进阶：球路 FSM 可选 · 赛季附录Advanced: Ball Path FSM Optional · Season Appendix

4.1 为什么需要更复杂的状态机？4.1 Why Do We Need More Complex State Machines?

上一节的 PushBack Block 系统已经有 8 个状态了。但在某些赛季，球路系统还要处理更复杂的情况：The PushBack Block system from the previous section already had 8 states. But in some seasons, the ball path system needs to handle even more complex situations:

• 颜色分拣 — 我方球和对方球颜色不同，要自动识别Color sorting — our balls and opponent balls are different colors, requiring automatic identification
• 多种射球目标 — 高杆、中杆、吐球，每种力度和方向不同Multiple scoring targets — high stake, mid stake, eject — each needs different power and direction
• 球的排队管理 — 球在机器人内部排队等候，先进先出Ball queue management — balls line up inside the robot, first in first out

4.2 颜色检测 + 分拣逻辑4.2 Color Detection + Sorting Logic

2026 赛季 High Stakes 的球分红蓝两色。机器人需要：In the 2026 High Stakes season, balls come in red and blue. The robot needs to:

1. 吸入球Intake the ball
2. 光学传感器检测颜色Detect color with an optical sensor
3. 我方球 → 继续送到射球位置Our ball → continue to the scoring position
4. 对方球 → 反转吐出来Opponent ball → reverse and eject

// 简化的颜色分拣逻辑
void store() {
  // 吸取电机一直转
  intakeMotor.spin(forward);

  // 光学传感器检测到球了
  if (colorSensor.isNearObject()) {
    // 判断颜色
    if (colorSensor.hue() > 200) {
      // 蓝色球（假设我方是蓝色）→ 继续送
      indexMotor.spin(forward);
    } else {
      // 红色球（对方）→ 反转吐出
      indexMotor.spin(reverse);
    }
  }
}

// 简化的颜色分拣逻辑
void store() {
  // 吸取电机一直转
  intakeMotor.spin(forward);

  // 光学传感器检测到球了
  if (colorSensor.isNearObject()) {
    // 判断颜色
    if (colorSensor.hue() > 200) {
      // 蓝色球（假设我方是蓝色）→ 继续送
      indexMotor.spin(forward);
    } else {
      // 红色球（对方）→ 反转吐出
      indexMotor.spin(reverse);
    }
  }
}

// 简化的颜色分拣逻辑
void store() {
  // 吸取电机一直转
  intakeMotor.move(127);

  // 光学传感器检测到球了
  if (colorSensor.get_proximity() > 200) {
    // 判断颜色
    if (colorSensor.get_hue() > 200) {
      // 蓝色球（假设我方是蓝色）→ 继续送
      indexMotor.move(127);
    } else {
      // 红色球（对方）→ 反转吐出
      indexMotor.move(-127);
    }
  }
}

4.3 状态数量爆炸？不怕4.3 Too Many States? No Worries

当你的系统有很多状态时，代码量确实会增加。但只要遵循状态机的模式，结构始终是清晰的：When your system has many states, the code does get longer. But as long as you follow the state machine pattern, the structure stays clear:

1. enum class 列出所有状态enum class lists all states
2. 每个状态对应一个函数，处理该状态下的具体动作Each state maps to a function that handles the specific action
3. switch 把状态和函数连接起来switch connects states to functions
4. 状态切换在别的地方触发（按钮、传感器、自动逻辑）State transitions are triggered elsewhere (buttons, sensors, auto logic)

不管是 3 个状态还是 30 个状态，结构都一模一样。区别只是 switch 里的 case 多了几行。Whether you have 3 states or 30, the structure is identical. The only difference is a few more case lines in the switch.

4.4 思考题4.4 Think About It