Screwing manipulation on power transmission lines with a robotic system

Maintenance tasks with a robotic system on power transmission lines are challenging and still open. Taking adjustment of vibration dampers on transmission lines as a typical task, we in this paper address how to effectively fulfill screwing manipulation with a 5-DoF manipulator on a vehicle capable of moving along the lines. To reduce the restriction on end-effector orientation and to decrease the demand for driving force, we design a special wrench with a spherical knob as an assistant tool. Since workspace is a priori information for robotic manipulation, it is generated based on kinematic model of the manipulator. Especially, circular path of the end-effector is planned to drive the wrench for the screwing manipulation, and optimal kinematic performance is analyzed by taking the condition number of the manipulator Jacobian as a criterion in terms of the manipulator position with respect to the vibration damper. The success of screwing manipulation and the effectiveness of the special wrench and path planning are verified by simulation and experiment.