Page 196 - Anatomy of a Robot

07_200256_CH07/Bergren 4/10/03 3:30 PM Page 181
ENERGY CONTROL AND SOFTWARE 181
Pipelining (Premission)
Just as the robot’s computer can pipeline tasks, so too the robot designers can pipeline
tasks well in advance. It’s just a matter of how soon the logical order of execution can
be determined. In the case of real-time pipelining, the robot’s computer pipeline is strip-
ping out tasks that have been cobbled together at the last moment. The real-time pipeline
optimizes tasks that don’t make sense because they could not be predicted beforehand.
But with clever programming, the robot’s designers can also optimize ahead of time the
ways in which tasks are executed. It’s almost like performing pipelining well before the
tasks are to take place, and then feeding the robot’s real-time pipeline a stream of tasks
that don’t need any further optimization.
Consider a trivial example. Suppose the robot has “shoes” that are required for move-
ment. It does not take a genius to realize that putting on shoes should be done before
standing up. Those of us with kids, however, know the kid’s already up, in the car, and
down to the mall before we discover the surplus of pink wiggly toes. Given that humans
are leaps and bounds ahead of robots in their abilities and evolution, we leave it to the
reader to discover the advantage this sort of behavior conveys to the human species.
Why is the world put together like this? Once we, as humans, become smart enough to
discover the reason, we will surely build superior robots.
But I digress. The robot designers should be able to plan missions where the robot is
controlled well enough to put its shoes on before moving. In fact, with the proper devel-
opment software, the premission planners should have the tools that will make proper
robot control largely an automatic occurrence.
Taking one step back, robot designers should also be able to optimize all the software
instructions to conserve power. We’ve already seen the example of the IF instruction
optimized for speed or power. Most compilers are capable of optimizing the software
for various things. With certain flags set at compile time, a compiler can turn out fast
code or condensed code that uses little memory. A good compiler will also eliminate
code that will never be executed.

SAFEGUARDS

The robot’s control software should have control loops that will sense the inordinate
consumption of power and other serious situations. This is especially vital in space mis-
sions or when the robot cannot be repaired. Two types of events should be watched care-
fully with separate software watchdogs:

Security breaches Communication coming into the robot should be scanned for
evidence of hackers and other more random interference. If it’s determined that