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?

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

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

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

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

2 / 12

Describe the effect of excessive Derivative Action.

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

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

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.

3 / 12

With reference to engine governors, explain hunting.

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.

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.

4 / 12

What happens when the flow out is increased in a system where the water tank level is controlled by a float and lever proportional system?

A) The float rises, causing the control valve to open more to increase the inflow.

D) The float drops, causing the control valve to open more to increase the inflow.

B) The float drops, causing the control valve to close, reducing the inflow.

C) The float rises, causing the control valve to close, reducing the inflow.

5 / 12

Explain hysteresis in control terms.

D) Hysteresis is the speed at which a control system can respond to input changes. Reason: This describes response time rather than hysteresis, which involves differences in response based on input history.

C) Hysteresis is the effect of system instability caused by rapid changes in input. Reason: This describes system instability or oscillations rather than the lag or memory effect described by hysteresis.

B) Hysteresis is the ability of a control system to adapt its response based on changes in input conditions. Reason: This describes adaptability rather than hysteresis, which specifically deals with lag in response due to past inputs.

A) Hysteresis is the phenomenon where the output of a control system depends on its past input, causing a lag or delay in response. Reason: This describes hysteresis correctly, where the system’s output is influenced by the history of inputs, leading to different responses for increasing versus decreasing inputs.

6 / 12

Explain settling time in control terms.

D) Settling time is the time it takes for the system to completely stop moving after a control action has been implemented. Reason: Settling time focuses on stabilization around the set point, not complete cessation of movement.

C) Settling time is the total time it takes for the system to return to its original state after a disturbance has been removed. Reason: Settling time is related to stabilization around the new set point, not returning to the original state.

A) Settling time is the time it takes for a system's output to initially reach its desired value after a disturbance has been applied. Reason: Settling time is concerned with the time to stabilize around the desired value, not the initial reach.

B) Settling time is the time required for the system's output to remain within a specified range around the set point after a disturbance, and it measures the time until the output stops oscillating significantly. Reason: This correctly describes settling time as the time it takes for the output to stay within a certain percentage of the set point and cease significant oscillations.

7 / 12

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

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.

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.

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.

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.

8 / 12

How is the level in a water tank controlled by a float and lever proportional system?

C) The float rises with the water level, opening a valve to allow more water into the tank.

B) The float sinks as the water level rises, which directly activates a pump to remove excess water from the tank.

D) The lever controls the water level by switching between two fixed positions—completely open or completely closed.

A) The float rises with the water level, causing the lever to close a valve, stopping the inflow of water when the desired level is reached.

9 / 12

With reference to engine governors, explain speed droop.

A) Speed droop is the reduction in engine speed that occurs when the engine is subjected to an increase in load, relative to the no-load speed. Reason: Speed droop measures how much the engine speed decreases from its no-load speed when a load is applied.

B) Speed droop refers to the increase in engine speed when the governor's sensitivity is reduced. Reason: Reducing sensitivity affects response time, not speed droop.

D) Speed droop describes the governor's ability to maintain a constant engine speed despite fluctuations in ambient temperature. Reason: Speed droop is related to load changes, not temperature fluctuations.

C) Speed droop is the amount by which the governor’s set point changes to match variations in fuel quality. Reason: Speed droop pertains to load variations, not fuel quality.

10 / 12

Explain derivative action in control terms.

B) Derivative action describes the process of integrating the accumulated error over time to adjust the control output.

A) Derivative action involves adjusting the control output based on the rate of change of the error, aiming to predict future errors and reduce overshoot.

D) Derivative action is the component of the control system that maintains the steady-state error by constantly adjusting the control output proportionally.

C) Derivative action adjusts the control output based on the proportional deviation from the setpoint, with no regard to the rate of change.

11 / 12

Describe the effect of increasing the controller gain with respect to the steady-state tank level when the outflow is increased in a float and lever proportional system.

B) The steady-state tank level will oscillate more and be less stable.

C) The steady-state tank level will decrease more slowly in response to the increased outflow.

A) The steady-state tank level will become more stable and closer to the setpoint.

D) The steady-state tank level will remain unchanged regardless of the controller gain.

12 / 12

State the reasons for fitting a pneumatic process valve with a volume booster.

C) A volume booster is fitted to decrease the overall air consumption of the valve, thereby improving energy efficiency in the pneumatic system.

D) A volume booster is fitted to provide redundant control signals to the actuator, ensuring higher reliability in case of signal loss.

B) A volume booster is fitted to reduce the air pressure supplied to the actuator, which helps in minimizing the force required to operate the valve.

A) A volume booster is fitted to increase the flow rate of air to the actuator, enabling faster valve movement and reducing the time required to achieve the desired valve position.

Your score is