Automatic insertion work based on visual measurement and contact force estimation

This paper focuses on the automation of insertion work, such as inserting a metal sleeve into a wire terminal, necessary in distribution work. The major technical issues for this task automation are considered as: the detection of a target object in an unstructured, complex outdoor environment; and the insertion executed at the work site with restricted clearance. In the former, the target object is detected by applying 3D image processing and template matching techniques, based on the position and posture relationship between CCD cameras, the target object, and the background. In addition, the manipulator's targeting position is updated by commands from the visual sensor system, applying the video-rate stereo camera method. This allows for realtime visual feedback control; thus, misalignment due to deviation arising from manipulator's mechanism is avoided. In the latter issue, a new algorithm was developed for insertion. This algorithm can estimate contact force, based on the deviation between the present position and command position of the manipulator. An experiment using a testing robotic system revealed that the proposed robotic technology was effective for performing insertion work without assistance by humans.