U.S. Department of Energy Telerobotic Inspection of Toxic Waste Containers Using A Dexterous Manipulator

Drums containing toxic and/or radioactive waste are stored in DOE controlled warehouses. The EPA requires weekly inspection of these containers for signs of deterioration and/or leakage. Frequent exposure of human inspectors to toxic/radioactive waste is harmful. A semi-autonomous dexterous inspection system, with telepresence capabilities, is being developed for DOE to allow inspection of the hazardous waste without exposing human operators to any health risks.

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Quicktime graphic simulation of system deployment (1.2meg)

Dexterous Inspection Module Functions

Click for quicktime movies below

Inspection using overhead pan/tilt unit mounted camera

Close range inspection using an end effector mounted camera (225K)
Capture and decoding of bar code labels on the drum (324K)
Surface sampling (2.1Meg)

Dexterous Inspection Hardware

Click on the pictures for bigger versions, click on the descriptions for more information about the hardware.

IMI Zebra Zero Force Manipulator

Directed Perception Pan/Tilt Unit

End Effector Mounted Camera

Silicon Graphics Indy Workstation

Telepresence Module Functions

Telepresence allows a human operator to be immersed in a remote environment. During the course of developing the Dexterous Inspection Module, it was decided that watching video in a window on the operator workstation, and having to constantly reposition the camera with the overhead pan/tilt unit was not a very natural way to observe the remote environment. It was decided to attempt to adapt some tools normally associated with virtual reality research for use in a remote inspection. Virtual reality researchers use head mounted displays to immerse the user in a virtual environment. A magnetic tracker is attached to the head mounted display (also referred to as a helmet). The tracker reports the position and orientation of the user's head, and this information is used to position the viewer in the virtual environment. The same idea was implemented with the Telepresence Module, the only difference being that instead of controlling the position of a viewer in a virtual environment, the tracker now controls the orientation of the pan/tilt mounted cameras in the remote environment.

Since humans perceive the world in three dimensions through stereo vision, a stereo video display was deemed necessary for the operator to be immersed in the remote environment. This also requires two video cameras, with some fixed distance between them, to generate the left and right eye views.

The functions which the telepresence module should perform are listed below (click for quicktime movies). Perform proxy inspection (the TRC pan/tilt/vergence unit replaces the human operator in the remote/hostile environment)

Observe the Dexterous Inspection Module (1.9Meg)

Telepresence Module Hardware

TRC Unisight Pan/Tilt Base with BiSight Vergence Head

Stereo Head Mounted Display

Magnetic Tracker

For a video of the Dexterous Inspection Module and the Telepresence Module in operation,

please contact Dr. Darren Dawson at ddawson@eng.clemson.edu Tel: (864) 656-5924.

This research was funded by the U.S. Department of Energy.