The gasdynamic and electromagnetic factors affecting the position of arc roots in a tubular arc heater are analyzed.Magnitudes of the various factors are estimated through numerical modelling,and the overall action on...The gasdynamic and electromagnetic factors affecting the position of arc roots in a tubular arc heater are analyzed.Magnitudes of the various factors are estimated through numerical modelling,and the overall action on the arc assessed.It is found that the actions on the arc in the rear electrode can be balanced in a stable manner and the arc root can be stabilized at a certain axial position.In the front electrode,the various factors cannot be balanced,and the are root can only stay within the electrode through the mechanism of recurrent shunting.These conclusions agree with experimental observations.展开更多
Off line programming provides an essential link between CAD and CAM, whose development will result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is one of...Off line programming provides an essential link between CAD and CAM, whose development will result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is one of the most typical workcells. The inverse kinematics of robot and positioner is the foundation of the off line programming system. The previous researchers only focused on a special solution of the positioner inverse kinematics, which is the solution at down hand welding position. In this paper, we introduce a method for representing welding position. Then a general algorithm of rotating/tilting positioner inverse kinematics is presented, and an approach to find the unique solution of the inverse kinematics is discussed. The simulation experiment results show that the general algorithm can improve the ability of robotic arc welding off line programming system to program all types of welding positions.展开更多
基金The project supported by National Natural Science Foundation of China
文摘The gasdynamic and electromagnetic factors affecting the position of arc roots in a tubular arc heater are analyzed.Magnitudes of the various factors are estimated through numerical modelling,and the overall action on the arc assessed.It is found that the actions on the arc in the rear electrode can be balanced in a stable manner and the arc root can be stabilized at a certain axial position.In the front electrode,the various factors cannot be balanced,and the are root can only stay within the electrode through the mechanism of recurrent shunting.These conclusions agree with experimental observations.
基金ThispaperissupportedbyNationalNatureScienceFoundation (No .5 96 35 16 0 )AdvancedUniversityDoctoralSubjectFoundation (No .980 2 1311)
文摘Off line programming provides an essential link between CAD and CAM, whose development will result in greater use of robotic arc welding. An arc welding system with a robot and a rotating/tilting positioner is one of the most typical workcells. The inverse kinematics of robot and positioner is the foundation of the off line programming system. The previous researchers only focused on a special solution of the positioner inverse kinematics, which is the solution at down hand welding position. In this paper, we introduce a method for representing welding position. Then a general algorithm of rotating/tilting positioner inverse kinematics is presented, and an approach to find the unique solution of the inverse kinematics is discussed. The simulation experiment results show that the general algorithm can improve the ability of robotic arc welding off line programming system to program all types of welding positions.