태양 중력렌즈(SGL) 550AU 항법 & 1,000Hz 0-Alloc C# 아인슈타인 링 영상복원 서보 제어기

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

namespace ZeliDesk.Stem.RelativisticNavigation
{
    /// 

    /// SGL 망원경 아인슈타인 링 1ms 센서 프레임
    /// 
    [StructLayout(LayoutKind.Sequential)]
    public readonly struct SglRingFrame
    {
        public readonly uint TickMs;
        public readonly float RingIntensityTop;    // 12시 방향 원환 광도
        public readonly float RingIntensityBottom; // 6시 방향 원환 광도
        public readonly float RingIntensityLeft;   // 9시 방향 원환 광도
        public readonly float RingIntensityRight;  // 3시 방향 원환 광도
        public readonly float CoronaBackdropFlux;  // 태양 코로나 배경광 세기

        public SglRingFrame(uint ms, float top, float bottom, float left, float right, float corona)
        {
            TickMs = ms;
            RingIntensityTop = top;
            RingIntensityBottom = bottom;
            RingIntensityLeft = left;
            RingIntensityRight = right;
            CoronaBackdropFlux = corona;
        }
    }

    /// 

    /// 1,000Hz 0-Alloc 태양 중력 렌즈 초점면 성간 항법 서보 엔진
    /// 
    public ref struct SglFocalPlaneServo
    {
        private const float CenteringGainMetersPerVolt = 0.85f; // 0.85m/V 감도
        private const float AllowedOffsetMeters = 0.15f;         // 허용 중심 편차 (15cm)

        private Vector2 _positionOffsetMeters;
        private Vector2 _velocityEstimate;
        private Vector2 _lastOffset;

        public SglFocalPlaneServo(bool initialize = true)
        {
            _positionOffsetMeters = Vector2.Zero;
            _velocityEstimate = Vector2.Zero;
            _lastOffset = Vector2.Zero;
        }

        [MethodImpl(MethodImplOptions.AggressiveInlining)]
        public bool UpdateTick(in SglRingFrame frame, out Vector2 offsetMeters, out Vector2 thrusterForceMicroN)
        {
            // 1. 코로나 배경광 차감 후 대칭 편차 계산 (0-Alloc 스택)
            float netTop = MathF.Max(0.0f, frame.RingIntensityTop - frame.CoronaBackdropFlux);
            float netBottom = MathF.Max(0.0f, frame.RingIntensityBottom - frame.CoronaBackdropFlux);
            float netLeft = MathF.Max(0.0f, frame.RingIntensityLeft - frame.CoronaBackdropFlux);
            float netRight = MathF.Max(0.0f, frame.RingIntensityRight - frame.CoronaBackdropFlux);

            float totalFlux = netTop + netBottom + netLeft + netRight;
            if (totalFlux < 1e-4f)
            {
                offsetMeters = _positionOffsetMeters;
                thrusterForceMicroN = Vector2.Zero;
                return false;
            }

            // 2. 2차원 중심선 편차 (X: 좌우, Y: 상하)
            float normX = (netRight - netLeft) / totalFlux;
            float normY = (netTop - netBottom) / totalFlux;

            _positionOffsetMeters = new Vector2(normX * CenteringGainMetersPerVolt, normY * CenteringGainMetersPerVolt);
            offsetMeters = _positionOffsetMeters;

            // 3. 속도 추정 및 PD 제어 분사 지령 (1ms dt = 0.001s)
            _velocityEstimate = (_positionOffsetMeters - _lastOffset) / 0.001f;
            _lastOffset = _positionOffsetMeters;

            // 이온 추진기 마이크로뉴턴(uN) 추력 계산
            thrusterForceMicroN = new Vector2(
                -(45.0f * _positionOffsetMeters.X) - (12.0f * _velocityEstimate.X),
                -(45.0f * _positionOffsetMeters.Y) - (12.0f * _velocityEstimate.Y)
            );

            return _positionOffsetMeters.Length() < AllowedOffsetMeters;
        }
    }
}