altos: Missing parens and some bad arithmetic in the kalman code

[fw/altos] / src / ao_flight.c

diff --git a/src/ao_flight.c b/src/ao_flight.c
index 7f194e04d59c6a793a576a2b12504b843ce1812b..39325a69713f86116850a2314f2bcb6e20b7de4b 100644 (file)
--- a/src/ao_flight.c
+++ b/src/ao_flight.c
@@ -140,7 +140,7 @@ static __pdata int32_t              ao_k_accel;
 /*
  * Above this speed, baro measurements are unreliable
  */
-#define AO_MAX_BARO_SPEED      300
+#define AO_MAX_BARO_SPEED      200
 
 static void
 ao_kalman_predict(void)
@@ -153,6 +153,11 @@ ao_kalman_predict(void)
 
                return;
        }
+       if (ao_flight_debug) {
+               printf ("predict speed %g + (%g * %g) = %g\n",
+                       ao_k_speed / (65536.0 * 16.0), ao_accel / 16.0, AO_K_STEP_100 / 65536.0,
+                       (ao_k_speed + (int32_t) ao_accel * AO_K_STEP_100) / (65536.0 * 16.0));
+       }
 #endif
        ao_k_height += ((int32_t) ao_speed * AO_K_STEP_100 +
                        (int32_t) ao_accel * AO_K_STEP_2_2_100) >> 4;
@@ -180,12 +185,20 @@ ao_kalman_err_height(void)
                e = -e;
        if (e > 127)
                e = 127;
+#if HAS_ACCEL
+       ao_error_h_sq_avg -= ao_error_h_sq_avg >> 2;
+       ao_error_h_sq_avg += (e * e) >> 2;
+#else
        ao_error_h_sq_avg -= ao_error_h_sq_avg >> 4;
        ao_error_h_sq_avg += (e * e) >> 4;
+#endif
 
        height_distrust = ao_raw_height - AO_MAX_BARO_HEIGHT;
 #if HAS_ACCEL
-       speed_distrust = (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) >> 4;
+       /* speed is stored * 16, but we need to ramp between 200 and 328, so
+        * we want to multiply by 2. The result is a shift by 3.
+        */
+       speed_distrust = (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) >> (4 - 1);
        if (speed_distrust <= 0)
                speed_distrust = 0;
        else if (speed_distrust > height_distrust)
@@ -195,9 +208,21 @@ ao_kalman_err_height(void)
                height_distrust = 0;
 
        if (height_distrust) {
+#ifdef AO_FLIGHT_TEST
+               int     old_ao_error_h = ao_error_h;
+#endif
                if (height_distrust > 0x100)
                        height_distrust = 0x100;
-               ao_error_h = (int16_t) ((int32_t) ao_error_h * (0x100 - height_distrust)) >> 8;
+               ao_error_h = (int16_t) (((int32_t) ao_error_h * (0x100 - height_distrust)) >> 8);
+#ifdef AO_FLIGHT_TEST
+               if (ao_flight_debug) {
+                       printf("over height %g over speed %g distrust: %g height: error %d -> %d\n",
+                              (double) (ao_raw_height - AO_MAX_BARO_HEIGHT),
+                              (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) / 16.0,
+                              height_distrust / 256.0,
+                              old_ao_error_h, ao_error_h);
+               }
+#endif
        }
 }
 
@@ -241,17 +266,35 @@ ao_kalman_correct_both(void)
 
 #ifdef AO_FLIGHT_TEST
        if (ao_flight_tick - ao_flight_prev_tick > 5) {
+               if (ao_flight_debug) {
+                       printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n",
+                               ao_k_speed / (65536.0 * 16.0),
+                               (double) ao_error_h, AO_BOTH_K10_10 / 65536.0,
+                               (double) ao_error_a, AO_BOTH_K11_10 / 65536.0,
+                               (ao_k_speed +
+                                (int32_t) AO_BOTH_K10_10 * ao_error_h +
+                                (int32_t) AO_BOTH_K11_10 * ao_error_a) / (65536.0 * 16.0));
+               }
                ao_k_height +=
                        (int32_t) AO_BOTH_K00_10 * ao_error_h +
-                       (int32_t) (AO_BOTH_K01_10 >> 4) * ao_error_a;
+                       (int32_t) AO_BOTH_K01_10 * ao_error_a;
                ao_k_speed +=
-                       ((int32_t) AO_BOTH_K10_10 << 4) * ao_error_h +
+                       (int32_t) AO_BOTH_K10_10 * ao_error_h +
                        (int32_t) AO_BOTH_K11_10 * ao_error_a;
                ao_k_accel +=
-                       ((int32_t) AO_BOTH_K20_10 << 4) * ao_error_h +
+                       (int32_t) AO_BOTH_K20_10 * ao_error_h +
                        (int32_t) AO_BOTH_K21_10 * ao_error_a;
                return;
        }
+       if (ao_flight_debug) {
+               printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n",
+                       ao_k_speed / (65536.0 * 16.0),
+                       (double) ao_error_h, AO_BOTH_K10_100 / 65536.0,
+                       (double) ao_error_a, AO_BOTH_K11_100 / 65536.0,
+                       (ao_k_speed +
+                        (int32_t) AO_BOTH_K10_100 * ao_error_h +
+                        (int32_t) AO_BOTH_K11_100 * ao_error_a) / (65536.0 * 16.0));
+       }
 #endif
        ao_k_height +=
                (int32_t) AO_BOTH_K00_100 * ao_error_h +
@@ -264,23 +307,23 @@ ao_kalman_correct_both(void)
                (int32_t) AO_BOTH_K21_100 * ao_error_a;
 }
 
+#ifdef FORCE_ACCEL
 static void
 ao_kalman_correct_accel(void)
 {
        ao_kalman_err_accel();
 
-#ifdef AO_FLIGHT_TEST
        if (ao_flight_tick - ao_flight_prev_tick > 5) {
                ao_k_height +=(int32_t) AO_ACCEL_K0_10 * ao_error_a;
                ao_k_speed  += (int32_t) AO_ACCEL_K1_10 * ao_error_a;
                ao_k_accel  += (int32_t) AO_ACCEL_K2_10 * ao_error_a;
                return;
        }
-#endif
        ao_k_height += (int32_t) AO_ACCEL_K0_100 * ao_error_a;
        ao_k_speed  += (int32_t) AO_ACCEL_K1_100 * ao_error_a;
        ao_k_accel  += (int32_t) AO_ACCEL_K2_100 * ao_error_a;
 }
+#endif
 #endif /* HAS_ACCEL */
 
 __xdata int32_t ao_raw_pres_sum;
@@ -567,23 +610,31 @@ ao_flight(void)
                        if ((ao_accel < AO_MSS_TO_ACCEL(-2.5) && ao_height > AO_M_TO_HEIGHT(100)) ||
                            (int16_t) (ao_flight_tick - ao_launch_tick) > BOOST_TICKS_MAX)
                        {
+#if HAS_ACCEL
                                ao_flight_state = ao_flight_fast;
+#else
+                               ao_flight_state = ao_flight_coast;
+#endif
                                ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
                                break;
                        }
                        break;
+#if HAS_ACCEL
                case ao_flight_fast:
                        /*
                         * This is essentially the same as coast,
                         * but the barometer is being ignored as
                         * it may be unreliable.
                         */
-                       if (ao_speed < AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) {
+                       if (ao_speed < AO_MS_TO_SPEED(AO_MAX_BARO_SPEED) &&
+                           (ao_raw_alt >= AO_MAX_BARO_HEIGHT || ao_error_h_sq_avg < 30))
+                       {
                                ao_flight_state = ao_flight_coast;
                                ao_wakeup(DATA_TO_XDATA(&ao_flight_state));
                                break;
                        }
                        break;
+#endif
                case ao_flight_coast:
 
                        /* apogee detect: coast to drogue deploy:
@@ -594,7 +645,11 @@ ao_flight(void)
                         * the measured altitude reasonably closely; otherwise
                         * we're probably transsonic.
                         */
-                       if (ao_speed < 0 && (ao_raw_alt >= AO_MAX_BARO_HEIGHT || ao_error_h_sq_avg < 100))
+                       if (ao_speed < 0
+#if !HAS_ACCEL
+                           && (ao_raw_alt >= AO_MAX_BARO_HEIGHT || ao_error_h_sq_avg < 30)
+#endif
+                               )
                        {
                                /* ignite the drogue charge */
                                ao_ignite(ao_igniter_drogue);