Vibration suppression of flexible beams for robotic assembly using vision and wrist motion

Abstract

Industrial robots are used in assembly operations to increase the productivity of the manufacturing process. In this operation, a robot grasp either a rigid or flexible object like beams, wires and sheets that may encounter undesired vibration in this object due to high speed motion of the robot. The present work designs a high-level control strategy using a robot vision system to suppress the vibrations of the flexible beams during the assembly process. The robot vision approach is used to detect the beam held by the gripper of the robot and measure the dimensions keeping an account of the change in perspective. The free response of the flexible beam is used for system identification regardless of dimension and material properties. To suppress the vibration of the flexible beam actively, the proposed high-level controller uses the wrist motion of the robot. The efficacy of the proposed approach is demonstrated by implementing it on a commercially available ABB 1410 industrial robot without modifying its controller for the beam-in-slot assembly operation. The proposed controller can suppress vibration amplitude up to 97.83% within 2.36 s and reduce suppression time by 96.23% compared to the control to no control scenario