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PHANTOM UAV – Autopilot Set Up

 

Flight Controller Board Installation

    Wiring Diagrams

Transmitter Mode Control Set Up

Mission Planner Software Set Up

    Download and Install Mission Planner Software on a PC

    Connect Mission Planner to the APM Board

    Install Arduplane Software in the APM Board

    Flight Modes

    Compass Set Up

    Transmitter Calibration

    Levelling Calibration

    PID Parameter Set Up

    Optional Hardware – Power Module

    Optional Hardware – 3DR Telemetry Radio

    Optional Hardware – Airspeed Sensor

    Optional Hardware – Stabilised Camera Gimbal

    Optional Hardware - Steering Control

Failsafe Set Up

    Transmitter Signal Loss - Throttle Failsafe

    Loss of Telemetry (GCS)

    Loss of GPS

Take Off Set Up

    Throwing To Launch

    Take Off On Undercarriage

    Climb Rate

Throttle Control Parameters

Attitude Control Parameters

TECS Parameters

Ready To Fly

 

Previous Page -  Manual Flying                  

Next Page – DX7 Transmitter Configuration

 

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Flight Controller Board Installation

HKPilot

The flight controller board is the

HKPilot Mega V2.5.

This is also called the APM (Auto Pilot Module).

Ublox GPS

This is the Ublox LEA-6H GPS.

 

The flight controller board is available from here :

http://hobbyking.com/hobbyking/store/__37328__HKPilot_Mega_V2_5_Flight_Controller_USB_GYRO_ACC_MAG_BARO.html?strSearch=mega%202.5

 

The GPS module is available from here :

http://hobbyking.com/hobbyking/store/__42833__UBLOX_LEA_6H_GPS_Module_w_Built_in_Antenna_2_5m_Accuracy_V1_01.html?strSearch=ublox

 

 

The receiver, APM board and the GPS are mounted on a 3mm thick balsa sheet covered in reinforcing tape.

 

The APM board is wrapped in static absorbing plastic. This provides some protection against RF interference. It also holds in place a small block of foam over the barometric sensor.

 

The battery sits in a plastic tray attached to the base of the instrument bay with adhesive backed Velcro. The battery slides into this tray under the component board and is secured with two loops of double sided Velcro.

Instrument Bay

Wiring Diagrams

The wiring diagram without optional hardware shows how the basic devices are connected.

 

Remove the on board link which connects the main board power to the servo power. The servos should have their own power supply so that the power drain caused by the servos does not affect the components on the APM board. This power is supplied by a separate BEC powered from the battery.

 

The wiring diagram with optional hardware shows how all the devices including optional devices are connected. Here the BEC has been replaced with the power module.

Transmitter Mode Control Set Up

On the Spektrum DX7 transmitter, the 2 position rudder switch and the 3 position flap switch are used to select a combination of 6 autopilot modes. Mix 1 is used to make the two switches control the PWM value of channel 6 (flap channel) to set the APM mode.

 

RUDDER

SWITCH

FLAP

SWITCH

Channel 6

Pulse Width (mS)

APM Mode / Range (mS)

0

N

1686

5 / 1621 – 1749

0

1

1469

3 / 1361 – 1490

0

2

1100

1 / 0000 – 1230

1

N

1830

6 / 1750 +

1

1

1505

4 / 1490 – 1620

1

2

1321

2 / 1231 - 1360

 

Refer to the following DIY Drones web site for the DX7 mode programming.

http://hobbyking.com/hobbyking/store/__37328__HKPilot_Mega_V2_5_Flight_Controller_USB_GYRO_ACC_MAG_BARO.html?strSearch=mega%202.5

 

The assignment of APM flight modes to the switch combinations of the rudder and flap switches is described here in the ‘Mission Planner Software Set Up’ section.

Mission Planner Software Set Up

The following sections set up the ‘Mission Planner’ software on the PC and Arduplane software in the APM.

Download and Install Mission Planner Software on a PC

Download the latest version of APM:Plane (Mission Planner) here.

http://ardupilot.com/downloads/?did=107

 

Follow the instructions to install Mission Planner.

 

After installation, run Mission Planner and when the ‘Flight Data’ screen is displayed, the set up process can begin.

 

Img_301

Connect Mission Planner to the APM Board

 

CAUTION

Disconnect the battery before plugging in the USB cable OR disconnect the USB cable before plugging in the battery. If the battery and the USB cable are both plugged in at the same time, the APM may be damaged!

 

Connect the USB cable between the PC and the APM. The USB supplies power to the APM so connecting the plane’s battery is not only unnecessary, it may damage the APM.

On Mission Planner, at the top right hand corner, select from the drop down list the Arduino Mega 2560 port. Select baud rate = 11520.

 

Click CONNECT to connect to the APM.

 

When connected the symbol changes to DISCONNECT.

This connection is known as the MAVLink.

Install Arduplane Software in the APM Board

On Mission Planner, select the ‘Initial Setup’ page, then ‘Install Firmware’ from the left column of options.

 

The version of the plane software is displayed below the plane icon. It defaults to the latest.

(To change it. Click “Pick previous firmware” in the bottom right hand corner of the page and select from the drop down table. On selection, the versions under the icons change.)

 

To send the Arduplane software to the APM, click on the plane icon and follow the instructions.

Flight Modes

On Mission Planner, select the ‘Software’ page and then ‘Flight Modes’ from the left column of options.

Set each flight mode number to the modes in the following table.

 

Flight Mode Number

Flight Mode

Description

Pulse Width Range (uS)

1

RTL

Return to launching place

0000 - 1230

2

Auto

Follow way points

1231 – 1360

3

Stabilise

Sticks centred = level flight

1361 – 1490

4

Training

Roll and pitch limites

1491 – 1619

5

Manual

No flight assistance

1620 – 1749

6

Manual

No flight assistance

1750 +

 

When the modes have been set, click the ‘Save Modes’ button.

The process is complete when the button displays ‘Complete’. (almost immediately)

Compass Set Up

On Mission Planner, select the ‘Initial Setup’ page, then ‘Mandatory Hardware’ and then ‘Compass’ from the left hand column of options.

Ensure the ‘Enable’ box is ticked.

Ensure the ‘Auto Dec’ box is ticked.

Enter magnetic declination for Melbourne as 11.34. This converts to 11 degree 34 minutes EAST.

Transmitter Calibration

On Mission Planner, select the ‘Initial Setup’ page, then ‘Mandatory Hardware’ and then ‘Compass’ from the left hand column of options.

 

Tick the boxes as shown in this table.

Box

Tick

 

Roll Reverse

No

 

Pitch Reverse

No

 

Throttle Reverse

No

 

Yaw Reverse

No

 

Elevons

Yes

 

Elevon Rev

No

 

Elevons CH1 Rev

No

 

Elevons CH2 Rev

Yes

 

To start calibration, press the ‘Calibrate Radio’ button.

 

Follow these instructions and click OK.

 

Click OK to start calibration.

 

Move the elevator stick fully down and hold while moving the aileron stick fully to the left and fully to the right.

Now move the elevator stick fully up and hold while moving the aileron stick fully to the left and fully right.

Centre the elevator and aileron sticks.

Move the throttle fully up and fully down.

To calibrate channel 6, set the rudder switch to 1 while the flap switch is in position N, and then set the rudder switch to 0 while the flap switch is in position 2.

 

Now click the ‘Click when Done’ button.

 

Press OK when the sticks are in position.

 

 

These are the calibration values.

 

 

 

 

 

 

Press OK and ‘Completed’ is displayed.

 

Calibration is now complete.

 

The calibration values are also shown on the screen as shown in the following figure.

 

 

When the transmitter is Manual Mode, check that the following controls move the elevons correctly.

 

Transmitter Action

Elevon Movement

 

Plane Movement

Elevon Movement

Elevator down

Both elevons down

 

Nose down

No elevon movement

Elevator up

Both elevons up

 

Nose up

No elevon movement

Aileron left

Left elevon up

Right elevon down

 

Left wing down

No elevon movement

Aileron right

Right elevon up

Left elevon down

 

Right wing down

No elevon movement

 

When the transmitter is in Stabilise mode, check that the following controls move elevons correctly.

 

Transmitter Action

Elevon Movement

 

Plane Movement

Elevon Movement

Elevator down

Both elevons down

 

Nose down

Both elevons up

Elevator up

Both elevons up

 

Nose up

Both elevons down

Aileron left

Left elevon up

Right elevon down

 

Left wing down

Left elevon down

Right elevon up

Aileron right

Right elevon up

Left elevon down

 

Right wing down

Right elevon down

Left elevon up

Levelling Calibration

This section sets the manual levelling calibration so that levelling calibration is not required every time the APM is turned on.

 

On Mission Planner, select the ‘Initial Setup’ page, then ‘Mandatory Hardware’ and then ‘ArduPlane Level’ from the left column of options.

The ‘Accelerometer Calibration’ page is displayed.

Use a spirit level relative to the ledges in the instrumentation bay for the following procedure.

1. Click the ‘Calibrate Accel’ button.

2. ‘Place APM level and press any key’ is displayed.

    Set the plane on a surface and ensure the plane is level from side to side and front to back.

    Click the ‘Click When Done’ button.

3. ‘Place APM on its left side and press any key’ is displayed.

    Hold the right wing at the reinforcing tube and let the plane hang down.

    Click the ‘Click When Done’ button.

4. ‘Place APM on its right side and press any key’ is displayed.

    Hold the left wing at the reinforcing tube and let the plane hang down.

    Click the ‘Click When Done’ button.

5. ‘Place the APM nose DOWN’ message is displayed.

    Rest the plane on its nose.

    Click the ‘Click When Done’ button.

6. ‘Place the APM nose UP’ message is displayed.

    Rest the plane on its wing tips with its nose vertically up.

    Click the ‘Click When Done’ button.

7. ‘Place the APM on its BACK’ message is displayed.

    Lie the plane on its back..

    Click the ‘Click When Done’ button.

The levelling process is complete when the message ‘Calibration Successful’ is displayed.

 

PID Parameter Set Up

These are the default PID settings.

 

 

The modified settings are as follows

 

Parameter

Default Value

New Value

Notes

Servo Pitch PID –P

0.600

0.450

 

Servo Roll PID – P

0.400

0.850

 

Throttle Cruise

45.0

55.0

Autopilot cruise throttle value

Throttle Max

75.0

100.0

Autopilot maximum throttle value

Servo Pitch PID – I

0.000

0.100

 

Servo Roll PID - I

0.000

0.100

 

Optional Hardware – Power Module

The power module was sourced from UAV Robotics

http://www.uavrobotics.com.au/power-module-with-xt60-connectors-p-109.html

 

Refer to the Wiring Diagram to connect the power module.

 

In Mission Planner, select ‘Initial Setup’, ‘Optional Hardware’ then ‘Battery Monitor’ and set up as follows

 

Battery Monitor Page

 

To Set up ‘MP Alert on Low Battery’ select as follows.

 

What do you want to say?

WARNING Battery at {batv} volt, {batp} percent

 

What voltage do you want to warn at?

14.4

4 cell battery

What percentage do you want to warn at?

40

 

 

Voltage display on Mission Planner Flight Data screen        16.25 – 16.33 (varying)

Voltage measured by Cell Meter 8                                         16.27 – 16.28 (varying)    Close enough!

 

For further reference, see the APM Plane manual here.

http://plane.ardupilot.com/wiki/common-measuring-battery-voltage-and-current-consumption-with-apm/

Optional Hardware – 3DR Telemetry Radio

The radio Telemetry Kit 915MHz was sourced from Hobby King here.

http://hobbyking.com/hobbyking/store/__42846__FPV_Radio_Telemetry_Kit_915Mhz.html?strSearch=telemetry%20915

 

This is compatible with the 3Drobotics 3DR Radio Set here.

https://store.3drobotics.com/products/3dr-radio

 

The Quick Start Guide can be downloaded from here under heading Telemetry Radio.

http://3drobotics.com/learn/

 

The aircraft was connected according to the Quick Start Guide.

The aircraft was then powered up.

The ground module was plugged into the PC USB port. A driver was automatically found and installed for windows 7.

In Mission Planner, the baud rate was set to 57600 and COM5 was selected. ‘Connect’ was clicked, the link established and the ‘Flight Data’ page showed the current status. Select ’Initial Setup’, then ‘Optional Hardware’, then ‘3DR Radio’.

In the top right corner, disconnect the MAVLink, the click ‘Load Settings’.

The ‘3DR Radio’ set up screen is shown as follows with the default settings.

 

3DR Radio Page

 

These parameters are stored in the local radio module and the remote radio module. (They are not stored in the APM.)

 

Ensure the following parameters are set.

Parameter

Value

Notes

Air Speed

64 kbps

Communication baud rate

ECC

Enabled

Error correction

Tx Power

20dBm

20dBm = 100mW

Duty Cycle

100%

Max % of time tx packets can be transmitted.

Mavlink

Mavlink

Raw Data : ??

Mavlink : Normal selection

Low Latency : Used for tablet based joysticks

LBT

0

Listen Before Talk is signal strength considered busy.

 

For two radios to communicate, the following must be the same at both ends of the link:

- radio firmware version

- AIR_SPEED

- MIN_FREQ

- MAX_FREQ

- NUM_CHANNELS

- NETID

- ECC setting

- LBT_RSSI setting

- MAX_WINDOW setting

 

For further reference, see APM manual, here

http://plane.ardupilot.com/wiki/common-using-the-3dr-radio-for-telemetry-with-apm-and-px4/

Optional Hardware – Airspeed Sensor

The airspeed sensor was sourced from UAV Robotics, here

http://www.uavrobotics.com.au/advanced_search_result.php?keywords=air+speed&x=12&y=12

 

The airspeed sensor is connected to the A0 port on the APM board. Refer to the Wiring Diagram for details.

Use silicon tubing to connect the top port to the straight tube exiting the pitot tube. (air speed port)

Use silicon tubing to connect the bottom port to the angled tube exiting the pitot tube. (air pressure port)

 

To enable the sensor, in Mission Planner tick ‘Enable’ and tick ‘Use Airspeed’ as follows.

 

Airspeed Page

 

For further reference, see the APM Plane manual here.

http://plane.ardupilot.com/wiki/airspeed-3/

 

To calibrate the airspeed sensor, in the parameter list set ARSPD_AUTOCAL = 1. The default value = 0.

If this is enabled then the APM automatically adjusts the ARSPD_RATIO parameter during flight, based on an estimation filter using ground speed and true airspeed. The automatic calibration saves the new ratio to EEPROM every 2 minutes if it changes by more than 5%.

 

Leave the other parameters with their default values.

 

Airspeed parameters

 

After the autocalibration flight, ARSPD_AUTOCAL is set back to 0.

The default values in auto throttle modes of minimum airspeed ARSPD_FBW_MIN and maximum airspeed ARSPD_FBW_MAX are used.

They are 9 m/S and 22 m/S. (32 k/h and 79 k/h)

 

The airspeed set value in auto mode is TRIM ARSPD_CM in centimetres / second.

The default value of TRIM ARSPD_CM is used. It is 1200 cm/S. (12 m/S or 43 k/h)

 

Trim Airspeed

Optional Hardware – Stabilised Camera Gimbal

The camera I use is a HD Wing Camera, 1280x720 pixel, 30fps, 5 megapixels, available from Hobby King, here.

http://hobbyking.com/hobbyking/store/__36573__HD_Wing_Camera_1280x720p_30fps_5MP_CMOS_AU_Warehouse_.html?strSearch=hd%20camera

 

 

RD32 Case

 

 

The camera as supplied is surrounded by transparent heat shrink tube. The camera is not supplied with a case.

 

I made this case by vacuum forming a sheet of HIPS (High Impact Polystyrene).

 

The camera can still be used on this gimbal without a case.

Mobius

 

 

 

 

The Mobius ActionCam would also be suitable to use with this gimbal.

 

The Mobius camera is available from Hobby King, here.

http://hobbyking.com/hobbyking/store/__51954__Mobius_ActionCam_a_1080p_HD_Video_Camera_Set_With_Live_Video_Out.html

 

Camera Platform

An aluminium vibration absorbing platform was first made to mount the gimbal on. The base of the platform is screwed into nylon threaded standoffs glued into the foam. The vibration dampening balls have a rated load of 100g each.

 

image053

Initially the camera was mounted on a balsa wood wedge which held the camera at an angle of 24°. In the camera’s image, the horizon is just below the top of the frame and the ground occupies most of the frame.

 

The gimbal was also made from aluminium and mounted on the platform.

 

Gimbal   RD32 on Gimbal

 

 

RD32 Front on Gimbal

 

 

The camera is attached with double sided foam tape.

 

The complete assembly is very rigid and presents a low surface area to air flow.

 

The servos used are type Turnigy TGY-S306C, digital, metal gears, 2.4kg-cm @ 4.8V, 0.07sec/60° @ 4.8V.

 

 

The weight of the complete assembly including the camera is 159 gm.

 

A video showing the gimbal operation is here :

http://www.youtube.com/watch?feature=player_detailpage&v=0HGa-9Ns_Nw

 

To set up a stabilised camera gimbal, make the following changes in Mission Planner. Select ‘Initial Setup’, ‘Optional Hardware’ and then ‘Camera Gimbal’.

 

 

Tilt Channel

Select RC5 (output channel 5) from the pull down menu.

Tick the ‘Stabilise Tilt’ box.

Servo Limits: Min = 900 uS, Max = 2100 uS. (See below for setting the offset)

Angle Limits: Min = -60 Degrees, Max = 60 Degrees.

Input Channel = Disable.

Tick the ‘Reverse’ box.

 

Roll Channel

Select RC7 (output channel 7) from the pull down menu.

Tick the ‘Stabilise Roll’ box.

Servo Limits: Min = 900 uS, Max = 2100 uS. (See below for setting the offset)

Angle Limits: Min = -60 Degrees, Max = 60 Degrees.

Input Channel = Disable.

Leave the ‘Reverse’ box unticked.

 

Setting the Servo Offset

When the gimbal is first turned on, each servo will probably not be in a position that holds the camera horizontal. To achieve this, each servo needs an offset. To do this, add a number to (or subtract from) each servo limit value so that the camera becomes horizontal. For example, the roll servo limits above have been changed from Min = 900 and Max = 2100, to Min = 960 and Max = 2160 by adding 60 to each limit.

 

Important Gimbal Design Notes

 

RD32 on Top Gimbal    RD32 Side on Gimbal

To prevent unwanted vibration and gear wear, follow these guidelines.

  1. Ensure the camera weight is balanced around the tilt servo axis.
  2. Ensure the weight on the roll servo is also balanced along the servo axis.
  3. Ensure the centre of gravity of the assembly is placed over the centre of the platform.

These features minimise secondary vibrations arising in the assembly.

 

Field Of View

If the camera is horizontal, the horizon is across the middle of the picture and the top half is sky. I set the tilt angle to about 24° so that the camera’s field of view had the horizon just below the top of the frame and the rest of the frame is filled with the ground in front of the aircraft.

 

RD32 Side Tilted on Gimbal

Police Paddocks

 

Field of view with the camera tilted down 24°.

 

A demonstration of the camera gimbal is shown here.

https://www.youtube.com/watch?v=0HGa-9Ns_Nw&feature=player_detailpage

Optional Hardware - Steering Control

Steering Control is enabled by setting the parameter GROUND_STEER_ALT to a non zero value.

The turning circle diameter was measured as 3.05 metres. Therefore the parameter STEER2SRV_P = 3.05.

The other initial parameter values were set to the ones suggested in the arduplane manual.

 

Parameter

Default Values

Initial Tuning Values

Final Values

STEER2SRV_P

1.8

3.05

3.05

STEER2SRV_I

0.2

0.1

0.1

STEER2SRV_D

0.005

0.02

0.02

STEER2SRV_IMAX

1500

1500

1500

STEER2SRV_MINSPD (m/Sec.)

1

1

1

STEER2SRV_TCONST (Sec.)

0.75

0.5

0.5

GROUND_STEER_ALT (metres)

0

5

5

 

After testing during several auto mode take offs, I was satisfied that the tuning values did not need changing.

Failsafe Set Up

The failsafe parameters are summarised in the following table.

 

PARAMETER

VALUE

UNITS

Comments

FS_SHORT_TIMEOUT

20

Seconds

Failsafe event must be present for this time before implementing ‘Short Action’.

FS_SHORT_ACTN

1

-

If in ‘Stabilisation mode, enter ‘Circle’ mode.

If in ‘Auto’ mode,

0 : Continue with mission.

1 :Enter Circle mode.

2 : Enter FBWA mode with zero throttle and level attitude to glide in.

FS_LONG_TIMEOUT

20

Seconds

‘Short Action’ state must be present for this time before implementing ‘Long Action’.

FS_LONG_ACTN

1

-

If in ‘Stabilisation’ mode, enter ‘RTL’ mode.

If in ‘Auto’ mode, and if FS_SHORT_ACTN = 1, then enter RTL.

If in ‘Auto’ mode, and if FS_SHORT_ACTN = 0 or 2,

0 : Continue with mission.

1 : Enter RTL mode.

2 : Enter FBWA mode with zero throttle.

 

The action chosen in the table above is described as follows.

 

In ‘Stabilisation’ mode, if a failsafe event is present for 20 seconds, ‘Circle’ mode is entered.

If the failsafe event is removed, then the ‘Stabilisation’ mode is resumed.

If the failsafe event continues for 20 seconds, then ‘RTL’ mode is entered.

 

In ‘Auto’ mode, if a failsafe event is present for 20 seconds, ‘Circle’ mode is entered.

If the failsafe event is removed, then the ‘Auto mode is resumed.

If the failsafe event continues for 20 seconds, then ‘RTL’ mode is entered.

 

The target altitude used by the ‘RTL’ command is the parameter ALT_HOLD_RTL. Its units are centimetres and its value is 10,000. (100m)

 

Param ALT_HOLD_RTL

 

The failsafe functions detect the following events.

  1. Transmitter signal loss. It does this by monitoring the throttle PWM value. The receiver is set up to make the throttle PWM value lower than the THR_FS_VALUE when it does not receive a transmitter signal.
  2. Loss of Telemetry for more than 20 seconds.
  3. Detect loss of GPS signal for more than 20 seconds.

Transmitter Signal Loss - Throttle Failsafe

Follow this procedure to bind the receiver so that when it loses signal, the throttle PWM value is less than 950 uSec.

  1. Enable throttle failsafe by setting THR_FAILSAFE to 1 (0=Disabled, 1=Enabled).
  2. First turn on your transmitter and enable the throttle range to extend past -100%, we want to extend the throttle range past its low threshold.
  3. Once this is done, bind with your receiver. This will let your receiver know the lowest possible value for your throttle channel.
  4. Next revert the first change you made to the transmitter to limit the throttle to the original range.
  5. Do the radio calibration using the Mission Planner.
  6. Once the radio calibration is completed, drop the throttle on your transmitter and read what PWM value is being outputted to the mission planner on that channel.
  7. Turn off the transmitter. You should see the value drop significantly. This will be the PWM value relayed to the autopilot in the event RC link was lost during flight.
  8. Make sure THR_FS_VALUE is an adequate number to trigger the failsafe function on the autopilot.
  9. Make sure FS_SHORT_ACTN and FS_LONG_ACTN are both enabled (set to 1).
  10. Connect on the mission planner with your RC transmitter on. Verify on the bottom right corner of the HUD that you are “flying” in a non auto mode (Manual, Stabilize, FBW are ok).
  11. Turn off your transmitter. After 1.5 sec the flight mode should switch to Circle. After 20 sec the flight mode should switch to RTL. If you observe this behavior, your failsafe function has been set up correctly.

The throttle setting with the transmitter on and the throttle stick at minimum is 1096.

After this procedure, the throttle setting with the transmitter off is 926.

THR_FS_VALUE is set = 950.

Normal throttle range (above 1096) is always above the THR_FS_VALUE of 950 so failsafe is not triggered.

With the transmitter off, however, the throttle value is 926 which is less than the THR_FS_VALUE of 950 and therefore triggers the short failsafe state.

 

 The throttle setting with the transmitter off is shown on this ‘Radio Calibration’ page.

 

FS Throttle Setting

 

The transmitter signal loss failsafe parameters are summarised in the following table.

 

PARAMETER

VALUE

UNITS

Comments

THR_FAILSAFE

1

-

0 : Throttle failsafe disabled

1 : Throttle failsafe enabled

THR_FS_VALUE

950

microSeconds

 

 

Throttle failsafe is enabled.

Loss of Telemetry (GCS)

The GCS failsafe parameters are summarised in the following table.

 

PARAMETER

VALUE

UNITS

Comments

FS_GCS_ENABLE

0

-

0 : GCS failsafe disabled

1 : GCSfailsafe enabled

FS_LONG_TIMEOUT

20

Seconds

Note that this is the same parameter that is used by Long Failsafe Action.

 

The failsafe on loss of telemetry works as follows.

If the APM stops receiving MAVLink heartbeat messages for more than the FS_LONG_TIMEOUT (20 seconds), then long failsafe state is entered. In this state, the APM is in RTL mode.

 

GCS failsafe is disabled.

Loss of GPS

If the GPS signal is lost for more than 20 seconds, then Dead Reckoning mode is used until the GPS signal is restored.

 

Take Off Set Up

Throwing To Launch

‘Stabilise’ mode or ‘Auto’ mode keep the wings level after the aircraft is released making launching less demanding on the pilot.

If ‘Auto’ mode with a takeoff command in the command list is used, the aircraft can be launched by hand even without holding the transmitter. The aircraft will stabilise and climb automatically after leaving your hand.

The parameter TKOFF_ROTATE_SPD should be 0 for all hand launches.

 

No Auto Throttle Control

If the parameter TKOFF_THR_MINACC is zero, then the throttle starts immediately after ‘Auto’ mode is selected.

When no auto throttle control is used, these are the parameter values used.

 

PARAMETER

DEFAULT

SET VALUE

UNIT

TKOFF_THR_DELAY

0

0

0.1 sec

TKOFF_THR_MINACC

0

0

m/s/s

TKOFF_THR_MINSPD

0

0

m/s

TKOFF_ROTATE_SPD

0

0

m/s

 

Auto Throttle Control

If the parameter TKOFF_THR_MINACC is not zero, then the throttle is armed only after the time in TKOFF_THR_DELAY has passed and the GPS ground speed is above TKOFF_THR_SPD.

This feature is used when launching by hand

 

 

 

When auto throttle control is used, these are the parameter values used.

 

PARAMETER

DEFAULT

SET VALUE

UNIT

TKOFF_THR_DELAY

0

2

0.1 sec

TKOFF_THR_MINACC

0

15

m/s/s

TKOFF_THR_MINSPD

0

4

m/s

TKOFF_ROTATE_SPD

0

0

m/s

Take Off On Undercarriage

Throttle Control

The maximum throttle value during takeoff is set to the same as THR_MAX.

 

 

The maximum throttle slew rate during takeoff is set to the same as THR_SLEWRATE.

 

 

The TKOFF_ROTATE_SPD parameter is set to 8 m/s.

The parameters TKOFF_TDRAG_ELEV and TKOFF_TDRAG_SPD1 are left at the default value 0 because they only apply to tail dragging configuration aircraft.

 

 

Steering

In ‘Manual’ mode, the steering is controlled by the rudder control on the transmitter only

In all other modes, the APM controls the steering automatically until the aircraft is above the altitude in the GROUND_STEER_ALT parameter. I have set this to 5 metres.

I have used the default value of GROUND_STEER_DPS as 90 degrees per second.

 

 

For take off on an undercarriage, these are the parameter values used.

 

PARAMETER

DEFAULT

SET VALUE

UNIT

Notes

TKOFF_THR_MAX

0

0

%

Set equal to TH_MAX

TKOFF_THROTTLE_SLEW

0

0

%

Set equal to THR_SLEWRATE

TKOFF_ROTATE_SPD

0

8

m/S

 

TKOFF_TDRAG_ELEV

0

0

%

 

TKOFF_TDRAG_SPD1

0

0

m/S

 

GROUND_STEER_ALT

5

5

m

 

GROUND_STEER_DPS

90

90

°/S

 

Climb Rate

The Fly By Wire altitude change rate FBWB_CLIMB_RATE default value is used. It is 2.0 m/S.

 

FBWB Climb Rate

 

PARAMETER

DEFAULT

SET VALUE

UNIT

FBWB_CLIMB_RATE

2

2

m/S

 

Throttle Control Parameters

The throttle parameters are set as follows.

 

Throttle Params

 

The throttle setting for normal flight TRIM_THROTTLE is set to 55%. This throttle setting is used when there is no airspeed sensor.

Throttle Trim

 

Attitude Control Parameters

The attitude parameters are set as follows.

 

Acro Params

 

Pitch Params

 

TECS Parameters

The tuning procedures for TECS (Total Energy Control System ) control can be found here.

http://plane.ardupilot.com/wiki/tecs-total-energy-control-system-for-speed-height-tuning-guide/

 

This table shows the TECS parameter default values.

 

TECS Params

 

These default parameter values have not been changed.

Ready to Fly

 

IMG_2426a

 

With the set up of the plane completed and an insight into what knowledge is needed to fly an autopilot controlled aircraft, the next step is to learn how to prepare for each flight.

 

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