Summary of Contents for Xflighttech AUTOPILOT / TRIM
- Page 1 Xflight Technologies LLC AUTOPILOT / TRIM User & Installation Guide Version 3.4 (Mini Pix Flight Controller) July 2020 Xflighttech.com...
- Page 2 A. Terms, Conditions and Warranty. These products are only intended to be used in LSA Class Experimental Aircraft or Ultralights (as defined by the FAA in the USA) under the full responsibility of the pilot. AHRS and Autopilot components are intended to be used for informational purposes or to manipulate secondary control surfaces only, allowing the pilot full manual control of the aircraft See Appendix A for details B.
- Page 3 6. Safety Enable should already be connected from the Flight Controller to the Raspberry Pi (AUTOPILOT) GPIO pins 32 & 30 7. Servo Test Switch should already be installed in the Raspberry Pi (AUTOPILOT) GPIO pins 33 & 34 (this can be removed once calibration is complete) 8.
- Page 4 D. Startup 1. Leave servos switched off until you are ready to use the Autopilot in flight. Always power up the AUTOPILOT circuit first. 2. Make sure you are outside with a view to the sky. Upon startup the AUTOPILOT will connect to the Flight Controller, maintaining a heartbeat (ignore the login prompt).
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Page 5: Operation
E. Operation: When operating normally the display will provide a smooth indication of attitude as well as the various flight data parameters detailed below. 1. AUTOPILOT ON/OFF • Switches the AUTOPILOT ON in Manual flight mode, ready for an automated flight mode to be set (i.e. - Page 6 • Once the flight plan / mission has been uploaded and started will switch to ON (Green) and start to execute the mission • OFF (red) switches NAV mode off and returns to MANUAL flight mode 5. HOME Mode ON/OFF •...
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Page 7: Physical Installation
Physical Installation Wire AUTOPILOT and servo power circuits separately with their own fuse and switch: AUTOPILOT, Flight Controller Power Module Switch and 5A fuse (or 10A w/ TRIM system) and touchscreen (and optional TRIM system) Pitch and Roll Servos Switch and fuse as per servo requirements A backup power supply may be used and connected to the touchscreen micro USB connector. - Page 8 2. Flight Controller The Flight Controller needs to be close to the AUTOPILOT and the GPS antenna which is typically mounted on the dashboard. Mount the Flight Controller horizontally and flat facing forward, sitting on a padded or foam base (provided) to reduce vibration, and make sure it cannot move in flight.
- Page 9 3. AUTOPILOT / TRIM and Flight Controller Wiring The Flight Controller, AUTOPILOT and TRIM System all need to be on a separate switched and fused (5A) circuit to the servo(s) circuit. They need to be powered up at the same time. The AUTOPILOT / TRIM circuit always needs to be switched on before the servo(s) circuit.
- Page 10 The Safety Enable will already be connected, but for your reference this connects the AUTOPILOT (Raspberry Pi) pin 32 (GPIO 12 signal) and pin 30 (Ground) to the Flight Controller (Mini Pix) via the special cable provided (opto-isolator switch): Copyright © 2019 Xflight Technologies LLC, Florida, USA...
- Page 11 4. SERVO Considerations This AUTOPILOT is designed to work for trim tabs (or secondary control surfaces) that are relatively small in area, sufficient to control surfaces for Experimental LSA class aircraft or Ultralights. The PWM servos (high torque) will need to be selected such that they have adequate torque to move these control surfaces in flight against the expected air flow loads.
- Page 12 Option 1: Xflight Servo Voltage Regulator Option 2: Xflight Servo Voltage Regulator with Differential Drivers Copyright © 2019 Xflight Technologies LLC, Florida, USA...
- Page 13 It is recommended that shielded cable be used for the servo signal wiring (with the shield connected to ground). Differential drivers are strongly recommended for cable runs greater than 10 feet (available from xflighttech.com). Copyright © 2019 Xflight Technologies LLC, Florida, USA...
- Page 14 Overall Layout Copyright © 2019 Xflight Technologies LLC, Florida, USA...
- Page 15 G. AHRS / COMPASS Calibration Basic calibration for straight and level is achieved by touching the central reference plane and waiting a few seconds (this only works on the ground when not moving in AP OFF mode) For tailwheel aircraft make sure that the tail is lifted up, so the aircraft is straight and level to the horizon, as it would be flying.
- Page 16 iii. The top right corner of the Mission Planner will show a <CONNECT> button. First select the COM port previously identified from the drop-down box, specify 115200 baud rate and hit <CONNECT>. Once connected it will download the Flight Controller parameters and the connection icon will turn green. c.
- Page 17 AHRS Calibration For tailwheel aircraft make sure that the tail is lifted up, so the aircraft is straight and level to the horizon, as it would be flying. When on the ground touching the center yellow reference plane will calibrate the AHRS to straight &...
- Page 18 important to ensure the AHRS is straight and level when the aircraft is trimmed and flying straight and level. For tailwheel aircraft make sure that the tail is lifted up, so the aircraft is straight and level to the horizon, as it would be flying. AHRS_TRIM_X Roll angle tuning in radians* (positive to roll the AHRS reference plane left) AHRS_TRIM_Y Pitch angle tuning in radians* (positive to pitch the AHRS reference plane down *note 0.01 radians is approx.
- Page 19 Compass / Accelerometer Calibration Compasses The Compasses have been calibrated, however fine adjustments can be made manually in order to ensure the direction is properly indicated in your aircraft, depending on proximity of metal in the airframe and other effects. The full automated calibration process will also be explained. The AHRS uses 2 compasses and the GPS.
- Page 20 Compasses can also be enabled / disabled in the parameters: You can perform the full compass and accelerometer calibration process prior to installation if desired, by selecting <INITIAL SETUP> from the navigation buttons, then follow the setup wizard prompts under >>...
- Page 21 Live Calibration: Move the flight controller / GPS antenna as directed: Point North, and rotate around pitch axis until level, then turn 90 degrees and rotate around the roll axis until level, hitting every white dot. Copyright © 2019 Xflight Technologies LLC, Florida, USA...
- Page 22 Accelerometers Select <Accel Calibration>, select the two calibration options and follow the prompts. Copyright © 2019 Xflight Technologies LLC, Florida, USA...
- Page 23 H. SERVO Setup It is important to ensure the servos are correctly orientated and ranges set. The Flight Controller has been pre-configured to the following servo mappings: Function Parameter Value Servo (Output Channel) Elevator (Pitch) SERVO1 19 (Elevator) Aileron (Roll) SERVO2 4 (Aileron) PWM (Pulse Width Modulation) servos act over a range of pulse width values typically ranging from...
- Page 24 Servo Installation Tips: • The control surface should be neutrally balanced to begin with. For example, an elevator spring could be used to hold the elevator at the neutral position • Install servos such that they do not interfere with primary control surface operation. Even if servos get stuck fully extended, you should still have full manual control of the aircraft •...
- Page 25 The following sections will check for correct servo orientation and calibration The first step is to ensure the aircraft flies straight and level (additional or existing static trim tabs may also be used to achieve this) with the servo control surfaces / trim tabs in a neutral position with the servos at their mid-range values (1500).
- Page 26 PITCH and ROLL Servo Orientation (on the ground) With the AUTOPILOT installed and AHRS/Compass calibration complete for straight and level and the elevator trim tab and servo installed with the aircraft flying straight and level, you will now be able to set up the pitch and roll servo orientation.
- Page 27 6. To remove the Test Switch: Remove the autopilot from behind the instrument panel and remove the screen: • remove the 4 screws holding the frame to the screen (and instrument panel) • Remove the HDMI connector connecting the screen to the Raspberry Pi (this is very firmly connected;...
- Page 28 J. TRIM System Servo Orientation (on the ground) With the AUTOPILOT installed and AHRS/Compass calibration complete for straight and level and the elevator trim tab and servo installed with the aircraft flying straight and level, you will now be able to test the TRIM system / servo orientations.
- Page 29 K. ROLL Axis Gain Calibration (in flight) This step will calibrate the roll axis only to ensure the gain is set correctly to allow for a smooth correction to roll and heading in flight. Pick a clear area on a good weather day with very little wind for this test and fly at a safe altitude away from populated areas.
- Page 30 13. If you are not able to achieve smooth roll reactions, then recheck AHRS level configurations and/or roll axis orientation. A more detailed explanation can be found here: http://ardupilot.org/plane/docs/roll-pitch-controller-tuning.html If all else fails, then contact steve@xflighttech.com for support. Copyright © 2019 Xflight Technologies LLC, Florida, USA...
- Page 31 L. PITCH Axis Gain Calibration (in flight) This step will calibrate the pitch axis only to ensure the gain is set correctly to allow for a smooth correction to pitch and altitude in flight. Pick a clear area on a good weather day with very little wind for this test and fly at a safe altitude away from populated areas.
- Page 32 12. If you are not able to achieve smooth pitch reactions, then recheck AHRS level configurations and/or pitch axis orientation. A more detailed explanation can be found here: http://ardupilot.org/plane/docs/roll-pitch-controller-tuning.html If all else fails, then contact steve@xflighttech.com for support. In Summary This table shows an overall general summary of the effect of raising PID gain values:...
- Page 33 M. CRUISE and HOME Flight Tests The final flight test will be to test pitch and roll together as well as return to HOME location. Again, pick a clear area on a good weather day with very little wind for this test and fly at a safe altitude away from populated areas.
- Page 34 N. NAV L1 Controller Tuning The Arduplane L1 Navigation Controller controls turns and loiter circles and involves tuning one key parameter – the NAVL1_PERIOD (optionally the NAVL1_DAMPING parameter can also be adjusted). 1. Make sure you have already tuned the roll and pitch controllers as per sections above 2.
- Page 35 O. NAV Connection and Setup The NAV mode allows you to upload missions specified in the Ardupilot QGroundControl App. The mission can be uploaded to the AUTOPILOT when in NAV WAIT mode. 1. Download the QGroundControl app and install on your Android or iOS mobile device (this is a free opensource application) 2.
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Page 36: Nav Mode
P. NAV Mode 1. Power up the AUTOPILOT (Leave the SERVO circuit powered down). 2. Select AP ON. This will enable the Servo PWM signals and start flight logging. 3. Wait a second or two, then select NAV ON to enter NAV mode. The Button should show NAV WAIT. - Page 37 Q. LOGFILE Access Log files are available via the Mission Planner. This will give you access to many different flight parameters as well as the ability to view your flight track on Google Earth. While connected to the Flight Controller, select <FLIGHT DATA> from the navigation buttons, then select <DataFlash Logs>...
- Page 38 Note that you will NOT have the tlogs (telemetry logs) A more detailed description of the logs and graphing options is available here: http://ardupilot.org/plane/docs/common-downloading-and-analyzing-data-logs-in-mission- planner.html Track and Elevation Profile (speed/altitude) on Google Earth Copyright © 2019 Xflight Technologies LLC, Florida, USA...
- Page 39 The pink track below shows the HOME / RTL (Return to Land) track and 1-mile radius loiter circles above the HOME location. There are 2 ½ circles here, with the autopilot maintaining very high precision orbits. For a full description of all parameters please visit: http://ardupilot.org/plane/docs/parameters.html But please note this includes all the ArduPlane parameters, which are not all relevant.
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Page 40: Appendix A. Xflight Technologies Llc Terms, Conditions And Warranty
Appendix A. Xflight Technologies LLC Terms, Conditions and Warranty 1. PARTIES. This Contract represents the terms and conditions of sale of Xflight Technologies Products by and between Xflight Technologies LLC, of 1982 State Rd 44, New Smyrna Beach, Florida 32168, USA (“Seller”), and Buyer (“Buyer”). 2. - Page 41 liability, if any, for defective Goods, is limited to replacement, repair or refund of the defective Goods, at Seller's option for up to 30 days from date of purchase. 6. PERSONAL USE. Buyer agrees to limit the operation and use of purchased Goods to personal recreational use.
- Page 42 providing notice, the failure to cure the default(s) within such time period shall result in the automatic termination of this Contract. 10. ARBITRATION. Any controversies or disputes arising out of or relating to this Contract shall be resolved by binding arbitration in accordance with the then-current Commercial Arbitration Rules of the American Arbitration Association.
- Page 43 15. WAIVER OF CONTRACTUAL RIGHT. The failure of either party to enforce any provision of this Contract shall not be construed as a waiver or limitation of that party's right to subsequently enforce and compel strict compliance with every provision of this Contract.
- Page 44 EXCHANGE OF GOODS The following provisions relate to the physical exchange of Goods and payment forming the transaction of this agreement. 17. TITLE/RISK OF LOSS. Title to and risk of loss of goods shall pass to the buyer upon delivery F.O.B. at the seller's place of home or business to an agent of the buyer including a common carrier, notwithstanding any prepayment or allowance of freight by the seller.