Research On High Viscosity Colloid Coating Technology For Spacecraft Structural Plate Surface

In order to protect spacecraft from the influence of various space radiation,it is usually necessary to mount Optical Solar Reflector(OSR)on the surface of its structural plate.The coating of adhesive on the surface of structural plate is an important process before mounting OSR.At present,the coating of spacecraft structural plate adhesive is still completed by manual scraping,which leads to low production efficiency and difficult to control the production quality stably.In order to solve this problem,this paper studied the coating technology of high viscosity adhesive on the surface of spacecraft structural plate.The specific contents are as follows:A coating system for high-viscosity adhesives was designed according to the coating requirements of spacecraft structural panels.A rotary rheometer was used to measure the adhesive used to mount the OSR sheet,and the dynamic viscosity is 44940m Pa·s,which was used as the basis for subsequent research and design.In view of the characteristics of the surface structure of the structural plate,the extrusion coating method was selected,and the basic composition of the coating system was determined according to the characteristics of the coating method.The outlet size of the coating actuator was determined to be a rectangle of20mm×0.2mm.According to the results,the internal flow channel structure of the coating actuator was preliminarily designed.The flow of adhesive in the channel was simulated and analyzed.The structure of the channel was optimized with the goal of uniform transverse flow velocity at the outlet.The average deviation of the flow velocity at the outlet of the channel was1.56%.The falling process of adhesive extruded from the outlet of coating actuator was simulated and analyzed,determine that the coating spacing should be less than 6mm.The actual coating actuator was produced by 3D printing,and the coating experiment was carried out to verify the feasibility of the coating system.The automatic planning algorithm of coating trajectory was designed.Based on the grid method,according to the size of the coating actuator and the coating area,the grid size was selected as 20mm×20mm.By reading and analyzing the data in the ENTITIES section of the spacecraft structural board CAD drawings,a digital map of the coating area expressed in matrix form was established.Based on the matrix map,a trajectory planning algorithm for the full coverage of the coating area was designed according to the obstacle avoidance strategy.The simulation was carried out by programming,and the results showed that the algorithm can realize the data reading of the structural board CAD drawings,the establishment of the matrix map,and the full coverage path planning,which verified the correctness of the coating area map creation method and full coverage trajectory planning algorithm.According to the analysis of project requirements,the overall structure of the high-viscosity adhesive automatic coating platform for the spacecraft structural plate was designed,and the theoretical coating efficiency can reach 6m~2/h.The load coating actuator of gantry motion system driven by two axes can achieve high positioning accuracy±0.1 mm,which can realize the omni-directional coating of multi size spacecraft structural plates.The main components of the motion system were designed and selected in detail.The main load-bearing parts of the coating platform were statically analyzed,and the maximum deformations of the Y-axis and Z-axis were only 0.086mm and 0.049mm,which verified that the structure met the requirements of strength and rigidity.The installation method of the coating actuator was designed to realize the gapless coating of the two coating actuators.