The Research Of Parallel Robot Used In Automation Riveting Based On Digital Mock-up Technology

Research and application of automatic riveting technology has increasingly matured in aviation industry of the developed countries, and it is developing toward flexible assembly system including flexible assembly equipment, modularization of machining unit, numerical control positioning system, system of automatically feeding material and digital checkout system. Although some domestic aircraft factories introduced automatic riveting machine from abroad, airplane assembly is still based on manual method. Long-term exposure to vibration and noise produced by riveting not only causes partial vibration disease and noise-induced hearing loss but also has a bad influence on human cardiovascular system and nervous system. Therefore, a kind of automatic assembly system based on two parallel robots coordination is given in this paper. As preliminary study, parallel robot used for riveting is studied by virtual prototype technology in this paper. The specific work is as follows:The structure of aircraft wing and joint type of its subassembly are introduced. Automatic riveting system’s function is ascertained. After a comparison with two structure types of automatic riveting system, a new automatic riveting system based on double parallel robots is put forward. Then, the techniques process of the assembly of aircraft wing is formulated. After framework design of parallel robot is completed and the structure type of rotary table is determined, the digital mock-up model of parallel robot and rotary table are created by using PROE software.The kinematics problems of the parallel robot are analyzed in details. Those problems include inverse position analysis of the robot, inverse and direct position analysis of the parallel locking mechanism, relationships of velocity and acceleration between driving links and actuators, Jacobian matrix of the robot, the links’ velocity and acceleration of the parallel locking mechanism, kinematics simulation of the robot. The parallel robot’s workspace is also analyzed and searched with the Numerical method.By applying the ADAMS software, a virtual prototype model of parallel robot is developed. The simulation results of the length speed and acceleration changing curves of driving links are provided and discussed when riveter moving along X, Y, Z axis. The simulation results, acquiring the driving force changing curves of the driving links with uniform velocity and acceleration in the straight line, are presented. The kinematics model is verified by comparison. These provide a basis for control system.The rigid and flexible bodies system of parallel robot is established in ADAMS/AutoFlex module, which acts as a mechanical model in vibration system. Based on ADAMS/Vibration, the vibration model of the parallel robot is established. After vibration simulation analysis, the frequency response has been gotten, which provides reference for configuration design of parallel robot.At last, the correctness of the DMU of parallel robot is verified by testing.