I probably found a bug in sw/airborne/modules/nav/nav_catapult.c
What happened is that motor was not starting automatically on a catapult launch.
I checked the code and found that we are using imu.accel.x for the acceleration threshold detection.
It might work on some cases, but not on others (eg: if we set the IMU in a different orientation - what I did).
I have a BODY_TO_IMU_PSI set to -90°, so x axis becomes y axis and vice versa.
As a reference, at 638s, I'm rolling the plane left and right, and bungee start is done at 647s.
Quick and dirty fix (will work only in SOME cases too): I replaced ACCEL_FLOAT_OF_BFP(imu.accel.x) with ACCEL_FLOAT_OF_BFP(imu.accel.y)
It would be better if we could use the body longitudinal acceleration instead of imu.accel.x, but I'm not sure where it is stored.
Paparazzi-devel mailing list