高精度伺服驱动太阳能跟踪平台：最大化光能捕获

组件与物料清单

所需工具与辅助材料

• 手工具、螺丝螺母（制作支架）
• 木块（作为水平舵机固定底座）
• 3mm 厚铝条（约 2cm 宽，折弯成 L 型支架）
• 薄钢带（风管固定带，预留安装孔，连接面板与俯仰舵机）

软件工具

• Arduino IDE
• Microsoft Excel（记录实验数据）

项目原理

采用双 180° 舵机 + 四角光敏电阻实现太阳能板双轴跟踪。控制器读取四角光照差异，驱动舵机微调面板姿态，使四角光照均衡（即面板正对光源）。系统包含：

• 状态指示 RGB LED（绿=跟踪中，红=禁用，蓝=诊断模式）
• 两枚按钮：绿键启用跟踪，红键禁用并脱离舵机
• 串口命令接口：支持手动定位、平滑移动、自动跟踪开关等指令

核心算法：光照差分跟踪

读取四 LDR 值：LDR1(左上)、LDR2(右上)、LDR3(左下)、LDR4(右下)

• 水平(扭转)轴：比较左侧平均 (LDR1+LDR3)/2 与右侧平均 (LDR2+LDR4)/2，亮侧方向转动。
• 垂直(俯仰)轴：比较上侧平均 (LDR1+LDR2)/2 与下侧平均 (LDR3+LDR4)/2，亮侧方向转动。
• 每次扫描步进 5°，配合 125ms 循环周期，实现平滑跟踪。

平滑移动机制

舵机直接写入目标角度会全速运动，导致机械冲击。代码实现 smoothMoveTwist() 与 smoothMoveTilt()：每循环仅步进 1°，直到到达目标角度，避免剧烈抖动。

串口命令协议

格式：CCCCVVV（前 2 位命令类，后 3 位参数值）

完整 Arduino 代码 (Q2 v2.0)

// Scott Mangiacotti, Tucson, Arizona, May 2018
#include <Servo.h>

const int GIVE_BACK_TIME = 125;  // 主循环让出时间 ms

// 引脚定义
const int I_RED_BUTTON_PIN = 4;
const int I_GREEN_BUTTON_PIN = 2;
const int I_LDR1_PIN = A3;  // 左上
const int I_LDR2_PIN = A2;  // 右上
const int I_LDR3_PIN = A1;  // 左下
const int I_LDR4_PIN = A0;  // 右下
const int O_RED_LED_PIN = 9;
const int O_GREEN_LED_PIN = 11;
const int O_BLUE_LED_PIN = 10;
const int O_TWIST_SERVO_PIN = 5;
const int O_TILT_SERVO_PIN = 6;

// 全局变量
bool gRunning = false;
bool gTrackToLightEnabled = false;
bool gVerboseDiagMode = false;
Servo gServoTwist; int gServoTwistPositionCommand; bool gServoTwistMoveIP;
Servo gServoTilt;  int gServoTiltPositionCommand;  bool gServoTiltMoveIP;
int gLDR1, gLDR2, gLDR3, gLDR4;

void setup() {
  Serial.begin(9600);
  pinMode(I_RED_BUTTON_PIN, INPUT);
  pinMode(I_GREEN_BUTTON_PIN, INPUT);
  pinMode(O_RED_LED_PIN, OUTPUT);
  pinMode(O_GREEN_LED_PIN, OUTPUT);
  pinMode(O_BLUE_LED_PIN, OUTPUT);
  startup();
}

void loop() {
  // 串口命令处理
  if (Serial.available() > 0) {
    int code = Serial.parseInt();
    processSerialMessage(code);
  }
  // 绿键启用
  if (digitalRead(I_GREEN_BUTTON_PIN) == HIGH && !gRunning) { enableTracking(); gTrackToLightEnabled = true; }
  // 红键禁用
  if (digitalRead(I_RED_BUTTON_PIN) == HIGH && gRunning) { disableTracking(); }

  readPhotoResistors();

  if (gRunning) {
    if (gTrackToLightEnabled) trackToLightSensors();
    else { smoothMoveTwist(); smoothMoveTilt(); }
  }
  delay(GIVE_BACK_TIME);
}

// 启用跟踪：挂载舵机、绿灯亮
void enableTracking() {
  gRunning = true;
  gServoTwist.attach(O_TWIST_SERVO_PIN);
  gServoTilt.attach(O_TILT_SERVO_PIN);
  digitalWrite(O_GREEN_LED_PIN, HIGH); digitalWrite(O_RED_LED_PIN, LOW);
  Serial.println("servos enabled");
}

// 禁用跟踪：卸载舵机、红灯亮
void disableTracking() {
  gRunning = false; gTrackToLightEnabled = false;
  gServoTwist.detach(); gServoTilt.detach();
  gServoTwistPositionCommand = gServoTwist.read(); gServoTwistMoveIP = false;
  gServoTiltPositionCommand = gServoTilt.read(); gServoTiltMoveIP = false;
  digitalWrite(O_RED_LED_PIN, HIGH); digitalWrite(O_GREEN_LED_PIN, LOW);
  Serial.println("servos disabled");
}

// 自动跟踪光源核心逻辑
void trackToLightSensors() {
  float fTop = (gLDR1 + gLDR2) / 2.0;
  float fBottom = (gLDR3 + gLDR4) / 2.0;
  float fLeft = (gLDR1 + gLDR3) / 2.0;
  float fRight = (gLDR2 + gLDR4) / 2.0;
  int moveAmt = 5;
  int twistCmd = gServoTwist.read();
  int tiltCmd = gServoTilt.read();

  if (fLeft > fRight) twistCmd += moveAmt; else if (fRight > fLeft) twistCmd -= moveAmt;
  if (fTop > fBottom) tiltCmd += moveAmt; else if (fBottom > fTop) tiltCmd -= moveAmt;

  twistCmd = constrain(twistCmd, 0, 179);
  tiltCmd = constrain(tiltCmd, 45, 135);  // 俯仰限幅防机械干涉

  gServoTwist.write(twistCmd);
  gServoTilt.write(tiltCmd);

  if (gVerboseDiagMode) {
    Serial.print("LDRs: "); Serial.print(gLDR1); Serial.print(","); Serial.print(gLDR2); Serial.print(","); Serial.print(gLDR3); Serial.print(","); Serial.println(gLDR4);
    Serial.print("Avg: "); Serial.print(fTop); Serial.print(","); Serial.print(fBottom); Serial.print(","); Serial.print(fLeft); Serial.print(","); Serial.println(fRight);
    Serial.print("Cmd: "); Serial.print(twistCmd); Serial.print(","); Serial.println(tiltCmd);
  }
}

// 读取四路 LDR
void readPhotoResistors() {
  gLDR1 = analogRead(I_LDR1_PIN);
  gLDR2 = analogRead(I_LDR2_PIN);
  gLDR3 = analogRead(I_LDR3_PIN);
  gLDR4 = analogRead(I_LDR4_PIN);
}

// 平滑移动水平舵机
void smoothMoveTwist() {
  const int step = 1;
  int cur = gServoTwist.read();
  if (cur == gServoTwistPositionCommand) { gServoTwistMoveIP = false; return; }
  gServoTwistMoveIP = true;
  int next = cur + (cur < gServoTwistPositionCommand ? step : -step);
  next = constrain(next, 0, 179);
  gServoTwist.write(next);
}

// 平滑移动垂直舵机
void smoothMoveTilt() {
  const int step = 1;
  int cur = gServoTilt.read();
  if (cur == gServoTiltPositionCommand) { gServoTiltMoveIP = false; return; }
  gServoTiltMoveIP = true;
  int next = cur + (cur < gServoTiltPositionCommand ? step : -step);
  next = constrain(next, 0, 179);
  gServoTilt.write(next);
}

// 串口命令分发
void processSerialMessage(int code) {
  int cmd = code / 1000;
  int val = code % 1000;
  Serial.print("code: "); Serial.println(code);
  Serial.print("cmd: "); Serial.println(cmd);
  Serial.print("val: "); Serial.println(val);

  if (cmd == 10) {  // 杂项
    switch (val) {
      case 0: gVerboseDiagMode = true; digitalWrite(O_BLUE_LED_PIN, HIGH); Serial.println("diag on"); break;
      case 1: gVerboseDiagMode = false; digitalWrite(O_BLUE_LED_PIN, LOW); Serial.println("diag off"); break;
      case 2: reportProductInfo(); break;
      case 3: digitalWrite(O_RED_LED_PIN, HIGH); break;
      case 4: digitalWrite(O_RED_LED_PIN, LOW); break;
      case 5: digitalWrite(O_GREEN_LED_PIN, HIGH); break;
      case 6: digitalWrite(O_GREEN_LED_PIN, LOW); break;
      case 7: digitalWrite(O_BLUE_LED_PIN, HIGH); break;
      case 8: digitalWrite(O_BLUE_LED_PIN, LOW); break;
      case 9: Serial.print("LDR1: "); Serial.println(gLDR1); break;
      case 10: Serial.print("LDR2: "); Serial.println(gLDR2); break;
      case 11: Serial.print("LDR3: "); Serial.println(gLDR3); break;
      case 12: Serial.print("LDR4: "); Serial.println(gLDR4); break;
      case 13: enableTracking(); break;
      case 14: disableTracking(); break;
      case 19: if (gRunning && !gServoTwistMoveIP && !gServoTiltMoveIP) { gServoTwistPositionCommand = 90; gServoTiltPositionCommand = 90; Serial.println("home 90°"); } break;
      case 21: if (gRunning) { gTrackToLightEnabled = true; Serial.println("track on"); } break;
      case 22: gTrackToLightEnabled = false; Serial.println("track off"); break;
      default: Serial.print("invalid val: "); Serial.println(val);
    }
  } else if (cmd == 11 && val >= 0 && val <= 179) {  // 水平舵机
    if (gRunning && !gServoTwistMoveIP) { gServoTwistPositionCommand = val; gServoTwistMoveIP = true; Serial.print("twist->"); Serial.println(val); }
  } else if (cmd == 12 && val >= 0 && val <= 179) {  // 垂直舵机
    if (gRunning && !gServoTiltMoveIP) { gServoTiltPositionCommand = val; gServoTiltMoveIP = true; Serial.print("tilt->"); Serial.println(val); }
  }
  Serial.println("-----");
}

// 自检启动序列
void startup() {
  int d = 500;
  reportProductInfo(); delay(d);
  processSerialMessage(10003); delay(d);  // 红灯亮
  processSerialMessage(10004); processSerialMessage(10005); delay(d);  // 红灭绿亮
  processSerialMessage(10006); processSerialMessage(10007); delay(d);  // 绿灭蓝亮
  processSerialMessage(10008); processSerialMessage(10009); processSerialMessage(10010); processSerialMessage(10011); processSerialMessage(10012); delay(d);  // 显示4 LDR
  enableTracking(); delay(d);
  processSerialMessage(10019); delay(d);  // 归中
  disableTracking();
  Serial.println("startup done");
}

void reportProductInfo() {
  Serial.println("q version 2");
  Serial.println("tucson, arizona usa");
  Serial.println("may 2018");
  Serial.println("checksum 58BA-D969-2F82-08FD-2078-2777-396D-E1AA");
}

3D 打印/机械结构文件

装配细节 STEP/ZIP 包：q2_assembly_details_RCbi893qzA.zip

原理图

Fritzing 原理图文件：q2_schematic_TVp7kakwNa.fzz