Advantages of open loop

Answer 1

cheaper than closed loop

open loop

turn the switch you assume the light is on

closed loop

turn the switch observe the current observe the light level...

can predict how much below optimal the performance is and predict when total failure will occur

Answer 2

Advantages of Closed Loop control - stability and repeatabilitywithin the closed loop system the difference between the output and input will be fed into the control system.

• Closed loop control, with the appropriate sensor, provides much greater stability.
• If the magnetic field is controlled by setting the current of the power supply, then as the magnet or supply temperature changes the current can vary - so the field will deviate from its desired setting. If you are measuring the field directly then you can hold the field constant, despite external influences.
• This can have the big spin-off that you no longer need a very tightly regulated power supply, and you don't need very precise temperature stability in it either - reducing the cost of the power supply considerably.
• Stability is of particular interest in keeping a beam on target for a long period, and is vital for big ring magnet systems.
• Closed loop control will also give much better repeatability.
• If you ask for a particular field, that is what you get, no matter what the temperature is, or was, and no matter what the history of the magnet. Closed loop control overcomes temperature and hysteresis effects.
• In a production environment the repeatability of field can speed up switching between ion species or energies. If you ask for the same field as last time, you know the beam will be in the right place. It is almost vital if a machine wants to be able to operate on a "recipe" type system.

the open loop system will be unstable...the output will not be accurate

Answer 3

cheaper than closed loop

open loop

turn the switch you assume the light is on

closed loop

turn the switch observe the current observe the light level...

can predict how much below optimal the performance is and predict when total failure will occur

Answer 4

An open loop system is simple and straightforward, requiring fewer physical or logical connections as the closed loop design. It lacks the feedback offered by closed loop designs. As such, it is often considered inferior to a closed loop design.

A closed loop design assures the initiator that the signal has not only been transmitted but also received. However, this often creates a false sense of security, as the semantics of a feedback signal may be ambiguous. For example, a light might feed back it's on or off signal regardless of the actual state of the luminaire, while a more sophisticated design might sample light levels and thus drive the feedback based on the real state of the luminaire. For another example, consider a closed loop multicast design where one controller (switch) drives multiple actuators (lights). Does the presence of a feedback signal indicate that at least one, or that all, lights assume the required state?

In summary, a closed loop design is generally superior and desirable, provided that the behaviour of this particular closed loop system is well known. A closed loop system without such detailed knowledge does not generally offer higher reliability, but requires typically twice the cost in physical or logical connections.

Answer 5

Well, In open loop as there is no feedback so it is less prone to oscillatiory response where as in closed loop, as feed back is there so if sensitivity is high, oscillations are always there hence less stable response.

hope it helps !!

Answer 6

Open loop is when the control system responds to the environment. For instance, a furnace would use a thermostat to regulate the temperature of a building. A closed loop would be if the thermostat were replaced with a switch. Then, a human would need to work the switch and keep the temperature within a good range.

Answer 7

Stability and simplicity in design