starting to implement realistic Vehicle simulation

app/simulation/modules/gearbox.py

@@ -0,0 +1,34 @@
+# app/simulation/modules/gearbox.py
+from __future__ import annotations
+from ..vehicle import Vehicle, Module
+
+class GearboxModule(Module):
+    """Koppelt Engine-RPM ↔ Wheel-Speed; registriert speed_kmh/gear fürs Dashboard."""
+    def __init__(self):
+        self.speed_tau = 0.3
+        self.rpm_couple = 0.2
+
+    def apply(self, v: Vehicle, dt: float) -> None:
+        # Dashboard registration
+        v.register_metric("speed_kmh", label="Geschwindigkeit", unit="km/h", fmt=".1f", source="gearbox", priority=30)
+        v.register_metric("gear",      label="Gang", source="gearbox", priority=25)
+
+        g = int(v.ensure("gear", 0))
+        rpm = float(v.ensure("rpm", 1200))
+        speed = float(v.ensure("speed_kmh", 0.0))
+        ratios = v.config.get("gearbox", {}).get("kmh_per_krpm", [0.0])
+
+        if g <= 0 or g >= len(ratios):
+            speed = max(0.0, speed - 6.0*dt)
+            v.set("speed_kmh", speed)
+            return
+
+        kmh_per_krpm = float(ratios[g])
+        target_speed = (rpm/1000.0) * kmh_per_krpm
+        alpha = min(1.0, dt / max(0.05, self.speed_tau))
+        speed = (1-alpha) * speed + alpha * target_speed
+        v.set("speed_kmh", speed)
+
+        wheel_rpm = (speed / max(0.1, kmh_per_krpm)) * 1000.0
+        rpm = (1-self.rpm_couple) * rpm + self.rpm_couple * wheel_rpm
+        v.set("rpm", int(rpm))