Can feedback make an unstable system stable?

Detailed Solution. The gain of the system should be increased to make an unstable system stable. For positive feedback of the system, the gain is more and for negative feedback, the gain is reduced for which the stable system can become unstable. Also, the gain is inversely proportional to the steady-state error.

Can an open loop system be unstable?

Well, Open loop systems are always unstable because there is no feedback to correct/modify the output.

What should be done to make unstable system stable?

Which of the following should be done to make an unstable system stable? Explanation: The gain of the system should be increased to make an unstable system stable and for positive feedback of the system the gain is more and for the negative feedback the gain is reduced for which the stable system can become unstable.

Is the open loop system stable?

The open loop control system is absolutely stable if all the poles of the open loop transfer function present in left half of ‘s’ plane. Similarly, the closed loop control system is absolutely stable if all the poles of the closed loop transfer function present in the left half of the ‘s’ plane.

Does feedback can always reduce the effects of noise and disturbance on system performance?

Feedback can always reduce the effects of noise and disturbance on system performance? Explanation: Feedback has many advantages as it can reduces the effects of noise and disturbance on system performance by increasing speed of response.

Which of the following should be done to make an unstable system stable?

Why is open-loop more stable?

Detailed Solution. As compared to closed loop system an open loop control system is more stable as all its roots are in left half of s plane only, but it less accurate since there is no feedback to measure the output value and compare it with the input value.

What is open-loop unstable system?

Internal open-loop instability occurs when an individual unit operation is open-loop unstable, i.e., one or more open-loop eigenvalues with positive real parts. External open-loop instability occurs when a collection of open-loop stable units are connected in such a way that the coupled system is open-loop unstable.

What is the difference between stability and feedback?

Stability is desirable, because then we can control a stable system more easily. If a system is unstable, you would need more and more control authority to produce the same desired result. You can think of feedback as being able to “increase stability”, but that’s only true if you design a controller correctly.

Are there any open loop systems that are stable?

There are many open loop systems that are stable. Think about your car going down a straight highway with no bumps. If you let off the gas and the steering wheel, you will just roll to a stop (equilibrium point). The same is true for a pendulum, or a guitar string.

What is the difference between stable and unstable systems?

A stable system is one, which does not sustain/increase oscillations or output over time. It is supposed to reach the set point at some point of time. An unstable system has infinite/saturated output at infinite time. An open loop system may or may not be stable, depending on whether its output saturates or dampens.

Is an open loop system as helpless as a blind man?

However, in case the environment is not conducive, i.e, there is some unexpected change, then an open loop system is as helpless as a blind man. It continues performing the same pre-programmed task again and again. A stable system is one, which does not sustain/increase oscillations or output over time.