add basic engine simulation + working gauge

engine.py

@@ -1,50 +1,127 @@
 import math
 
 class Engine:
-    rpm = 0
-    throttle = 0
-    load = 0
-    instant_torque = 0
-    gear = 0
-    flywheel_inertia = 0
-    idle_rpm = 750
-    max_rpm = 6500
+    def __init__(self,
+                 idle_rpm=750,
+                 max_rpm=7000,
+                 redline_rpm=6500,
+                 flywheel_inertia=0.025,
+                 fuel_efficiency=0.3,
+                 torque_curve=None):
+        
+        # General stuff
+        self.rpm = idle_rpm
+        self.throttle = 0.0
+        self.load = 0.0
+        self.gear = None
+        self.ignition = True
+        self.revCut = False
 
-    fuel_rate = 0
-    afr = 0
-    coolant_temp = 0
-    oil_temp = 0
+        self.idle_rpm = idle_rpm
+        self.max_rpm = max_rpm
+        self.redline_rpm = redline_rpm
+        self.flywheel_inertia = flywheel_inertia
+        self.fuel_efficiency = fuel_efficiency
+        self.torque_curve = torque_curve or self.default_torque_curve
+        self.instant_torque = 0
+        self.wheel_speed = 0
+        self.engineFriction = 5
+        self.peak_torque = 163 # Nm -> 120 ft/lb
+        self.engine_brake_strength = 40 # Nm
+        self.engine_brake_torque = 0
+        self.starting = False
 
-    ignition_timing = 0
+        # Fluids
+        self.oil_temp = 0
+        self.oil_pressure = 0
+        self.oil_capacity = 0
 
-    ambient_temp = 0
-    altitude = 0
-    intake_pressure = 0
-    vehicle_mass = 0
-    drivetrain_loss = 0
+        self.coolant_temp = 0
+        self.coolant_pressure = 0
+        self.coolant_capacity = 0
 
-    oil_pressure = 0
-    turbo_boost = 0
-    kr = 0
-    exhaust_temp = 0
+        self.fuel_capacity = 0
 
-    def start(self):
-        rpm = 250
+        # Fuel
+
+        self.fuel_rate = 0
+        self.afr = 0
+
+        # Timing stuff
+        self.kr = 0
+        self.timing_advance = 0
+        self.ignition_timing = 0
+
+        # Exhaust stuff
+        self.exhaust_temp = 0
+        self.turbo_boost = 0
+
+        # Environment
+        self.ambient_temp = 0
+        self.altitude = 0
+        self.intake_pressure = 0
+        self.vehicle_mass = 0
+        self.drivetrain_loss = 0
+
+    # Just a parabolic curve for now
+    def default_torque_curve(self, rpm):
+        rpm_ratio = rpm / self.max_rpm
+        return max(0.0, -4 * (rpm_ratio - 0.5) ** 2 + 1)
+
+    def start(self, dt):
+        self.ignition = True
+        self.starting = True
+            
     
     def update(self, throttle, load, dt):
-        
-        if not self.running:
-            return
-
         self.throttle = throttle
         self.load = load
 
-        # Apply simplified engine RPM dynamics
-        rpm_change = (throttle - load) * self.torque_curve(self.rpm) / self.flywheel_inertia
-        self.rpm += rpm_change * dt
-        self.rpm = max(self.idle_rpm, min(self.rpm, self.max_rpm))
+        if self.starting:
+            available_torque = self.torque_curve(self.rpm)
+            self.instant_torque = (available_torque * self.peak_torque) + 10
+            rpm_change = (self.instant_torque / self.flywheel_inertia)
+            self.rpm += rpm_change * dt
+            if self.rpm > 2000:
+                self.starting = False
+                throttle = 0
+
+        # Idle -- Eventually should have learning alg to find the % throttle needed
+        if (self.rpm < self.idle_rpm):
+            self.throttle = 0.1
+
+        # Rev limit
+        if (self.rpm > self.redline_rpm):
+            self.revCut = True
+        
+        if self.revCut and self.rpm > self.redline_rpm - 100:
+            self.throttle = 0
+        else:
+            self.revCut = False
+
+
+        # Engine friction
+        if (self.rpm > 0):
+            friction_force = self.engineFriction
+        else: 
+            friction_force = 0
+
+        # Engine braking torque (If throttle closed)
+        if self.throttle < 0.1 and self.rpm > self.idle_rpm + 200 or not self.ignition:
+            engine_brake_torque = self.engine_brake_strength * (self.rpm / self.max_rpm)
+        else:
+            engine_brake_torque = 0
+
+        # Calculate torque
+        if self.ignition:
+            available_torque = self.torque_curve(self.rpm)
+        else:
+            available_torque = 0
+
+        self.instant_torque = (self.throttle * available_torque * self.peak_torque) - engine_brake_torque - friction_force
+        rpm_change = (self.instant_torque / self.flywheel_inertia)
+        self.rpm += rpm_change * dt
 
-        self.torque = self.torque_curve(self.rpm) * throttle
         self.fuel_rate = self.rpm * throttle * self.fuel_efficiency
 
-        self._update_temps(dt)
+        #self._update_temps(dt)