2 * Copyright © 2011 Keith Packard <keithp@keithp.com>
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful, but
10 * WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * General Public License for more details.
14 * You should have received a copy of the GNU General Public License along
15 * with this program; if not, write to the Free Software Foundation, Inc.,
16 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
19 #ifndef AO_FLIGHT_TEST
21 #include "ao_flight.h"
24 #include "ao_sample.h"
25 #include "ao_kalman.h"
27 static ao_k_t ao_k_height;
28 static ao_k_t ao_k_speed;
29 static ao_k_t ao_k_accel;
31 #define AO_K_STEP_100 to_fix_v(0.01)
32 #define AO_K_STEP_2_2_100 to_fix_v(0.00005)
34 #define AO_K_STEP_10 to_fix_v(0.1)
35 #define AO_K_STEP_2_2_10 to_fix_v(0.005)
37 #define AO_K_STEP_1 to_fix_v(1)
38 #define AO_K_STEP_2_2_1 to_fix_v(0.5)
44 static ao_k_t ao_avg_height_scaled;
48 #if !HAS_ACCEL || AO_FLIGHT_TEST
49 #define AO_ERROR_H_SQ_AVG 1
53 ao_v_t ao_error_h_sq_avg;
61 ao_kalman_predict(void)
64 if ((int16_t) (ao_sample_tick - ao_sample_prev_tick) > 50) {
65 ao_k_height += ((ao_k_t) ao_speed * AO_K_STEP_1 +
66 (ao_k_t) ao_accel * AO_K_STEP_2_2_1) >> 4;
67 ao_k_speed += (ao_k_t) ao_accel * AO_K_STEP_1;
71 if ((int16_t) (ao_sample_tick - ao_sample_prev_tick) > 5) {
72 ao_k_height += ((ao_k_t) ao_speed * AO_K_STEP_10 +
73 (ao_k_t) ao_accel * AO_K_STEP_2_2_10) >> 4;
74 ao_k_speed += (ao_k_t) ao_accel * AO_K_STEP_10;
78 if (ao_flight_debug) {
79 printf ("predict speed %g + (%g * %g) = %g\n",
80 ao_k_speed / (65536.0 * 16.0), ao_accel / 16.0, AO_K_STEP_100 / 65536.0,
81 (ao_k_speed + (ao_k_t) ao_accel * AO_K_STEP_100) / (65536.0 * 16.0));
84 ao_k_height += ((ao_k_t) ao_speed * AO_K_STEP_100 +
85 (ao_k_t) ao_accel * AO_K_STEP_2_2_100) >> 4;
86 ao_k_speed += (ao_k_t) ao_accel * AO_K_STEP_100;
91 ao_kalman_err_height(void)
96 ao_v_t height_distrust;
98 ao_v_t speed_distrust;
101 ao_error_h = ao_sample_height - (ao_v_t) (ao_k_height >> 16);
103 #if AO_ERROR_H_SQ_AVG
109 ao_error_h_sq_avg -= ao_error_h_sq_avg >> 4;
110 ao_error_h_sq_avg += (e * e) >> 4;
113 if (ao_flight_state >= ao_flight_drogue)
115 height_distrust = ao_sample_alt - AO_MAX_BARO_HEIGHT;
117 /* speed is stored * 16, but we need to ramp between 248 and 328, so
118 * we want to multiply by 2. The result is a shift by 3.
120 speed_distrust = (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) >> (4 - 1);
121 if (speed_distrust > AO_MAX_SPEED_DISTRUST)
122 speed_distrust = AO_MAX_SPEED_DISTRUST;
123 if (speed_distrust > height_distrust)
124 height_distrust = speed_distrust;
126 if (height_distrust > 0) {
127 #ifdef AO_FLIGHT_TEST
128 int old_ao_error_h = ao_error_h;
130 if (height_distrust > 0x100)
131 height_distrust = 0x100;
132 ao_error_h = (ao_v_t) (((ao_k_t) ao_error_h * (0x100 - height_distrust)) >> 8);
133 #ifdef AO_FLIGHT_TEST
134 if (ao_flight_debug) {
135 printf("over height %g over speed %g distrust: %g height: error %d -> %d\n",
136 (double) (ao_sample_alt - AO_MAX_BARO_HEIGHT),
137 (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) / 16.0,
138 height_distrust / 256.0,
139 old_ao_error_h, ao_error_h);
148 ao_kalman_correct_baro(void)
150 ao_kalman_err_height();
151 #ifdef AO_FLIGHT_TEST
152 if ((int16_t) (ao_sample_tick - ao_sample_prev_tick) > 50) {
153 ao_k_height += (ao_k_t) AO_BARO_K0_1 * ao_error_h;
154 ao_k_speed += (ao_k_t) AO_BARO_K1_1 * ao_error_h;
155 ao_k_accel += (ao_k_t) AO_BARO_K2_1 * ao_error_h;
158 if ((int16_t) (ao_sample_tick - ao_sample_prev_tick) > 5) {
159 ao_k_height += (ao_k_t) AO_BARO_K0_10 * ao_error_h;
160 ao_k_speed += (ao_k_t) AO_BARO_K1_10 * ao_error_h;
161 ao_k_accel += (ao_k_t) AO_BARO_K2_10 * ao_error_h;
165 ao_k_height += (ao_k_t) AO_BARO_K0_100 * ao_error_h;
166 ao_k_speed += (ao_k_t) AO_BARO_K1_100 * ao_error_h;
167 ao_k_accel += (ao_k_t) AO_BARO_K2_100 * ao_error_h;
174 ao_kalman_err_accel(void)
178 accel = (ao_config.accel_plus_g - ao_sample_accel) * ao_accel_scale;
180 /* Can't use ao_accel here as it is the pre-prediction value still */
181 ao_error_a = (accel - ao_k_accel) >> 16;
184 #if !defined(FORCE_ACCEL) && HAS_BARO
186 ao_kalman_correct_both(void)
188 ao_kalman_err_height();
189 ao_kalman_err_accel();
191 #ifdef AO_FLIGHT_TEST
192 if ((int16_t) (ao_sample_tick - ao_sample_prev_tick) > 50) {
193 if (ao_flight_debug) {
194 printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n",
195 ao_k_speed / (65536.0 * 16.0),
196 (double) ao_error_h, AO_BOTH_K10_1 / 65536.0,
197 (double) ao_error_a, AO_BOTH_K11_1 / 65536.0,
199 (ao_k_t) AO_BOTH_K10_1 * ao_error_h +
200 (ao_k_t) AO_BOTH_K11_1 * ao_error_a) / (65536.0 * 16.0));
203 (ao_k_t) AO_BOTH_K00_1 * ao_error_h +
204 (ao_k_t) AO_BOTH_K01_1 * ao_error_a;
206 (ao_k_t) AO_BOTH_K10_1 * ao_error_h +
207 (ao_k_t) AO_BOTH_K11_1 * ao_error_a;
209 (ao_k_t) AO_BOTH_K20_1 * ao_error_h +
210 (ao_k_t) AO_BOTH_K21_1 * ao_error_a;
213 if ((int16_t) (ao_sample_tick - ao_sample_prev_tick) > 5) {
214 if (ao_flight_debug) {
215 printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n",
216 ao_k_speed / (65536.0 * 16.0),
217 (double) ao_error_h, AO_BOTH_K10_10 / 65536.0,
218 (double) ao_error_a, AO_BOTH_K11_10 / 65536.0,
220 (ao_k_t) AO_BOTH_K10_10 * ao_error_h +
221 (ao_k_t) AO_BOTH_K11_10 * ao_error_a) / (65536.0 * 16.0));
224 (ao_k_t) AO_BOTH_K00_10 * ao_error_h +
225 (ao_k_t) AO_BOTH_K01_10 * ao_error_a;
227 (ao_k_t) AO_BOTH_K10_10 * ao_error_h +
228 (ao_k_t) AO_BOTH_K11_10 * ao_error_a;
230 (ao_k_t) AO_BOTH_K20_10 * ao_error_h +
231 (ao_k_t) AO_BOTH_K21_10 * ao_error_a;
234 if (ao_flight_debug) {
235 printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n",
236 ao_k_speed / (65536.0 * 16.0),
237 (double) ao_error_h, AO_BOTH_K10_100 / 65536.0,
238 (double) ao_error_a, AO_BOTH_K11_100 / 65536.0,
240 (ao_k_t) AO_BOTH_K10_100 * ao_error_h +
241 (ao_k_t) AO_BOTH_K11_100 * ao_error_a) / (65536.0 * 16.0));
245 (ao_k_t) AO_BOTH_K00_100 * ao_error_h +
246 (ao_k_t) AO_BOTH_K01_100 * ao_error_a;
248 (ao_k_t) AO_BOTH_K10_100 * ao_error_h +
249 (ao_k_t) AO_BOTH_K11_100 * ao_error_a;
251 (ao_k_t) AO_BOTH_K20_100 * ao_error_h +
252 (ao_k_t) AO_BOTH_K21_100 * ao_error_a;
258 ao_kalman_correct_accel(void)
260 ao_kalman_err_accel();
262 #ifdef AO_FLIGHT_TEST
263 if ((int16_t) (ao_sample_tick - ao_sample_prev_tick) > 5) {
264 ao_k_height +=(ao_k_t) AO_ACCEL_K0_10 * ao_error_a;
265 ao_k_speed += (ao_k_t) AO_ACCEL_K1_10 * ao_error_a;
266 ao_k_accel += (ao_k_t) AO_ACCEL_K2_10 * ao_error_a;
270 ao_k_height += (ao_k_t) AO_ACCEL_K0_100 * ao_error_a;
271 ao_k_speed += (ao_k_t) AO_ACCEL_K1_100 * ao_error_a;
272 ao_k_accel += (ao_k_t) AO_ACCEL_K2_100 * ao_error_a;
275 #endif /* else FORCE_ACCEL */
276 #endif /* HAS_ACCEL */
279 static ao_k_t ao_k_height_prev;
280 static ao_k_t ao_k_speed_prev;
283 * While in pad mode without a barometric sensor, remove accumulated
284 * speed and height values to reduce the effect of systematic sensor
288 ao_kalman_reset_accumulate(void)
290 ao_k_height -= ao_k_height_prev;
291 ao_k_speed -= ao_k_speed_prev;
292 ao_k_height_prev = ao_k_height;
293 ao_k_speed_prev = ao_k_speed;
303 if (ao_flight_state <= ao_flight_coast) {
305 ao_kalman_correct_accel();
307 ao_kalman_correct_both();
311 ao_kalman_correct_baro();
314 ao_kalman_correct_accel();
317 ao_height = from_fix(ao_k_height);
318 ao_speed = from_fix(ao_k_speed);
319 ao_accel = from_fix(ao_k_accel);
320 if (ao_height > ao_max_height)
321 ao_max_height = ao_height;
323 ao_avg_height_scaled = ao_avg_height_scaled - ao_avg_height + ao_sample_height;
325 ao_avg_height_scaled = ao_avg_height_scaled - ao_avg_height + ao_height;
327 #ifdef AO_FLIGHT_TEST
328 if ((int16_t) (ao_sample_tick - ao_sample_prev_tick) > 50)
329 ao_avg_height = (ao_avg_height_scaled + 1) >> 1;
330 else if ((int16_t) (ao_sample_tick - ao_sample_prev_tick) > 5)
331 ao_avg_height = (ao_avg_height_scaled + 7) >> 4;
334 ao_avg_height = (ao_avg_height_scaled + 63) >> 7;