PID Basics

Question 1

PID Controller

1. Time Dependent Equation
2. Laplace Transform

Answer 1

1. u(t) = K_pe(t) + K_iint(e(t)*dt) + K_d * de(t)/dt

2. (K_ds^2+K_ps+K_i)/s

Question 2

Characteristics of Proportional Gain

Answer 2

1. Increase in reaction time
2. Increases overshoot
3. Reduction in steady-state error

Question 3

Characteristics of Derivative Term

Answer 3

1. Anticipaces error
2. Adds damping to system which decreases overshoot
3. Does not affect steady state
4. Little effect on reaction time

Question 4

Characteristic of Integral Term

Answer 4

1. Reduces Steady state error
2. System is more sluggish (oscillatory)
3. Increases reaction time

Question 5

PID Controller Design

Answer 5

1. Obtain open-loop response and determine what needs to be improved
2. Add P control to improve rise time
3. Add D control to reduce overshoot
4. Add I control to reduce steady state error