Hi

I used the following simple algorithm to impement a control system. I had to maintain a process variable at a set-point entered by the user by altering the actuator position. The actuator position is decided by an 8-bit DAC O/P signal:

pseudocode:
;DAC is on port 1
Set_Point equ r0
Actual_Value equ r1
Deviation equ r2
DAC equ r3
Delta_DAC equ r4

mov DAC,#00h
mov P1,DAC
enter Set_Point

Loop:

Get Actual_Value
Deviation = Set_Point - Actual_Value

if ( |Deviation| > 10){
Delta_DAC = 20
sjmp Action
}
if ( 10 > |Deviation| > 5 ){
Delta_DAC = 10
sjmp Action
}
if ( 5 > |Deviation| > 0)
Delta_DAC = 5
sjmp Action
if ( 1 > |Deviation| >0.05 )
Delta_DAC = 1
else
Delta_DAC = 0


Action:
if ( Deviation > 0 )
DAC = DAC - Delta_DAC
else
DAC = DAC + Delta_DAC

mov p1,DAC

ljmp Loop

I found that this algorithm was sufficient for my application, and easier to implement than PI or PID etc. :D
Then a friend suggested it might be a fuzzy control system, and it seems possible, hence this query :)

Kundi