SA_Sweep_Example.py

#!/usr/bin/env python
from src.TireModel import SolverMode
from src.TireModel.PAC2002 import PAC2002
from src.Core import TireState

import numpy as np
import matplotlib.pyplot as plt

if __name__ == "__main__":

    # Initialize the tire model
    #myTireModel = ot.tire('PAC2002')
    myTireModel = PAC2002()

    # Initialize the tire state
    state = TireState()
    state.FZ = 4000
    state.IA = 0.0
    state.SR = 0.0
    state.SA = 0.0
    state.FY = 0.0
    state.V = 10.0
    state.P = 260000

    # Define the slip angle range
    slip_angles = np.linspace(-15, 15, 50) * 3.14 / 180

    # Print out some pretty formatting
    print('OpenTire Slip Angle Sweep Demo\n')
    print('{0:>10} | {1:>10} | {2:>10} | {3:>10} | {4:>10}'
          .format('SA [deg]',
                  'FZ [N]',
                  'FY [N]',
                  'MZ [Nm]',
                  'MX [Nm]'))
    print('=' * 62)

    # Pre-allocate an array for the result
    FyArray = []
    MzArray = []
    MxArray = []

    # Calculate and print out the tire model outputs
    for sa in slip_angles:
        state.SA = sa
        myTireModel.solve(state, SolverMode.PureFy)

        # Grab results for plotting
        FyArray.append(state.FY)
        #MzArray.append(state.MZ)
        #MxArray.append(state.MX)

        print('{0:>10.1f} \t {1:>10.0f} \t {2:>10.1f} \t {3:>10.1f} \t {4:>10.1f}'
              .format(state.SA * 180 / 3.14,
                      state.FZ,
                      state.FY,
                      state.MZ,
                      state.MX))

# Plot results
fig = plt.figure()

ax1 = fig.add_subplot(211)
ax1.plot(slip_angles, FyArray)
ax1.set_xlabel("Slip Angle (rad)")
ax1.set_ylabel("FY (N)")
ax1.set_title("Lateral Force")

ax2 = fig.add_subplot(223)
ax2.plot(slip_angles, MzArray)
ax2.set_xlabel("Slip Angle (rad)")
ax2.set_ylabel("MZ (Nm)")
ax2.set_title("Self aligning moment")

ax3 = fig.add_subplot(224)
ax3.plot(slip_angles, MxArray)
ax3.set_xlabel("Slip Angle (rad)")
ax3.set_ylabel("MX (Nm)")
ax3.set_title("Overturning  moment")
plt.tight_layout()
plt.show()