[modules] air_data: cut at zero instead of fabs

paparazzi · Oct 12, 2014 · c2a8c12 · c2a8c12
1 parent e8a641b
commit c2a8c12
Showing 1 changed file with 2 additions and 1 deletion.
diff --git a/sw/airborne/modules/air_data/air_data.c b/sw/airborne/modules/air_data/air_data.c
@@ -109,7 +109,8 @@ static void pressure_diff_cb(uint8_t __attribute__((unused)) sender_id, const fl
 {
   air_data.differential = *pressure;
   if (air_data.calc_airspeed) {
-    air_data.airspeed = sqrtf(fabs(air_data.differential) * air_data.airspeed_scale);
+    /* lower bound of differential pressure at zero, no flying backwards guys */
+    air_data.airspeed = sqrtf(Max(air_data.differential, 0) * air_data.airspeed_scale);
     stateSetAirspeed_f(&air_data.airspeed);
   }
 }