[Paparazzi-devel] Changes in the CVS head

[Pascal Brisset]

Hi,

your next update will probably require some modifications in your 
airframe configurations files. Some cleaning has been done, mainly in 
the infrared module (infrared.c) which has been simplified:
- the dynamic estimation on the contrast (e.g. "lls") and the initial 
contrast calibration feature (just after boot) have been removed;
- the "IR360" mode is now the default single mode;
- the configuration of the sensors should :-) be easier.
Some other old code has been removed: wavecard modem (link agent and 
airborne code), harware ground audio modem (link agent), RC transmitter 
events,...

Some examples for the infrared sensor configuration can be found in the 
updated airframe files.

1) The sensor neutrals are now defined on the sensor channels:  
ADC_ROLL_NEUTRAL and ADC_PITCH_NEUTRAL are replaced by ADC_IR1_NEUTRAL 
and ADC_IR2_NEUTRAL. These two values should be around 512 and are tuned 
with the "cupboard test": Put the aircraft in a close box (a cupboard) 
and read the values of the IR_SENSORS message (ir1, ir2 and vertical); 
Set the neutrals (they are subtracted from the measurement) to get null 
values. E.g. if you read 5 for the ir1 value with ADC_IR1_NEUTRAL equal 
to 512, change it to 517.

2) Two installation setups are predefined for the horizontal sensor, 
"aligned" and "tilted".
- If the sensor is aligned with the airframe (example in 
twinstar6.xml), set the corresponding flag:
   <define name="HORIZ_SENSOR_ALIGNED" value="1"/>
and declare the longitudinal channel as ADC_IR2 and the lateral one as 
ADC_IR1. Set the IR_IR1_SIGN (resp. IR_IR2_SIGN) to -1 if needed: In the 
IR_SENSORS message, the lateral value must be positive when it is warmer 
on the right side; the longitudinal value must be positive when it is 
warmer on the back side.
- If the sensor is tilted at 45° (example in microjet6.xml), set
   <define name="HORIZ_SENSOR_TILTED" value="1"/>
and declare the rear-left -- front-right sensor as IR1, the rear-right 
-- front-left as IR2.
  IR1_SIGN and IR2_SIGN must give positive values when it's warm on the 
right side.

If your sensor is tilted at 30° :-) or if you want to keep your old 
working configuration, the RollOfIrs() and PitchOfIrs() macros (example 
in microjet5.xml) are still working.

3) The three infrared axis should approximatively give the same maximum 
values (level for the vertical sensor, tilted on the right wing for the 
lateral value, nose-up for the longitudinal value). The following 
factors can be set to adjust these values:
   <define name="LATERAL_CORRECTION" value="1."/>
   <define name="LONGITUDINAL_CORRECTION" value="1."/>
   <define name="VERTICAL_CORRECTION" value="1."/>
E.g., if 200 is the maximum value on the vertical axis,  300 on the 
lateral axis and 100 on the longitudinal axis, we must set:
    <define name="LATERAL_CORRECTION" value="0.66"/>
   <define name="LONGITUDINAL_CORRECTION" value="2."/>
   <define name="VERTICAL_CORRECTION" value="1."/>

4) To take into account the fact that your horizontal sensor is probably 
not strictly aligned with the airframe, you will need to adjust the 
ROLL_NEUTRAL (positive to roll right) and PITCH_NEUTRAL (positive to 
pitch up) angles. It can be done only in flight.

5) Finally, an asymmetric (left/right, front/rear) correction can be 
added with a last set of factors:
   <define name="CORRECTION_UP" value="1.0"/>
   <define name="CORRECTION_DOWN" value="1.0"/>
   <define name="CORRECTION_LEFT" value="1.0"/>
   <define name="CORRECTION_RIGHT" value="1.0"/>
These corrections are set on the angles.

All this should go in the wiki asap ...

This new code has not been heavily tested so don't hesitate to ask for help.

Happy update

--Pascal