Investigation and Reproduction of the Issue
We investigate whether the behaviours was caused by the PX4 and QGC versions. Additionally, after the VTOL enters POSCTL mode, does using different guidance methods lead to a crash?
We tested various PX4 version(1.14.2, 1.15.2) and QGC(4.4.4, 4.4.0) versions. In each version, multiple guidance methods were also tested(MISSION, HOLD-MC-FW-MISSION, HOLD-MISSION, MC-FW-MISSION).
Ultimately, we found that crashes only occurred in PX4 version 1.15.2 and QGC version 4.4.4 and the operation is switching VTOL in MISSION directly.
| Number | Result | QGC Version | PX4 Firmware Version | QGC Operation after POSCTL mode |
|---|---|---|---|---|
| 1 | Crash | 4.4.4 | 1.15.2 | MISSION |
| 2 | Continue Mission | 4.4.4 | 1.15.2 | HOLD-MC-FW-MISSION |
| 3 | Continue Mission | 4.4.4 | 1.15.2 | HOLD-MISSION |
| 4 | Continue Mission | 4.4.4 | 1.15.2 | MC-FW-MISSION |
| 5 | Continue Mission | 4.4.4 | 1.14.2 | MISSION |
| 6 | Continue Mission | 4.4.4 | 1.14.2 | HOLD-MC-FW-MISSION |
| 7 | Continue Mission | 4.4.4 | 1.14.2 | HOLD-MISSION |
| 8 | Continue Mission | 4.4.4 | 1.14.2 | MC-FW-MISSION |
| 9 | Continue Mission | 4.4.0 | 1.14.2 | MISSION |
| 10 | Continue Mission | 4.4.0 | 1.14.2 | HOLD-MC-FW-MISSION |
| 11 | Continue Mission | 4.4.0 | 1.14.2 | HOLD-MISSION |
| 12 | Continue Mission | 4.4.0 | 1.14.2 | MC-FW-MISSION |
| 13 | Continue Mission | 4.4.0 | 1.15.2 | Wait for a while-MISSION |
| 14 | Continue Mission | 4.4.0 | 1.15.2 | Immediately-MISSION |
| 15 | Continue Mission | 4.4.0 | 1.15.2 | MISSION |
| 16 | Continue Mission | 4.4.0 | 1.15.2 | HOLD-MC-FW-MISSION |
| 17 | Continue Mission | 4.4.0 | 1.15.2 | HOLD-MISSION |
| 18 | Continue Mission | 4.4.0 | 1.15.2 | MC-FW-MISSION |
We frequently encountered errors when uploading flight paths to the QGC. We wanted to determine whether the crashes were caused by this issue.
| Number | Result | QGC Version | PX4 Firmware Version | Operation of Plan Uploading in QGC |
|---|---|---|---|---|
| 1 | Crash | 4.4.4 | 1.15.2 | "QGC already has a path |
| 2 | Crash | 4.4.4 | 1.15.2 | "QGC already has a path. After uploading a new path |
| 3 | Crash | 4.4.4 | 1.15.2 | QGC already has a path. Without uploading a new path, slide the control directly to take off. |
| 4 | Continue Mission | 4.4.4 | 1.15.2 | "QGC already has a path. After uploading a new path |
| 5 | Continue Mission | 4.4.4 | 1.15.2 | Upload the path, then start the program when NOT READY is displayed in red. |
| 6 | Continue Mission | 4.4.4 | 1.15.2 | QGC already has a path. After uploading a new path, slide the control to take off. |
| 7 | Continue Mission | 4.4.4 | 1.15.2 | QGC has no path. After uploading a new path, slide the control to take off. |
| 8 | Continue Mission | 4.4.4 | 1.15.2 | "Start the program first. Halfway through |
After testing various scenes, we found that crashes mainly occurred when the plan was not re-uploaded.
Consistent QGC ground station operations to avoid bug:
Try sliding to switch back to Mission. Maintain the same program breakpoint positions. Use PX4 version 1.15.2, QGC version 4.4.4. Ensure QGC remains Disconnected before starting simulation and script.
| Number | Result | QGC Version | PX4 Firmware Version |
|---|---|---|---|
| 1 | Continue Mission | 4.4.4 | 1.15.2 |
| 2 | Continue Mission | 4.4.4 | 1.15.2 |
| 3 | Continue Mission | 4.4.4 | 1.15.2 |
No crashes occurred in the simulation. However, we cannot guarantee that crashes will not happen in real-world experiments.