This section describes the CAN Bus protocol actually in use for the communication between the Arbiter and the Autopilots in Redundant Veronte Autopilot. Veronte is able to use both Standard CAN and Extended CAN messages. In this first integration step, the messages are configured following the Standard CAN communication protocol.

CAN Parameters

The following Standard CAN parameters are described in according to the Veronte Pipe configuration:

  • Baudrate: 1 [Mbps].
  • TX Ini: in this section is set the Start Message. Period has a value of 1 [s].
  • TX: this section has to be configured as it is shown below. Period has to be set to 0.1 [s]
  • RX: None.

CAN Message Structure

The message that each Autopilot (Veronte or External) connected to the Arbiter must send through CAN Bus has to be like the following:

Name:Variable 1Variable 2Variable 3Start Message (TX Ini)
EndiannessLittle EndianLittle EndianLittle EndianLittle Endian
IDAutopilot IDAutopilot IDAutopilot IDAutopilot ID

Can Message Structure

  • Variable X: variable sent to the Arbiter. In this first integration phase, they are Roll, Pitch and Yaw angles.

Variable X – Veronte AP 1

  • Start Message: the arbiter will start to arbitrate only when it reaches the start message from all Autopilots. The start message must be like the following:
 Name:Matcher 1Matcher 2Matcher 3
Bits Number16 bits16 bits1 bit
ValueAutopilot ID655351

Start Message Structure

Where:

Name:Veronte AP 1Veronte AP 2Veronte AP 3External AP
Autopilot ID0123

Autopilot ID Number

The following image shows this configuration using Veronte Pipe and Veronte AP 1.

Start Message – Veronte AP 1 

  • Endianness: In this case, all the messages are configured with a Little Endian structure.
  • ID: The ID of the Autopilot that is sending the message (value from 0 to 3).

Single Message Structure

The structure of the messages including the single variables sent from the Autopilots must be configured like the following:

Matcher 1Matcher 2Variable
16 bits16 bits32 bits

Variable Message Structure

Where:

  • Matcher 1: Autopilot Identifier. In this case the value must be from 0 to 3.
Veronte Autopilot 1Veronte Autopilot 2Veronte Autopilot 3External Autopilot
0123

Autopilot ID Number

  • Matcher 2: Value ranging from 0 to 2 meaning the variable ID.
  • Variable: the variable that the Arbiter will receive and monitor. In this first integration step the variables are:
VariableDescriptionRange [rad]Variable IDBitsType
RollRoll Angle measured from Veronte Autopilot in real time in Body Axes.(-π, π)032Float
PitchPitch Angle measured from Veronte Autopilot in real time in Body Axes.(-π, π)132Float
YawYaw Angle measured from Veronte Autopilot in real time in Body Axes.(0, 2π)232Float

Variable ID

The following figure shows the configuration for Variable 1 – Roll, using Veronte AP 1.

Variable 1 – Roll 

The variables can be modified in the Autopilot CAN configuration using Veronte Pipe. To do this it is sufficient to change the variables in the single message in both the Autopilot configurations. The list of the available variables can be found in section 6.11 of our manual.

External Autopilot Simulation

When the External Autopilot is not connected to the Redundant network, it is possible to simulate its presence allowing the Arbiter to start the arbitration. To do this, it is sufficient to add a message sent from one of the active autopilots through the CAN Bus that contains the Start message of the External Autopilot (ID: 3). The following example represents this kind of message sent from Veronte Autopilot 1 (ID: 0):

MessageAutopilot IDVariable IDTypeValueDescription
100VariableRoll AngleRoll Angle variable of Veronte Autopilot 1 
201VariablePitch AnglePitch Angle variable of Veronte Autopilot 1
302VariableYaw AngleYaw Angle variable of Veronte Autopilot 1
4 – TX Ini065535Start Message1Start message of Veronte Autopilot 1
5 – TX Ini365535Start Message1Start message of External Autopilot

External Autopilot Structure

Once the Arbiter starts to arbitrate, the External Autopilot will be automatically discarded and the process will be carried out using the Veronte Autopilots only.

CAN Protocol for 4-Autopilots Configuration

When the system in configured integrating four Autopilots (including then: three Veronte Autopilots, one Arbiter and one External Autopilot) the CAN Protocol structure does not change. In this case, the arbiter will expect to receive the Start Message from 4 Autopilots with different ID value that will go from 0 to 3.

The user must take into account that:

  • the ID order is not important (Veronte 1 can be configured using ID:2 and vice-versa).
  • the Arbiter does not need any information about the Autopilot type (External or Veronte).
  • when the number of the Autopilots changes, the Arbiter software has to be modified.
  • when the number of the monitored variables changes, the Arbiter software has to be modified

The following tables represent a possible configuration of the messages sent from four Autopilots using three monitored variables.

  • Veronte Autopilot 1:

 

MessageAutopilot IDVariable IDTypeValueDescription
100VariableRoll AngleRoll Angle variable of Veronte Autopilot 1 
201VariablePitch AnglePitch Angle variable of Veronte Autopilot 1
302VariableYaw AngleYaw Angle variable of Veronte Autopilot 1
4 – TX Ini065535Start Message1Start message of Veronte Autopilot 1

Message Structure AP1

  • Veronte Autopilot 2:
MessageAutopilot IDVariable IDTypeValueDescription
110VariableRoll AngleRoll Angle variable of Veronte Autopilot 2 
211VariablePitch AnglePitch Angle variable of Veronte Autopilot 2
312VariableYaw AngleYaw Angle variable of Veronte Autopilot 2
4 -TX Ini165535Start Message1Start message of Veronte Autopilot 2

Message Structure AP2

  • Veronte Autopilot 3:
MessageAutopilot IDVariable IDTypeValueDescription
120VariableRoll AngleRoll Angle variable of Veronte Autopilot 3 
221VariablePitch AnglePitch Angle variable of Veronte Autopilot 3
322VariableYaw AngleYaw Angle variable of Veronte Autopilot 3
4 -TX Ini265535Start Message1Start message of Veronte Autopilot 3

Message Structure AP3

  • External Autopilot:
MessageAutopilot IDVariable IDTypeValueDescription
130VariableRoll AngleRoll Angle variable of External Autopilot
231VariablePitch AnglePitch Angle variable of External Autopilot
332VariableYaw AngleYaw Angle variable of External Autopilot
4 – TX Ini365535Start Message1Start message of External Autopilot

Message Structure External