Characteristic Analysis And Control Research Of Stabilized Platform Of An Aerial Camera

Aerial camera is one of the main tools for studying the surface of the earth.Along with the development of aviation and aerospace technology,the information obtained by aerial photography has been widely used in various fields of the national economy.For example topographic map compilation,building construction,hydrographic survey,forest survey,geological exploration,glacier survey,archaeological research and weather forecasting,etc.It plays an irreplaceable role in the military for scouting and damage assessment of targets.The application of the stable platform device effectively improves the imaging quality of the aerial camera.Based on the comprehensive understanding of the working principle of the two-axis stabilization platform,we will carry out research on the stable platform,which is to solve the three problems of framing stepping,isolating aircraft disturbance and image shift compensation required by CCD aerial camera in this dissertation.In this dissertation,we will carry out research on the stable platform,which is to solve the three problems of step framing,isolating aircraft disturbance and image shift compensation required by CCD aerial camera.The research will provide a theoretical basis for actual production,reduce technical risks,reduce design costs,and shorten development cycles.Through research and analysis,we obtained the key points needed for the stable platform under the conditions of CCD aerial camera,and then analyzed and calculated these key points.According to the use scenario of the stable platform,mathematical modeling and characterization of the stable platform were carried out in the paper.Finally,various factors affecting the stability of the stable platform are determined by kinetic modeling,which provides a basis for the overall design of the stable platform.Referring to the analysis results,we designed the overall solution for the stable platform firstly.The platform requires a digital level to provide a measurement reference outside of it.We use the data provided by the digital level to establish a geographic coordinate system that provides a baseline for the stable platform to measure the step angle.The stable platform carries the imaging subsystem,tracks the measurement reference in real time,and realizes the working mode of step-by-step photography on three routes.The overall design of the stable platform also includes subsystem composition,structure selection,material selection and platform accuracy analysis.The structural design of the platform is carried out according to the overall design scheme,and then the strength analysis and thermodynamic analysis of the structural design of the stable platform are performed.Control design of stable platform after structural design.Control design is divided into five steps: the first step: select the appropriate servo original device for the platform;the second step: control system design;the third step: establish a mathematical model of the platform control system;the fourth step: mathematical model calculation;the fifth step,the simulation is based on the calculation results of the mathematical model to verify the rationality of the platform design.Theoretical calculation and simulation provide a basis for practical design and production.Finally,in the process of assembly and debugging of CCD aerial camera,various experiments were carried out on the stable platform.We tested the actual indicators of the platform in the case of open loop,closed loop,step,disturbance,etc.The results show that all the indicators are close to the simulation results and meet the design specifications.According to the parameters and control methods determined in this paper,we have produced some stable platforms.These stable platforms have been used in some mid-high altitude drones equipped with CCD aerial cameras.These CCD aerial cameras have passed various routine and reliability tests and have been mass produced.It turns out that this stable platform has shown strong stability and reliability during the experiment,which meets the requirements of design indicators.