During AUTO_MISSION (3) flights on PX4 v1.15.4, the vehicle sometimes suddenly descends even when nav_state does not change (setpoint briefly goes to 0), and in other cases nav_state jumps from AUTO_MISSION (3) to AUTO_RTL (5). Logs show z_valid = 1 (height estimate valid), battery normal (no battery failsafe), RC link OK, GF_ACTION = 2, and mission state 0 prior to the event. Disabling multi-EKF did not eliminate the issue.
Additionally, I observed multiple clip triggers during mission flights. However, the vehicle does not always descend immediately when clip is triggered, and in manual/position mode I cannot reproduce the issue (the drone remains stable regardless of aggressive maneuvers).
I’d appreciate guidance on:
-
Which conditions or code paths could force a zero setpoint/auto-descent or trigger RTL in mission mode.
-
Could repeated clip events contribute to the sudden descent behavior?
-
Which files/functions are most relevant for debugging (e.g.
navigator_main.cpp,mission.cpp,mission_base.cpp, and failsafe logic).
摘要（中文，PX4 v1.15.4）
在 PX4 v1.15.4 的任务模式（3）飞行中，飞机有时在 nav_state 未变化的情况下出现突然下降（setpoint 短暂归零），也有出现从 任务模式（3）直接切到 自动返航（5） 的情况。日志显示 z_valid = 1（高度估计有效）、电量正常（未触发电量保护）、RC 正常、GF_ACTION = 2，且事件发生前 mission 状态为 0。关闭多 EKF 实例后问题仍存在。
另外，日志中在任务飞行过程中多次出现 clip 触发，但并不是每次触发都会导致无人机立即下降；而在手动/定点模式下，无论如何做机动飞行，都不会触发自动降落。
想请教社区：
-
在任务模式下，哪些条件或代码路径可能导致 setpoint 置零/自动下降 或 触发 RTL？
-
clip 是否可能是导致突然下降的原因之一？
-
调试时应重点关注哪些代码（如
navigator_main.cpp、mission.cpp、mission_base.cpp及相关 failsafe 逻辑）？
