Six-degree-of-freedom haptic rendering in virtual teleoperation

Six-degree-of-freedom (6-DoF) haptic rendering of the telerobotic operation method using virtual joint coupling (VJC) is proposed. This algorithm couples six joints of a virtual robot with those of a 6-DoF haptic device based on a spring-damper model to render force and torque feedback to a user and drive the virtual robot in the teleoperation simulation. Our rigid body dynamics is decoupled from the haptic rendering loop with an open dynamic simulation library Open Dynamics Engine, which runs at a lower update rate, thereby alleviating computation demand and improving the stability of the system. To illustrate the role of haptics and physically based simulation in teleoperation, a path-following experiment with virtual constraints is carried out. An experiment of virtual assembly, in which a user performs assembly tasks by means of manipulation of a gripper mounted at the end of a virtual robot, is also implemented to verify the VJC algorithm.