1. X-Pilot: Autopilot Solutions C. Edwards, J. Lasseigne, W. Overstreet, B. Penland X-pilot flight testing X-pilot groundstation demonstrating waypoint navigation and one possible autopilot application— crop dusting. X-Pilot Features: Costs under $2500 to produce Utilizes open source code for easy user modification Capable of autonomous flight by waypoint navigation Users can integrate custom hardware Equipped with an AGL for use with low level flight For use with fixed-wing or flying-wing aircraft X-pilot with labeled components Design Constraints and Implementation: Technical ConstraintDescriptionImplementation Waypoint Navigation Accuracy Waypoint navigation must be accurate to within ±10 meters. Achieved by using gains and verifying with flight log files. Low Altitude AccuracyX-pilot must be capable of accurate readings at low altitudes (±0.08 m). Low altitude accuracy achieved through an AGL using ultrasonic range finders. Real-TimeThe autopilot must have an update rate between 1 Hz and 50 Hz. By using threading, the autopilot achieved an update rate of 50 Hz. Control SurfacesX-Pilot must capable of controlled flight for a fixed-wing aircraft. X-pilot is capable of controlling the five control surfaces of a fixed-wing aircraft (two ailerons, an elevator, a rudder, and a throttle). CompatibilityThe groundstation software must be POSIX and Windows compatible. The groundstation is written in C++ and uses OpenGC. Dynamic Re-taskingX-Pilot must be capable of dynamic re- tasking at all times. The autopilot and groundstation communicate over wireless at all times so new waypoints can be uploaded at any time. Practical ConstraintDescriptionImplementation CostParts for one AGL must cost less than $200. By using ultrasonic range finders, the AGL price was kept under $200. FailsafeX-Pilot is equipped with an RC manual override. Channel 5 on the RC receiver is used to disable the autopilot mode and act as a manual override. Secure CommunicationsCommunication to the autopilot must be secure. Because an 802.11 wireless router is being used, any encryption supported by the router can be implemented. Expandable DesignX-Pilot is capable of user upgrades and modifications. All software is open source, therefore the user can easily upgrade or modify the software. Operating TemperaturesThe system must operate in temperatures of 0- 45°C. All hardware used for X- pilot is rated for an operating temperature range of at least 0-45°C. X-pilot’s Above-Ground-Level (AGL) sensor Project Description: The X-Pilot: Autopilot Solutions project is developing a complete autopilot system (hardware in the air vehicle and groundstation software) that can be easily integrated into fixed- wing airplanes and is user programmable while in flight. The autopilot hardware is based on a Crossbow hardware platform and includes a custom-built AGL (Above- Ground-Level) sensor. The software includes the associated autopilot software along with the groundstation software. X-Pilot Components: Crossbow MNav sensor platform Crossbow Stargate Linux computer Standard 802.11 wireless card Custom ultrasonic AGL sensor 6.0 Volt nickel metal hydride battery to power MNav and Stargate 9.0 Volt alkaline battery to power AGL sensor Software components for the autopilot and the groundstation (both written in C++) Hammond 1590T aluminum electrical enclosure Testing: Testing for all X-pilot components occurs in three stages. First, the component is tested with a ground software simulation. Second, the component is tested with a ground hardware simulation. Finally the component is flight tested. All software and hardware simulations were completed, however flight testing was not completed due to a problem re- flashing the Mnav’s firmware. X-pilot’s groundstation software and associated icon Second Semester Progress: Implemented the AGL on a PC Board Fixed GPS connecter from last semester Completed range tests for both wireless and RC communication Performed hard iron calibration of the Mnav Loaded local map into the groundstation Designed a custom icon for the groundstation Packaged the final product (autopilot in an aluminum case, software on a bootable CD, and the AGL on the PC Board) Final packaged product Below: X-pilot autopilot software Above: Foam plane used for hardware ground testing