first commit

utils/tests/visual_track_control/frame_transform_test.py

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+"""frame_transform_test.py —— rotate_body_to_ned 单元测试。
+
+移植自 reference-c++/visual_track_control/tests/frame_transform_test.cpp。
+覆盖（物理追踪思路 §2.3，A4）：零航向恒等、朝东时机体前向 → 东向、
+垂直分量不变、模长守恒。
+"""
+
+import math
+
+import pytest
+
+from visual_track_control.frame_transform import rotate_body_to_ned
+
+
+def test_zero_yaw_is_identity():
+    north, east, down = rotate_body_to_ned(1.0, 0.5, -2.0, 0.0)
+    assert north == pytest.approx(1.0, abs=1e-12)   # 北 = 前
+    assert east == pytest.approx(0.5, abs=1e-12)    # 东 = 右
+    assert down == pytest.approx(-2.0, abs=1e-12)
+
+
+def test_yaw_east_90_maps_forward_to_east():
+    north, east, _ = rotate_body_to_ned(2.0, 0.0, 0.0, math.pi / 2.0)  # 机头朝东
+    assert north == pytest.approx(0.0, abs=1e-9)  # 北向 ≈ 0
+    assert east == pytest.approx(2.0, abs=1e-9)   # 东向 = 前向速度
+
+
+def test_right_is_east_when_heading_north():
+    north, east, _ = rotate_body_to_ned(0.0, 1.0, 0.0, 0.0)
+    assert north == pytest.approx(0.0, abs=1e-12)
+    assert east == pytest.approx(1.0, abs=1e-12)
+
+
+def test_down_component_unchanged():
+    _, _, down = rotate_body_to_ned(1.0, 1.0, 3.5, math.pi / 3.0)
+    assert down == 3.5
+
+
+def test_preserves_horizontal_norm():
+    # 旋转为正交变换：水平合速度不变（限幅约束不被破坏的前提）
+    north, east, _ = rotate_body_to_ned(3.0, -4.0, 1.0, 0.7)
+    assert math.hypot(north, east) == pytest.approx(math.hypot(3.0, -4.0),
+                                                    abs=1e-9)

utils/tests/visual_track_control/line_of_sight_test.py

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+"""line_of_sight_test.py —— PixelToAngle 单元测试。
+
+移植自 reference-c++/visual_track_control/tests/line_of_sight_test.cpp。
+覆盖（物理追踪思路 §4.1/§5.1，C2）：零偏移、画面边缘偏移 = 半视场角、
+奇对称、单调性、与线性近似的偏离（全程针孔模型）、构造期非法参数抛异常。
+"""
+
+import math
+
+import pytest
+
+from visual_track_control.line_of_sight import PixelToAngle
+
+
+def test_zero_offset_gives_zero_angle():
+    conv = PixelToAngle(1000.0, math.radians(90.0))
+    assert conv.convert(0.0) == 0.0
+
+
+def test_half_size_offset_gives_half_fov():
+    # 针孔模型：偏移 = size/2 时 angle = atan(tan(θ/2)) = θ/2
+    conv = PixelToAngle(1000.0, math.radians(90.0))
+    assert conv.convert(500.0) == pytest.approx(math.radians(45.0), abs=1e-12)
+    assert conv.convert(-500.0) == pytest.approx(-math.radians(45.0), abs=1e-12)
+
+
+def test_odd_symmetry():
+    conv = PixelToAngle(1920.0, math.radians(60.0))
+    for offset in (1.0, 100.0, 730.5):
+        assert conv.convert(-offset) == pytest.approx(-conv.convert(offset),
+                                                      abs=1e-15)
+
+
+def test_monotonic_increasing():
+    conv = PixelToAngle(1080.0, math.radians(35.0))
+    prev = conv.convert(-600.0)
+    for x in range(-500, 601, 100):
+        cur = conv.convert(float(x))
+        assert cur > prev
+        prev = cur
+
+
+def test_deviates_from_linear_approximation():
+    # C2：全程针孔模型。θ=90°、偏移比例 0.25 处线性近似误差约 4°，
+    # 针孔结果必须与之明显偏离（证明未走线性支路）。
+    conv = PixelToAngle(1000.0, math.radians(90.0))
+    pinhole_deg = math.degrees(conv.convert(250.0))  # atan(250·2·tan45°/1000)
+    linear_deg = 250.0 * (90.0 / 1000.0)             # θ·offset/size = 22.5°
+    assert pinhole_deg == pytest.approx(math.degrees(math.atan(0.5)), abs=1e-9)
+    assert abs(pinhole_deg - linear_deg) > 2.0
+
+
+def test_constructor_rejects_invalid_args():
+    with pytest.raises(ValueError):
+        PixelToAngle(0.0, 1.0)
+    with pytest.raises(ValueError):
+        PixelToAngle(-10.0, 1.0)
+    with pytest.raises(ValueError):
+        PixelToAngle(1000.0, 0.0)
+    with pytest.raises(ValueError):
+        PixelToAngle(1000.0, math.pi)
+    with pytest.raises(ValueError):
+        PixelToAngle(1000.0, math.pi + 0.1)

utils/tests/visual_track_control/mavsdk_gateway_test.py

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+"""mavsdk_gateway_test.py —— MavsdkCommandGateway 单元测试（mock offboard）。
+
+移植自 reference-c++/visual_track_control/tests/mavlink_command_gateway_test.cpp。
+C++ 版校验 MAVLink ID 84 线格式字节流；Python 版采用 MAVSDK 语义映射，
+改为以 FakeOffboard 捕获设定点对象，校验三分支映射（物理追踪思路 §2.2、
+A2 掩码三分支的语义等价）：
+
+  角速率非零 → 机体速度设定点 + 非零 yawspeed；
+  航向角非零（角速率为零）→ NED 速度设定点 + 绝对 yaw；
+  两者均零 → 机体速度设定点 + 零 yawspeed（保持航向，A2 回归语义）；
+  刹车 → 全零机体速度设定点。
+  传输失败（异常）→ 返回 False 且不向外抛。
+"""
+
+import asyncio
+
+import pytest
+
+from visual_track_control.mavsdk_gateway import MavsdkCommandGateway
+from visual_track_control.types import ControlOutput
+
+
+class FakeOffboard:
+    """捕获式 offboard mock：记录每次调用的设定点，可注入失败。"""
+
+    def __init__(self):
+        self.body_setpoints = []
+        self.ned_setpoints = []
+        self.attempts = 0
+        self.start_count = 0
+        self.stop_count = 0
+        self.succeed = True
+
+    async def set_velocity_body(self, setpoint):
+        self.attempts += 1  # 与 C++ CaptureTransport 一致：失败也计入发送次数
+        if not self.succeed:
+            raise RuntimeError("mock transport failure")
+        self.body_setpoints.append(setpoint)
+
+    async def set_velocity_ned(self, setpoint):
+        self.attempts += 1
+        if not self.succeed:
+            raise RuntimeError("mock transport failure")
+        self.ned_setpoints.append(setpoint)
+
+    async def start(self):
+        if not self.succeed:
+            raise RuntimeError("mock start failure")
+        self.start_count += 1
+
+    async def stop(self):
+        self.stop_count += 1
+
+    @property
+    def send_count(self):
+        return self.attempts
+
+
+class FakeDrone:
+    def __init__(self):
+        self.offboard = FakeOffboard()
+
+
+def run(coro):
+    return asyncio.run(coro)
+
+
+def make_gateway():
+    drone = FakeDrone()
+    return MavsdkCommandGateway(drone), drone.offboard
+
+
+def test_start_sends_initial_setpoint_then_starts():
+    gateway, offboard = make_gateway()
+    assert run(gateway.start())
+    assert offboard.start_count == 1
+    # PX4 要求先流式发送首条设定点（全零）再请求启动
+    assert len(offboard.body_setpoints) == 1
+    sp = offboard.body_setpoints[0]
+    assert sp.forward_m_s == 0.0
+    assert sp.right_m_s == 0.0
+    assert sp.down_m_s == 0.0
+    assert sp.yawspeed_deg_s == 0.0
+
+
+def test_start_failure_returns_false():
+    gateway, offboard = make_gateway()
+    offboard.succeed = False
+    assert not run(gateway.start())
+
+
+def _make_velocity_heading_output():
+    from visual_track_control.types import ControlMode
+    out = ControlOutput()
+    out.mode = ControlMode.VELOCITY_HEADING
+    return out
+
+
+def test_yaw_rate_branch_uses_body_frame_with_yawspeed():
+    from visual_track_control.types import ControlMode
+    gateway, offboard = make_gateway()
+    out = _make_velocity_heading_output()
+    out.vx_body_mps = 1.5
+    out.vz_mps = 0.25
+    out.yaw_rate_dps = 5.0
+    assert run(gateway.send_velocity_heading(out, 12345))
+    assert offboard.send_count == 1
+    assert len(offboard.body_setpoints) == 1
+    sp = offboard.body_setpoints[0]
+    assert sp.forward_m_s == pytest.approx(1.5)
+    assert sp.right_m_s == 0.0
+    assert sp.down_m_s == pytest.approx(0.25)
+    assert sp.yawspeed_deg_s == pytest.approx(5.0)
+    assert offboard.ned_setpoints == []
+
+
+def test_yaw_only_branch_uses_ned_frame_with_absolute_yaw():
+    # 航向角非零且角速率为零 → 航向掩码语义：NED 速度 + 绝对航向
+    gateway, offboard = make_gateway()
+    out = _make_velocity_heading_output()
+    out.vx_mps = 2.0
+    out.vy_mps = -1.0
+    out.vz_mps = 0.5
+    out.yaw_deg = 10.0
+    out.yaw_rate_dps = 0.0
+    assert run(gateway.send_velocity_heading(out, 1))
+    assert offboard.send_count == 1
+    assert len(offboard.ned_setpoints) == 1
+    sp = offboard.ned_setpoints[0]
+    assert sp.north_m_s == pytest.approx(2.0)
+    assert sp.east_m_s == pytest.approx(-1.0)
+    assert sp.down_m_s == pytest.approx(0.5)
+    assert sp.yaw_deg == pytest.approx(10.0)
+    assert offboard.body_setpoints == []
+
+
+def test_both_zero_keeps_heading_via_body_zero_yawspeed():
+    # A2 回归：两者均零时机体速度设定点配零角速率 = 保持当前航向，
+    # 不得误发绝对航向 0（正北）。
+    gateway, offboard = make_gateway()
+    out = _make_velocity_heading_output()
+    out.vx_body_mps = 1.0
+    out.yaw_rate_dps = 0.0
+    out.yaw_deg = 0.0
+    assert run(gateway.send_velocity_heading(out, 1))
+    assert len(offboard.body_setpoints) == 1
+    sp = offboard.body_setpoints[0]
+    assert sp.forward_m_s == pytest.approx(1.0)
+    assert sp.yawspeed_deg_s == 0.0
+    assert offboard.ned_setpoints == []  # 不得走绝对航向支路
+
+
+def test_brake_hover_sends_zero_velocity_body():
+    gateway, offboard = make_gateway()
+    assert run(gateway.send_brake_hover(777))
+    assert offboard.send_count == 1
+    sp = offboard.body_setpoints[0]
+    assert sp.forward_m_s == 0.0
+    assert sp.right_m_s == 0.0
+    assert sp.down_m_s == 0.0
+    assert sp.yawspeed_deg_s == 0.0
+
+
+def test_transport_failure_propagates_as_false():
+    gateway, offboard = make_gateway()
+    offboard.succeed = False
+    out = _make_velocity_heading_output()
+    assert not run(gateway.send_velocity_heading(out, 1))
+    assert not run(gateway.send_brake_hover(1))
+    assert offboard.send_count == 2
+
+
+def test_stop_calls_offboard_stop():
+    gateway, offboard = make_gateway()
+    run(gateway.stop())
+    assert offboard.stop_count == 1

utils/tests/visual_track_control/pid_controller_test.py

@@ -0,0 +1,103 @@
+"""pid_controller_test.py —— PidController 单元测试。
+
+移植自 reference-c++/visual_track_control/tests/pid_controller_test.cpp。
+覆盖（物理追踪思路 §6.2/§6.4）：位置式 P/I/D 三项、积分钳位、输出限幅、
+异常节拍保护、anti-windup 条件积分（C1 修复回归）、ResetIntegral / Reset。
+"""
+
+import pytest
+
+from visual_track_control.pid_controller import PidController, PidParams
+
+
+def make_params(kp, ki, kd, integral_limit, output_limit, filter_coef=0.0):
+    return PidParams(kp=kp, ki=ki, kd=kd, integral_limit=integral_limit,
+                     derivative_filter_coef=filter_coef, output_limit=output_limit)
+
+
+def test_proportional_only():
+    pid = PidController(make_params(2.0, 0.0, 0.0, 0.0, 0.0))
+    assert pid.update(3.0, 0.1) == 6.0
+    assert pid.update(-1.5, 0.1) == -3.0
+
+
+def test_integral_accumulates():
+    pid = PidController(make_params(0.0, 1.0, 0.0, 0.0, 0.0))
+    # 两拍 error=2、dt=0.5：积分累计 1.0 → 2.0
+    assert pid.update(2.0, 0.5) == 1.0
+    assert pid.update(2.0, 0.5) == 2.0
+
+
+def test_integral_clamped_to_limit():
+    pid = PidController(make_params(0.0, 1.0, 0.0, integral_limit=1.0, output_limit=0.0))
+    for _ in range(5):
+        pid.update(10.0, 1.0)
+    # 积分候选值被钳位在 1.0 → 输出恒为 1.0
+    assert pid.last_output == 1.0
+
+
+def test_output_clamped_to_limit():
+    pid = PidController(make_params(10.0, 0.0, 0.0, 0.0, output_limit=3.0))
+    assert pid.update(1.0, 0.1) == 3.0
+    assert pid.update(-1.0, 0.1) == -3.0
+
+
+def test_anti_windup_freeze_while_saturated_same_direction():
+    # kp=0、ki=2、output_limit=5：error=+1 持续饱和时积分冻结，
+    # 输出恒钉在 +5（10 拍累计也不会让积分继续增长）。
+    pid = PidController(make_params(0.0, 2.0, 0.0, 0.0, 5.0))
+    for _ in range(10):
+        assert pid.update(10.0, 1.0) == 5.0
+
+
+def test_anti_windup_unwinds_after_error_flips():
+    # C1 回归：误差反号后积分必须立即回卷（旧判据"积分与输出同向"会
+    # 冻结回卷、输出一直钉在 +5）。
+    # kp=0、ki=2、limit=5：+10 饱和 3 拍、积分冻结在 0；
+    # error=-1 首拍 → 输出 2×(-1) = -2（立即回卷）；
+    # 持续负误差使输出到达负饱和 -5（积分冻结在 -2，输出 = clamp(-6)）。
+    pid = PidController(make_params(0.0, 2.0, 0.0, 0.0, 5.0))
+    for _ in range(3):
+        assert pid.update(10.0, 1.0) == 5.0
+    assert pid.update(-1.0, 1.0) == -2.0  # 首拍立即回卷
+    out = -2.0
+    for _ in range(11):
+        out = pid.update(-1.0, 1.0)
+    assert out == pytest.approx(-5.0, abs=1e-9)  # 旧判据此处仍为 +5.0
+
+
+def test_derivative_first_step_is_zero():
+    pid = PidController(make_params(0.0, 0.0, 1.0, 0.0, 0.0))
+    # 首拍无微分历史：微分项为 0
+    assert pid.update(5.0, 1.0) == 0.0
+
+
+def test_derivative_with_low_pass_filter():
+    pid = PidController(make_params(0.0, 0.0, 1.0, 0.0, 0.0, filter_coef=0.5))
+    pid.update(0.0, 1.0)  # 建立微分历史（导数 0）
+    # 第二拍原始导数 1.0，低通后 0.5×0 + 0.5×1.0 = 0.5
+    assert pid.update(1.0, 1.0) == 0.5
+
+
+def test_zero_or_negative_dt_holds_last_output():
+    pid = PidController(make_params(1.0, 0.0, 0.0, 0.0, 0.0))
+    assert pid.update(2.0, 0.1) == 2.0
+    assert pid.update(99.0, 0.0) == 2.0
+    assert pid.update(99.0, -1.0) == 2.0
+
+
+def test_reset_integral_clears_only_integral():
+    pid = PidController(make_params(0.0, 1.0, 1.0, 0.0, 0.0))
+    pid.update(2.0, 1.0)  # 积分 = 2
+    pid.reset_integral()
+    # 积分清零、微分历史保留：输出应为 kd×(0−2)/1 = −2
+    assert pid.update(0.0, 1.0) == -2.0
+
+
+def test_reset_clears_everything():
+    pid = PidController(make_params(1.0, 1.0, 1.0, 0.0, 0.0))
+    pid.update(5.0, 1.0)
+    pid.reset()
+    assert pid.last_output == 0.0
+    # 全清后等同全新控制器：首拍无微分历史
+    assert pid.update(3.0, 1.0) == 3.0 + 3.0  # kp·e + ki·∫e

utils/tests/visual_track_control/rate_limiter_test.py

@@ -0,0 +1,68 @@
+"""rate_limiter_test.py —— Clamp / SlewRateLimiter 单元测试。
+
+移植自 reference-c++/visual_track_control/tests/rate_limiter_test.cpp。
+覆盖（物理追踪思路 §8、状态机设计 S6）：静态限幅、变化率限幅步进、
+首条指令从零渐变、异常节拍保护、Reset 归零。
+"""
+
+import pytest
+
+from visual_track_control.rate_limiter import SlewRateLimiter, clamp
+
+
+def test_clamp_clamps_value():
+    assert clamp(5.0, -2.0, 2.0) == 2.0
+    assert clamp(-5.0, -2.0, 2.0) == -2.0
+    assert clamp(1.5, -2.0, 2.0) == 1.5
+    # 边界值：落在区间内
+    assert clamp(2.0, -2.0, 2.0) == 2.0
+    assert clamp(-2.0, -2.0, 2.0) == -2.0
+
+
+def test_first_command_ramps_from_zero():
+    # S6：初始输出为 0，首条大指令只能按变化率渐变
+    lim = SlewRateLimiter(2.0)
+    assert lim.limit(10.0, 0.5) == 1.0    # 0 + 2×0.5
+    assert lim.limit(10.0, 0.5) == 2.0    # 继续渐变
+    assert lim.limit(10.0, 10.0) == 10.0  # 步长足够 → 到达目标
+
+
+def test_tracks_target_within_step():
+    lim = SlewRateLimiter(10.0)
+    # 步长 10×1=10，目标 3 在步长内 → 直接到达
+    assert lim.limit(3.0, 1.0) == 3.0
+    assert lim.limit(3.0, 1.0) == 3.0  # 已在目标：保持
+
+
+def test_negative_direction():
+    lim = SlewRateLimiter(2.0)
+    assert lim.limit(-10.0, 0.5) == -1.0
+    assert lim.limit(-10.0, 0.5) == -2.0
+
+
+def test_zero_or_negative_dt_holds():
+    lim = SlewRateLimiter(2.0)
+    lim.limit(10.0, 1.0)  # 输出 2.0
+    assert lim.limit(10.0, 0.0) == 2.0
+    assert lim.limit(10.0, -1.0) == 2.0
+
+
+def test_zero_rate_limit_freezes_output():
+    lim = SlewRateLimiter(0.0)
+    assert lim.limit(5.0, 1.0) == 0.0
+
+
+def test_reset_to_value():
+    lim = SlewRateLimiter(2.0)
+    lim.limit(10.0, 1.0)
+    lim.reset()
+    assert lim.last_output == 0.0
+    lim.reset(3.5)
+    assert lim.last_output == 3.5
+    # 复位后从新值继续渐变
+    assert lim.limit(10.0, 1.0) == 5.5  # 3.5 + 2×1
+
+
+def test_custom_initial_value():
+    lim = SlewRateLimiter(1.0, initial=5.0)
+    assert lim.limit(10.0, 1.0) == 6.0

utils/tests/visual_track_control/staleness_checker_test.py

@@ -0,0 +1,32 @@
+"""staleness_checker_test.py —— is_stale 单元测试。
+
+移植自 reference-c++/visual_track_control/tests/staleness_checker_test.cpp。
+覆盖（物理追踪思路 §7.1）：从未取样判超龄、有效期内新鲜、超出有效期超龄、
+边界恰好在有效期上（不算超龄）、时间戳不一致判超龄（C4）。
+"""
+
+from visual_track_control.staleness_checker import is_stale
+
+
+def test_never_sampled_is_stale():
+    assert is_stale(0, 1000, 200)
+    assert is_stale(-5, 1000, 200)
+
+
+def test_within_validity_is_fresh():
+    assert not is_stale(900, 1000, 200)
+    assert not is_stale(1000, 1000, 200)  # 刚取样
+
+
+def test_beyond_validity_is_stale():
+    assert is_stale(799, 1000, 200)  # 201 > 200
+
+
+def test_exactly_at_boundary_is_fresh():
+    # 超龄判定为严格大于：恰好等于有效期仍算新鲜
+    assert not is_stale(800, 1000, 200)
+
+
+def test_inconsistent_timestamp_is_stale():
+    # C4：now < sample 时间戳不一致 → 年龄不可信 → 判超龄（宁降级不轻信）
+    assert is_stale(2000, 1000, 200)

utils/tests/visual_track_control/tracking_control_law_test.py

@@ -0,0 +1,338 @@
+"""tracking_control_law_test.py —— TrackingControlLaw 主控律单元测试。
+
+移植自 reference-c++/visual_track_control/tests/tracking_control_law_test.cpp。
+覆盖（物理追踪思路 §2.3/§4/§5/§6/§7/§9）：超龄降级（姿态缺失/过期、视觉
+超龄、降级优先级）、判丢零速刹车、Coast 清积分与标志、速率式/位置式航向
+通道（含绝对航向合成与回绕，A2）、垂直统一速度支路（A1）、距离通道三种
+无距离降级动作、首拍变化率限幅（S6）、机体系→NED 输出旋转（A4）。
+"""
+
+import math
+
+import pytest
+
+from visual_track_control.config import (HeadingMode, NoDistanceAction,
+                                         TrackingConfig)
+from visual_track_control.tracking_control_law import TrackingControlLaw
+from visual_track_control.types import (ControlMode, ControlSnapshot,
+                                        DegradedReason, TrackState)
+
+
+def make_config() -> TrackingConfig:
+    """测试基准配置：大限幅使限幅器近似透明，便于独立验证各通道数学。
+    画面 1000×1000、视场角 90° → 针孔系数 2·tan(45°)/1000 = 0.002，
+    偏移 100 像素 → 视线角 atan(0.2) ≈ 11.3099°。
+    """
+    cfg = TrackingConfig()
+    cfg.control.frequency_hz = 20.0
+    cfg.control.visual_stale_ms = 200
+    cfg.control.radar_stale_ms = 500
+    cfg.control.attitude_stale_ms = 300
+    cfg.camera.image_width = 1000
+    cfg.camera.image_height = 1000
+    cfg.camera.fov_h_deg = 90.0
+    cfg.camera.fov_v_deg = 90.0
+    cfg.heading.mode = HeadingMode.RATE
+    cfg.heading.gain = 1.0
+    cfg.heading.yaw_rate_limit_dps = 30.0
+    cfg.heading.yaw_slew_limit_dps2 = 100000.0
+    cfg.vertical.vz_gain_mps_per_deg = 0.1
+    cfg.vertical.vz_limit_mps = 2.0
+    cfg.distance.d_exp_m = 10.0
+    cfg.distance.kp = 0.5
+    cfg.distance.ki = 0.0
+    cfg.distance.kd = 0.0
+    cfg.distance.integral_limit = 0.0
+    cfg.distance.derivative_filter_coef = 0.0
+    cfg.distance.approach_velocity_limit_mps = 3.0
+    cfg.distance.retreat_velocity_limit_mps = 1.0
+    cfg.distance.no_distance_action = NoDistanceAction.HOLD
+    cfg.distance.no_distance_approach_limit_mps = 0.5
+    cfg.accel_limit.ax_mps2 = 1000.0
+    cfg.accel_limit.ay_mps2 = 1000.0
+    cfg.accel_limit.az_mps2 = 1000.0
+    return cfg
+
+
+def make_snapshot(now_ms: int) -> ControlSnapshot:
+    """新鲜快照：目标在画面中心，姿态/追踪/雷达均新鲜。"""
+    return ControlSnapshot(
+        track=TrackState(tracked=True, is_predicted=False,
+                         center=(500.0, 500.0)),
+        track_time_ms=now_ms,
+        attitude_present=True,
+        attitude_time_ms=now_ms,
+    )
+
+
+# ---- 超龄降级（§7.1 / §9.2） ----
+
+def test_attitude_missing_degrades():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.attitude_present = False
+    out = law.update(snap, 1000)
+    assert out.mode is ControlMode.DEGRADED_HOLD
+    assert out.degraded_reason is DegradedReason.ATTITUDE_STALE
+    assert not out.valid
+
+
+def test_attitude_stale_degrades():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.attitude_time_ms = 600  # 400 ms 前 > 300 ms 阈值
+    out = law.update(snap, 1000)
+    assert out.mode is ControlMode.DEGRADED_HOLD
+    assert out.degraded_reason is DegradedReason.ATTITUDE_STALE
+
+
+def test_vision_stale_degrades():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.track_time_ms = 700  # 300 ms 前 > 200 ms 阈值
+    out = law.update(snap, 1000)
+    assert out.mode is ControlMode.DEGRADED_HOLD
+    assert out.degraded_reason is DegradedReason.VISION_STALE
+
+
+def test_never_sampled_track_degrades():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.track_time_ms = 0  # 从未取样
+    out = law.update(snap, 1000)
+    assert out.mode is ControlMode.DEGRADED_HOLD
+    assert out.degraded_reason is DegradedReason.VISION_STALE
+
+
+def test_attitude_stale_beats_vision_stale():
+    # 降级优先级：姿态校验在前（§9.2 姿态过期禁止一切空间转换）
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.attitude_present = False
+    snap.track_time_ms = 0
+    out = law.update(snap, 1000)
+    assert out.degraded_reason is DegradedReason.ATTITUDE_STALE
+
+
+# ---- 判丢刹车（§6.4） ----
+
+def test_lost_target_brakes():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.track.tracked = False
+    out = law.update(snap, 1000)
+    assert out.mode is ControlMode.BRAKE_HOVER
+    assert out.valid
+    assert out.vx_mps == 0.0
+    assert out.vy_mps == 0.0
+    assert out.vz_mps == 0.0
+
+
+# ---- Coast（§6.4） ----
+
+def test_coast_sets_flag_and_keeps_tracking():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.track.is_predicted = True
+    out = law.update(snap, 1000)
+    assert out.mode is ControlMode.VELOCITY_HEADING
+    assert out.coast_active
+    assert out.valid
+
+
+# ---- 水平航向通道（§4.2，A2） ----
+
+def test_rate_mode_maps_beta_to_yaw_rate():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.track.center = (600.0, 500.0)  # 目标偏右 100 像素
+    out = law.update(snap, 1000)
+    beta_deg = math.degrees(math.atan(0.2))  # ≈ 11.31°
+    assert out.yaw_rate_dps == pytest.approx(beta_deg, abs=1e-6)  # gain=1，右转正
+    assert out.yaw_deg == 0.0
+
+
+def test_rate_mode_clamps_to_yaw_rate_limit():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.track.center = (950.0, 500.0)  # 大偏移：β≈43.5° > 30°/s 上限
+    out = law.update(snap, 1000)
+    assert out.yaw_rate_dps == pytest.approx(30.0, abs=1e-9)
+
+
+def test_position_mode_composes_absolute_heading():
+    # A2：位置式输出为绝对 NED 航向 = 当前航向 + 限幅修正量
+    cfg = make_config()
+    cfg.heading.mode = HeadingMode.POSITION
+    law = TrackingControlLaw(cfg)
+    snap = make_snapshot(1000)
+    snap.track.center = (600.0, 500.0)
+    snap.yaw_rad = math.radians(45.0)
+    out = law.update(snap, 1000)
+    beta_deg = math.degrees(math.atan(0.2))
+    assert out.yaw_deg == pytest.approx(45.0 + beta_deg, abs=1e-6)
+    assert out.yaw_rate_dps == 0.0
+
+
+def test_position_mode_wraps_around_180():
+    cfg = make_config()
+    cfg.heading.mode = HeadingMode.POSITION
+    law = TrackingControlLaw(cfg)
+    snap = make_snapshot(1000)
+    snap.track.center = (600.0, 500.0)
+    snap.yaw_rad = math.radians(175.0)
+    out = law.update(snap, 1000)
+    beta_deg = math.degrees(math.atan(0.2))
+    # 175 + 11.31 = 186.31 → 回绕到 ≈ -173.69
+    assert out.yaw_deg == pytest.approx(175.0 + beta_deg - 360.0, abs=1e-6)
+    assert -180.0 < out.yaw_deg < 180.0
+
+
+# ---- 垂直统一速度支路（§5，A1） ----
+
+def test_vertical_offset_drives_vz():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.track.center = (500.0, 600.0)  # 目标偏低 100 像素 → α>0 → 下降
+    out = law.update(snap, 1000)
+    alpha_deg = math.degrees(math.atan(0.2))
+    assert out.vz_mps == pytest.approx(0.1 * alpha_deg, abs=1e-6)
+    assert out.mode is ControlMode.VELOCITY_HEADING  # A1：不切姿态微调模式
+
+
+def test_vertical_velocity_clamped():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.track.center = (500.0, 990.0)  # α≈44.5° × 0.1 = 4.45 > 2 上限
+    out = law.update(snap, 1000)
+    assert out.vz_mps == pytest.approx(2.0, abs=1e-9)
+
+
+# ---- 距离通道（§6.2 / §6.3） ----
+
+def test_distance_approach_when_far():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.radar_distance_m = 30.0  # Δd = +20 → kp 输出 10 → 限幅 3
+    snap.associated_to_target = True
+    snap.radar_time_ms = 1000
+    out = law.update(snap, 1000)
+    assert out.vx_mps == pytest.approx(3.0, abs=1e-9)
+
+
+def test_distance_retreat_clamped_when_too_close():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.radar_distance_m = 5.0  # Δd = -5 → kp 输出 -2.5 → 后退限幅 -1
+    snap.associated_to_target = True
+    snap.radar_time_ms = 1000
+    out = law.update(snap, 1000)
+    assert out.vx_mps == pytest.approx(-1.0, abs=1e-9)
+
+
+def test_no_distance_hold_zeros_vx():
+    law = TrackingControlLaw(make_config())  # 缺省 kHold
+    snap = make_snapshot(1000)
+    snap.associated_to_target = False
+    out = law.update(snap, 1000)
+    assert out.mode is ControlMode.VELOCITY_HEADING
+    assert out.vx_mps == 0.0
+
+
+def test_no_distance_slow_approach():
+    cfg = make_config()
+    cfg.distance.no_distance_action = NoDistanceAction.SLOW_APPROACH
+    law = TrackingControlLaw(cfg)
+    snap = make_snapshot(1000)
+    snap.associated_to_target = False
+    out = law.update(snap, 1000)
+    assert out.vx_mps == pytest.approx(0.5, abs=1e-9)
+
+
+def test_no_distance_exit_degrades():
+    cfg = make_config()
+    cfg.distance.no_distance_action = NoDistanceAction.EXIT
+    law = TrackingControlLaw(cfg)
+    snap = make_snapshot(1000)
+    snap.associated_to_target = False
+    out = law.update(snap, 1000)
+    assert out.mode is ControlMode.DEGRADED_HOLD
+    assert out.degraded_reason is DegradedReason.NO_DISTANCE_EXIT
+    assert not out.valid
+
+
+def test_stale_radar_falls_back_to_no_distance():
+    law = TrackingControlLaw(make_config())  # kHold
+    snap = make_snapshot(1000)
+    snap.radar_distance_m = 30.0
+    snap.associated_to_target = True
+    snap.radar_time_ms = 400  # 600 ms 前 > 500 ms 阈值 → 距离不可用
+    out = law.update(snap, 1000)
+    assert out.mode is ControlMode.VELOCITY_HEADING
+    assert out.vx_mps == 0.0
+
+
+# ---- 首拍/限幅（§8、S6） ----
+
+def test_first_tick_vx_slews_from_zero():
+    # S6：首条速度指令必须经变化率限幅，从 0 渐变而非阶跃
+    cfg = make_config()
+    cfg.accel_limit.ax_mps2 = 2.0
+    law = TrackingControlLaw(cfg)
+    snap = make_snapshot(1000)
+    snap.radar_distance_m = 30.0  # 通道输出本应为 3.0
+    snap.associated_to_target = True
+    snap.radar_time_ms = 1000
+    out = law.update(snap, 1000)  # 首拍：dt 按 1/20 Hz 兜底
+    assert out.vx_mps == pytest.approx(2.0 * (1.0 / 20.0), abs=1e-9)  # 0.1
+
+
+# ---- 机体系 → NED 旋转（§2.3，A4） ----
+
+def test_output_rotated_to_ned_by_yaw():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.yaw_rad = math.pi / 2.0  # 机头朝东
+    snap.radar_distance_m = 30.0
+    snap.associated_to_target = True
+    snap.radar_time_ms = 1000
+    out = law.update(snap, 1000)
+    # 机体前向 3.0 → 东向 3.0，北向 ≈ 0
+    assert out.vx_mps == pytest.approx(0.0, abs=1e-9)
+    assert out.vy_mps == pytest.approx(3.0, abs=1e-9)
+
+
+def test_zero_yaw_keeps_forward_as_north():
+    law = TrackingControlLaw(make_config())
+    snap = make_snapshot(1000)
+    snap.yaw_rad = 0.0
+    snap.radar_distance_m = 30.0
+    snap.associated_to_target = True
+    snap.radar_time_ms = 1000
+    out = law.update(snap, 1000)
+    assert out.vx_mps == pytest.approx(3.0, abs=1e-9)
+    assert out.vy_mps == pytest.approx(0.0, abs=1e-9)
+
+
+# ---- Reset（§6.4） ----
+
+def test_reset_restores_slew_from_zero():
+    cfg = make_config()
+    cfg.accel_limit.ax_mps2 = 2.0
+    law = TrackingControlLaw(cfg)
+    snap = make_snapshot(1000)
+    snap.radar_distance_m = 30.0
+    snap.associated_to_target = True
+    snap.radar_time_ms = 1000
+    for t in range(1000, 3000, 50):
+        snap.track_time_ms = t
+        snap.radar_time_ms = t
+        snap.attitude_time_ms = t
+        law.update(snap, t)  # 若干拍后 vx 已爬升到限幅 3.0
+    law.reset()
+    snap.track_time_ms = 3000
+    snap.radar_time_ms = 3000
+    snap.attitude_time_ms = 3000
+    out = law.update(snap, 3000)
+    # Reset 后限幅器归零：又从 0.1 开始渐变
+    assert out.vx_mps == pytest.approx(0.1, abs=1e-9)

utils/tests/visual_track_control/vtc_config_test.py

@@ -0,0 +1,171 @@
+"""vtc_config_test.py —— TrackingConfig::load_from_json 单元测试。
+
+移植自 reference-c++/visual_track_control/tests/vtc_config_test.cpp。
+覆盖（物理追踪思路 §8、需求分析 NFR-007）：真实配置文件加载成功与取值
+正确（含 A1/A2 修改后的字段结构）、缺字段 / 缺分组 / 非法枚举 / 非法数值 /
+文件缺失均抛带字段名的 ValueError。
+
+C++ 版用字符串替换构造非法变体；Python 版改为 dict 变异（更稳健），
+临时文件经 pytest 的 tmp_path 提供。
+"""
+
+import json
+from pathlib import Path
+
+import pytest
+
+from visual_track_control.config import (HeadingMode, NoDistanceAction,
+                                         load_from_json)
+
+_REPO_ROOT = Path(__file__).resolve().parents[3]
+REAL_CONFIG = _REPO_ROOT / "reference-c++" / "visual_track_control" / "config" / "track_control.json"
+
+
+def full_config() -> dict:
+    """与真实配置同构的完整合法配置（用于派生各非法变体）。"""
+    return {
+        "control": {
+            "frequency_hz": 20.0,
+            "visual_stale_ms": 200,
+            "radar_stale_ms": 500,
+            "attitude_stale_ms": 300,
+        },
+        "camera": {
+            "image_width": 1920,
+            "image_height": 1080,
+            "fov_h_deg": 60.0,
+            "fov_v_deg": 35.0,
+        },
+        "heading": {
+            "mode": "rate",
+            "gain": 1.0,
+            "yaw_rate_limit_dps": 30.0,
+            "yaw_slew_limit_dps2": 60.0,
+        },
+        "vertical": {
+            "vz_gain_mps_per_deg": 0.1,
+            "vz_limit_mps": 2.0,
+        },
+        "distance": {
+            "d_exp_m": 10.0,
+            "kp": 0.5,
+            "ki": 0.05,
+            "kd": 0.1,
+            "integral_limit": 2.0,
+            "derivative_filter_coef": 0.2,
+            "approach_velocity_limit_mps": 3.0,
+            "retreat_velocity_limit_mps": 1.0,
+            "no_distance_action": "hold",
+            "no_distance_approach_limit_mps": 0.5,
+        },
+        "accel_limit": {
+            "ax_mps2": 2.0,
+            "ay_mps2": 2.0,
+            "az_mps2": 1.5,
+        },
+    }
+
+
+def write_temp_json(tmp_path: Path, config: dict, name: str) -> str:
+    path = tmp_path / name
+    path.write_text(json.dumps(config), encoding="utf-8")
+    return str(path)
+
+
+def test_load_real_config_succeeds():
+    cfg = load_from_json(str(REAL_CONFIG))
+    assert cfg.control.frequency_hz == 20.0
+    assert cfg.control.visual_stale_ms == 200
+    assert cfg.camera.image_width == 1920
+    assert cfg.camera.image_height == 1080
+    assert cfg.camera.fov_h_deg == 60.0
+    assert cfg.heading.mode is HeadingMode.RATE  # A2：默认速率式
+    assert cfg.heading.yaw_rate_limit_dps == 30.0
+    assert cfg.vertical.vz_gain_mps_per_deg == 0.1
+    assert cfg.vertical.vz_limit_mps == 2.0
+    assert cfg.distance.d_exp_m == 10.0
+    assert cfg.distance.no_distance_action is NoDistanceAction.HOLD
+    assert cfg.accel_limit.ax_mps2 == 2.0
+
+
+def test_full_json_round_trip_matches_expected(tmp_path):
+    # 内嵌合法配置与真实配置文件行为一致
+    path = write_temp_json(tmp_path, full_config(), "vtc_cfg_full.json")
+    cfg = load_from_json(path)
+    assert cfg.heading.mode is HeadingMode.RATE
+    assert cfg.distance.kp == 0.5
+
+
+def test_position_mode_accepted(tmp_path):
+    config = full_config()
+    config["heading"]["mode"] = "position"
+    path = write_temp_json(tmp_path, config, "vtc_cfg_position.json")
+    cfg = load_from_json(path)
+    assert cfg.heading.mode is HeadingMode.POSITION
+
+
+def test_missing_file_throws_with_path():
+    with pytest.raises(ValueError) as exc_info:
+        load_from_json("/nonexistent/vtc_no_such_file.json")
+    assert "vtc_no_such_file.json" in str(exc_info.value)
+
+
+def test_malformed_json_throws(tmp_path):
+    path = tmp_path / "vtc_cfg_bad.json"
+    path.write_text("{ this is not json", encoding="utf-8")
+    with pytest.raises(ValueError):
+        load_from_json(str(path))
+
+
+def test_missing_field_throws_with_field_name(tmp_path):
+    config = full_config()
+    del config["heading"]["gain"]
+    path = write_temp_json(tmp_path, config, "vtc_cfg_missing.json")
+    with pytest.raises(ValueError) as exc_info:
+        load_from_json(path)
+    assert "heading.gain" in str(exc_info.value)
+
+
+def test_missing_section_throws(tmp_path):
+    config = full_config()
+    del config["accel_limit"]
+    path = write_temp_json(tmp_path, config, "vtc_cfg_nosection.json")
+    with pytest.raises(ValueError) as exc_info:
+        load_from_json(path)
+    assert "accel_limit" in str(exc_info.value)
+
+
+def test_invalid_heading_mode_throws(tmp_path):
+    config = full_config()
+    config["heading"]["mode"] = "magic"
+    path = write_temp_json(tmp_path, config, "vtc_cfg_badmode.json")
+    with pytest.raises(ValueError) as exc_info:
+        load_from_json(path)
+    assert "heading.mode" in str(exc_info.value)
+
+
+def test_invalid_no_distance_action_throws(tmp_path):
+    config = full_config()
+    config["distance"]["no_distance_action"] = "zoom"
+    path = write_temp_json(tmp_path, config, "vtc_cfg_badaction.json")
+    with pytest.raises(ValueError) as exc_info:
+        load_from_json(path)
+    assert "no_distance_action" in str(exc_info.value)
+
+
+def test_negative_frequency_throws(tmp_path):
+    config = full_config()
+    config["control"]["frequency_hz"] = -1.0
+    path = write_temp_json(tmp_path, config, "vtc_cfg_negfreq.json")
+    with pytest.raises(ValueError) as exc_info:
+        load_from_json(path)
+    assert "control.frequency_hz" in str(exc_info.value)
+
+
+def test_fov_out_of_range_throws(tmp_path):
+    config = full_config()
+    config["camera"]["fov_h_deg"] = 200.0
+    path = write_temp_json(tmp_path, config, "vtc_cfg_badfov.json")
+    with pytest.raises(ValueError) as exc_info:
+        load_from_json(path)
+    assert "camera.fov_h_deg" in str(exc_info.value)