Design of operator control
stations for teleoperators poses the same types of problems as design of controls
and displays for aircraft, highway vehicles, and trains. The displays must show
the important variables unambiguously to whatever accuracy is required, but
more than that must show the variables in relation to one another so as to
clearly portray the current “situation” (situation awareness is
currently a popular test of the human operator in complex systems). Alarms must
get the operator’s attention, indicate by text, symbol, or location on a
graphic display what is abnormal, where in the system the failure occurred,
what is the urgency, if response is urgent, and even suggest what action to
take. (For example, the ground-proximity warning in an aircraft gives a loud “Whoop,
whoop!” followed by a distinct spoken command “Pull up, pull up!”) Controls —
whether analogic joysticks, master-arms, or knobs — or symbolic special-purpose
buttons or general-purpose keyboards — must be natural and easy to use, and
require little memory of special procedures (computer icons and windows do well
here). The placement of controls and instruments and their mode and direction
of operation must correspond to the desired direction and magnitude of system
response.
