View source for Foils

The foils of the solar boat is a system that is comprised of the following:

* Wing design
* Foil assembly
* [[Autopilot]]

A small overview is given below what any of these signify in the hydrofoils.

== Wing design ==
[[File:Nick-Wings1.jpeg|thumb|The Nick wings made with prepreg CF used for the first real flying trials]]
The wing design is based on the calculation of the airfoil database website: http://airfoiltools.com/plotter/index 

From this database an implementation has been made into matlab to tweak some parameters as well as a plot for generating the wing shape. 

The matlab scripts are on the [https://git.engineersofinnovation.nl git] and can be found [https://git.engineersofinnovation.nl/matlab-scripts/Hydrofoil_Design here].

The Scripts here make an assumption of a Driver weight of 75 kg and a total boat & driver weight of 180 kg. This gives a mass on rudder of 62.3 kg, mass on each of 2 foils of 58.8 kg. 

[[File:cenus_lift_aoa.png|thumb|Lift vs Angle of Attack for the first Cenus wing]]

== Foil assembly ==
The foil assembly connects the wing to the foil mast and then to the hull of the boat.
[[File:Foil assembly.gif|center|thumb|230x230px|Scaled down for showing moving of the foil assembly.]]

== Autopilot ==
The [[autopilot]] is the control electronics that controls the servos of the foil assembly. This a signal PCB with that measures the angle of the solar boat and adjust accordingly towards keeping the hull above the water.

== Height sensors ==
We use ultrasonic height sensors for sensing distance between water and our hull. Currently we use cheap A02 RS485 sensors from DYP. 

Datasheets can be found https://www.dypcn.com/uploads/A02-Datasheet.pdf and https://www.dypcn.com/uploads/A02-Output-Interfaces.pdf

Data from this sensor is being processed by our RS485 to CAN interface.

== Servo Specifications == 
The wings have a max positive AoA of 9.5°, and max negative AoA of -7.5°. Note that the neutral lift axis is about -4.3°, so there is not much deflection downward. At the servo this translates to +15° and -12.5° of travel. for servo values +1650uS to -1375uS. Note that the sign is fliped on the other side as the servos are "mirrored". The rough speed of the wing is 0.4s/60°

==== Pinout ====
{| class="wikitable"
|-
! Pin#!!Wire Colour !!Signal on wire
|-
| 1|| style="background: #0065B2;color:white;" | Blue||
|-
|2|| style="background: #241F21;color:white;" | Black||
|-
| 3|| style="background: #FFFFFF;" | White||
|-
|4|| style="background: #83603A;" | Brown||
|-
|5|| style="background: #B2B3B7;" | Gray||
|}
= CAN Messages =
All multi-byte values are little-endian. Any state byte not listed maps to <code>Unknown</code> on the receiver side.
{| class="wikitable"
!Message
!CAN ID
!DLC
!Byte
!Field
!Type
!Values / Range
|-
|ServoRudderSetpoint
|0x010
|2
|0–1
|Setpoint
|u16 LE
|1000–2000
|-
|HeightSensorFrontLeft
|0x011
|3
|0
|State
|u8 enum
|0=NotPluggedIn, 1=ModbusError, 2=Operational, 0xFF=Unknown
|-
|
|
|
|1–2
|Height value
|u16 LE
|distance in mm
|-
|HeightSensorFrontRight
|0x012
|3
|0
|State
|u8 enum
|0=NotPluggedIn, 1=ModbusError, 2=Operational, 0xFF=Unknown
|-
|
|
|
|1–2
|Height value
|u16 LE
|distance in mm
|-
|HeightSensor (placement TBD)
|0x013
|3
|0
|State
|u8 enum
|0=NotPluggedIn, 1=ModbusError, 2=Operational, 0xFF=Unknown
|-
|
|
|
|1–2
|Height value
|u16 LE
|distance in mm
|-
|HeightSensor (placement TBD)
|0x014
|3
|0
|State
|u8 enum
|0=NotPluggedIn, 1=ModbusError, 2=Operational, 0xFF=Unknown
|-
|
|
|
|1–2
|Height value
|u16 LE
|distance in mm
|-
|ServoRudderStatus
|0x020
|3
|0
|State
|u8 enum
|0=Uninitialized, 1=Operational, 0xFF=Unknown
|-
|
|
|
|1–2
|Current setpoint
|u16 LE
|1000–2000
|-
|ServoRudderCommand
|0x021
|1
|0
|Command
|u8 enum
|0=Initialize
|}