WorksheetsAutomatic Control Systems Quiz
Total questions: 20
Worksheet time: 10mins
Which of the following best describes an On-Off control system?
The output varies continuously with the error.
The output is either fully ON or fully OFF.
The system uses proportional, integral, and derivative actions.
The system predicts disturbances before they occur.
In marine boiler water level control, an On-Off controller would typically:
Maintain water level at a fixed proportional ratio.
Switch the feed pump fully ON or fully OFF depending on setpoint.
Gradually adjust the feedwater valve opening.
Ignore the actual water level.
The figure Q3 below shows a two-position control output. This represents:
Sequential control
On-Off control
PID control
Feedforward control
Sequential control in marine systems is mainly applied in:
Controlling engine speed continuously
Operating ballast water pumps in order
Predicting fuel flow disturbance
Sensing shaft torque
Which automatic control system works based on a step-by-step logical order of operations?
On-Off control
Sequential control
PID control
Feedforward control
The diagram below shows a ladder logic diagram. Which control method does it represent?
Feedback control
Sequential control
On-Off control
PID control
Which of the following is NOT an advantage of Sequential control?
Ensures safe startup and shutdown sequences
Provides precise logical steps
Allows continuous adjustment of control variable
Prevents human error in routine tasks
A marine governor that maintains a steady engine speed despite load variation is an example of:
Sequential control
Feedback control
Feedforward control
Program control
In feedback control, the controller action depends on:
Predicting disturbances in advance
Actual output compared with desired setpoint
Fixed sequence of operations
Fully ON or OFF states only
Which diagram best represents a feedback control system?
Feedforward system
Open-loop system
Feedback system
Sequential system
The main difference between Feedback and Feedforward control is:
Feedback reacts to error, Feedforward prevents error
Feedback uses only sensors, Feedforward does not
Feedback is always better than Feedforward
Feedforward ignores disturbances
In marine fuel injection, Feedforward control can:
React only after engine speed changes
Anticipate required fuel before speed changes
Stop the engine in sequence
Keep output always ON
Which of the following graphs shows proportional control action?
On-Off
Proportional
Sequential
Feedforward
PID control combines three actions. They are:
Pulse, Integral, Direct
Proportional, Integral, Derivative
Pressure, Input, Discharge
Predictive, Ideal, Digital
Which part of PID control helps eliminate steady-state error?
Proportional
Integral
Derivative
Sequential
The derivative action in PID control is useful for:
Reducing overshoot
Removing offset
Producing ON/OFF output
Ignoring disturbances
The diagram shows the effect of PID tuning on system response. Which curve represents a well-tuned PID controller?
A (Overdamped - very slow response)
B (Underdamped - oscillatory)
C (Balanced - fast & stable)
D (Uncontrolled - unstable)
In marine autopilot systems, PID control is applied to maintain:
Engine firing order
Ship's course and heading
Sequential valve opening
ON/OFF cargo pump
Program control is most suitable for:
Ballast water sequence
CNC machining in shipyard
Autopilot navigation
Boiler drum level
The main characteristic of program control is:
Depends only on feedback loop
Works with continuous proportional signals
Follows a pre-set sequence based on time or events
Ignores logical operations
