analysis and verification,it is shown that the system’s motion speed measurement capability can reach 100m/s,and the measurement accuracy is 1%.After the small fan assigns the speed to the dust particles,the tail length extraction algorithm is used for processing and analysis.And the accuracy of the algorithm and the rationality of high-speed particle measurement are evaluated.Speed measurement to verify its ability to accurately measure low-speed and high-density particles;multiframe tracking processing of particle images with 10,000-level cleanliness to prove the algorithm’s desirability for low-speed,low-density particle speed measurement.The error correction and elimination are carried out in the results after,and the factors that affect the speed measurement results are analyzed. |
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