refactor(aiot): 离岗检测算法v2.0 - 全面重构

重构目标：
- 更清晰的状态机设计
- 滑动窗口平滑检测结果
- 更准确的告警判断逻辑

核心改进：
1. 状态机优化（6个状态 → 7个状态）
   - INIT: 初始化
   - CONFIRMING_ON_DUTY: 上岗确认中
   - ON_DUTY: 在岗
   - CONFIRMING_OFF_DUTY: 离岗确认中
   - OFF_DUTY_COUNTDOWN: 离岗倒计时
   - ALARMED: 已告警
   - NON_WORK_TIME: 非工作时间

2. 滑动窗口机制
   - 10秒滑动窗口，存储检测历史
   - 计算命中率（person_count / total_frames）
   - 上岗条件：命中率 ≥ 70%（允许30%漏检）
   - 离岗条件：命中率 = 0（窗口内完全没人）

3. 参数优化
   - confirm_on_duty_sec: 上岗确认（默认10秒）
   - confirm_off_duty_sec: 离岗确认（默认30秒）
   - confirm_return_sec: 回岗确认（默认10秒）
   - leave_countdown_sec: 离岗倒计时（默认300秒）
   - 向后兼容：confirm_leave_sec → confirm_off_duty_sec

4. 状态监控增强
   - get_state() 返回详细状态信息
   - 包含倒计时剩余时间、检测命中率等

5. 日志分级
   - INFO: 关键状态转换（确认上岗、确认离岗）
   - DEBUG: 次要状态转换（进入确认状态）
   - WARNING: 告警触发

技术细节：
- 使用deque实现O(1)滑动窗口更新
- 兼容旧参数名（confirm_leave_sec）
- 回岗自动发送resolve事件
- 非工作时间自动清理状态

影响范围：
- 告警判断更准确（抗漏检干扰）
- 状态转换更合理（细化确认流程）
- 调试更友好（详细状态信息）

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

algorithms.py

@@ -17,44 +17,71 @@ sys.path.insert(0, os.path.dirname(os.path.dirname(os.path.abspath(__file__))))
 
 
 class LeavePostAlgorithm:
-    STATE_WAITING = "WAITING"
-    STATE_CONFIRMING = "CONFIRMING"
-    STATE_ON_DUTY = "ON_DUTY"
-    STATE_LEAVING = "LEAVING"
-    STATE_OFF_DUTY = "OFF_DUTY"
-    STATE_NON_WORK_TIME = "NON_WORK_TIME"
+    """
+    离岗检测算法（优化版 v2.0）
+
+    状态机：
+    INIT → CONFIRMING_ON_DUTY → ON_DUTY → CONFIRMING_OFF_DUTY
+         → OFF_DUTY_COUNTDOWN → ALARMED → (回岗) → CONFIRMING_ON_DUTY
+
+    业务流程：
+    1. 启动后检测到人 → 上岗确认期（confirm_on_duty_sec，默认10秒）
+    2. 确认上岗后 → 在岗状态（ON_DUTY）
+    3. 人离开ROI → 离岗确认期（confirm_off_duty_sec，默认30秒）
+    4. 确认离岗后 → 离岗倒计时（leave_countdown_sec，默认300秒）
+    5. 倒计时结束 → 触发告警（ALARMED状态）
+    6. 人员回岗 → 回岗确认期（confirm_return_sec，默认10秒）
+    7. 确认回岗 → 发送resolve事件 → 重新上岗确认
+    """
+
+    # 状态定义
+    STATE_INIT = "INIT"                                   # 初始化
+    STATE_CONFIRMING_ON_DUTY = "CONFIRMING_ON_DUTY"       # 上岗确认中
+    STATE_ON_DUTY = "ON_DUTY"                             # 在岗
+    STATE_CONFIRMING_OFF_DUTY = "CONFIRMING_OFF_DUTY"     # 离岗确认中
+    STATE_OFF_DUTY_COUNTDOWN = "OFF_DUTY_COUNTDOWN"       # 离岗倒计时中
+    STATE_ALARMED = "ALARMED"                             # 已告警（等待回岗）
+    STATE_NON_WORK_TIME = "NON_WORK_TIME"                 # 非工作时间
 
     def __init__(
         self,
-        confirm_on_duty_sec: int = 10,
-        confirm_leave_sec: int = 30,
-        leave_countdown_sec: int = 300,  # 新增：离岗倒计时（默认5分钟）
-        cooldown_sec: int = 600,
+        confirm_on_duty_sec: int = 10,      # 上岗确认窗口（持续检测到人的时长）
+        confirm_off_duty_sec: int = 30,     # 离岗确认窗口（持续未检测到人的时长）
+        confirm_return_sec: int = 10,       # 回岗确认窗口（告警后回来需确认时长）
+        leave_countdown_sec: int = 300,     # 离岗倒计时（确认离岗后等待告警的时长）
+        cooldown_sec: int = 600,            # 告警冷却期（两次告警的最小间隔）
         working_hours: Optional[List[Dict]] = None,
         target_class: Optional[str] = "person",
+        # 兼容旧参数名（向后兼容）
+        confirm_leave_sec: Optional[int] = None,
     ):
+        # 时间参数（处理向后兼容）
         self.confirm_on_duty_sec = confirm_on_duty_sec
-        self.confirm_leave_sec = confirm_leave_sec
-        self.leave_countdown_sec = leave_countdown_sec  # 离岗倒计时
+        self.confirm_off_duty_sec = confirm_leave_sec if confirm_leave_sec is not None else confirm_off_duty_sec
+        self.confirm_return_sec = confirm_return_sec
+        self.leave_countdown_sec = leave_countdown_sec
         self.cooldown_sec = cooldown_sec
+
+        # 工作时间和目标类别
         self.working_hours = working_hours or []
         self.target_class = target_class
 
+        # 状态变量
+        self.state: str = self.STATE_INIT
+        self.state_start_time: Optional[datetime] = None
+
+        # 滑动窗口（用于平滑检测结果）
+        self.detection_window: deque = deque()  # [(timestamp, has_person), ...]
+        self.window_size_sec = 10  # 滑动窗口大小：10秒
+
+        # 告警追踪
+        self._last_alarm_id: Optional[str] = None
+        self._leave_start_time: Optional[datetime] = None  # 人员离开时间（用于计算持续时长）
+        self._alarm_triggered_time: Optional[datetime] = None  # 告警触发时间
         self.alert_cooldowns: Dict[str, datetime] = {}
 
-        self.state: str = self.STATE_WAITING
-        self.state_start_time: Optional[datetime] = None
-        self.detection_history: deque = deque()
-
-        self.alarm_sent: bool = False
-        self.last_person_time: Optional[datetime] = None
-
-        self._last_alarm_id: Optional[str] = None      # 最近一次告警ID
-        self._off_duty_start_time: Optional[datetime] = None  # OFF_DUTY状态开始时间（用于倒计时）
-        self._alarm_triggered: bool = False  # 是否已触发告警（OFF_DUTY期间只告警一次）
-        self._leave_start_time: Optional[datetime] = None  # 离岗开始时间（LEAVING 状态的开始时间）
-
     def _is_in_working_hours(self, dt: Optional[datetime] = None) -> bool:
+        """检查是否在工作时间"""
         if not self.working_hours:
             return True
 
@@ -92,31 +119,43 @@ class LeavePostAlgorithm:
             return 0
 
     def _check_detection_in_roi(self, detection: Dict, roi_id: str) -> bool:
+        """检查检测结果是否在ROI内"""
         matched_rois = detection.get("matched_rois", [])
-        for roi in matched_rois:
-            if roi.get("roi_id") == roi_id:
-                return True
-        return False
+        return any(roi.get("roi_id") == roi_id for roi in matched_rois)
 
-    def _check_target_class(self, detection: Dict, target_class: Optional[str]) -> bool:
+    def _check_target_class(self, detection: Dict, target_class: str) -> bool:
+        """检查是否为目标类别"""
         if not target_class:
             return True
         return detection.get("class") == target_class
 
-    def _get_detection_window(self, current_time: datetime) -> List[bool]:
-        detections = []
-        while self.detection_history and (current_time - self.detection_history[0][0]).total_seconds() > max(self.confirm_on_duty_sec, self.confirm_leave_sec):
-            self.detection_history.popleft()
-        for _, has_person in self.detection_history:
-            detections.append(has_person)
-        return detections
-
     def _get_latest_bbox(self, tracks: List[Dict], roi_id: str) -> List[float]:
+        """获取ROI内最新的检测框"""
         for det in tracks:
-            if self._check_detection_in_roi(det, roi_id):
+            if self._check_detection_in_roi(det, roi_id) and self._check_target_class(det, self.target_class):
                 return det.get("bbox", [])
         return []
 
+    def _update_detection_window(self, current_time: datetime, has_person: bool):
+        """更新滑动窗口"""
+        self.detection_window.append((current_time, has_person))
+
+        # 移除窗口外的旧数据
+        while self.detection_window:
+            oldest_time, _ = self.detection_window[0]
+            if (current_time - oldest_time).total_seconds() > self.window_size_sec:
+                self.detection_window.popleft()
+            else:
+                break
+
+    def _get_detection_ratio(self) -> float:
+        """计算滑动窗口内的检测命中率"""
+        if not self.detection_window:
+            return 0.0
+
+        person_count = sum(1 for _, has_person in self.detection_window if has_person)
+        return person_count / len(self.detection_window)
+
     def process(
         self,
         roi_id: str,
@@ -124,125 +163,135 @@ class LeavePostAlgorithm:
         tracks: List[Dict],
         current_time: Optional[datetime] = None,
     ) -> List[Dict]:
-        current_time = current_time or datetime.now()
+        """
+        处理单帧检测结果
 
-        in_work = self._is_in_working_hours(current_time)
+        Args:
+            roi_id: ROI区域ID
+            camera_id: 摄像头ID
+            tracks: 检测结果列表
+            current_time: 当前时间（用于测试，生产环境传None）
+
+        Returns:
+            告警列表 [{"alert_type": "leave_post", ...}, {"alert_type": "alarm_resolve", ...}]
+        """
+        current_time = current_time or datetime.now()
         alerts = []
 
-        if not in_work:
-            if self.state == self.STATE_OFF_DUTY and self._last_alarm_id and self._leave_start_time:
-                duration_ms = int((current_time - self._leave_start_time).total_seconds() * 1000)
-                alerts.append({
-                    "alert_type": "alarm_resolve",
-                    "resolve_alarm_id": self._last_alarm_id,
-                    "duration_ms": duration_ms,
-                    "last_frame_time": current_time.strftime('%Y-%m-%d %H:%M:%S'),
-                    "resolve_type": "non_work_time",
-                })
-                self._last_alarm_id = None
-                self._leave_start_time = None
-            self.state = self.STATE_NON_WORK_TIME
-            self.detection_history.clear()
-            self.alarm_sent = False
-            return alerts
+        # 检查ROI内是否有目标
+        roi_has_person = any(
+            self._check_detection_in_roi(det, roi_id) and self._check_target_class(det, self.target_class)
+            for det in tracks
+        )
 
-        if self.state == self.STATE_NON_WORK_TIME:
-            self.state = self.STATE_WAITING
-            self.state_start_time = None
-            self.detection_history.clear()
-            self.alarm_sent = False
-            self.alert_cooldowns.clear()  # 新工作时段，清除冷却记录
+        # 更新滑动窗口
+        self._update_detection_window(current_time, roi_has_person)
+        detection_ratio = self._get_detection_ratio()
 
-        roi_has_person = False
-        for det in tracks:
-            if self._check_detection_in_roi(det, roi_id) and self._check_target_class(det, self.target_class):
-                roi_has_person = True
-                break
+        # 检查工作时间
+        in_working_hours = self._is_in_working_hours(current_time)
 
-        if self.state == self.STATE_WAITING:
-            if roi_has_person:
-                # 检测到人，进入上岗确认阶段
-                self.state = self.STATE_CONFIRMING
-                self.state_start_time = current_time
-                self.detection_history.clear()
-                self.detection_history.append((current_time, True))
-            else:
-                pass
-
-        elif self.state == self.STATE_CONFIRMING:
-            self.detection_history.append((current_time, roi_has_person))
-            if not roi_has_person:
-                # 人消失，回到等待状态
-                self.state = self.STATE_WAITING
-                self.state_start_time = None
-                self.detection_history.clear()
-            else:
-                elapsed = (current_time - self.state_start_time).total_seconds()
-                if elapsed >= self.confirm_on_duty_sec:
-                    # 持续在岗达到确认时长，正式确认上岗
-                    self.state = self.STATE_ON_DUTY
-                    self.state_start_time = current_time
-                    # 确认在岗后清除冷却记录，允许新一轮离岗检测告警
-                    self.alert_cooldowns.clear()
-
-        elif self.state == self.STATE_ON_DUTY:
-            self.detection_history.append((current_time, roi_has_person))
-            if not roi_has_person:
-                self.state = self.STATE_LEAVING
-                self.state_start_time = current_time
-
-        elif self.state == self.STATE_LEAVING:
-            self.detection_history.append((current_time, roi_has_person))
-            elapsed = (current_time - self.state_start_time).total_seconds()
-
-            if roi_has_person:
-                # 人回来了，回到ON_DUTY
-                self.state = self.STATE_ON_DUTY
-                self.state_start_time = current_time
-            elif elapsed >= self.confirm_leave_sec:
-                # 离岗确认期结束 → 进入OFF_DUTY开始倒计时（暂不触发告警）
-                leaving_start_time = self.state_start_time  # 保存人员离开时间
-                self.state = self.STATE_OFF_DUTY
-                self.state_start_time = current_time
-                self._off_duty_start_time = current_time  # 记录OFF_DUTY开始时间用于倒计时
-                self._leave_start_time = leaving_start_time  # 保存LEAVING开始时间（人员离开时间）
-                self._alarm_triggered = False  # 重置告警标志
-
-        elif self.state == self.STATE_OFF_DUTY:
-            # OFF_DUTY 状态：离岗倒计时 + 等待人员回岗
-            off_duty_elapsed = (current_time - self._off_duty_start_time).total_seconds() if self._off_duty_start_time else 0
-
-            if roi_has_person:
-                # 人员回岗
-                if self._last_alarm_id and self._leave_start_time and self._alarm_triggered:
-                    # 如果已经触发过告警，发送resolve事件
+        # === 非工作时间处理 ===
+        if not in_working_hours:
+            if self.state != self.STATE_NON_WORK_TIME:
+                # 进入非工作时间，清理状态
+                if self._last_alarm_id and self._leave_start_time:
+                    # 如果有未结束的告警，发送resolve事件（非工作时间自动关闭）
                     duration_ms = int((current_time - self._leave_start_time).total_seconds() * 1000)
                     alerts.append({
                         "alert_type": "alarm_resolve",
                         "resolve_alarm_id": self._last_alarm_id,
                         "duration_ms": duration_ms,
                         "last_frame_time": current_time.strftime('%Y-%m-%d %H:%M:%S'),
-                        "resolve_type": "person_returned",
+                        "resolve_type": "non_work_time",
                     })
-                # 清理告警追踪信息
+
+                self.state = self.STATE_NON_WORK_TIME
+                self.state_start_time = None
+                self.detection_window.clear()
                 self._last_alarm_id = None
                 self._leave_start_time = None
-                self._off_duty_start_time = None
-                self._alarm_triggered = False
-                # 回到确认在岗状态
-                self.state = self.STATE_CONFIRMING
+                self._alarm_triggered_time = None
+            return alerts
+
+        # === 工作时间处理 ===
+
+        # 从非工作时间恢复
+        if self.state == self.STATE_NON_WORK_TIME:
+            self.state = self.STATE_INIT
+            self.state_start_time = current_time
+            self.detection_window.clear()
+
+        # === 状态机处理 ===
+
+        if self.state == self.STATE_INIT:
+            # 初始化状态：等待检测到人
+            if roi_has_person:
+                self.state = self.STATE_CONFIRMING_ON_DUTY
                 self.state_start_time = current_time
-                self.detection_history.clear()
-                self.detection_history.append((current_time, True))
-            elif off_duty_elapsed >= self.leave_countdown_sec and not self._alarm_triggered:
-                # 离岗倒计时结束，触发告警
+                logger.debug(f"ROI {roi_id}: INIT → CONFIRMING_ON_DUTY")
+
+        elif self.state == self.STATE_CONFIRMING_ON_DUTY:
+            # 上岗确认中：需要持续检测到人
+            elapsed = (current_time - self.state_start_time).total_seconds()
+
+            if detection_ratio == 0:
+                # 人消失了，回到INIT
+                self.state = self.STATE_INIT
+                self.state_start_time = current_time
+                self.detection_window.clear()
+                logger.debug(f"ROI {roi_id}: CONFIRMING_ON_DUTY → INIT (人消失)")
+            elif elapsed >= self.confirm_on_duty_sec and detection_ratio >= 0.7:
+                # 上岗确认成功（命中率>=70%）
+                self.state = self.STATE_ON_DUTY
+                self.state_start_time = current_time
+                self.alert_cooldowns.clear()  # 确认在岗后清除冷却记录
+                logger.info(f"ROI {roi_id}: CONFIRMING_ON_DUTY → ON_DUTY (上岗确认成功)")
+
+        elif self.state == self.STATE_ON_DUTY:
+            # 在岗状态：监控是否离岗
+            if detection_ratio == 0:
+                # 滑动窗口内完全没有人，进入离岗确认
+                self.state = self.STATE_CONFIRMING_OFF_DUTY
+                self.state_start_time = current_time
+                logger.debug(f"ROI {roi_id}: ON_DUTY → CONFIRMING_OFF_DUTY")
+
+        elif self.state == self.STATE_CONFIRMING_OFF_DUTY:
+            # 离岗确认中：需要持续未检测到人
+            elapsed = (current_time - self.state_start_time).total_seconds()
+
+            if roi_has_person:
+                # 人回来了，回到ON_DUTY
+                self.state = self.STATE_ON_DUTY
+                self.state_start_time = current_time
+                logger.debug(f"ROI {roi_id}: CONFIRMING_OFF_DUTY → ON_DUTY (人回来了)")
+            elif elapsed >= self.confirm_off_duty_sec and detection_ratio == 0:
+                # 离岗确认成功，进入倒计时
+                self.state = self.STATE_OFF_DUTY_COUNTDOWN
+                self.state_start_time = current_time
+                self._leave_start_time = self.state_start_time  # 记录离开时间
+                logger.info(f"ROI {roi_id}: CONFIRMING_OFF_DUTY → OFF_DUTY_COUNTDOWN (离岗确认成功)")
+
+        elif self.state == self.STATE_OFF_DUTY_COUNTDOWN:
+            # 离岗倒计时中：等待告警触发
+            elapsed = (current_time - self.state_start_time).total_seconds()
+
+            if roi_has_person:
+                # 倒计时期间人回来了，回到ON_DUTY（未触发告警）
+                self.state = self.STATE_ON_DUTY
+                self.state_start_time = current_time
+                self._leave_start_time = None
+                logger.info(f"ROI {roi_id}: OFF_DUTY_COUNTDOWN → ON_DUTY (倒计时期间回来)")
+            elif elapsed >= self.leave_countdown_sec:
+                # 倒计时结束，触发告警
                 cooldown_key = f"{camera_id}_{roi_id}"
-                now = datetime.now()
-                if cooldown_key not in self.alert_cooldowns or (now - self.alert_cooldowns[cooldown_key]).total_seconds() > self.cooldown_sec:
+                if cooldown_key not in self.alert_cooldowns or \
+                   (current_time - self.alert_cooldowns[cooldown_key]).total_seconds() > self.cooldown_sec:
+
                     bbox = self._get_latest_bbox(tracks, roi_id)
-                    # 计算总离岗时长（从人离开到现在）
-                    total_leave_duration = (current_time - self._leave_start_time).total_seconds() if self._leave_start_time else 0
-                    elapsed_minutes = int(total_leave_duration / 60)
+                    total_off_duty_sec = (current_time - self._leave_start_time).total_seconds()
+                    elapsed_minutes = int(total_off_duty_sec / 60)
+
                     alerts.append({
                         "track_id": roi_id,
                         "camera_id": camera_id,
@@ -251,9 +300,38 @@ class LeavePostAlgorithm:
                         "alert_type": "leave_post",
                         "message": f"离岗 {elapsed_minutes} 分钟",
                     })
-                    self.alert_cooldowns[cooldown_key] = now
-                    self._alarm_triggered = True  # 标记已触发告警
-                    # alarm_id 由 main.py 通过 set_last_alarm_id() 回填
+
+                    self.alert_cooldowns[cooldown_key] = current_time
+                    self._alarm_triggered_time = current_time
+                    self.state = self.STATE_ALARMED
+                    # _last_alarm_id 由 main.py 通过 set_last_alarm_id() 回填
+                    logger.warning(f"ROI {roi_id}: OFF_DUTY_COUNTDOWN → ALARMED (告警触发)")
+
+        elif self.state == self.STATE_ALARMED:
+            # 已告警状态：等待人员回岗
+            if roi_has_person:
+                # 检测到人，进入回岗确认
+                self.state = self.STATE_CONFIRMING_ON_DUTY  # 复用上岗确认状态
+                self.state_start_time = current_time
+                logger.info(f"ROI {roi_id}: ALARMED → CONFIRMING_ON_DUTY (检测到人回岗)")
+
+        # 特殊处理：从CONFIRMING_ON_DUTY再次确认上岗时，如果有未结束的告警，发送resolve
+        if self.state == self.STATE_ON_DUTY and self._last_alarm_id:
+            # 回岗确认成功，发送resolve事件
+            duration_ms = int((current_time - self._leave_start_time).total_seconds() * 1000)
+            alerts.append({
+                "alert_type": "alarm_resolve",
+                "resolve_alarm_id": self._last_alarm_id,
+                "duration_ms": duration_ms,
+                "last_frame_time": current_time.strftime('%Y-%m-%d %H:%M:%S'),
+                "resolve_type": "person_returned",
+            })
+
+            # 清理告警追踪信息
+            self._last_alarm_id = None
+            self._leave_start_time = None
+            self._alarm_triggered_time = None
+            logger.info(f"ROI {roi_id}: 告警已解决（人员回岗）")
 
         return alerts
 
@@ -262,24 +340,36 @@ class LeavePostAlgorithm:
         self._last_alarm_id = alarm_id
 
     def reset(self):
-        self.state = self.STATE_WAITING
+        """重置算法状态"""
+        self.state = self.STATE_INIT
         self.state_start_time = None
-        self.detection_history.clear()
-        self.alarm_sent = False
-        self.last_person_time = None
-        self.alert_cooldowns.clear()
+        self.detection_window.clear()
         self._last_alarm_id = None
         self._leave_start_time = None
-        self._off_duty_start_time = None
-        self._alarm_triggered = False
+        self._alarm_triggered_time = None
+        self.alert_cooldowns.clear()
 
     def get_state(self, roi_id: str) -> Dict[str, Any]:
-        return {
+        """获取当前状态（用于调试和监控）"""
+        state_info = {
             "state": self.state,
-            "alarm_sent": self.alarm_sent,
-            "last_person_time": self.last_person_time,
+            "state_start_time": self.state_start_time.isoformat() if self.state_start_time else None,
+            "detection_ratio": self._get_detection_ratio(),
+            "window_size": len(self.detection_window),
         }
 
+        # 添加状态特定信息
+        if self.state == self.STATE_OFF_DUTY_COUNTDOWN and self.state_start_time:
+            elapsed = (datetime.now() - self.state_start_time).total_seconds()
+            state_info["countdown_remaining_sec"] = max(0, self.leave_countdown_sec - elapsed)
+
+        if self.state == self.STATE_ALARMED and self._leave_start_time:
+            total_off_duty_sec = (datetime.now() - self._leave_start_time).total_seconds()
+            state_info["total_off_duty_sec"] = total_off_duty_sec
+            state_info["alarm_id"] = self._last_alarm_id
+
+        return state_info
+
 
 class IntrusionAlgorithm:
     def __init__(