1. System Configuration
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Firmware version: PX4 v1.14.3
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Vehicle type: Standard VTOL
2. Problem Description
During a mission flight (https://drive.google.com/file/d/1Q0gEKXC9RUsEw9KI3TNK0r1E8pADIbI_/view?usp=drive_link), the vehicle first took off in multicopter mode and climbed to the target altitude. It then transitioned into fixed-wing mode, after which I controlled the aircraft using Offboard velocity commands.
In previous flights (https://drive.google.com/file/d/1hA-IeU19F-2g4MGiAY5xYAbBhN0dhI7P/view?usp=drive_link), this control method worked reliably. The aircraft was able to follow the commanded velocity setpoints in fixed-wing mode without any issues. The successful log figure is shown as follows:
However, in this particular flight, immediately after switching to Offboard mode, an abnormal behavior occurred:
the fixed-wing roll_rate could not track the commanded values, leading to increasing control deviation and eventually causing the vehicle to lose control and crash. The failed log figure is shown as follows:
At the moment, I am unable to determine the root cause. Possible suspects include:
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Aileron or other actuator saturation/abnormal response in fixed-wing mode
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A malfunction or instability in TECS (Total Energy Control System) during Offboard control
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A control-mode or attitude-controller inconsistency introduced during the VTOL transition
I would appreciate help from the PX4 community in analyzing what might have caused the roll_rate tracking failure, and what further diagnostics or tests I can run to narrow down the issue.
