Pose Accuracy Compensation Technology in Robot-aided Aircraft Assembly Drilling Process

摘要

In automatic aircraft assembly,one focus of attention is robotic drilling technology with its high flexibility and relatively low cost.However,pose errors hard to compensate of the robotic end tool may exist which are caused not only by the dynamic and static error of the robot,but also by errors in the calibration and transformation of the coordinate frames.To improve the accuracy of the position and orientation of the robotic end tool,a robot-aided aircraft assembly drilling system is constructed based on laser tracker closed-loop feedback.Methods to build key coordinate frames of the system using the laser tracker are first discussed.Then,the constitutive factors of the robotic tool pose error are analyzed.A pose difference matrix between the theoretical pose and actual pose of the robotic tool in the drilling position is evaluated to eliminate remnant errors caused by the robotic dynamic error,static error,machining error,matching error and measuring error,etc.Finally,a simulation test for validating the feasibility of the above algorithm and a drilling test of ribbed-plate parts is executed.For a robotic drilling prototype system,by introducing the laser tracker closed-loop feedback compensation,the robotic drilling error is such that the position precision is effectively controlled within ±0.2 mm and the orientation precision of the normal angle is within ±1.The accuracy and quality obtained by the above robot-aided drilling method can satisfy the requirements of aircraft assembly.