Page 50 - Introduction to AI Robotics

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1.5 Teleoperation
for many applications because of limited bandwidth. Video telephones, pic-
ture phones, or video-conferencing over the Internet with their jerky, asyn-
chronous updates are usually examples of annoying limited bandwidth. In
these instances, the physical restrictions on how much and how fast informa-
tion can be transmitted result in image updates much slower than the rates
human brains expect. The result of limited bandwidth is jerky motion and
increased cognitive fatigue. So adding more cameras only exacerbates the
problem by adding more information that must be transmitted over limited
bandwidth.
TELEPRESENCE One area of current research in teleoperation is the use of telepresence to
reduce cognitive fatigue and simulator sickness by making the human-robot
VIRTUAL REALITY interface more natural. Telepresence aims for what is popularly called virtual
reality, where the operator has complete sensor feedback and feels as if she
were the robot. If the operator turns to look in a certain direction, the view
from the robot is there. If the operator pushes on a joystick for the robot to
move forward and the wheels are slipping, the operator would hear and feel
the motors straining while seeing that there was no visual change. This pro-
vides a more natural interface to the human, but it is very expensive in terms
of equipment and requires very high bandwidth rates. It also still requires
one person per robot. This is better than traditional teleoperation, but a long
way from having one teleoperator control multiple robots.

1.5.2 Semi-autonomous control

SEMI-AUTONOMOUS Another line of research in teleoperation is semi-autonomous control,often
CONTROL called supervisory control, where the remote is given an instruction or por-
SUPERVISORY CONTROL
tion of a task that it can safely do on its own. There are two flavors of
semi-autonomous control: continuous assistance, or shared control,and con-
trol trading.
SHARED CONTROL In continuous assistance systems, the teleoperator and remote share con-
trol. The teleoperator can either delegate a task for the robot to do or can
do it via direct control. If the teleoperator delegates the task to the robot,
the human must still monitor to make sure that nothing goes wrong. This is
particularly useful for teleoperating robot arms in space. The operator can
relax (relatively) while the robot arm moves into the specified position near
a panel, staying on alert in case something goes wrong. Then the operator
can take over and perform the actions which require hand-eye coordination.
Shared control helps the operator avoid cognitive fatigue by delegating bor-
ing, repetitive control actions to the robot. It also exploits the ability of a