Simple Feedback System

Feedback system

A system in which the controlled variable is measured by a sensor and the measured information is fed back to the controller to influence the controlled variable is called a ______.

Controlled variable

The variable being regulated by a feedback system, such as temperature or speed, is called the ______.

Sensor

In a feedback system, the ______ measures the controlled variable so that information about it can be fed back to the controller.

Setpoint

The desired value about which the controlled variable is regulated is called the ______.

Reference

The ______ specifies the desired value of the controlled variable and is the same thing as the setpoint or desired input.

Desired input

The ______ is another name for the reference or setpoint of a feedback control system.

Setpoint = Reference = Desired input

The textbook states that these three terms all refer to the same thing: ______.

On-off control

In the thermostat example, the furnace is switched fully on or fully off rather than continuously adjusted. This type of operation is called ______.

Process

The central component of a feedback system whose output is to be controlled is the ______.

Output

The quantity produced by the process and ultimately being controlled is the ______.

Disturbance

An external influence acting on the process that affects the controlled output is called a ______.

Actuator

The device that can influence the controlled variable of the process is called the ______.

Plant

The actuator and process together are enclosed within the ______ in the elementary feedback-control diagram.

Controller

The component that uses information from the reference and feedback path to determine the control action is the ______.

Control signal

The signal produced by the controller and sent toward the actuator is called the ______.

Input filter

The reference passes through the ______ before entering the comparison portion of the elementary feedback system.

Sensor noise

Unwanted information or interference entering through the measurement path is called ______.

Heat loss, Q_out

In the household-temperature example, the disturbance to the process is the ______ from the house due to conduction and other effects.

Heat input, Q_in

When the furnace is on, the thermal energy supplied to the house is represented by ______.

House

In the thermostat example, the ______ is the process whose output is the room temperature.

Gas furnace

In the thermostat example, the ______ acts as the actuator that influences the controlled room temperature.

Room temperature

In the household feedback-control example, the output of the process is the ______.

Outside temperature

The room temperature tends to fall toward the ______ when the furnace is turned off.

Thermostat

In the household example, the ______ turns the furnace on when the temperature falls sufficiently below the setpoint and turns it off after the temperature rises sufficiently above it.

Temperature cycling

Because the furnace repeatedly switches on and off, the room temperature repeatedly rises above and falls below the setpoint; this behavior is called ______.

Process design

The textbook emphasizes that good ______ can have a major impact on the effectiveness of the controls.

Well-insulated house

A ______ is easier to control because its heat loss is reduced compared with a poorly insulated house.

Early consideration of control

The earlier control concepts are introduced into the ______, the better the resulting system performance can be.