A Master-Slave Robotic System for Haptic Teleoperation

This paper proposes a telerobotic system made up of an haptic master and a slave anthropomorphic robot communicating through the Internet. In the proposed teleoperation system the operator drives the robot by manipulating a five-dof pen-shaped master haptic device, whose movements are repeated by the robot. Moreover, the operator is provided with force feedback in order not only to let him feel the physical environment the robot is interacting with, but also to guide him through the correct execution of the teleoperation task. To this purpose, the slave system end-effector (a drill) is mounted on a home-made single axis load cell used to measure drilling forces. This work, in particular, addresses the problem of implementing an on-line trajectory planner assuring a smooth motion of the slave robot in the presence of piecewise constant and unpredictable position references received by the haptic master, even in the presence of random communication time delay. Additionally, in order to improve the drilling task outcome and to prevent the execution of inappropriate and abrupt operators’ movements, an algorithm has been developed, which makes use of a local force feedback to appropriately delay the position references received by the master.