Parameters Optimization Of Robotic Precision Drilling For Automatic Aircraft Assembly

In the aircraft manufacturing process, the quality of assembly and connection will affect the lifeof aircraft directly. At present, the main way of assembly and connection is still manual drilling andriveting. While most of the aircraft fatigue failure occurred in the connection hole, the life of aircraftcan be improved by improving the connection hole quality. Robotic automatic drilling technology canimprove the accuracy and quality of the hole. However, for the weak rigidity of the robot and otherissues, the reacting forces produced by drilling, the vibrations of manipulators and workpiece andchatter will make impact on the hole quality. The reacting forces and vibrations are correlated withcutting parameters. So, in order to meet the technical requirements of aircraft assembly, roboticprecision drilling parameters must be well optimized, to ensure the accuracy of robot drilling. In thispaper, the related technologies of robotic automatic drilling parameters optimization have beenresearched from three aspects:Firstly, the finite element model of drilling process was built, the generation mechanism ofcutting forces and the relationship between cutting forces and three cutting parameters: feed rate,cutting speed and drill diameter were analyzed. Based on the simulation results, the proper drillingparameters were given preliminary.Secondly, the analytical model of drilling forces was established, the relationship between theanalytical and the following factors: feed rate, drill diameter and the cutting coefficients was built.Thirdly, the generation mechanism of robot drilling vibrations was researched and the stabilityprediction model of robotic automatic drilling system was established based on drilling force model.Robotic drilling system’s stability leaf disc figure was drawn. According to this, the effects of cuttingparameters on robotic drilling system’s stability was analyzed. Optimize the cutting parameters fromcutting stability.Finally, the cutting forces of robotic automatic drilling were researched by experiments, theinfluence law of cutting parameters on cutting forces was analyzed and proper cutting parameterswere given. Comprehensive the optimization results of simulation and test, with the purpose ofmachining quality and efficiency, optimal parameters of robotic precision drilling were determined.And experiments with optimal parameters have been done.This paper established a finite element model of a robotic drilling, analyzed robotic drillingsystem’s stability based on the analytical model of drilling forces and did technology test. In the optimal parameters, the precision of the hole drilled by robot can reach H9. It can meet the technicalrequirements of aircraft automatic drilling. This technology research improved the quality of roboticdrilling, and provided a theoretical and experimental foundation for the aircraft automatic assembly.