init

fan_autopid.py

@@ -0,0 +1,105 @@
+import pigpio
+import time
+
+PWM_PIN = 18
+TACH_PIN = 23
+
+TARGET_TEMP = 40.0
+
+# 初始参数
+Kp = 1.0
+Ki = 0.0
+Kd = 0.0
+
+integral = 0
+last_error = 0
+last_temp = None
+
+pulse_count = 0
+last_time = time.time()
+
+pi = pigpio.pi()
+
+pi.set_PWM_frequency(PWM_PIN, 25000)
+pi.set_PWM_range(PWM_PIN, 255)
+
+def tach_cb(gpio, level, tick):
+    global pulse_count
+    pulse_count += 1
+
+pi.set_mode(TACH_PIN, pigpio.INPUT)
+pi.set_pull_up_down(TACH_PIN, pigpio.PUD_UP)
+pi.callback(TACH_PIN, pigpio.FALLING_EDGE, tach_cb)
+
+last_tem = 0
+
+def get_temp():
+    global last_tem
+    with open("/sys/class/thermal/thermal_zone0/temp") as f:
+        temp_filtered = 0.8 * last_tem + 0.2 * int(f.read()) / 1000
+        last_tem = temp_filtered
+        return temp_filtered
+
+def get_rpm():
+    global pulse_count, last_time
+    now = time.time()
+    dt = now - last_time
+    count = pulse_count
+    pulse_count = 0
+    last_time = now
+    return (count / 2) / dt * 60
+
+def adaptive_pid(temp):
+    global Kp, Ki, Kd, integral, last_error, last_temp
+
+    error = temp - TARGET_TEMP
+    integral += error
+    integral = max(min(integral, 100), -100)
+    derivative = error - last_error
+
+    # ===== 自适应调参 =====
+
+    if last_temp is not None:
+        temp_rate = temp - last_temp
+
+        # 响应太慢 → 增大 Kp
+        if abs(error) > 5 and abs(temp_rate) < 0.1:
+            Kp += 0.001
+
+        # 震荡 → 降低 Kp，提高 Kd
+        if abs(temp_rate) > 0.5:
+            Kp *= 0.95
+            Kd += 0.0005
+
+        # 长期偏差 → 增大 Ki
+        if abs(error) > 2:
+            Ki += 0.0001
+
+    last_temp = temp
+    last_error = error
+
+    output = Kp * error + Ki * integral + Kd * derivative
+
+    return output
+
+try:
+    while True:
+        temp = get_temp()
+        rpm = get_rpm()
+
+        out = adaptive_pid(temp)
+
+        duty = max(10, min(255, int(out * 5)))
+
+        pi.set_PWM_dutycycle(PWM_PIN, duty)
+
+        print(f"\rT={temp:.1f}C RPM={rpm:.0f} PWM={duty} Kp={Kp:.2f} Ki={Ki:.2f} Kd={Kd:.2f}              ", end="")
+
+        time.sleep(0.05)
+
+except KeyboardInterrupt:
+    pass
+
+finally:
+    pi.set_PWM_dutycycle(PWM_PIN, 0)
+    pi.stop()