The Research On The Pose Measurement Of The Location Datum For Drilling Robot Based On Vision

As the rapid development of industrial robot,automated drilling system based on industrial robot has become one of the most important strategy of the field.By equipped with different machining terminal,the drilling robot can be applied to different types of workpieces,hence it's quite low-cost and flexible.While in our country,the automated drilling still relies on the advanced equipment introduced abroad so much,and the independent research on robot drilling system is just starting out.Drilling large-scale aerospace workpieces with mobile robot workstation is an important development tendency.While there exists accumulative error caused by the frequent datum changes and the dynamic and static error of robot,assistant posemeasuring unit must be introduced to measure the relative pose between robot the datum on workpieces on line.Therefore,we adopt the vision metrology as the assistant pose-measuring unit of the drilling robot,and research on the pose estimation method of location datum based on vision:Firstly,we proposed the key pose estimation algorithm for the drilling robot.The algorithm can estimate the 3-D pose of the datum hole with only single image,it transformes the irregular oblique elliptic cone geometry to the upright elliptic geometry,and recover part of depth of the datum hole by the geometric relationships of several extreme points,and finally obtained the pose of the circle.The proposed algorithm has the shortcoming of polykeys and singularity,to solve the problem,we added a camera to make up a binocular system.The binocular vision system eliminates the polykeys by the intersection of the points measured by the two cameras and reduces the singularity error by synthesizing the solution of the camera,making the method more robust.Then,we developed a robot drilling system based on vision,the hybrid robot TriMule is the drilling equipment,and the binocular vision system installed on the mobile platform can estimated the pose of datum hole on line to align the robot frame and workpiece frame.The result shows the binocular vision system is accurate moderately,and hold great precision for the long distance and low camera,so it satisfies the requirement of automated drilling for aerospace manufacture.