ackermann

FullVehicleSim/Mech/steering.py

@@ -57,6 +57,19 @@ def calculateVirtualSlipAngle(parameters):
     #
     # return (Fy / CF) * (1 + term1Num/Term1Denom + term2Num/term2Denom + term3)
 
+# Returns a tuple with (in, out) steering angle
+def calculateAckermann(steerAngle, aPercent):
+    # We can assume that front and rear slip angles evolve identically in the small step steer so delta = l/r
+    wheelBase = params["wheelBase"]
+    turnRadius = wheelBase / steerAngle
+
+    innerRadiusWheel = np.arctan(wheelBase/(turnRadius - params["trackWidthAvg"]))
+    outerRadiusWheel = np.arctan(wheelBase/(turnRadius + params["trackWidthAvg"]))
+
+    return (np.degrees(innerRadiusWheel), np.degrees(outerRadiusWheel))
+
+
+
 def calculateYawRate(currYawRate, speed, stepSteerInput, timeSinceLastSteer, frontCorneringStiffnessDeg_, rearCorneringStiffnessDeg_, parameters):
     # This model is based on Performance Vehicle Dynamics
     # It is a pretty meh model which uses euler's method to approximate transient behavior

FullVehicleSim/params.json

@@ -14,7 +14,8 @@
         "tractiveIMax": 300,
 
         "Mass": 300,
-        "wheelBase": 1.65471,
+        "wheelBase": 1.5898989,
+        "trackWidthAvg": 1210.004,
         "a": 0.853506,
         "frontWeightDist": 46.46,
         "CoG-height": 0.999628,

VDCalculators/README.md

@@ -1 +1,4 @@
 Calculators that are not to be integrated into the full Vehicle Dynamics model.
+
+# Ackermann optimizer
+This calculator aims to optimize the ackermann percentages of FS4

VDCalculators/ackermannOptimizer.py

@@ -0,0 +1,14 @@
+import os
+import sys
+import json
+sys.path.append("../FullVehicleSim/Mech")
+from steering import *
+
+import json
+magic:dict
+parameters:dict
+with open('../FullVehicleSim/params.json', 'r') as file:
+    params = json.load(file)
+    Magic = params["Magic"]
+    Parameters = params["Parameters"]
+    del params