Design And Research On Robotic Drilling System Based On Pressure Foot's Pneumatic Control

Automatic drilling technology is one of the most technologies in the process of aircraft digtal assembly. However, there is an obvious gap between the advanced drilling technology abroad and the traditional manual drilling in China. Because of high flexibility and accessibility, robotic drilling system can improve drilling efficiency and accuracy greatly in the process of aircraft assembly. Automatic drilling system using robot is the integration of a variety of high-tech, and it's of great value in engineering to research on it. This paper conducted an in-depth research on drilling end-effector and the depth's control of countersink. The detailed contents are as follows:1 The research and application status of automatic drilling technology in the aircraft assembly at home and abroad are introduced firstly. Then it introduces some applications about the end-effector in robotic drilling system.2 Automatic drilling system using industrial robot is introduced. Then the mechanical structures of spindle feed system and pressure foot system of end-effector are carried out in details. The constitution of control system about end-effector is described, and selecting suitable components. In the end, the control strategy of spindle system is established.3 Drilling requirements and robotic drilling process flow in the aircraft assembly are given firstly. Then the chapter has an analysis of the difficulties of countersink's depth control, and proposes a solution for this problem. The solution is integrating the spindle base with pressure foot. After an analysis in detail, the paper decides to use pneumatic cylinders as actuators of pressure foot.4 A simple description about the design of pressure foot pneumatic control system is given, and an experiment is used to verify the effection. For open-loop force control is not accurate enough, the chapter has an analysis of pneumatic control mechanisms and modeling the system. Then an analysis of the selection of sensor location is given, and it proposes a solution modeling precise using system identification. In the end, the paper designs a force controller and verifies the performance of the controller by simulation. The result of simulation indicates that optimum control+PI control has a faster response speed and a better ability of anti-interference.5 Summary for the whole work in this dissertation is given, and future work is discussed.