Hardware Installation

Mechanical

Veronte Autopilot 4x is covered with an aluminium enclosure with enhanced EMI shielding and IP protection, with 750 g as total weight.

Pressure lines

Veronte Autopilot 4x has seven redundant pressure input lines; four for static pressure to determine the absolute pressure and three for pitot in order to determine the dynamic pressure.

For the fittings it is recommended to use a polyurethane tube of 2.5 mm inner diameter and 4 mm outer diameter.

  • Pressure Intake

    • Pressure intakes must be located in order to prevent clogging.

    • Do not install pressure intakes on the propeller flow.

    • Design pressure tubing path in order to avoid tube constriction.

  • Static Pressure

    • It is not recommended to use inside fuselage pressure if it is not properly vented.

  • Pitot Tube

    • Pitot tube must be installed facing the airflow.

    • It is recommended to install it near the aircraft’s x axis in order to avoid false measures during manoeuvres.

    • For low-speed aircraft it is recommended at least 6.3 mm tubes to prevent any rain obstruction.

../_images/autopilot_4x_pressure_ports.png

Location

The location of Veronte Autopilot 4x has no restrictions. It is only required to configure its relative position respect to the centre of mass of the aircraft and the GNSS antenna. The configuration of the location of each Autopilot 1x can be easily configured using 1x PDI Builder.

Orientation

The orientation of Veronte Autopilot 4x has no restrictions either. It is only required to configure axes respect to the aircraft by means of a rotation matrix or a set of correspondences between axes. The configuration of the orientation can be easily configured using 1x PDI Builder for each Autopilot 1x.

Axes are printed on the Autopilot 4x box. Aircraft coordinates are defined by the standard aeronautical conventions, shown in the following figure.

../_images/aircraft-axis.jpg

Aircraft Coordinates (Standard Aeronautical Convention)

Vibration Isolation

Although Veronte Autopilot 4x rejects noise and high-frequency vibration modes with electronic filters, there may be situations where external isolation is needed.

Autopilot 1x can be mounted in different ways in order to reject the airframe vibration, but it is recommend to use the Damping System designed for that porpuse. It covers a wide frequency range of different aircraft types.

Note

The user should take into account that wiring should be loose enough so that vibrations are not transmitted to Autopilot 4x.

Damping System

Embention offers the Damping System as a solution to isolate Veronte Autopilot 4x from vibrations.

Important

Only effective with Autopilot 4x in horizontal position.

This damping system weighs 76 g.

../_images/dampsystem.png

Damping System

Warning

The Damping System is designed for version 1.8 of Autopilot 4x.

Dimensions
../_images/dampsystem_dimensions.png

Damping system dimensions (mm)

Assembly steps

To assembly the Damping System into a vehicle with an Autopilot 4x, read the following steps.

  1. Remove the six nuts located under the platform.

    ../_images/dampsystem3.png

    Step 1

  2. Screw the platform on the aircraft frame. The included screws have M3.

    ../_images/dampsystem4.png

    Step 2

  3. Screw the Autopilot 4x on the Damping system.

    ../_images/dampsystem1.png
    ../_images/dampsystem2.png

    Step 3

../_images/dampsystem_result.png

Result

Antenna Integration

The system uses different kinds of antenna to operate, they must be installed on the airframe. Here you can find some advice for obtaining the best performance and for avoiding antenna interferences.

  • Antenna Installation

    • Maximize separation between antennas as much as possible.

    • Keep antennas far away from alternators or other interference generators.

    • Always isolate the antenna ground panel from the aircraft structure.

    • Make sure antennas are securely mounted.

    • Always use high-quality RF wires minimising the wire length.

    • Always follow the antenna manufacturer manual.

    • SSMA connections shall be tightened applying 1Nm of torque.

    • For all-weather aircraft, insert SSMA lightning protectors.

  • GNSS Antenna

    • Antenna top side must point to the sky.

    • Install them on a top surface with direct sky view.

    • Never place wires or parts made of memetal or carbon above the antenna.

    • It is recommended to install antennas on a small ground plane.

    • For all-weather aircrafts, insert SSMA lightning protectors.

  • Recommended specifications for GNSS antennas

    Specifications

    Range

    Antenna frequency L1

    1561.098 MHz to 1602 MHz

    Antenna frequency L2

    1207.14 MHz to 1246 MHz

    Amplifier gain

    17 dB to 35 dB

    Out-of-band rejection

    40 dB

    Note

    Higher values are preferable.

    30dB is considered the minimum acceptable value.

    Polarization

    RHCP (Right-Hand Circular Polarization)

    Minimum supply voltage

    2.7 V to 3.3 V

    Maximum supply current

    50 mA

Electrical

Power supply

Autopilot 4x can use unregulated DC (6.5 V to 36 V) for the internal Veronte autopilots and also for the Management Board. All power supply pins are not common. It is possible to supply them with different voltages since they are internally protected with diodes. Nonetheless, all power supply pins must be connected to a power supply, in order to guarantee that Autopilot 4x will work in case of failing one of them. These pins are summarized in the following table:

Connector

PIN

Signal

Main Connector

68

BAT_0

67

BAT_1

64

BAT_2

Arbiter Connector

68

VCC_ARBITER

LiPo batteries between 2S and 8S can be used without voltage regulation. Remaining battery can be controlled by the internal voltage sensor and by configuring the voltage warnings on the PC application.

For higher voltage installations, voltage regulators must be used. For dimensioning voltage regulators take into account that a blocked servo can activate regulator thermal protection.

Warning

Power Veronte Autopilot 4x out of the given range can cause irreversible damage to the system. Please read carefully the manual before powering the system.

Autopilots and servos can be powered by the same or different batteries. In case there are more than one battery on the system, a single point ground union is needed to ensure a good performance. The ground signal should be isolated from other system ground references (e.g. engines).

It is recommendable to use independent switches for autopilot and motor/actuators. During the system initialization, PWM signal will be fixed to low level (0V), please make sure that actuators/motor connected support this behavior before installing a single switch for the whole system.

Power Domains

Veronte Autopilot 4x has two internal power domains (A and B). Power domains are isolated each other; hence, if one of them fails, the other one will remain operational. Many of the signals on the pinout are powered by one power domain.

Separated power domains allow to manage redundancy against internal power failures. For example, if the aircraft requires to measure a critical temperature of an external device, the user can use two different analog sensors and connect them to analog inputs of different power domains. One option for this example is connecting them to pin 38 (domain A) and pin 22 (domain B). Thus, if there is an internal failure and power domain A fails, the autopilot will still read measurements from pin 22.

Any power supply pin (pins 64, 67 and 68 from Main Connector and pin 68 from Arbiter Connector) powers both domains. Nonetheles, this is independent of the power supply for each internal Autopilot 1x. Since pins 64, 67 and 68 from Main Connector power one single autopilot (appart from power domains).

Pinout

Warning

Pins can transfer 2 A as maximum current.

../_images/pinout2.png

Warning

Check the pin number before connecting. The color code is repeated 3 times due to the amount of pins. First section (yellow) corresponds to pins 1-30, the second section (blue) to pins 31-60 and the third one (red) to pins 61-68. Pin number increases following the black line of the pictures above: counterclockwise for the connector and clockwise for the plug.

Main Connector pinout

PIN

Signal

Type

Internal Power Domain

Description

1

I/O_0_MUXED

I/O

A

MUXED PWM / Digital I/O signal (0-3.3V)

Warning

Each pin withstands a maximum current of 1.65 mA.

2

I/O_1_MUXED

I/O

B

3

I/O_2_MUXED

I/O

A

4

I/O_3_MUXED

I/O

B

5

I/O_4_MUXED

I/O

A

6

I/O_5_MUXED

I/O

B

7

I/O_6_MUXED

I/O

A

8

I/O_7_MUXED

I/O

B

9

GND*

GROUND

Ground pin for signals 1-8

10

I/O_8_MUXED

I/O

A

MUXED PWM / Digital I/O signal (0-3.3V)

Warning

Each pin withstands a maximum current of 1.65 mA.

11

I/O_9_MUXED

I/O

B

12

I/O_10_MUXED

I/O

A

13

I/O_11_MUXED

I/O

B

14

I/O_12_MUXED

I/O

A

15

I/O_13_MUXED

I/O

B

16

I/O_14_MUXED

I/O

A

17

I/O_15_MUXED

I/O

B

18

GND*

GROUND

Ground pin for signals 10-17

19

MUXED_RS232_TX

OUTPUT

A

MUXED RS-232 output

20

MUXED_RS232_RX

INPUT

A

REDUNDANT RS-232 input

21

V2_USB_DP

I/O

Autopilot 2 USB positive data line

22

ANALOG_3

INPUT

B

REDUNDANT analog input (0-36V)

23

ANALOG_4

INPUT

B

24

V2_USB_DN

I/O

Autopilot 2 USB negative data line

25

CANA_ARB_P

I/O

A

CAN-bus interface. It supports data rates up to 1 Mbps.

A 120 Ohm Zo is required and twisted pair is recommended.

26

CANA_ARB_N

I/O

A

27

GND*

GROUND

GROUND pin for buses (except USB)

28

CANB_ARB_P

I/O

CAN-bus interface. It supports data rates up to 1 Mbps.

A 120 Ohm Zo is required and twisted pair is recommended

29

CANB_ARB_N

I/O

30

V2_USB2_GND

GROUND

Autopilot 2 USB ground

31

I2C_CLK

OUTPUT A

MUXED Clock line for I2C bus (0.3V to 3.3V)

32

I2C_DATA

I/O

A

MUXED data line for I2C bus

33

GND*

GROUND

Ground for 3.3V power supply

34

V1_ARB_TX

OUTPUT

Microcontroller UART transmitter for Autopilot 1

35

V1_ARB_RX

INPUT

Microcontroller UART receiver for Autopilot 1

36

V2_ARB_TX

OUTPUT

Microcontroller UART transmitter for Autopilot 2

37

V2_ARB_RX

INPUT

Microcontroller UART receiver for Autopilot 2

38

ANALOG_0

INPUT

A

REDUNDANT analog input (0-36V)

39

ANALOG_1

INPUT

A

40

ANALOG_2

INPUT

A

41

GND*

GROUND

Ground signal for buses

42

V3_USB_DP

I/O

Autopilot 3 USB positive data line

43

V3_USB_DN

I/O

Autopilot 3 USB negative data line

44

GND*

GROUND

Ground signal for buses

45

V3_ARB_TX

OUTPUT

Microcontroller UART transmitter for Autopilot 3

46

V3_ARB_RX

INPUT

Microcontroller UART receiver for Autopilot 3

47

GND*

GROUND

Ground signal for buses

48

49

V3_USB3_GND

GROUND

Autopilot 3 USB ground

50

OUT_RS485_P

OUTPUT

B

MUXED non-inverted output RS-485 bus

51

OUT_RS485_N

OUTPUT

B

MUXED inverted output RS-485 bus

52

IN_RS485_N

INPUT

REDUNDANT inverted inout RS-485 bus

53

IN_RS485_P

INPUT

REDUNDANT non-inverted input RS-485 bus

54

RS485_GND

GROUND

Ground for RS-485 bus

55

EQEP_A

INPUT

A for autopilots 1 and 2

B for autopilot 3

Encoder quadrature redundant input A (0-5V)

56

EQEP_B

INPUT

Encoder quadrature redundant input B (0-5V)

57

EQEP_S

INPUT

Encoder strobe redundant input (0-5V)

58

EQEP_I

INPUT

Encoder index redundant input (0-5V)

59

GND*

GROUND

Autopilot 3 ground pin

60

V1_USB_DP

I/O

Autopilot 1 USB positive data line

61

V1_USB_DN

I/O

Autopilot 1 USB negative data line

62

V1_USB1_GND

GROUND

Autopilot 1 USB ground

63

GND*

GROUND

Ground signal for buses

64

BAT_2

POWER

Autopilot 3 power supply (6.5 to 36V)

65

GND*

GROUND

Autopilot 2 ground pin

66

GND*

GROUND

Autopilot 1 ground pin

67

BAT_1

POWER

Autopilot 2 power supply (6.5 to 36V)

68

BAT_0

POWER

Autopilot 1 power supply (6.5 to 36V)

Warning

Common grounds are marked with *.

Note

MUXED (multiplexed) signals are connected to the Autopilot 1x decided by the Management Board, then only the selected autopilot is connected to MUXED pins.

REDUNDANT signals are connected to the three inner autopilots, so all of them receive the same REDUNDANT signals.

To know the differences between version 1.2 and 1.8 (this one), read the Pinout changes from Autopilot 4x 1.2 - Troubleshooting section of the present manual.

Arbiter Connector pinout

Although being the same component, Main Connector and Arbiter connector are polarized differently, but they have different mechanical connections to avoid wiring swapping.

PIN

Signal

Type

Internal Power Domain

Description

1

I/O_0_EXTERNAL

I/O

A

External MUXED PWM / Digital I/O signal (0-3.3V). In case of employing an additional external autopilot, its pins I/XX must be connected here.

Each signal I/O_XX_EXTERNAL will be sent to I/XX of Main Connector if the arbiter commands it.

Warning

Input current must be limited to 25 mA for each I/O EXTERNAL pin.

2

I/O_1_EXTERNAL

I/O

B

3

I/O_2_EXTERNAL

I/O

A

4

I/O_3_EXTERNAL

I/O

B

5

I/O_4_EXTERNAL

I/O

A

6

I/O_5_EXTERNAL

I/O

B

7

I/O_6_EXTERNAL

I/O

A

8

I/O_7_EXTERNAL

I/O

B

9

I/O_8_EXTERNAL

I/O

A

10

I/O_9_EXTERNAL

I/O

B

11

I/O_10_EXTERNAL

I/O

A

12

I/O_11_EXTERNAL

I/O

B

13

ARBITER_ANALOG_7

INPUT

Arbiter analog input (0-36V)

14

EXTERNAL_ANALOG_0

OUTPUT

A

External analog signal (0-3V). This is the analog signal from ANALOG_0 on Main Connector, which is reduced from 0-36V to 0-3V.

15

EXTERNAL_ANALOG_1

OUTPUT

A

External analog signal (0-3V). This is the analog signal from ANALOG_1 on Main Connector, which is reduced from 0-36V to 0-3V.

16

EXTERNAL_ANALOG_2

OUTPUT

A

External analog signal (0-3V). This is the analog signal from ANALOG_2 on Main Connector, which is reduced from 0-36V to 0-3V.

17

EXTERNAL_ANALOG_3

OUTPUT

B

External analog signal (0-3V). This is the analog signal from ANALOG_3 on Main Connector, which is reduced from 0-36V to 0-3V.

18

FTC_VOTING_B

OUTPUT

B

This pin is an open drain output (0 - 48V), which is open or connected to GND depending on the FTS signals of the Autopilots 1x. This logic is implemented at the Voting Stage, explained in detail in the Flight Termination System section of this manual.

Use this pin for an emergency device; for example the ground of a relay that activates a parachute.

FTC_VOTING_A (pin 53) and FTC_VOTING_B (pin 18) do the same function, but they have dissimilarity.

19

EXT_RS232_TX

INPUT

A

In case of employing an additional external autopilot, its pin RS 232 TX must be connected here. If arbiter decides to multiplex this signal, it will be transmitted to MUXED_RS232_TX on Main Connector with RS232 protocol.

20

EXT_RS232_RX

OUTPUT

A

In case of employing an additional external autopilot, its pin RS 232 RX must be connected here. If arbiter decides to multiplex this signal, it will be transmitted to MUXED_RS232_TX on Main Connector with RS232 protocol.

21

IN_RS485_P

OUTPUT

This pin is connected with IN_RS485_P from Main Connector

22

IN_RS485_N

OUTPUT

This pin is connected with IN_RS485_N from Main Connector

23

EXT_OUT_RS485_P

INPUT

B

In case of employing an additional external autopilot, its pin OUT_RS485_P must be connected here. If arbiter decides to multiplex this signal and EXT_DETECT of Arbiter Connector is connected to GND, it will be transmitted to OUT_RS485_P on Main Connector with RS232 protocol

24

EXT_OUT_RS485_N

INPUT

B

In case of employing an additional external autopilot, its pin OUT_RS485_N must be connected here. If arbiter decides to multiplex this signal and EXT_DETECT of Arbiter Connector is connected to GND, it will be transmitted to OUT_RS485_N on Main Connector with RS232 protocol

25

CANA_P_ARB_A

I/O

This pin is connected with CANA_ARB_P from Main Connector

26

CANA_N_ARB_A

I/O

This pin is connected with CANA_ARB_N from Main Connector

27

ARBITER_ANALOG_8

INPUT

Arbiter analog input (0-36V)

28

CANB_P_ARB_B

I/O

This pin is connected with CANB_ARB_P from Main Connector

29

CANB_N_ARB_B

I/O

This pin is connected with CANB_ARB_N from Main Connector

30

OUT_RS485_ARB_P

OUTPUT

A

Non-inverted output for arbiter A RS-485 bus

31

OUT_RS485_ARB_N

OUTPUT

A

Inverted output for arbiter A RS-485 bus

32

IN_RS485_ARB_N

INPUT

A

Inverted output for arbiter A RS-485 bus

33

IN_RS485_ARB_P

INPUT

A

Non-inverted input for arbiter A RS-485 bus

34

TX_OUT_P

OUTPUT

A

Arbiter A ARINC positive output

35

TX_OUT_N

OUTPUT

A

Arbiter A ARINC negative output

36

RIN1_ARINC_P

INPUT

A

Arbiter A ARINC positive input

37

RIN1_ARINC_N

INPUT

A

Arbiter A ARINC negative input

38

GND*

GROUND

Ground pin for buses

39

SCL_A_OUT_ARB

OUTPUT

A

Clock signal for arbiter A I2C bus

40

SDA_A_OUT_ARB

I/O

A

Data signal for arbiter A I2C bus

41

DSP_232_RX_B

INPUT

A

Arbiter A RS-232 input B

42

DSP_232_TX_B

OUTPUT

A

Arbiter A RS-232 output B

43

DSP_232_RX_A

INPUT

A

Arbiter A RS-232 input A

44

DSP_232_TX_A

OUTPUT

A

Arbiter A RS-232 output A

45

GND*

GROUND

Ground pin for analog signals

46

ARBITER_ANALOG_0

INPUT

A

Arbiter A analog input (0-36V)

47

ARBITER_ANALOG_1

INPUT

A

48

ARBITER_ANALOG_2

INPUT

A

49

ARBITER_ANALOG_3

INPUT

A

50

ARBITER_ANALOG_4

INPUT

A

51

ARBITER_ANALOG_5

INPUT

A

52

ARBITER_ANALOG_6

INPUT

A

53

FTC_VOTING_A

OUTPUT

A

This pin is an open drain output (0 - 48V), which is open or connected to GND depending on the FTS signals of the Autopilots 1x. This logic is implemented at the Voting Stage, explained in detail in the Flight Termination System section of this manual.

Use this pin for an emergency device; for example the ground of a relay that activates a parachute.

FTC_VOTING_A (pin 53) and FTC_VOTING_B (pin 18) do the same function, but they have dissimilarity.

54

GPIO_8_ARB

I/O

A

Arbiter A PWM / digital I/O signal (0-3.3V)

55

GPIO_9_ARB

I/O

A

56

WD_EXT

INPUT

A

Watchdog signal from external autopilot to arbiter A (0-3.3V)

57

EXT_DETECT

INPUT

A

Connect to GND if external autopilot is connected, otherwise keep open

58

GND*

GROUND

Ground signal for GPIO

59

GPIO_0_ARB

I/O

A

Arbiter A PWM / digital I/O signal (0-3.3V)

60

GPIO_1_ARB

I/O

A

61

GPIO_2_ARB

I/O

A

62

GPIO_3_ARB

I/O

A

63

GPIO_4_ARB

I/O

A

64

SEL_AP

OUTPUT

A

CAP signal indicating the AP selected

65

FTS1_OUT

OUTPUT

A

Deadman signal from comicro

66

FTS2_OUT

OUTPUT

A

System OK bit

67

GND*

GROUND

Management Board ground

68

VCC_ARBITER

POWER

Power supply for Management Board (6.5 to 36 V)

Warning

Common grounds are marked with *.

Important

Apart from CAN buses, all communications are established only with arbiter A (I2C, RS-232, RS-485 and ARINC).

To know the differences between version 1.2 and 1.8 (this one), read the Pinout changes from Autopilot 4x 1.2 - Troubleshooting section of the present manual.

Harnesses

../_images/pinout_harness.png

Pinout of Harness plug of both connectors

Warning

Check the pin number before connecting. The color code is repeated 3 times due to the amount of pins. First section (yellow) corresponds to pins 1-30, the second section (blue) to pins 31-60 and the third one (red) to pins 61-68. Pin number increases following the black line of the pictures above: counterclockwise for the connector and clockwise for the plug.

A wire harness is a structured assembly of cables and connectors used to organize and manage wiring in electrical and electronic systems. It is designed to ensure a tidy and secure installation of cables, preventing tangles, electromagnetic interference, and facilitating maintenance.

The connection between Autopilot 4x and its harnesses is made through the following connectors:

Main Connector: HEW.LM.368.XLNP

Harness plug connector: FGW.LM.368.XLCT

Connector 4: HER.LM.368.XLNP

Harness plug connector: FGR.LM.368.XLCT

Veronte Autopilot 4x 1.8 has the following compatible harnesses:

For Main Connector

Veronte Harness Blue 68P

Veronte Harness CS for 1.8

harness_blue

harness_cs

Harness available on demand with the Embention reference P001114

Harness available on demand with the Embention reference P007695

For Connector 4: Veronte Harness Yellow 68P

harness_yellow

Harness available on demand with the Embention reference P001118

Dimensions

  • Harness plug dimensions:

    ../_images/dimensions_harness_cm.png

    Connector FGW.LM.368.XLCT/FGR.LM.368.XLCT dimensions (cm)

  • Harness Blue/Yellow 68P wire gauge: 22 AWG

  • Cables lenght: 52 cm

Connector color code

Warning

Check the pin number before connecting. The color code is repeated 3 times due to the amount of pins. First section (yellow) corresponds to pins 1-30, the second section (blue) to pins 31-60 and the third one (red) to pins 61-68. Pin number increases following the black line of the pictures above: counterclockwise for the connector and clockwise for the plug.

PIN

Color code

PIN

Color code

1

White

35

Gray

2

Brown

36

Pink

3

Green

37

Blue

4

Yellow

38

Red

5

Gray

39

Black

6

Pink

40

Violet

7

Blue

41

Gray - Pink

8

Red

42

Red - Blue

9

Black

43

White - Green

10

Violet

44

Brown - Green

11

Gray - Pink

45

White - Yellow

12

Red - Blue

46

Yellow - Brown

13

White - Green

47

White - Gray

14

Brown - Green

48

Gray - Brown

15

White - Yellow

49

White - Pink

16

Yellow - Brown

50

Pink - Brown

17

White - Gray

51

White - Blue

18

Gray - Brown

52

Brown - Blue

19

White - Pink

53

White - Red

20

Pink - Brown

54

Brown - Red

21

White - Blue

55

White - Black

22

Brown - Blue

56

Brown - Black

23

White - Red

57

Gray - Green

24

Brown - Red

58

Yellow - Green

25

White - Black

59

Pink - Green

26

Brown - Black

60

Yellow - Pink

27

Gray - Green

61

White

28

Yellow - Green

62

Brown

29

Pink - Green

63

Green

30

Yellow - Pink

64

Yellow

31

White

65

Gray

32

Brown

66

Pink

33

Green

67

Blue

34

Yellow

68

Red

Flight Termination System (FTS)

The Flight Termination System determines the behavior of Autopilot 4x in case of severe failure. There are FTS output signals of 4x for failures of Autopilots 1x (FTC_VOTING_A and FTC_VOTING_B) and for failure of the Arbitration system (FTS1_OUT and FTS2_OUT).

Autopilots 1x failure - Voting Stage

Autopilot 4x FTS works based on a Voting Stage, a simple hardware circuit made of logic gates, which analyzes the FTS signals of each Autopilot 1x in order to determine if terminating the mission or not.

The FTS signals of Autopilots 1x, which correspond with the voting signals considered in the Voting Stage, are the following:

../_images/FTS_signals.svg

Voting System Inputs

  • Pin 63 - FTS_OUT_MPU: Its output is 0 V when the system is working as expected and 3.3 V when some error is detected.

  • Pin 64 - FTS2_OUT_MPU: Its output is 0 V when the system is working as expected and 3.3 V when some error is detected.

  • Pin 49 - FTS3_OUT_MPU: MPU alive voting signal. Its output is a square wave at [100,125] Hz.

Note

For further information regarding these pins, please refer to Pinout - Hardware Installation section in 1x Hardware Manual.

The functionality of the Voting Stage is to implement the following logic:

  • Isolate internal Flight Termination Units (FTUs) with failure. When a deadman signal indicates that an internal Veronte FTU has a failure, this FTU will be excluded from the voting scheme.

  • If all three internal FTUs are OK, then termination will occur if two of three FTUs detect that the vehicle is out of the restricted area.

  • If two FTUs are ok and one is dead, then termination will occur if one of the remaining FTUs detect that the vehicle is out of the restricted area.

  • If one FTU is ok and two are dead, then termination will occur if the remaining FTU detects that the vehicle is out of the restricted area.

  • If all three FTUs are dead, terminate the mission.

In Autopilot 4x, there are two Voting Systems available whose output signals are FTC_VOTING_A and FTC_VOTING_B (pins 53 and 18).

Note

These pins will be open in case of terminating the mission and connected to GND when continuing the mission.

Arbitration failure

The Management Board also includes two FTS pins in the Arbiter Connector:

  • Pin 65 - FTS1_OUT: Deadman signal. Its output is a square wave.

  • Pin 66 - FTS2_OUT: System OK. Its output will be 3.3 V when an error has been detected and 0V when the arbitration system is working normally.

Electrical diagram of CAN bus

Autopilot 4x requires two termination resistors (120 \(\Omega\)) to allow multiple CAN Bus devices to be connected to the same line.

Since there is already an internal 120 \(\Omega\) CAN resistor in the Autopilot 4x (connecting the line to CAN A or CAN B), it is only necessary to place an external 120 \(\Omega\) resistor at the end of the cable:

../_images/can_resistor.png

CAN resistor