ROBO!!!!! <3

Question 1

R

Answer 1

Input/Reference signal

Question 2

U

Answer 2

Manipulated variable

Causes the plant to behave a certain way

Question 3

Y

Answer 3

System output

Question 4

G

Answer 4

Plant/System

USED FOR…..

Question 5

When is Open Loop Control Used?

Answer 5

• C and G have known transfer functions - System if fully identified
• C and G are linear and time invariant

Question 6

C

Answer 6

Controller

Generates the actuation signal that drives the process

Question 7

Reasons to not use Open Loop

Answer 7

• To make the output of the system more consistent
• Voltage can vary over time…drop when load is too much/messes with system
• Improve Open loop by using a higher voltage source with less internal resistance. Also thicker wires for less resistance. i.e. over sizing controller and plant

Question 8

Closed-loop Control

Answer 8

Used to provide more precise control of outputs
Feeds back a signal that is proportional to the output
Reduces the effect of variation (non-linearity) in plant characteristics on the output system

Question 9

Correcting signal

Answer 9

• Output from the combination of the input and feedback value
• Bigger difference in expected and actual output leads to a greater value in correction

Question 10

Summing Junction/Comparator

Answer 10

Circle with plus and minus

Combines R and Y

Question 11

E

Answer 11

Error i.e. difference between expected and actual output

Question 12

Model-reference control

Answer 12

The accuracy of the predicted output determines the changes needed to adjust the feedback signal

Question 13

Benefits of Closed-loop Systems

Answer 13

• More precise control - decreasing sensitivity to variation and disturbances in the system
• Input tracking allows for a faster dynamic response
• Drives the PLANT harder so gets the most out of it’s functionality?

Question 14

Cross-over distortion

Answer 14

Don’t know what it is. But it can be rectified by using a feedback loop with…high forward path gain

Presents it’self in both the frequency and time domain

Question 15

Saturation Distortion

Answer 15

When a voltage is input, the output rises linearly and after a certain point the output falls of and settles to a certain level

Can be rectified by using a feedback loop with high forward path gain

Outputs in freq domain at harmonics start to present themselves

Question 16

Transient Response

Answer 16

Concerned with how changing the load on a circuit effects the voltage being given in the system

Adding load –> decrease in voltage before it levels off again

Removing load –> increase in voltage before it levels off again

Question 17

High gain

Answer 17

May cause the performance of the system to be unstable

Might present itself in oscillations in the output

Question 18

Assumptions for Laplace Analysis

Answer 18

Assume the systems under inspection are linear

Question 19

Analysing properties of transfer function

Answer 19

If you replace s by j.omega, you can see how the frequency determines the functionality of the plant (through it’s transfer function)

Question 20

Open-loop control

Answer 20

Transfer functions are (approximately) liner and time invariant despite changes in operating conditions.

So the gains don’t change much due to disturbances (temperature, power-supply voltage, loading etc.)

In these conditions the input (R) and output (Y) have an approximately constant and repeatable relationship