--- /dev/null
+/*
+ * Copyright © 2011 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#ifndef AO_FLIGHT_TEST
+#include "ao.h"
+#include "ao_flight.h"
+#endif
+
+#include "ao_sample.h"
+#include "ao_kalman.h"
+
+
+static __pdata int32_t ao_k_height;
+static __pdata int32_t ao_k_speed;
+static __pdata int32_t ao_k_accel;
+
+#define AO_K_STEP_100 to_fix16(0.01)
+#define AO_K_STEP_2_2_100 to_fix16(0.00005)
+
+#define AO_K_STEP_10 to_fix16(0.1)
+#define AO_K_STEP_2_2_10 to_fix16(0.005)
+
+#define AO_K_STEP_1 to_fix16(1)
+#define AO_K_STEP_2_2_1 to_fix16(0.5)
+
+__pdata int16_t ao_height;
+__pdata int16_t ao_speed;
+__pdata int16_t ao_accel;
+__xdata int16_t ao_max_height;
+static __pdata int32_t ao_avg_height_scaled;
+__xdata int16_t ao_avg_height;
+
+__pdata int16_t ao_error_h;
+__pdata int16_t ao_error_h_sq_avg;
+
+#if HAS_ACCEL
+__pdata int16_t ao_error_a;
+#endif
+
+static void
+ao_kalman_predict(void)
+{
+#ifdef AO_FLIGHT_TEST
+ if (ao_sample_tick - ao_sample_prev_tick > 50) {
+ ao_k_height += ((int32_t) ao_speed * AO_K_STEP_1 +
+ (int32_t) ao_accel * AO_K_STEP_2_2_1) >> 4;
+ ao_k_speed += (int32_t) ao_accel * AO_K_STEP_1;
+
+ return;
+ }
+ if (ao_sample_tick - ao_sample_prev_tick > 5) {
+ ao_k_height += ((int32_t) ao_speed * AO_K_STEP_10 +
+ (int32_t) ao_accel * AO_K_STEP_2_2_10) >> 4;
+ ao_k_speed += (int32_t) ao_accel * AO_K_STEP_10;
+
+ 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;
+ ao_k_speed += (int32_t) ao_accel * AO_K_STEP_100;
+}
+
+static void
+ao_kalman_err_height(void)
+{
+ int16_t e;
+ int16_t height_distrust;
+#if HAS_ACCEL
+ int16_t speed_distrust;
+#endif
+
+ ao_error_h = ao_sample_height - (int16_t) (ao_k_height >> 16);
+
+ e = ao_error_h;
+ if (e < 0)
+ 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
+
+ if (ao_flight_state >= ao_flight_drogue)
+ return;
+ height_distrust = ao_sample_alt - AO_MAX_BARO_HEIGHT;
+#if HAS_ACCEL
+ /* 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)
+ height_distrust = speed_distrust;
+#endif
+ if (height_distrust > 0) {
+#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);
+#ifdef AO_FLIGHT_TEST
+ if (ao_flight_debug) {
+ printf("over height %g over speed %g distrust: %g height: error %d -> %d\n",
+ (double) (ao_sample_alt - 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
+ }
+}
+
+static void
+ao_kalman_correct_baro(void)
+{
+ ao_kalman_err_height();
+#ifdef AO_FLIGHT_TEST
+ if (ao_sample_tick - ao_sample_prev_tick > 50) {
+ ao_k_height += (int32_t) AO_BARO_K0_1 * ao_error_h;
+ ao_k_speed += (int32_t) AO_BARO_K1_1 * ao_error_h;
+ ao_k_accel += (int32_t) AO_BARO_K2_1 * ao_error_h;
+ return;
+ }
+ if (ao_sample_tick - ao_sample_prev_tick > 5) {
+ ao_k_height += (int32_t) AO_BARO_K0_10 * ao_error_h;
+ ao_k_speed += (int32_t) AO_BARO_K1_10 * ao_error_h;
+ ao_k_accel += (int32_t) AO_BARO_K2_10 * ao_error_h;
+ return;
+ }
+#endif
+ ao_k_height += (int32_t) AO_BARO_K0_100 * ao_error_h;
+ ao_k_speed += (int32_t) AO_BARO_K1_100 * ao_error_h;
+ ao_k_accel += (int32_t) AO_BARO_K2_100 * ao_error_h;
+}
+
+#if HAS_ACCEL
+
+static void
+ao_kalman_err_accel(void)
+{
+ int32_t accel;
+
+ accel = (ao_config.accel_plus_g - ao_sample_accel) * ao_accel_scale;
+
+ /* Can't use ao_accel here as it is the pre-prediction value still */
+ ao_error_a = (accel - ao_k_accel) >> 16;
+}
+
+#ifndef FORCE_ACCEL
+static void
+ao_kalman_correct_both(void)
+{
+ ao_kalman_err_height();
+ ao_kalman_err_accel();
+
+#ifdef AO_FLIGHT_TEST
+ if (ao_sample_tick - ao_sample_prev_tick > 50) {
+ 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_1 / 65536.0,
+ (double) ao_error_a, AO_BOTH_K11_1 / 65536.0,
+ (ao_k_speed +
+ (int32_t) AO_BOTH_K10_1 * ao_error_h +
+ (int32_t) AO_BOTH_K11_1 * ao_error_a) / (65536.0 * 16.0));
+ }
+ ao_k_height +=
+ (int32_t) AO_BOTH_K00_1 * ao_error_h +
+ (int32_t) AO_BOTH_K01_1 * ao_error_a;
+ ao_k_speed +=
+ (int32_t) AO_BOTH_K10_1 * ao_error_h +
+ (int32_t) AO_BOTH_K11_1 * ao_error_a;
+ ao_k_accel +=
+ (int32_t) AO_BOTH_K20_1 * ao_error_h +
+ (int32_t) AO_BOTH_K21_1 * ao_error_a;
+ return;
+ }
+ if (ao_sample_tick - ao_sample_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 * ao_error_a;
+ ao_k_speed +=
+ (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 * 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 +
+ (int32_t) AO_BOTH_K01_100 * ao_error_a;
+ ao_k_speed +=
+ (int32_t) AO_BOTH_K10_100 * ao_error_h +
+ (int32_t) AO_BOTH_K11_100 * ao_error_a;
+ ao_k_accel +=
+ (int32_t) AO_BOTH_K20_100 * ao_error_h +
+ (int32_t) AO_BOTH_K21_100 * ao_error_a;
+}
+
+#else
+
+static void
+ao_kalman_correct_accel(void)
+{
+ ao_kalman_err_accel();
+
+ if (ao_sample_tick - ao_sample_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;
+ }
+ 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 /* else FORCE_ACCEL */
+#endif /* HAS_ACCEL */
+
+void
+ao_kalman(void)
+{
+ ao_kalman_predict();
+#if HAS_ACCEL
+ if (ao_flight_state <= ao_flight_coast) {
+#ifdef FORCE_ACCEL
+ ao_kalman_correct_accel();
+#else
+ ao_kalman_correct_both();
+#endif
+ } else
+#endif
+ ao_kalman_correct_baro();
+ ao_height = from_fix(ao_k_height);
+ ao_speed = from_fix(ao_k_speed);
+ 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_sample_height;
+#ifdef AO_FLIGHT_TEST
+ 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 = (ao_avg_height_scaled + 63) >> 7;
+}
projects / fw / altos / blobdiff