AME 11 End of Unit – SVE Study

AME 11 End of Unit Quiz

1 / 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.

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

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

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

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

2 / 12

Describe a possible effect of excessive Integral Action.

A) Excessive Integral Action can lead to a quick and accurate response to setpoint changes, reducing the time required to reach the target value.

C) Excessive Integral Action can make the control system unresponsive to errors, resulting in a steady and stable system performance.

B) Excessive Integral Action can cause the system to oscillate or exhibit sustained oscillations around the setpoint due to an overcompensation of errors.

D) Excessive Integral Action can increase the system’s ability to predict future errors accurately, leading to improved overall system stability.

3 / 12

Describe the effect of excessive Derivative Action.

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

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.

4 / 12

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

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.

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.

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.

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.

5 / 12

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

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.

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.

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

6 / 12

Explain proportional bandwidth in control terms.

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.

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

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

7 / 12

State with reasons, the type of actuator fitted to the process valves for a fuel supply system in which the valve must not move on loss of power to the control system.

C) Hydraulic Actuator with Manual Override: Reason: While this actuator allows for manual control, it is not ideal for maintaining valve position during power loss, as it may require manual intervention to secure the valve.

D) Solenoid Actuator: Reason: This actuator is not suitable as it relies on continuous power to maintain the valve position and will fail to hold the valve in place if power is lost.

A) Electric Actuator with Fail-Safe Mechanism: Reason: This actuator includes a fail-safe mechanism that ensures the valve remains in its last position or moves to a predetermined safe position if there is a loss of power.

B) Pneumatic Actuator with Spring Return: Reason: This actuator is designed to return to a default position using a spring when power is lost, which could result in undesired movement or system instability.

8 / 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.

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.

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

9 / 12

With reference to engine governors, explain isochronous governing.

A) Isochronous governing ensures that the engine speed remains constant regardless of the load applied, maintaining the same speed even with varying demands. Reason: Isochronous governing is designed to keep the engine speed constant, independent of changes in load.

C) Isochronous governing adjusts the engine speed only during idle periods to maintain stability. Reason: Isochronous governing applies to all operating conditions, not just idle periods.

B) Isochronous governing allows the engine speed to fluctuate slightly around the set point to accommodate load changes. Reason: This describes droop control rather than isochronous governing, where slight fluctuations are acceptable.

D) Isochronous governing is a technique where the engine speed is allowed to drift with load changes, optimizing fuel efficiency. Reason: Allowing speed drift with load changes describes a droop control system, not isochronous governing.

10 / 12

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

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

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.

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

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.

11 / 12

Define the term Proportional Action.

B) Proportional action integrates the error over time to adjust the control output, aiming to eliminate steady-state error.

A) Proportional action adjusts the control output based on the magnitude of the error, where the output is directly proportional to the difference between the setpoint and the actual value.

D) Proportional action uses a fixed output level regardless of the error magnitude to maintain system stability.

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

12 / 12

What is a potential drawback of using an On-Off control system?

B) It is unable to achieve precise control, leading to oscillations around the set point.

D) It consumes more energy than other types of control systems.

C) It is more expensive than proportional control systems.

A) It requires complex programming to function.

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