# "manual closed loop control" is there such a thing?

Discussion in 'Electronic Basics' started by misterroy, Jan 18, 2006.

1. ### misterroyGuest

Hi, I teach Technology in Scotland. In our arrangements documents
mention is made of "manual closed loop control" It seems to mean for
example, that whilst you are driving your car you become part of the
system and provide the feedback, hence "manual closed loop control".
To me thats plain old manual control. Google seems to back me up, only
28 hits for "manual closed loop control"
Any thoughts?

Roy

2. ### John PopelishGuest

I agree that they are probably using manual closed loop control to
mean manual control while you observe some feedback variable or
variables The control algorithm you use to make your control
decisions may be conscious (and either logical or illogical) or
unconscious.

Some people apply manual closed loop control, fail miserably, and
never realize that either the variables they observe are not connected
to what they are controlling the way they think they are, or their
control algorithm is completely wrong. This is especially true in
personal interaction loops and all superstition.

3. ### Charles SchulerGuest

Semantics. I taught an EET course in servos and noted that some textbook
authors used that as an example. You know, cruise control closes the loop
with a circuit or a human closes the loop with her eyes, brain and foot on
the gas pedal. Within this paradigm, open loop means no control whatsoever
(I suppose ... again, all semantics).

4. ### Pooh BearGuest

Manual closed loop control might mean keeping the car on the road though !

Graham

5. ### dick on the langwangGuest

Possibly just refers to a closed loop control system with a human in
the control loop, something like trying to hold the position of a
meter, reading some process value, with a control valve. Very
unreliable component to have in any control loop ..... would recomend
getting rid of the human element where ever possible !!

6. ### Fred BartoliGuest

Ever tried to drive with closed eyes?

That's still manual but open loop... not for long.

7. ### John LarkinGuest

A long time ago, I worked for an outfit that had no controls
experience but proposed to design and build a control console for a
steamship. I worked up a control algorithm for the main drive engine,
a steam turbine with an electro-hydraulic main steam valve. I
simulated the transient response, in terms of valve position, steam
flow, and RPMs vs time (on an HP9100 calculator) and plotted it in
nice colors; the dynamics were interesting, given the various
constraints on valve operation and boiler loading. We took it to a
meeting and made a presentation. An old crusty steamship engineer
looked at the curves and said "that's exactly the response you'd see
if an experienced operator worked the valve by hand" so we got the
job. This was for the LASH ships, built at Avondale. The company,
TANO, is still in the marine automation business.

The Wright brothers airplane was dynamically unstable, as are some
modern fighter planes. They used experience, we use computers.

John

8. ### John PopelishGuest

John Larkin wrote:
(snip)
It must have been quite a thrill building that experience a few feet
above the sand.

9. ### John LarkinGuest

They started with gliders, tethered in the wind at Kitty Hawk. I bet
they crashed a lot.

There was a TV show on a while back. Some people built a Wright
replica and learned to fly it. It didn't look easy.

John

10. ### Homer J SimpsonGuest

The flyer was the first heavier-than-air to kill anyone IIRC.

11. ### Homer J SimpsonGuest

You could play the relevant sections from "Metropolis" - or Madonna's rip
off of it!