| Since the early 1980 s,China introduced ship construction technology from abroad.After more than 40 years of rapid development,ship construction technology has developed rapidly,but there is still a big gap between the ship painting and today’s advanced shipbuilding enterprises.It is mainly reflected in the low degree of automation,poor quality of paint film coating,workers’ labor intensity and other problems,so the use of machines instead of manual work has become a trend.At present,wall-climbing,rail and overhead mounted spraying robots focus on the interior and exterior coating of ship dock,while they are powerless to paint ship sections.The main difficulty lies in the variety of ship sections and the complex surface structure.Therefore,this thesis aims to carry out the design and trajectory planning research of gantry spraying robot system oriented to ship segmentation,and develop a gantry spraying robot system oriented to ship segmentation,in order to improve the automatic and intelligent level of Chinese ship segmentation painting.This article uses large-scale ship segments as spraying research objects.Research on the structure surface and non-compliant surface automatic coating technology in the ship segment.The main research content of the thesis is as follows:(1)Development of gantry spraying robot.By analyzing and summarizing the advantages and disadvantages of ship painting robots at home and abroad,a painting robot system with gantry and six degrees of freedom manipulator structure was proposed and developed.Secondly,the spraying robot system,spraying system for the control system design,so that the spraying robot has automatic,semi-automatic,manual control mode,spraying system has automatic,manual spraying mode.Finally,the equivalent scale physical prototype is built to pave the way for the preliminary research.(2)Kinematics analysis.Firstly,forward and inverse kinematics of the gantry spraying robot was established based on the improved D-H method.Aiming at the unknown motion reachability space in 3P3 R and 3P6 R modes,Monte Carlo method was used to solve the working reachability space.The results show that the 3P6 R working space increases by about48.4% compared with 3P3 R working space.Finally,linear interpolation and circular interpolation are carried out in Cartesian coordinate system,and polynomial joint interpolation is carried out in joint coordinate system.(3)Study on film thickness distribution of high-pressure airless spraying.Firstly,it was determined that the spraying method was high pressure airless spraying,and the spraying trajectory was grating spraying trajectory.Secondly,on the basis of reasonable assumptions,spray film forming models under different working conditions were established,and relevant spraying experiments were carried out to determine the key parameters.When the spraying height is 300 mm,the spraying speed is 0.22m/s,the installation distance between two spray guns is 151.096 mm,and the distance between tracks is 302.192 mm,the film thickness distribution is uniform.Finally,a spray spray flow field was constructed to simulate the spray spray flow field.The results showed that the fitting degree between the simulated paint film thickness and the theoretical value reached 98.2%,and the distribution trend of the two film thickness was basically the same.(4)Research on trajectory planning of spraying.Due to the large span of each spraying surface area in ship section,it is difficult to spray after one-time trajectory planning.In this thesis,ship section is divided into five single area planes according to the division principle of structural plane and non-structural plane.Then slice algorithm is used to plan the trajectory of each single area surface,and the experiment proves that the method is feasible and effective.Finally,aiming at the shortest transition path problem of each single region connection,the graph theory method is applied to convert the shortest transition path problem into the rural postman problem to find the shortest transition path. |
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