Fault Diagnosis for Discrete Event Systems Using Partially Observed Petri Nets

Algorithm 2

Computation of the minimal number of flow-out.

	Input: , an observed sequence , initial marking
	Output:
	(1) for each do
	(2)  derive
	(3) end for
	(4)
	(5) let , , ,
	(6) if is an empty string then
	(7)  let
	(8) else
	(9)  for, and t is the first transition of do
	(10)   if t is enabled at M then
	(11)   let
	(12)   else
	(13)   if i = 1 then
	(14)    go to 23
	(15)   else
	(16)    let i = i − 1
	(17)   end if
	(18)  end if
	(19) end for
	(20) end if
	(21) let , go to 6
	(22) let i = i − 1
	(23) ifthen
	(24)  fordo
	(25)   if t is enabled at M, q = q + 1 then
	(26)    let , go to 6
	(27)   else
	(28)    let
	(29)   end if
	(30)  end for
	(31) else
	(32)  fordo
	(33)   if t is enabled at M then
	(34)    let , go to 6
	(35)   else
	(36)    let
	(37)   end if
	(38)  end for
	(39) end if
	(40) ifthen
	(41)  let i = i+1, go to 23
	(42) else
	(43)  fordo
	(44)   if t is enabled at M then
	(45)    let , go to 6
	(46)   else
	(47)    let
	(48)   end if
	(49)  end for
	(50) end if
	(51) let i = i+1, go to 23
	(52) fordo
	(53)  if t is enabled at M, q = q+1 then
	(54)   let , go to 6
	(55)  else
	(56)   let
	(57)  end if
	(58) end for
	(59) end the algorithm