修改问题.md，且新增data_logger.py画图模块

data_logger.py

@@ -0,0 +1,189 @@
+"""逐周期保存控制数据，并在运行结束时生成三联曲线图。"""
+
+import csv
+from datetime import datetime
+import math
+from pathlib import Path
+
+
+CSV_FIELDS = (
+    "time_s",
+    "timestamp",
+    "target_flow_slm",
+    "measured_flow_slm",
+    "opening_pct",
+    "pressure_kpa",
+    "error_slm",
+    "motor_position",
+    "actual_dt_s",
+    "status",
+)
+
+
+class FlowRunRecorder:
+    """把每个控制周期写入 CSV，并在结束时输出一张三联图。"""
+
+    def __init__(self, output_directory, *, plot_dpi=160):
+        output_dir = Path(output_directory)
+        output_dir.mkdir(parents=True, exist_ok=True)
+
+        run_id = datetime.now().strftime("%Y%m%d_%H%M%S")
+        self.csv_path = output_dir / f"flow_run_{run_id}.csv"
+        self.image_path = output_dir / f"flow_run_{run_id}.png"
+        self.plot_dpi = int(plot_dpi)
+
+        self._file = self.csv_path.open("w", newline="", encoding="utf-8-sig")
+        self._writer = csv.DictWriter(self._file, fieldnames=CSV_FIELDS)
+        self._writer.writeheader()
+        self._file.flush()
+        self._first_timestamp = None
+        self.sample_count = 0
+        self._closed = False
+
+    def record(self, result):
+        """保存一个 ControlStepResult；每次写入后立即刷新到磁盘。"""
+        if self._closed:
+            raise RuntimeError("记录器已经关闭")
+
+        if self._first_timestamp is None:
+            self._first_timestamp = float(result.timestamp)
+        elapsed_s = max(0.0, float(result.timestamp) - self._first_timestamp)
+
+        self._writer.writerow(
+            {
+                "time_s": f"{elapsed_s:.6f}",
+                "timestamp": f"{float(result.timestamp):.6f}",
+                "target_flow_slm": self._format_value(result.target_flow_slm),
+                "measured_flow_slm": self._format_value(
+                    result.measured_flow_slm
+                ),
+                "opening_pct": self._format_value(result.opening_pct),
+                "pressure_kpa": self._format_value(result.pressure_kpa),
+                "error_slm": self._format_value(result.error_slm),
+                "motor_position": self._format_value(result.motor_position),
+                "actual_dt_s": self._format_value(result.actual_dt_s),
+                "status": result.status,
+            }
+        )
+        self._file.flush()
+        self.sample_count += 1
+
+    def finalize(self):
+        """关闭 CSV 并生成 PNG；无采样点时只保留 CSV。"""
+        self.close()
+        if self.sample_count == 0:
+            return None
+        self._create_plot()
+        return self.image_path
+
+    def close(self):
+        if not self._closed:
+            self._file.flush()
+            self._file.close()
+            self._closed = True
+
+    def _create_plot(self):
+        # 使用无界面后端，保证从终端运行和无显示器环境都能保存图片。
+        import matplotlib
+
+        matplotlib.use("Agg")
+        import matplotlib.pyplot as plt
+
+        time_s = []
+        target_flow = []
+        measured_flow = []
+        opening = []
+        pressure = []
+
+        with self.csv_path.open("r", newline="", encoding="utf-8-sig") as file:
+            for row in csv.DictReader(file):
+                time_s.append(float(row["time_s"]))
+                target_flow.append(self._float_or_nan(row["target_flow_slm"]))
+                measured_flow.append(
+                    self._float_or_nan(row["measured_flow_slm"])
+                )
+                opening.append(self._float_or_nan(row["opening_pct"]))
+                pressure.append(self._float_or_nan(row["pressure_kpa"]))
+
+        figure, axes = plt.subplots(
+            3,
+            1,
+            figsize=(12, 10),
+            sharex=True,
+            constrained_layout=True,
+        )
+        figure.suptitle("Gas Flow Control Response", fontsize=15)
+
+        axes[0].plot(
+            time_s,
+            measured_flow,
+            color="#1565C0",
+            linewidth=1.4,
+            label="Measured flow",
+        )
+        axes[0].plot(
+            time_s,
+            target_flow,
+            color="#D84315",
+            linewidth=1.5,
+            linestyle="--",
+            label="Target flow",
+        )
+        axes[0].set_ylabel("Flow (SLM)")
+        axes[0].set_title("Flow response")
+        axes[0].legend(loc="best")
+
+        axes[1].plot(
+            time_s,
+            opening,
+            color="#2E7D32",
+            linewidth=1.4,
+        )
+        axes[1].set_ylabel("Opening (%)")
+        axes[1].set_title("Valve opening")
+        axes[1].set_ylim(-2, 102)
+
+        if any(math.isfinite(value) for value in pressure):
+            axes[2].plot(
+                time_s,
+                pressure,
+                color="#6A1B9A",
+                linewidth=1.4,
+            )
+        else:
+            axes[2].text(
+                0.5,
+                0.5,
+                "No pressure data",
+                transform=axes[2].transAxes,
+                ha="center",
+                va="center",
+                color="gray",
+            )
+        axes[2].set_ylabel("Pressure (kPa)")
+        axes[2].set_xlabel("Time (s)")
+        axes[2].set_title("Pressure")
+
+        for axis in axes:
+            axis.grid(True, alpha=0.3, linestyle="--")
+            axis.margins(x=0)
+
+        figure.savefig(self.image_path, dpi=self.plot_dpi, bbox_inches="tight")
+        plt.close(figure)
+
+    @staticmethod
+    def _format_value(value):
+        if value is None:
+            return ""
+        number = float(value)
+        return "" if not math.isfinite(number) else f"{number:.6f}"
+
+    @staticmethod
+    def _float_or_nan(value):
+        if value in (None, ""):
+            return math.nan
+        try:
+            return float(value)
+        except (TypeError, ValueError):
+            return math.nan
+