what are the advantages of a fully automatic closed loop system over their open loop counterparts?

Answer 1

Think of it this way
You are driving on a straight line road from A to B, regardless of how many cars, obstacles are in your way.

Open loop system. Your eyes are closed, all you see in the first couple seconds when you take off.

Closed system. Your eyes are open, you change your trajectory more or less depending on which obstacles you encounter.

Consider that for a simple environment, both will get there as fast as the other. But in a complicated environment (lots of obstacles, changes, etc) in the open loop case you might end up completely off track. not with the close loop

Answer 2

Theoretically, an open loop control system should be able to do whatever their closed loop counter parts do. All you need is a 100% accurate mathematical model of your system, and every other environmental factor which could affect the systems operation.

Ok, we want to control real stuff. In reality you can never model a system accurately 100% (it is just too hard!) , and it's even harder to account for environmental factors (or noise if you like). Thus you see a good amount of deviation from what you modeled in your real implementation.

How does a feedback control system work? It doesn't care about the internals of the system, just looks at it as a black box. It will look at the outputs of the system and will say: "hm... I'd like the output to be 10, but it is 8, so let's increase the input a bit. ok, now it's better, we're getting to 10... oh oh , we passed 10 and are now at 10.5, oh boy, let's decrease the input a bit. Ok, that's better, output is at 10 now, I'm done! But I'll keep an eye on the output in case an unknown noise comes in, in which case I can compensate for it by changing the input."

Now the problem with the feedback control is that since our systems are real (the tech word is causal) and our controller cannot foresee the future (DUH, we're talking about real world!) and moreover it doesn't know that much about the system internals and noise, We will usually have overshoot (like the scenario I told you, i.e. we want 10, but for a short period we get 10.5) and oscillation (like 8...9...10...10.5...9.75...10.11...9.93...10) unless you set your feedback controller to work really slow.

So to sum it up, open loop should work fine and beautifully, but only in your dreams! put an open loop controller before a real system, and you'll see deviations, which the controller cannot even correct. In real world we use feedback control systems all the time.

As an interesting side note, our brain controls our limbs in a feedback control system, which is set to overshoot and oscillate a bit for fast responses. Check it out: stretch your right arm, and then try to quickly bring your palm in front of your face, and stop it there. You'll surely see the overshoot and oscillation!

Answer 3

In oil industry, most of the equipment normally use the closed loop system which is totally automatic control. For example, to control flow in the pipe line we will use an automatic control. This closed loop basically consist of 3 element. First, the measuring instruments for example flow transmitter. Second is controller and the third is final element (let say control valve. ) The flow transmitter will give signal to the controller and the controller will compare the signal with it's set point. Finally the controller will produce a signal which will be delivered to the control valve either to open or closed the valve which mean to get more flow or less flow. This is the advantage of closed loop(automatic control).

Answer 4

Open Loop administration equipment: As we pronounced until now, an open-loop administration equipment is controlled without postpone, and only, via an enter sign. the ordinary gadgets of this sort consist only of an amplifier and a motor. The amplifier gets a low- point enter sign and amplifies it sufficient tochronic the motor to accomplish the needed job. The open-loop administration equipment is shown in ordinary block diagram sort in determine 2-a million. With this methodology, the enter is a sign it somewhat is fed to the amplifier. The output of the amplifier is proportional to the amplitude of the enter sign. The section (ac equipment) and polarity (dc equipment) of the enter sign determines the trail that the motor shaft will turn. After amplification, the enter sign is fed to the motor, which strikes the output shaft (load) interior the trail that corresponds with the enter sign. The motor won't provide up utilizing the output shaft until the enter sign is decreased to 0 or bumped off. this methodology generally demands an operator who controls velocity and path of flow of the output via various the enter. The operator ought to be controlling the enter via the two a mechanical or an electric linkage. Closed Loop platforms: A closed-loop controller makes use of feedback to administration states or outputs of a dynamical equipment. Its call comes from the help path interior the equipment: technique inputs (e.g. voltage utilized to an electric motor) have an result on the approach outputs (e.g. velocity or torque of the motor), that's measured with sensors and processed via the controller; the consequence (the administration sign) is used as enter to the approach, remaining the loop. the main ordinary sort of geothermal installation is a closed loop equipment. the warmth exchanger - a loop of piping full of fluid - is buried underground. The fluid circulates constantly interior the buried pipe, soaking up warmth from the earth for the duration of the wintry climate for use interior your homestead or company. In warmer months, the fluid takes warmth from indoors and transfers it decrease back into the earth.

Answer 5

closed loop you have safety's and feedback open loop you just know your controlling something and hopefully it is but without closed loop youcan not see what you did in real time.

Answer 6

to put it simply, feedback. a portion of the output is taken and "merged" with the input, to provide the feedback.

both positive and negative feedback. but what's more important is the negative feedback.

Hope this helps, Peace.