aoa_t4
Angle of Attack (AOA) sensor using angle input from a modiefied hall servo connected to a T4 Actuators Board. For the hardware and software used to make your own T4 Actuators board, find all information here: https://github.com/tudelft/t4_actuators_board/ To make it work, the motor of the servo needs to be removed, only the hall sensors is used for angle feedback. If the MOTOR is NOT REMOVED from the servo there will be to much friction and the sensor will NOT WORK properly. Budget wise it is a flexible solution for angle of attack sensor if one uses a T4 Actuators Board already. Aditionall a second servo can added to be assigned to fuction as a SideSlip angle (SSA) sensor. If SSA is added, it is assumed that both sensors are the same, offset and direction can be set to different values. A Servo modified for sensor use which works well is a Feetech STS3032. It is a 360 degree serial bus servo with hall sensor feedback. Simply add the “aoa_t4” module to your myname_airframe.xml file to be able to use this solution. Also for initial offset determination, enabeling the SYNC message is very helpfull. Just add the SYNC_SEND_AOA_T4 define. For a 3D design of a vane that can be 3D printed and mounted on the servo used, download it here:
Name |
Value |
Description |
|---|---|---|
AOA_T4_SERVO_ID |
10 |
Set the Servo ID of servo to use as an Angle Of Attack(AOA) sensor. |
AOA_T4_ANGLE_OFFSET |
3.14 |
How the sensor is physically mounted, a global offset in radian corresponding to the sensor mounting (default: 3.14) |
AOA_T4_OFFSET |
-0.123 |
Initial offset on the neutral angle value. |
AOA_T4_REVERSE |
TRUE|FALSE |
Set to TRUE to reverse AOA output rotation direction (sign) |
AOA_T4_USE_FILTER |
TRUE|FALSE |
Filter the AOA angle sensor output to avoid to much angle fluctuation |
AOA_T4_FILTER |
0.08 |
If filtered is true, then set how much to filter the output |
AOA_T4_SYNC_SEND |
TRUE|FALSE |
Enable telemetry report from AOA or SSA sensor, best set to TRUE to determine the neutral angle to set in offset |
AOA_T4_USE_COMPENSATION |
TRUE|FALSE |
Compensate the output |
USE_AOA |
TRUE|FALSE |
Enable AOA sensor values to the state (default: TRUE) |
AOA_T4_COMP_A1 |
0.0 |
|
AOA_T4_COMP_B1 |
0.0 |
|
AOA_T4_COMP_A2 |
-0.34 |
|
AOA_T4_COMP_B2 |
0.0 |
|
SSA_T4_SERVO_ID |
9 |
Set the Servo ID of servo to use as an SideSlip Angle(SSA) sensor |
SSA_T4_ANGLE_OFFSET |
3.14 |
How the sensor is physically mounted, a global offset in radian corresponding to the sensor mounting (default: 3.14) |
SSA_T4_OFFSET |
-0.456 |
Initial offset on the neutral angle value. |
SSA_T4_REVERSE |
TRUE|FALSE |
Set to TRUE to reverse AOA output rotation direction (sign) |
SSA_T4_USE_FILTER |
TRUE|FALSE |
Filter the AOA angle sensor output to avoid to much angle fluctuation |
SSA_T4_FILTER |
0.15 |
If filtered is true, then set how much to filter the output |
USE_SIDESLIP |
TRUE|FALSE |
Enable SSA sensor values into the state |