Research On Scanning Mechanism Design For Off-axis Three-mirror Telescope Overall Rotation

With the progress of aerospace technology,satellite remote sensing show a wide range,high frequency and the advantage of real time observation.Scanning mechanism is lots of space optical remote sensing instruments to accept feature high optical information of first part,the structure of the scanning mechanism performance quality is closely related with the image quality of the instrument.This topic designed system adopts the reflecting type of off-axis rotation telescope overall 360 DHS circular rotation + half Angle lens scanning,with large field of view,can be achieved from visible to thermal infrared segment's star on scaling,inhibition of stray light,reducing polarization sensitivity and better real-time calibration,improve the level of the quantitative application of the system.On the structure,the overall scanning mode greatly eliminate the "scan mirror" rotation shear stress,surface gravity,opposite the installation error model of distortion.Optical design scheme of system has been introduced in this paper,the scanning system and its working principle,each component and analysis of the mechanical structure and components selection principles and design ideas,finally determine the telescope rotating scanning system mechanical structure overall plan as a whole.Selection of motor and sensor,the selected mirror material and system design of mechanical parts such as fixed way.Design the structure of the half Angle lens system.Fully considering the dynamic characteristic of the half Angle lens itself,than connection ways,half Angle of mirror lens body,bearing,motor connection mode choice.Telescope motion mechanism for the static balance and dynamic balance analysis,In the MSC.ADAMS software to establish the multi-body dynamics,finite element simulation model of the tube,it is concluded that the distribution of the tube,and continuous scanning condition of bearing force.Through the simulation optimization design to reach minimum bearing load.Finally on the telescope system and half Angle lens system based on MSC.Nastran finite element modal analysis,obtained in the simulation experiments the x,y,z direction of the first and second order natural frequency.Weak position,according to the analysis results of Nastran analysis to the telescope tube,corresponding to add rib plate and the auxiliary support to reinforce,finally reached the design requirements.Finally,this topic the machine structure design combined with finite element technology and light,application in the engineering analysis to establish the dynamics virtual prototype model of telescopes scanning mechanism,the finite element model scanning system.Sums up the engineering of common ways of using the finite element analysis and general process,so this topic research content has a certain engineering significance and use value.