AME 11 End of Unit – SVE Study

AME 11 End of Unit Quiz

1 / 12

How can the gain of a control system be increased or decreased?

B) Increase the gain by increasing the integral time; decrease the gain by reducing the integral time.

C) Increase the gain by adding derivative control; decrease the gain by removing derivative control.

D) Increase the gain by reducing the setpoint; decrease the gain by increasing the setpoint.

A) Increase the gain by reducing the proportional band; decrease the gain by increasing the proportional band.

2 / 12

What is the primary characteristic of a Discontinuous (On-Off) control system?

C) The system adjusts output in small increments.

D) The system provides proportional control based on the error magnitude.

A) The output is continuously variable.

B) The output is either fully on or fully off, with no intermediate states.

3 / 12

Describe the reasons for integrating the error signal and the effect it has on the governor fuel rack.

D) Integrating the error signal helps in stabilizing the system by making the governor fuel rack adjustments slower, which prevents any rapid changes and ensures the engine speed remains constant.

C) Integrating the error signal helps in reducing the proportional gain needed for control, which simplifies the control system and makes the governor fuel rack less responsive to changes in engine speed.

B) Integrating the error signal helps in amplifying transient responses by applying a large correction immediately, causing abrupt changes to the governor fuel rack and quickly adjusting the engine speed.

A) Integrating the error signal helps in eliminating steady-state error by providing continuous correction over time, leading to a gradual adjustment of the governor fuel rack to maintain the desired engine speed.

4 / 12

With reference to engine governors, explain hunting.

D) Hunting is the term used for a governor’s ability to remain unaffected by variations in fuel quality. Reason: Fuel quality variations impact engine performance but are not described as hunting.

C) Hunting describes the process of adjusting the governor's sensitivity to improve engine speed stability. Reason: Adjusting sensitivity is related to tuning, not hunting, which involves excessive fluctuation in engine speed.

A) Hunting is the term used to describe a governor's inability to maintain a constant engine speed due to excessive fluctuation in engine speed around a set point. Reason: Hunting occurs when the governor repeatedly overshoots and undershoots the target speed, causing erratic engine performance.

B) Hunting refers to the governor’s ability to detect and compensate for sudden changes in load quickly. Reason: Quick load compensation is not referred to as hunting but rather as a desirable feature in governors.

5 / 12

Describe the effect of excessive Derivative Action.

C) Excessive Derivative Action can result in a system that quickly reaches the setpoint without overshooting or oscillating.

D) Excessive Derivative Action can decrease the system’s overall response time and improve its accuracy in maintaining the setpoint.

B) Excessive Derivative Action can cause the system to become overly sensitive to noise, leading to oscillations and instability.

A) Excessive Derivative Action can lead to a sluggish response time and an increase in steady-state errors.

6 / 12

How does hysteresis improve the performance of an On-Off control system?

D) It enables the system to predict and correct future errors.

B) It prevents rapid cycling by creating a dead zone between switching on and off.

A) It increases the switching frequency of the system.

C) It allows the system to adjust output continuously.

7 / 12

Describe integral action in a control system.

D) Integral action adjusts the control output to match the process variable to the setpoint instantly.

C) Integral action maintains a constant control output regardless of changes in the error signal.

A) Integral action adjusts the control output based on the rate of change of the error signal.

B) Integral action increases the control output to eliminate steady-state error over time by integrating the error signal.

8 / 12

Explain the purpose of Derivative Action.

A) Derivative Action aims to eliminate steady-state errors by continuously adjusting the control output based on the accumulated error over time.

D) Derivative Action compensates for errors in the system by applying a proportional correction based on the current error value alone.

C) Derivative Action adjusts the control output to maintain a constant error, ensuring that the system remains at a fixed setpoint without any fluctuations.

B) Derivative Action helps to anticipate future errors by reacting to the rate of change of the error, thereby improving the system’s stability and response time.

9 / 12

Explain the purpose of Integral Action.

D) Integral action maintains a constant output level regardless of the error to keep the system stable.

A) Integral action adjusts the control output based on the magnitude of the error, aiming to quickly correct deviations from the setpoint.

B) Integral action integrates the error over time to eliminate steady-state error, ensuring that the system eventually reaches the setpoint.

C) Integral action predicts future errors by adjusting the control output based on the rate of change of the error.

10 / 12

With reference to engine governors, explain stability.

A) Stability refers to the governor's ability to maintain a constant engine speed without oscillations or fluctuations when subjected to varying loads. Reason: Stability in governors is about how consistently the engine speed is maintained despite changes in load or other disturbances.

B) Stability describes the governor's capacity to change the engine speed quickly in response to sudden changes in fuel supply. Reason: Rapid response is more related to the governor's responsiveness, not its stability.

C) Stability is the measure of how much the governor's set point can drift from the desired speed due to wear and tear. Reason: Set point drift due to wear is not directly related to stability, which focuses on maintaining speed consistency.

D) Stability refers to the governor's ability to handle extreme variations in ambient temperature without affecting engine performance. Reason: While temperature variations can affect performance, stability specifically concerns speed consistency under load changes.

11 / 12

In an On-Off control system, what happens when the controlled variable exceeds the set point?

A) The system modulates the output to gradually reduce the variable.

C) The system increases the output to correct the error.

D) The system remains inactive until the variable drops significantly.

B) The system switches off the output to bring the variable back to the set point.

12 / 12

Explain proportional bandwidth in control terms.

A) Proportional bandwidth refers to the range of input values for which the proportional controller provides a linear response.

B) Proportional bandwidth is the range of frequencies over which the proportional controller effectively responds to changes in the process variable.

D) Proportional bandwidth describes the extent to which the proportional controller can correct errors before reaching the maximum output.

C) Proportional bandwidth is the width of the proportional band within which the control action is active and varies linearly with the error.

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