Research On Robot Pickup Control For Unfixed Posture Destination Object Based On Visual Feedback

At present,in industrial production lines,industrial robots are mature in grasping and transporting fixed-position target objects.However,the position and posture of target objects in actual industrial production lines are not always fixed or regular.There are still difficulties in grasping and transporting unfixed target objects.To this end,this thesis uses visual feedback method to automatically identify the position and posture of the workpiece in the production line,and is further associated with industrial robots to achieve intelligent control of industrial robots to grasp and transport workpieces.In this thesis,visual feedback method is used to identify and position unfixed posture target objects.The Xtion camera is used as a visual image acquisition system,which uses a combination of depth images and RGB images to identify target objects.The relative position relationship between the vision system and the industrial robot is obtained through hand-eye calibration;the model of the target object at the reference position is established to obtain the relative position relationship with the vision system,and the relative position relationship between the current target object position and the reference position template is obtained through the ICP matching algorithm,and then obtain the relative positional relationship between the target object and the industrial robot;finally,the position of the target object is achieved,that is,the pose coordinate of the target object in the robot base coordinate system.According to the posture coordinates of the unfixed posture target object obtained by visual feedback,the industrial robot picking control is performed.In this thesis,the actual UR3 six-axis industrial robot model is established,and its space constraints are determined.A method of joint and Cartesian space six-axis industrial robot path planning method is proposed.The industrial robot first moves through the joint space path planning to a fixed position pose,as the starting posture of Cartesian space path planning,and then carry out Cartesian space path planning,so that the robot can move to the target object posture obtained by visual feedback;control the clamping and release of the gripper to achieve the target object pick operation.In addition,collision detection has been implemented for industrial robots,so that when industrial robots collide with obstacles,they can stop their movements in time to ensure the safety of people and things.In this thesis,a visual feedback robot control system is built,and the research methods and technical routes adopted are verified.Through the recognition and stitching of the three parts of Kong Ming lock,the accuracy of target object recognition and positioning based on visual feedback and the feasibility of industrial robot pickup control method are verified.