limit_accel_xy() splits the acceleration command into along-track and cross-track components using the normalised velocity, and prioritises the cross-track component when the command saturates the maximum lean angle. As the velocity vector rotates through zero (e.g. a hard stick reversal in Loiter, where forward speed passes through zero before reversing) the unit velocity spins rapidly. With any small residual lateral velocity (wind crab, residual velocity from prior manoeuvring) this re-projects the saturated longitudinal braking command onto a rapidly rotating axis and emits a large lateral acceleration spike, seen as a roll wobble at the moment of the stop and as a PSCE.TAE spike at each PSCN.VN zero crossing. Fade the cross-track prioritisation out to a direction-preserving magnitude limit below LIMIT_ACCEL_XY_MIN_SPEED_MS (1 m/s). Above that speed behaviour is unchanged, so path/corner tracking is unaffected. The limiter only acts when the command saturates the lean-angle limit, and stationary hold already used the isotropic branch, so precision position hold is unaffected. Adds a regression test sweeping velocity through zero and asserting no lateral acceleration is injected. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
ArduPilot Project
ArduPilot is the most advanced, full-featured, and reliable open source autopilot software available. It has been under development since 2010 by a diverse team of professional engineers, computer scientists, and community contributors. Our autopilot software is capable of controlling almost any vehicle system imaginable, from conventional airplanes, quad planes, multi-rotors, and helicopters to rovers, boats, balance bots, and even submarines. It is continually being expanded to provide support for new emerging vehicle types.
The ArduPilot project is made up of
User Support & Discussion Forums
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Support Forum: https://discuss.ardupilot.org/
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Community Site: https://ardupilot.org
Developer Information
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Github repository: https://github.com/ArduPilot/ardupilot
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Main developer wiki: https://ardupilot.org/dev/
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Developer discussion: https://discuss.ardupilot.org
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Developer chat: https://discord.com/channels/ardupilot
Top Contributors
- Flight code contributors
- Wiki contributors
- Most active support forum users
- Partners who contribute financially
How To Get Involved
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The ArduPilot project is open source and we encourage participation and code contributions: guidelines for contributors to the ardupilot codebase
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We have an active group of Beta Testers to help us improve our code: release procedures
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Desired Enhancements and Bugs can be posted to the issues list.
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Help other users with log analysis in the support forums
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Improve the wiki and chat with other wiki editors on Discord #documentation
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Contact the developers on one of the communication channels
License
The ArduPilot project is licensed under the GNU General Public License, version 3.
Maintainers
ArduPilot is comprised of several parts, vehicles and boards. The list below contains the people that regularly contribute to the project and are responsible for reviewing patches on their specific area.
- Andrew Tridgell:
- Vehicle: Plane, AntennaTracker
- Board: Pixhawk, Pixhawk2, PixRacer
- Francisco Ferreira:
- Bug Master
- Grant Morphett:
- Vehicle: Rover
- Willian Galvani:
- Vehicle: Sub
- Board: Navigator
- Michael du Breuil:
- Subsystem: Batteries
- Subsystem: GPS
- Subsystem: Scripting
- Peter Barker:
- Subsystem: DataFlash, Tools
- Randy Mackay:
- Vehicle: Copter, Rover, AntennaTracker
- Siddharth Purohit:
- Subsystem: CAN, Compass
- Board: Cube*
- Tom Pittenger:
- Vehicle: Plane
- Bill Geyer:
- Vehicle: TradHeli
- Emile Castelnuovo:
- Board: VRBrain
- Georgii Staroselskii:
- Board: NavIO
- Gustavo José de Sousa:
- Subsystem: Build system
- Julien Beraud:
- Board: Bebop & Bebop 2
- Leonard Hall:
- Subsystem: Copter attitude control and navigation
- Matt Lawrence:
- Vehicle: 3DR Solo & Solo based vehicles
- Matthias Badaire:
- Subsystem: FRSky
- Mirko Denecke:
- Board: BBBmini, BeagleBone Blue, PocketPilot
- Paul Riseborough:
- Subsystem: AP_NavEKF2
- Subsystem: AP_NavEKF3
- Víctor Mayoral Vilches:
- Board: PXF, Erle-Brain 2, PXFmini
- Amilcar Lucas:
- Subsystem: Marvelmind
- Samuel Tabor:
- Subsystem: Soaring/Gliding
- Henry Wurzburg:
- Subsystem: OSD
- Site: Wiki
- Peter Hall:
- Vehicle: Tailsitters
- Vehicle: Sailboat
- Subsystem: Scripting
- Andy Piper:
- Subsystem: Crossfire
- Subsystem: ESC
- Subsystem: OSD
- Subsystem: SmartAudio
- Alessandro Apostoli:
- Subsystem: Telemetry
- Subsystem: OSD
- Rishabh Singh:
- Subsystem: Avoidance/Proximity
- David Bussenschutt:
- Subsystem: ESP32,AP_HAL_ESP32
- Charles Villard:
- Subsystem: ESP32,AP_HAL_ESP32