# L6-2_cruise.py - cruise control calculations for xferfcn lecture
# RMM, 6 Nov 2012

import control
import matplotlib.pyplot as plt

# Define parameters for the system
a = -0.01
b = 1.32
bg = 9.8

# System dynamics
P = control.tf([b], [1, -a])

# Define parameters for the controller
kp = 0.5
ki = 0.1

# Controller dynamics
C = control.tf([kp, ki], [1, 0])

# Transfer functions
Her = 1/(1 + P*C)
Hed = (bg/b) * P / (1 + P*C)
Hyr = P*C / (1 + P*C)

# Bode plots
plt.figure(1); control.bode(Hed)
plt.figure(2); control.bode(Hyr)
plt.figure(3); control.bode(Her)