1.原先程序启动后会先下发关闭位置，再开始闭环，现在启动后直接从当前阀门开度（默认全开）开始闭环。删除了safe_close相关的代码

2.新增open_loop.py进行开环控制，记录控流阀前后流量和压力数据，方便后面辨识拟合，以及观察动态特性。
3.新增README.md

flow_control.py

@@ -166,12 +166,9 @@ class FlowControlLoop:
         self.faulted = False
         self.running = True
 
-    def stop(self, close_valve=True):
-        """停止 PID；默认同时安全关阀。"""
+    def stop(self):
+        """停止 PID；阀门保持当前开度（默认全开）。"""
         self.running = False
-        self.pid.reset(initial_output=0.0)
-        if close_valve:
-            return self.safe_close("STOP_REQUESTED")
         return True
 
     def step(self, now=None):
@@ -290,39 +287,6 @@ class FlowControlLoop:
             actual_dt_s=actual_dt,
         )
 
-    def safe_close(self, reason="UNSPECIFIED"):
-        """尝试把阀门置于关闭端；失败时返回 False 并详细记录。"""
-        try:
-            success = bool(
-                self.hardware.set_motor_position(
-                    self.motor_closed_position,
-                    channel=self.motor_channel,
-                )
-            )
-        except Exception as exc:
-            self._log(
-                "critical",
-                "SAFE_CLOSE_FAILED reason=%s exception=%s context=%s",
-                reason,
-                repr(exc),
-                self._context(),
-            )
-            return False
-
-        if success:
-            self.last_opening_pct = 0.0
-            self.last_motor_position = self.motor_closed_position
-            self._log("warning", "阀门已安全关闭，原因=%s", reason)
-            return True
-
-        self._log(
-            "critical",
-            "SAFE_CLOSE_FAILED reason=%s hardware_return=False context=%s",
-            reason,
-            self._context(),
-        )
-        return False
-
     def _read_flow(self):
         try:
             value = self.hardware.get_flow(self.flow_channel)
@@ -409,8 +373,6 @@ class FlowControlLoop:
         context.update(extra_context or {})
         self.faulted = True
         self.running = False
-        close_ok = self.safe_close(code)
-        context["safe_close_success"] = close_ok
         fault = FlowControlFault(code, stage, message, context)
         self._log("critical", "%s", fault)
         raise fault