位置模式（多旋翼）

  

Position is an easy-to-fly RC mode in which roll and pitch sticks control acceleration over ground in the vehicle's left-right and forward-back directions (similar to a car's accelerator pedal), and throttle controls speed of ascent-descent. When the sticks are released/centered the vehicle will actively brake, level, and be locked to a position in 3D space — compensating for wind and other forces. With full stick deflection the vehicle accelerates initially with MPC_ACC_HOR_MAX ramping down until it reaches the final velocity MPC_VEL_MANUAL.

TIP

Position mode is the safest manual mode for new fliers. Unlike Altitude and Stabilized modes the vehicle will stop when the sticks are centered rather than continuing until slowed by wind resistance.

The diagram below shows the mode behaviour visually (for a mode 2 transmitter).

降落

该模式中降落是很容易的：

1. 使用横滚和俯仰杆控制无人机水平位置于降落点上方。
2. 松开横滚和俯仰杆并给予足够的时间使其完全停止。
3. 轻轻下拉油门杆直到机体触碰地面。
4. 将油门杆一直向下拉以促进和加快着陆检测。
5. The vehicle will lower propeller thrust, detect the ground and automatically disarm (by default).

WARNING

While very rare on a well calibrated vehicle, sometimes there may be problems with landing.

• 如果机体无法停止水平移动：
  • You can still land under control in Altitude mode. 方法与上述相同，除了您必须使用横滚和俯仰杆手动确保机体保持在降落点上方。
  • 降落后检查 GPS 和磁罗盘方向，并校准。
• If the vehicle does not detect the ground/landing and disarm:
  • After the vehicle is on the ground switch to Stabilized mode keeping the throttle stick low, and manually disarm using a gesture or other command. 或者，当机体已经在地面上时，您也可以使用断电开关。

技术总结

遥控模式下，横滚、俯仰、油门 (RPT) 杆控制相应轴/方向的运动。 摇杆居中使机体水平并将其保持在固定的高度和位置并抗风。

• Centered roll, pitch, throttle sticks (within RC deadzone MPC_HOLD_DZ) hold x, y, z position steady against any disturbance like wind.
• 外部中心：
  • Roll/Pitch sticks control horizontal acceleration over ground in the vehicle's left-right and forward-back directions (respectively).
  • Throttle stick controls speed of ascent-descent.
  • 偏航摇杆控制水平面上方的角度旋转速率。
• 起飞：
  • 降落时，如果将油门杆抬高至 62.5%（从油门杆最低开始的整个范围），无人机将起飞。
• Global position estimate is required.
• Manual control input is required (such as RC control, joystick).
  • Roll, Pitch, Throttle: Assistance from autopilot to hold position against wind.
  • Yaw: Assistance from autopilot to stabilize the attitude rate. Position of RC stick maps to the rate of rotation of vehicle in that orientation.

参数

All the parameters in the Multicopter Position Control group are relevant. 下面列出了一些特别值得注意的参数。

参数	描述
MPC_HOLD_DZ	启用位置保持的摇杆死区。 默认值：0.1（摇杆全行程的 10％）。
MPC_Z_VEL_MAX_UP	最大垂直上升速度。 默认：3m/s。
MPC_Z_VEL_MAX_DN	最大垂直下降速度。 默认：1m/s。
MPC_LAND_ALT1	触发第一阶段降速的高度。 Below this altitude descending velocity gets limited to a value between MPC_Z_VEL_MAX_DN (or MPC_Z_V_AUTO_DN) and MPC_LAND_SPEED. Value needs to be higher than MPC_LAND_ALT2. Default 10m.
MPC_LAND_ALT2	触发第二阶段降速的高度。 Below this altitude descending velocity gets limited to MPC_LAND_SPEED. Value needs to be lower than "MPC_LAND_ALT1". Default 5m.
RCX_DZ	RC dead zone for channel X. The value of X for throttle will depend on the value of RC_MAP_THROTTLE. For example, if the throttle is channel 4 then RC4_DZ specifies the deadzone.
MPC_XXXX	大多数 MPC_xxx参数会影响此模式下的飞行行为（至少在某种程度上）。 For example, MPC_THR_HOVER defines the thrust at which a vehicle will hover.
MPC_POS_MODE	从摇杆输入到机体动作的转换策略。 From PX4 v1.12 the default (Acceleration based) is that stick position controls acceleration (in a similar way to a car accelerator pedal). 其他选项允许操纵杆偏转直接控制地面速度，有或没有平滑和加速度限制。
MPC_ACC_HOR_MAX	最大水平加速度。
MPC_VEL_MANUAL	最大水平速度。
MPC_LAND_SPEED	Landing descend rate. Landing descend rate. Default 0.7 m/s.

附加信息

位置丢失/安全

位置模式依赖于一个可接受的位置估计。 If the estimate falls below acceptable levels, for example due to GPS loss, this may trigger a Position (GPS) Loss Failsafe. 如果估计值低于可接受的水平，例如由于 GPS 丢失，这可能会触发位置 (GPS) 丢失故障保护 根据配置，是否有遥控器，以及是否有足够的高度估计，PX4 可能会切换到高度模式、手动模式、降落模式或终止。

See Also

• Position Slow Mode