Key Technology Research On Automatic Riveting Of Cockpit Cover

As one of the key technologies of aircraft assembly,riveting technology is widely used in the aviation manufacturing industry.Traditional riveting is mainly done by hand,which has low efficiency,poor quality and low accuracy.Automatic riveting has high efficiency,good quality and high precision,which has gradually replaced manual riveting.As one of the main structures of aircraft assembly,the performance of the aircraft is affected by the quality of cockpit cover assembly,so this paper studied the key technology of automatic cockpit cover riveting.An automatic cockpit cover riveting end-effector was designed and its structural features and operating principle were described in detail.In order to ensure the riveting accuracy during the riveting process and keep the error with a reasonable range in a limited space,machine vision was selected for the riveting hole positioning calculation.The lower servo motor increased the torque through the RV reducer and the eccentric shaft linkage mechanism converted the torque into a cyclic reciprocating riveting force and calculated the maximum riveting force which the device could provide.The design and selection of the machine vision rivet hole positioning system was carried out according to the requirements.The image was pre-processed by Gaussian filtering.Then the image edges were extracted by using the Canny edge detection algorithm,and finally the centre coordinates of the riveted hole were extracted by the least square method and the angle of the towing nut was calculated.The riveted holes in the cockpit hood were positioned by machine vision in the end.Riveting device and riveting process were simulated by finite element mechanics.The dynamic structure of the riveting device was reasonably simplified and finite element preprocessed.Based on the finite element solution theory,the static analysis and fatigue life analysis of the dynamic mechanism were carried out to obtain the force and deformation clouds as well as the life clouds and safety factors of the structure.Finally,a finite element simulation of the whole riveting process was carried out to obtain the deformation diagram of the rivet at each moment of the riveting process and the corresponding stress change cloud diagram.The quality of the riveted joint was verified experimentally to satisfy the requirements of aviation standard HB/Z233.3-2003.