altos: Reduce height averaging filter time constant
authorKeith Packard <keithp@keithp.com>
Tue, 2 Aug 2011 08:49:35 +0000 (01:49 -0700)
committerKeith Packard <keithp@keithp.com>
Tue, 2 Aug 2011 08:53:33 +0000 (01:53 -0700)
Using the longer time constant could lead to false landing detection
just after apogee, which is definitely not a good idea.

Signed-off-by: Keith Packard <keithp@keithp.com>
src/ao_kalman.c

index ab97fc3..203d727 100644 (file)
@@ -277,18 +277,15 @@ ao_kalman(void)
        ao_accel = from_fix(ao_k_accel);
        if (ao_height > ao_max_height)
                ao_max_height = ao_height;
+       ao_avg_height_scaled = ao_avg_height_scaled - ao_avg_height + ao_height;
 #ifdef AO_FLIGHT_TEST
-       if (ao_sample_tick - ao_sample_prev_tick > 50) {
-               ao_avg_height = ao_height;
-       } else if (ao_sample_tick - ao_sample_prev_tick > 5) {
-               ao_avg_height_scaled = ao_avg_height_scaled - ao_avg_height + ao_height;
-               ao_avg_height = (ao_avg_height_scaled + 3) >> 2;
-       } else 
+       if (ao_sample_tick - ao_sample_prev_tick > 50)
+               ao_avg_height = (ao_avg_height_scaled + 1) >> 1;
+       else if (ao_sample_tick - ao_sample_prev_tick > 5)
+               ao_avg_height = (ao_avg_height_scaled + 7) >> 4;
+       else 
 #endif
-       {
-               ao_avg_height_scaled = ao_avg_height_scaled - ao_avg_height + ao_height;
-               ao_avg_height = (ao_avg_height_scaled + 15) >> 5;
-       }
+               ao_avg_height = (ao_avg_height_scaled + 63) >> 7;
 #ifdef AO_FLIGHT_TEST
        ao_sample_prev_tick = ao_sample_tick;
 #endif