Test: Introduction to Control Systems- 2 - Electrical Engineering (EE) MCQ

Option C represents the correct matching between functions and their laplace transform.

Reference Input in Closed-Loop Control Systems

- In a closed-loop control system, the reference input is a standard signal that is used for comparison with the output of the system.
- It represents the desired or target value that the system is trying to achieve.
- The reference input is typically a known signal that is used to evaluate the performance of the system.
- By comparing the output of the system to the reference input, the controller can make adjustments to ensure that the system operates as desired.
- The reference input can take various forms, such as a step input, ramp input, sinusoidal input, etc.
- The controller uses the error between the reference input and the actual output of the system to adjust the control signals and minimize the error.
- The reference input plays a crucial role in closed-loop control systems by providing a benchmark for performance evaluation and adjustment of control signals.

Actuating Signal

- The actuating signal is the difference between the output response and the reference signal in a control system.
- It is used to drive the system towards the desired setpoint by adjusting the input signals.
- The actuating signal is crucial for maintaining stability and accuracy in control systems.
- By continuously comparing the output response with the reference signal, the actuating signal ensures that the system stays on track and responds appropriately to any changes or disturbances.
- Overall, the actuating signal plays a key role in ensuring that the control system operates effectively and achieves its desired objectives.

The laplace transform of unity function i.e.

Limit Cycles and Jump Resonance in Non-linear Systems
 

• Limit Cycles in Non-linear Systems:
  Limit cycles are periodic orbits in non-linear dynamical systems where the system oscillates within a bounded region indefinitely without either converging towards a fixed point or diverging towards infinity. These cycles are characteristic of non-linear systems and can exhibit a variety of complex behaviors such as chaotic oscillations.



 
• Jump Resonance in Non-linear Systems:
  Jump resonance occurs in non-linear systems when the system response suddenly jumps to a different state due to a small change in the input or parameters. This phenomenon is a form of nonlinear resonance where the system's behavior changes abruptly, often leading to unexpected and complex dynamics. Jump resonance can arise in various systems such as mechanical, electrical, or biological systems.



 

In summary, limit cycles and jump resonance are interesting phenomena observed in non-linear systems, highlighting the rich dynamics and behaviors that can emerge in such systems. These behaviors are distinct from those seen in linear systems and can provide valuable insights into understanding and analyzing complex systems with non-linear dynamics.

Here, a = 2 and b = 3ω

Explanation of a robust control system:

- Low sensitivities: A robust control system should have low sensitivities to uncertainties and disturbances. This means that even if there are slight variations or disturbances in the system, the control system should be able to maintain stability and performance without significant changes. Low sensitivities ensure that the system can effectively handle variations in parameters without compromising its operation.

- Stable over a wide range of parameter variation: Another important aspect of a robust control system is its ability to remain stable over a wide range of parameter variations. This means that the system should be able to maintain its stability and performance even when there are significant changes in the parameters or operating conditions. A robust control system should be able to adapt to different conditions and still perform optimally.

- Both (a) and (b): Therefore, a robust control system is one that not only has low sensitivities to uncertainties and disturbances but also remains stable over a wide range of parameter variations. By combining these two characteristics, a robust control system can effectively handle uncertainties and variations in the system, ensuring reliable and consistent performance.

Radar tracking systems are generally closed-loop systems because they use feedback to continuously adjust and track an object. However, if this refers to the initial detection phase, it might not use feedback, making it an open-loop system. Without additional context, this might be incorrect.

The effect of parameter variation and internal noise is more in an open loop system.

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.