User-Friendly Robot Environment for Creation of Social Scenarios - Foundations on Natural and Artificial Computation - page 215

used rarely to remove all the residual processes that are scheduled and not in
execution, yet. While normal commands are appended, the flush command is
executed immediately.
Commands for controlling the LEDs. Activating and disabling the LEDs is
performedwiththe ledset command, in this case all leds are reached through
a unique name, and can be given a value between 0 ( ledoff )and1( ledon ).
For transition from the current color to a new color the ledto (also known as
ledfade) command is used and a duration in milliseconds is provided to control
the speed of change.
Audio commands. Two powerful audio commands say and play can be used
to accomplish either text to speech conversion or to play an audio signal from a
mp3 player engine.
Motor commands. The stiffness of a motor is usually set at the begin-
ning using the stiff command. A typical setting is for example stiff
(1.0, 1000, 0) that sets all motors to maximum (1.0) stiffness in 1 sec-
ond (1000ms) time. The movement of a single motor is defined by address-
ing the motor, and specifying the desired angle of change over a specific
time interval. For example move (HeadYaw, 30.0, 1000) moves the 'head
yaw' motor to an angle of 30 degrees in one second time. In practice mul-
tiple moves for multiple motors are performed through a string-like com-
mand [move (HeadYaw, 30.0, 1000) & move (HeadYaw, -30.0, 1000)] |
[move (HeadPitch, 20.0, 700) & move (HeadPitch, -20.0, 600)] .Th s
command can also be written in a more compact manner like movem (HeadYaw,
30.0, 1000, -30.0, 1000, HeadPitch, 20.0, 700, -20.0, 600) by using
the move multiple elements command.
3 Creating Behaviors with Incremental Complexity
The most simple robot behaviors are sequences of motor commands. Using sen-
sory information requires specific design choices that bring another degree of
complexity. Meta commands can combine behavioral sequences that are used
often in a certain order. It may imply usage of states requires to meet a con-
dition, before another behavioral t sequence can be started. Hybrid commands
bring yet different practical concerns. The main design choices for each level of
complexity is discussed in the upcoming subsections.
3.1 Using Sensory Information
Using sensory information is crucial for constructing reactiveormorecomplex
autonomous behaviors. However, it requires issues as how to construct parallel
behaviors that have different cycle (or update) speeds. Moreover, there is a huge
difference between the capacity of a robot to perceive (read sensory information)
and act behaviors - the behavioral capacity is around two orders of magnitude
smaller than the sensory capacity.