用时间控制机构Controlling Mechanisms with Time

1.1 最简单的方法：转几秒停下来1.1 The Simplest Way: Spin for a Few Seconds

在 Level 1 里，我们学会了让电机转动。现在假设机器人有一个升降臂（Lift），我们想让它升到一定高度。In Level 1, we learned how to make motors spin. Now suppose your robot has a lift arm, and we want to raise it to a certain height.

最直觉的方法：让电机转，等几秒，然后停。The most intuitive way: spin the motor, wait a few seconds, then stop.

// 升降臂上升 2 秒
LiftMotor.spin(forward);
wait(2, seconds);
LiftMotor.stop();

// 升降臂上升 2 秒
LiftMotor.spin(forward);
wait(2, seconds);
LiftMotor.stop();

// 升降臂上升 2 秒
LiftMotor.move(127);
pros::delay(2000);
LiftMotor.move(0);

逻辑很简单：开始转 → 等一会儿 → 停。The logic is simple: start spinning → wait → stop.

1.2 先碰壁再教1.2 Learn by Hitting the Wall

时间控制看起来很好用，但你很快会发现一个问题：Time-based control seems great, but you'll quickly discover a problem:

除了电池电压，还有这些因素会影响结果：Besides battery voltage, these factors also affect the result:

• 负载变化 — 臂上夹着球和空臂，阻力不一样Load changes — the arm holding a ball vs. empty has different resistance
• 摩擦力 — 机械磨损后摩擦变大，同样时间转得更少Friction — mechanical wear increases friction, resulting in less rotation in the same time
• 齿轮打滑 — 偶尔打滑一下，时间到了但没到位Gear slipping — occasional slips mean time is up but the arm hasn't reached the target

1.3 动手练习1.3 Practice

// 吸球
IntakeMotor.spin(forward);
wait(3, seconds);
IntakeMotor.stop();

// 暂停
wait(1, seconds);

// 吐球
IntakeMotor.spin(reverse);
wait(1, seconds);
IntakeMotor.stop();

// 吸球
IntakeMotor.spin(forward);
wait(3, seconds);
IntakeMotor.stop();

// 暂停
wait(1, seconds);

// 吐球
IntakeMotor.spin(reverse);
wait(1, seconds);
IntakeMotor.stop();

// 吸球
IntakeMotor.move(127);
pros::delay(3000);
IntakeMotor.move(0);

// 暂停
pros::delay(1000);

// 吐球
IntakeMotor.move(-127);
pros::delay(1000);
IntakeMotor.move(0);