143 lines
4.5 KiB
C#
143 lines
4.5 KiB
C#
namespace Car_simulation
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{
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public class Engine
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{
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// Energy state
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public float FlywheelEnergy { get; set; } // Joules
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// Values
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public float RPM => GetRPM();
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public float AngularVelocity => GetOmega();
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public float CurrentPower { get; private set; }
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// Physical properties
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public float MomentOfInertia { get; set; } = 0.25f; // kg·m²
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public float IdleRPM { get; set; } = 800f;
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public float StallSpeed { get; set; } = 200f;
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public float Throttle { get; set; } = 0f;
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public bool IsRunning => RPM > StallSpeed;
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// Torque characteristics
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public Dictionary<float, float> TorqueCurve { get; set; } = new()
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{
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// RPM - Torque Nm
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{ 0f, 0f },
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{ 800f, 150f }, // Idle
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{ 2000f, 200f }, // Peak torque
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{ 4500f, 250f },
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{ 7200f, 250f },
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{ 9200f, 250f },
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{ 10000f, 200f },
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{ 11000f, 0f }
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};
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public Engine()
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{
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// Start with idle energy
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FlywheelEnergy = GetEnergyFromRPM(IdleRPM);
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}
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// Calculations
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public float CalculateFrictionEnergy(float deltaTime)
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{
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// Real friction torque data for 2.0L engine (Nm)
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float frictionTorque;
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if (RPM < 500) frictionTorque = 15f; // Static/breakaway
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else if (RPM < 1000) frictionTorque = 14f;
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else if (RPM < 2000) frictionTorque = 16f;
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else if (RPM < 3000) frictionTorque = 18f;
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else if (RPM < 4000) frictionTorque = 21f;
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else if (RPM < 5000) frictionTorque = 25f;
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else if (RPM < 6000) frictionTorque = 30f;
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else if (RPM < 7000) frictionTorque = 36f;
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else frictionTorque = 44f;
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float frictionPower = frictionTorque * AngularVelocity;
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return frictionPower * deltaTime;
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}
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private float CalculateCombustionEnergy(float deltaTime)
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{
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float torque = GetTorqueOutput() * GetActualThrottle();
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return torque * AngularVelocity * deltaTime;
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}
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private float CalculateLoadEnergy(float deltaTime, float loadTorque)
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{
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return loadTorque * AngularVelocity * deltaTime;
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}
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// Get
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public float GetActualThrottle()
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{
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float idleThrottle = Math.Max((IdleRPM - RPM) / 10, 0);
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return Math.Clamp(Throttle + idleThrottle, 0, 1);
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}
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public float GetOmega()
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{
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if (FlywheelEnergy <= 0) return 0;
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return MathF.Sqrt(2f * FlywheelEnergy / MomentOfInertia);
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}
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public float GetRPM()
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{
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return GetOmega() * PhysicsUtil.RAD_PER_SEC_TO_RPM;
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}
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// Set
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public float GetEnergyFromRPM(float rpm)
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{
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float omega = rpm * PhysicsUtil.RPM_TO_RAD_PER_SEC;
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return 0.5f * MomentOfInertia * omega * omega;
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}
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// torque curve
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public float GetTorqueOutput()
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{
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if (RPM <= 0) return 0;
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var points = TorqueCurve.OrderBy(p => p.Key).ToList();
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if (RPM <= points.First().Key) return points.First().Value;
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if (RPM >= points.Last().Key) return points.Last().Value;
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for (int i = 0; i < points.Count - 1; i++)
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{
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if (RPM >= points[i].Key && RPM <= points[i + 1].Key)
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{
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float t = (RPM - points[i].Key) / (points[i + 1].Key - points[i].Key);
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return PhysicsUtil.Lerp(points[i].Value, points[i + 1].Value, t);
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}
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}
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return 0f;
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}
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public void ApplyTorque(float torque, float deltaTime)
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{
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if (torque == 0) return;
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float work = torque * AngularVelocity * deltaTime;
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FlywheelEnergy += work;
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FlywheelEnergy = Math.Max(FlywheelEnergy, 0);
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}
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public void Update(float deltaTime, float loadTorque)
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{
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float combustionEnergy = CalculateCombustionEnergy(deltaTime);
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float frictionEnergy = CalculateFrictionEnergy(deltaTime);
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float loadEnergy = CalculateLoadEnergy(deltaTime, loadTorque);
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float netEnergy = combustionEnergy - frictionEnergy - loadEnergy;
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CurrentPower = netEnergy / deltaTime;
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FlywheelEnergy += netEnergy;
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FlywheelEnergy = Math.Max(FlywheelEnergy, 0);
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}
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}
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} |