robot control system specification language

a lisp extension designed and described in [1], to specify a layer in .

The language assume a model of Definite State Machine of the layer.

Each state is of the following 4 types:

output

an output message -> actuator. (then enter a new state)

side effect

manipulate an internal variable of the layer (then enter a new state)

conditional dispatch

(if predicate stateA stateB). predicate use internal variable or inputs.

event dispatch

(cond predicateA stateA predicateB stateB predicateC stateC …).

(defmodule avoid 1
  :inputs (force heading)
  :outputs (command)
  :instance-vars (resultforce)
  :states
  ((nil (event-dispatch (and force heading) plan))
   (plan (setf resultforce (select-direction force heading))
         go)
   (go (conditional-dispatch (significant-force-p resultforce 1.0)
                             start
                             nil))
   (start (output command (follow-force resultforce))
          nil)))