Robotics

Author: Corde Lane

Operators of robotic systems use telepresence to help control the telerobot when performing difficult tasks. A telerobot is a robotic system controlled by a human operator at a remote control station. The Space Shuttle RMS (Remote Manipulator System) is such a device. An astronaut inside the Shuttle controls this arm in many tasks, such as docking with a satellite, removing payload, etc.

Telepresence With Underwater Robots

At the University of Maryland's Space System Laboratory, water is used to simulate the micro gravity of space. Studies look into using space robotics to conduct space operations. Telepresence allows the operator to become immersed in the robot's task. On the robot BAT (Beam Assembly Teleoperator), two cameras are side by side on a moveable platform. The two cameras transmit pictures, one corresponding to each eye, to the control station. At the control station, the operator then uses an HMD where the left eye monitor shows the left camera's picture and the right eye monitor shows the right camera's picture. The HMD also tracks the operator's head movements, which moves the camera's platform in real time.

The operators can place their arm in a mechanical housing; this device tracks the arm's position and orientation. The robotic arm can then mimic the same orientation in real time. This creates a knowledge of where the robotic arm is located at all times. This also helps make the operator aware of their telepresence environment.

The partial immersion of the operator keeps them focused on the difficult task that is being performed. The primary task of assembling structures requires fine manipulation and precision in positioning of components. BAT assembles a structure, consisting of six beams and four cluster nodes. When assembled, a tetrahedron is formed.

This routine assembly can be performed by space suited astronauts. However by using a robot to complete these mundane tasks, the divers are free to work in more intricate manipulation tasks.

Multimode Proximity Operations Device

Another vehicle, MPOD (Multimode Proximity Operations Device), uses another form of stereo vision to provide depth cues when performing docking and rendezvous operations. A pair of cameras is mounted to the vehicle. There is no moveable platform so the cameras provide a fixed frame of reference to the docking probe. The operator looks at a monitor with a special pair of glasses. The screen alternately flickers the left and right camera image. The glasses, which flicker at the same time, block the right eye's vision when the left camera view is on the monitor. The opposite occurs for the left eye; therefore stereo vision provides the depth needed when attempting to dock.

How To Get Involved

The best way to learn how robotics work is to actually design, debug and work with them. This practical experience can be acquired when taking design classes like Robotics.

References

Viggh, Herbert E.M., "Artificial Intelligence Applications in Teleoperated Robotic Assembly of the EASE Space Structure", Space Systems Laboratory, MIT, Cambridge, MA, 1988.

Shain, Eric B., "Design and Control of a Beam Assembly Teleoperator", Space Systems Laboratory, MIT, Cambridge, MA, 1983.

Human Interface Technology Laboratory