Haptic communication for remote mobile and manipulator robot operations in hazardous environments

Abstract

Nuclear decommissioning involves the use of remotely deployed mobile vehicles
\nand manipulators controlled via teleoperation systems. Manipulators are used for
\ntooling and sorting tasks, and mobile vehicles are used to locate a manipulator
\nnear to the area that it is to be operated upon and also to carry a camera into a
\nremote area for monitoring and assessment purposes.
\nTeleoperations in hazardous environments are often hampered by a lack of visual
\ninformation. Direct line of sight is often only available through small, thick
\nwindows, which often become discoloured and less transparent over time. Ideal
\ncamera locations are generally not possible, which can lead to areas of the cell not
\nbeing visible, or at least difficult to see. Damage to the mobile, manipulator, tool
\nor environment can be very expensive and dangerous.
\nDespite the advances in the recent years of autonomous systems, the nuclear
\nindustry prefers generally to ensure that there is a human in the loop. This is due
\nto the safety critical nature of the industry. Haptic interfaces provide a means
\nof allowing an operator to control aspects of a task that would be difficult or
\nimpossible to control with impoverished visual feedback alone. Manipulator endeffector
\nforce control and mobile vehicle collision avoidance are examples of such
\ntasks.
\nHaptic communication has been integrated with both a Schilling Titan II manipulator
\nteleoperation system and Cybermotion K2A mobile vehicle teleoperation
\nsystem. The manipulator research was carried out using a real manipulator
\nwhereas the mobile research was carried out in simulation. Novel haptic communication
\ngeneration algorithms have been developed. Experiments have been
\nconducted using both the mobile and the manipulator to assess the performance
\ngains offered by haptic communication.
\nThe results of the mobile vehicle experiments show that haptic feedback offered
\nperformance improvements in systems where the operator is solely responsible for
\ncontrol of the vehicle. However in systems where the operator is assisted by semi
\nautonomous behaviour that can perform obstacle avoidance, the advantages of
\nhaptic feedback were more subtle.
\nThe results from the manipulator experiments served to support the results from
\nthe mobile vehicle experiments since they also show that haptic feedback does not
\nalways improve operator performance. Instead, performance gains rely heavily on
\nthe nature of the task, other system feedback channels and operator assistance
\nfeatures. The tasks performed with the manipulator were peg insertion, grinding
\nand drilling.