altos: Rename 'core' to 'kernel'

core remains a bad name to use -- dirvish skips files (and
directories, it seems) with that name.

Signed-off-by: Keith Packard <keithp@keithp.com>

1 files changed, 295 insertions, 0 deletions

diff --git a/src/kernel/ao_kalman.c b/src/kernel/ao_kalman.c
new file mode 100644
index 00000000..9aea1f14
--- /dev/null
+++ b/src/kernel/ao_kalman.c
@@ -0,0 +1,295 @@
+/*
+ * 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;
+}