Minimalist Mobile Robotics

32

2.

Architecture

forces

the

internal state machine

to go to the

first state. Thus,

when the second module times out,

the

first module switches out

of its output producing loop and goes back to its original testing

loop.

(defmodule watchdog

: inputs (trigger)

:

outputs (reset)

:

states

((nil (event-dispatch trigger stretch))

(stretch

(event-dispatch

trigger stretch

(sleep

MONOSTABLE-TIME)

switch))

(switch

(output reset $true$)

nil)))

2.3

The

multiprocessor implementation

On

an

earlier robot [Brooks

and

Connell

86] we

tried using

telemetry and off-board computation,

but

found this to be highly

unreliable.

For

this reason we decided

to go

wit ...