System sensitivity to parameter variation

In a closed-loop control system, negative feedback is used to reduce the error between the desired output and the actual output. This feedback allows the system to adjust its control parameters in order to minimize the error and improve the system performance. One important characteristic of a closed-loop control system is its sensitivity to parameter variation, which refers to how much the system's output is affected by changes in its parameters.

Explanation

1. Sensitivity analysis

Sensitivity analysis is a technique used to assess the impact of parameter variations on the system's performance. It helps determine how sensitive the system's output is to changes in its parameters. Sensitivity analysis is particularly important in closed-loop control systems, as small changes in parameters can significantly affect the system's stability and performance.

2. Negative feedback

In a closed-loop control system, negative feedback is employed to reduce the error between the desired output and the actual output. It does so by comparing the actual output with the desired output and generating an error signal. This error signal is then used to adjust the control parameters of the system, aiming to minimize the error and improve the system's performance.

3. Effect of negative feedback on sensitivity

When negative feedback is introduced in a closed-loop control system, it has the effect of reducing the system's sensitivity to parameter variation. This means that the system becomes less affected by changes in its parameters.

3.1. Stability

Negative feedback improves the stability of the control system by reducing its sensitivity to parameter variation. When the system's parameters change, the control loop automatically adjusts the control signal to bring the system back to the desired operating point. This ensures that the system remains stable and continues to operate within its desired range.

3.2. Robustness

Negative feedback also enhances the robustness of the control system. Robustness refers to the ability of the system to maintain its performance in the presence of disturbances or uncertainties. By reducing the system's sensitivity to parameter variation, negative feedback helps the system remain robust and perform consistently even in the face of changing conditions.

4. Conclusion

In a closed-loop control system, negative feedback plays a crucial role in reducing the system's sensitivity to parameter variation. This improves the system's stability and robustness, allowing it to perform consistently even in the presence of changes in its parameters. Therefore, the correct answer to the question is option 'B' - the system's sensitivity to parameter variation decreases with negative feedback.