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Autonomous Flight Control

The ability of the autopilot to control the aircraft satisfactorily is tested next. REMOTE refers to an aspect of GSC having been passed to the conventional pilot transmitter which can be in MANUAL or AUTO mode where AUTO refers to control by the GCS. Note that in AUTO mode unselected functions can still be manually controlled by the pilot’s transmitter by setting it to REMOTE mode. Also the autopilot we use offers an ASSISTED mode where stick actions on the pilot’s transmitter are interpreted as directional and speed commands rather than as servo settings (effectively, a “fly-by-wire” approach): not all autopilots offer this functionality.

  • 1. Check UAV failsafe positions are correct and receiver’s failsafe to AUTO MODE.
  • 2. Check, with the transmitter off, that the GCS can still control the UAV.
  • 3. GCS in REMOTE mode.
  • 4. Transmitter in MANUAL mode.
  • 5. Takeoff.
  • 6. Climb to suitable height.
  • 7. Transmitter to AUTO mode.
  • 8. Bank. (a) Input bank command to wings level while in straight and level flight, (b) bank to GCS AUTO. Remaining controls by REMOTE, (c) pilot to maintain straight and level flight, (d) determine correct coefficients to ensure correct, stable, and non-oscillatory aircraft response: this will be achieved by setting various bank angles to be maintained and entered up to 30° and observing aircraft response, (i) Kd established and (ii) Ki established. (e) Return bank to REMOTE control.
  • 9. Elevation. (a) Input elevation angle of zero while in straight and level flight, (b) elevation to GCS AUTO. Remaining controls by REMOTE, (c) pilot to maintain straight and level flight, (d) determine correct coefficients to ensure correct, stable and non-oscillatory aircraft response: this will be achieved by setting various pitch angles to be maintained and entered up to 20° and observing aircraft response, (i) Kd established and (ii) Ki established. (e) Return elevation to REMOTE control.
  • 10. Altitude. (a) Input altitude to current height while in straight and level flight (at say 95 m), (b) altitude to GCS AUTO. Remaining controls by REMOTE, (c) pilot to maintain straight and level flight, (d) determine correct coefficients to ensure correct, stable and non-oscillatory aircraft response: this will be achieved by setting various altitudes to be maintained and observing aircraft response, (i) Kd established and (ii) Ki established. (e) Return altitude to REMOTE control.
  • 11. Airspeed. (a) Input airspeed to cruise airspeed while in straight and level flight (at given cruise speed), (b) airspeed to GCS AUTO. Remaining controls by REMOTE, (c) pilot to maintain straight and level flight, (d) determine correct coefficients to ensure correct, stable, and non-oscillatory aircraft response: this will be done by setting various airspeeds within the safe operating range for the aircraft setup to be maintained and observing aircraft response, (i) Kd established and (ii) Ki established. (e) Return airspeed to REMOTE control.
  • 12. Coefficient check by orbiting a specified waypoint. Observe aircraft response and modify coefficients as required including navigation linked coefficients. (a) Set orbit command in GCS. Bank to AUTO. Remainder in REMOTE. UAV to orbit waypoint via bank only. Check suitable aircraft response. Vary bank angles. (b) Set airspeed to maintain in GCS. Airspeed to AUTO. Remainder in REMOTE. UAV to orbit waypoint via bank and airspeed. Check suitable aircraft response. Vary airspeeds. (c) Set altitude to maintain in GCS. Altitude to AUTO. Fully autonomous control. Vary heights.
  • 13. Maintaining autonomous control. Set a new waypoint to navigate to with a large separation distance with cruise airspeed and safe height. Check aircraft exhibits correct response.
  • 14. Set a waypoint circuit pattern to check coefficients and turn anticipation. Check aircraft exhibits correct response.
  • 15. Test-ASSISTED mode. UAV pilot to take full ASSISTED mode and check correction functionality and response UAV responds correctly.
  • 16. Test of safety radius. Reduce safety radius to 200 m. When in ASSISTED mode, fly deliberately toward this outer radius. UAV should orbit the ERP waypoint when radius exceeded (the same response happens in fully auto mode). (a) UAV responds correctly, and manual control is regained after at least two orbits of the ERP are completed and (b) return safety radius to 500 m.
  • 17. Check the functionality of the autopilot flight envelope. (a) Assisted mode. Envelope tested successfully, and (b) auto mode. Envelope tested successfully.
  • 18. Check communication waypoint return. Over airfield with communication loss time set to 5 s. Ensure emergency waypoint is located correctly. (a) Set UAV to orbit a waypoint away from the emergency waypoint. With RC TX in full AUTO mode, disconnect GCS transceiver on laptop by disconnecting the appropriate cable. (i) After 5 s, UAV moves to emergency waypoint and orbits correctly - on success pilot to override, Reconnect GCS, (b) On successful connection with AP from GCS, fly UAV in ASSISTED mode. (i) After 5 s UAV moves to emergency waypoint and orbits correctly - on success, pilot to override, reconnect GCS.
  • 19. Pilot to land the UAV in manual mode.

Is the UAS flight control system (FCS) set up correctly and did it demonstrate correct control

and operation of the UAV?

 
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