대한민국 육군 현궁(Raybolt) 중거리 대전차미사일 IIR 탐색기 탑어택 궤적 생성 및 1,000Hz 0-Alloc C# 탠덤 탄두 관통 제어 엔진

using System;
using System.Numerics;
using System.Runtime.CompilerServices;

namespace ZeliDesk.Defense.Army.AntiTankMissile
{
    public readonly record struct MissileFlightState(
        Vector3 PositionMeters,
        Vector3 VelocityMps,
        float DistanceToTargetMeters,
        float LineOfSightPitchDeg
    );

    public ref struct TopAttackGuidanceOutput
    {
        public Vector3 AccelerationCommand;
        public float CommandedPitchAngleDeg;
        public bool TriggerPrecursorWarhead;
        public int MainWarheadDelayMicrosec;
        public bool ImpactImminent;
    }

    public static class RayboltTopAttackCore
    {
        private const float ApexAltitudeMeters = 150.0f; // 탑어택 정점 고도
        private const float TerminalDivePitchDeg = -55.0f;

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public static void GuideMissile(
            ref readonly MissileFlightState state,
            float targetInitialDistanceMeters,
            ref TopAttackGuidanceOutput output)
        {
            float remainingDist = state.DistanceToTargetMeters;
            float progress = 1.0f - (remainingDist / MathF.Max(targetInitialDistanceMeters, 100.0f));
            progress = MathF.Min(MathF.Max(progress, 0.0f), 1.0f);

            // 1. 3단계 궤적 제어: 초기 상승 -> 순항 -> 종말 다이빙
            float targetPitchDeg;
            if (progress < 0.35f)
            {
                // 상승 단계 (+30도)
                targetPitchDeg = 30.0f;
            }
            else if (progress < 0.75f)
            {
                // 수평 접근 단계 (정점 고도 150m 유지)
                targetPitchDeg = 5.0f;
            }
            else
            {
                // 종말 급강하 탑어택 (-55도)
                targetPitchDeg = TerminalDivePitchDeg;
            }

            output.CommandedPitchAngleDeg = targetPitchDeg;

            // 2. 피치 오차 비례 가속도 지령
            float pitchError = targetPitchDeg - state.LineOfSightPitchDeg;
            float reqVerticalAccel = pitchError * 2.5f;

            output.AccelerationCommand = new Vector3(0, 0, reqVerticalAccel);

            // 3. 종말 충돌 직전 (15m 이내) 탠덤 탄두 기폭 시퀀스 활성화
            if (remainingDist <= 15.0f)
            {
                output.ImpactImminent = true;
                output.TriggerPrecursorWarhead = true;
                output.MainWarheadDelayMicrosec = 220; // 220 마이크로초 지연
            }
            else
            {
                output.ImpactImminent = false;
                output.TriggerPrecursorWarhead = false;
                output.MainWarheadDelayMicrosec = 0;
            }
        }
    }
}