紧急通告：3.2版固件PosHold涉及飞行安全的BUG

今早确认一条官方消息：

AC 3.2 BUG
New issue
Copter: landing detector false-positive when slowing down in PosHold mode

We've had one incident of a false-positive on the landing-detector with AC3.2. The cause was a slight motor imbalance combined with a slow-down from fast-forward flight (15m/s) in PosHold mode. It seems during the slow-down that the propellers created extra lift which allowed the motors to go to near zero for an extended period (>1sec).



这个BUG 使使用3.2正式版固件的PosHold模式时，飞行器空中停轉！多数发生在POS HOLD 速度超过15 M/S 或者马达转速低的时候！

让我想起了前段时间一位模友高速飞行后飞行器直接马达停转炸机的视频，轻各位留意！

虽然我们很少飞到15米/秒的速度，但大家还是要注意！

还有一个BUG报告：
There seem to be some issues in the handling of the do-set-home mission command.

To reproduce the issue try this:
1. create a mission with a do-set-home command with zero lat, lon and alt followed by a waypoint.
2. when the do-set-home command executes, EKF produces a very large position variance which leads to the AHRS switching back and forth between DCM and EKF
3. the large position variance leads to an arithmetic exception in the dataflash logging of EKF as it tries to squeeze the variance into an int16_t.
4. the vehicle tries to fly off to a location that seems to be the waypoint target location plus the offset from the original home to the new home

3.2.1版固件信息：
Enhancements:
a) reduced twitch when passing Spline waypoints
b) Faster disarm after landing in Auto, Land, RTL
c) Pixhawk LED turns green before arming only after GPS HDOP falls below 2.3 (only in flight modes requiring GPS)
2) Safety Features:
a) Add desired descent rate check to reduce chance of false-positive on landing check
b) improved MPU6k health monitoring and re-configuration in case of in-flight failure
c) Rally point distance check reduced to 300m (reduces chance of RTL to far away forgotten Rally point)
d) auto-disarm if vehicle is landed for 15seconds even in Auto, Guided, RTL, Circle
e) fence breach while vehicle is landed causes vehicle to disarm (previously did RTL)
3) Bug Fixes:
a) Check flight mode even when arming from GCS (previously it was possible to arm in RTL mode if arming was initiated from GCS)
b) Send vehicle target destination in RTL, Guided (allows GCS to show where vehicle is flying to in these modes)
c) PosHold wind compensation fix
Thanks to Raph for the video. This is actually a video from AC3.2 until we have one specific to AC3.2.1.

现在官方已推出3.2.1版固件，期待社区尽快发出社区版专用的3.2.1系列固件！