| Lidar is an active remote sensing scientific research equipment integrating optical,mechanical,electrical and computer technologies,which is widely used in many fields such as atmospheric probing,environmental detection,aerospace and national defense.With the start of the Meridian Project Phase II,more lidar stations are being built in more areas of China to help study the middle and upper atmosphere,which also places higher demands on automation and intelligence of lidar,including automatic transmitter-receiver matching technology as one of the key components.Following the development of science and technology,lidar stations are constantly putting forward more application requirements.The single-channel transmitterreceiver matching system can no longer meet the needs of certain scientific research.Therefore,it is necessary to upgrade the transmitter-receiver matching system to further improve the automation and intelligence of the lidar control system.In this thesis,the traditional single-channel matching system was upgraded to a threechannel matching system in response to the requirements of the newly built lidar station at Lanzhou University.In addition,in response to the call for increasing the proportion of major scientific research equipment made in China,the drive module of this system was modified using only domestic components.The three-channel transmitter-receiver matching system in this thesis has achieved the expected goals after strict performance tests,which can meet the daily observation requirements of lidar and will be put into service in the "Meridian Project" related stations.The details of the work are as follows:(1)Overall scheme design.In this thesis,a matching technology scheme with a threechannel time-sharing drive under the same LAN is realized by using self-made equipment,according to the actual situation of the lidar station of Lanzhou University,combined with the experience of Beijing Yanqing lidar station,to tackle down the problems of too long alignment,too few channels,high cost of imported equipment and surplus functions.(2)Hardware design and building.After redesigning the motor control part of the matching system and reselecting all the underlying electronic components according to the requirements,a motor drive system with independent intellectual property rights was built with a high-precision stepper motor controlled by a domestic PLC and a domestic stepper motor driver.(3)Software design and development.A set of upper computer software was designed and developed in Python,using a serial server to realize PLC and position sensor communication under the same LAN,and a dynamic link library to control the photon counter,which achieved the three-channel transmit-receive matching function in multi-threaded.(4)Testing and debugging.Under the actual scenario,a test environment was set up and some tests were conducted on the assembled three-channel matching system.The results showed that the three channels could complete coarse matching within 1 minute and fine matching within 3 minutes at any position within the adjustable range,and the matching effect was similar to manual matching.The three-channel transmitter-receiver matching system designed and developed in this thesis is capable of automatic multi-channel transmitter-receiver matching and aims to solve the important engineering problems encountered in the construction of the lidar stations in the Meridian Project Phase II.The working methods and technical transformation ideas in this thesis will also provide technical references for the automation and engineering transformation of large research equipment like lidar. |
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