Chapter 3

Question 1

Plant

Answer 1

The system we are trying to control

Question 2

Actuators

Answer 2

Devices to manipulate the plant’s inputs to influence the plant’s outputs

Question 3

Sensors

Answer 3

Measure output/ signals

Question 4

Controller

Answer 4

Commands the actuators

Question 5

Open Loop (OL) Control

Answer 5

• Does not use sensors to measure output
• Actuator Commands are based on pre-determined functions of the reference
• Does not change regardless of environment

Question 6

Closed Loop (CL) Control

Answer 6

• Use sensors to measure output
• Actuators are commanded based on error (reference - output) to drive error to zero
• Change relative to disturbances

Question 7

Steady State Value

Answer 7

The final value as t –> ∞

Question 8

Rise Time (Tr)

Answer 8

Time from 10% to 90% in first order systems
Time from 0 to 100% in 2nd order systems

Question 9

Overshoot (Tp)

Answer 9

The difference between peak and steady state

Question 10

Settling time (Ts)

Answer 10

The time when it’s within +/- of the steady state

Question 11

Steady State Error

Answer 11

Reference - Current Value

Question 12

Basic CL

Answer 12

Simple Controller

Question 13

Robust CL

Answer 13

Maintains performance despite changes in the environment

Question 14

Adaptive CL

Answer 14

Adjusts its behavior to maintain performance

Question 15

Predictive CL

Answer 15

Looks ahead and predicts output and adjusts accordingly

Question 16

Simple Feedback Controller

Answer 16

Turning on and off controller with the upper and lower limit, hysteresis zone to avoid frequent switching

Question 17

P Controller

Answer 17

• u = Kp * e(t)
• There will be a steady state error
• Smooth Motor Response

Question 18

PI Controller

Answer 18

• u = Kp * e(t) + Ki ∫ e(t) dt
• No steady state error in most cases
• Integral can slow down system
• Reduce Stability