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; version 2 of the License.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public License along
14 * with this program; if not, write to the Free Software Foundation, Inc.,
15 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
18 #ifndef AO_FLIGHT_TEST
22 #include "ao_kalman.h"
24 static __pdata int32_t ao_k_height;
25 static __pdata int32_t ao_k_speed;
26 static __pdata int32_t ao_k_accel;
28 #define AO_K_STEP_100 to_fix16(0.01)
29 #define AO_K_STEP_2_2_100 to_fix16(0.00005)
31 #define AO_K_STEP_10 to_fix16(0.1)
32 #define AO_K_STEP_2_2_10 to_fix16(0.005)
34 #define AO_K_STEP_1 to_fix16(1)
35 #define AO_K_STEP_2_2_1 to_fix16(0.5)
37 __pdata int16_t ao_height;
38 __pdata int16_t ao_speed;
39 __pdata int16_t ao_accel;
40 __pdata int16_t ao_max_height;
42 __pdata int16_t ao_error_h;
43 __pdata int16_t ao_error_h_sq_avg;
46 __pdata int16_t ao_error_a;
50 ao_kalman_predict(void)
53 if (ao_sample_tick - ao_sample_prev_tick > 50) {
54 ao_k_height += ((int32_t) ao_speed * AO_K_STEP_1 +
55 (int32_t) ao_accel * AO_K_STEP_2_2_1) >> 4;
56 ao_k_speed += (int32_t) ao_accel * AO_K_STEP_1;
60 if (ao_sample_tick - ao_sample_prev_tick > 5) {
61 ao_k_height += ((int32_t) ao_speed * AO_K_STEP_10 +
62 (int32_t) ao_accel * AO_K_STEP_2_2_10) >> 4;
63 ao_k_speed += (int32_t) ao_accel * AO_K_STEP_10;
67 if (ao_flight_debug) {
68 printf ("predict speed %g + (%g * %g) = %g\n",
69 ao_k_speed / (65536.0 * 16.0), ao_accel / 16.0, AO_K_STEP_100 / 65536.0,
70 (ao_k_speed + (int32_t) ao_accel * AO_K_STEP_100) / (65536.0 * 16.0));
73 ao_k_height += ((int32_t) ao_speed * AO_K_STEP_100 +
74 (int32_t) ao_accel * AO_K_STEP_2_2_100) >> 4;
75 ao_k_speed += (int32_t) ao_accel * AO_K_STEP_100;
79 ao_kalman_err_height(void)
82 int16_t height_distrust;
84 int16_t speed_distrust;
87 ao_error_h = ao_sample_height - (int16_t) (ao_k_height >> 16);
95 ao_error_h_sq_avg -= ao_error_h_sq_avg >> 2;
96 ao_error_h_sq_avg += (e * e) >> 2;
98 ao_error_h_sq_avg -= ao_error_h_sq_avg >> 4;
99 ao_error_h_sq_avg += (e * e) >> 4;
102 if (ao_flight_state >= ao_flight_drogue)
104 height_distrust = ao_sample_alt - AO_MAX_BARO_HEIGHT;
106 /* speed is stored * 16, but we need to ramp between 200 and 328, so
107 * we want to multiply by 2. The result is a shift by 3.
109 speed_distrust = (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) >> (4 - 1);
110 if (speed_distrust <= 0)
112 else if (speed_distrust > height_distrust)
113 height_distrust = speed_distrust;
115 if (height_distrust > 0) {
116 #ifdef AO_FLIGHT_TEST
117 int old_ao_error_h = ao_error_h;
119 if (height_distrust > 0x100)
120 height_distrust = 0x100;
121 ao_error_h = (int16_t) (((int32_t) ao_error_h * (0x100 - height_distrust)) >> 8);
122 #ifdef AO_FLIGHT_TEST
123 if (ao_flight_debug) {
124 printf("over height %g over speed %g distrust: %g height: error %d -> %d\n",
125 (double) (ao_sample_alt - AO_MAX_BARO_HEIGHT),
126 (ao_speed - AO_MS_TO_SPEED(AO_MAX_BARO_SPEED)) / 16.0,
127 height_distrust / 256.0,
128 old_ao_error_h, ao_error_h);
135 ao_kalman_correct_baro(void)
137 ao_kalman_err_height();
138 #ifdef AO_FLIGHT_TEST
139 if (ao_sample_tick - ao_sample_prev_tick > 50) {
140 ao_k_height += (int32_t) AO_BARO_K0_1 * ao_error_h;
141 ao_k_speed += (int32_t) AO_BARO_K1_1 * ao_error_h;
142 ao_k_accel += (int32_t) AO_BARO_K2_1 * ao_error_h;
145 if (ao_sample_tick - ao_sample_prev_tick > 5) {
146 ao_k_height += (int32_t) AO_BARO_K0_10 * ao_error_h;
147 ao_k_speed += (int32_t) AO_BARO_K1_10 * ao_error_h;
148 ao_k_accel += (int32_t) AO_BARO_K2_10 * ao_error_h;
152 ao_k_height += (int32_t) AO_BARO_K0_100 * ao_error_h;
153 ao_k_speed += (int32_t) AO_BARO_K1_100 * ao_error_h;
154 ao_k_accel += (int32_t) AO_BARO_K2_100 * ao_error_h;
160 ao_kalman_err_accel(void)
164 accel = (ao_ground_accel - ao_sample_accel) * ao_accel_scale;
166 /* Can't use ao_accel here as it is the pre-prediction value still */
167 ao_error_a = (accel - ao_k_accel) >> 16;
171 ao_kalman_correct_both(void)
173 ao_kalman_err_height();
174 ao_kalman_err_accel();
176 #ifdef AO_FLIGHT_TEST
177 if (ao_sample_tick - ao_sample_prev_tick > 50) {
178 if (ao_flight_debug) {
179 printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n",
180 ao_k_speed / (65536.0 * 16.0),
181 (double) ao_error_h, AO_BOTH_K10_1 / 65536.0,
182 (double) ao_error_a, AO_BOTH_K11_1 / 65536.0,
184 (int32_t) AO_BOTH_K10_1 * ao_error_h +
185 (int32_t) AO_BOTH_K11_1 * ao_error_a) / (65536.0 * 16.0));
188 (int32_t) AO_BOTH_K00_1 * ao_error_h +
189 (int32_t) AO_BOTH_K01_1 * ao_error_a;
191 (int32_t) AO_BOTH_K10_1 * ao_error_h +
192 (int32_t) AO_BOTH_K11_1 * ao_error_a;
194 (int32_t) AO_BOTH_K20_1 * ao_error_h +
195 (int32_t) AO_BOTH_K21_1 * ao_error_a;
198 if (ao_sample_tick - ao_sample_prev_tick > 5) {
199 if (ao_flight_debug) {
200 printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n",
201 ao_k_speed / (65536.0 * 16.0),
202 (double) ao_error_h, AO_BOTH_K10_10 / 65536.0,
203 (double) ao_error_a, AO_BOTH_K11_10 / 65536.0,
205 (int32_t) AO_BOTH_K10_10 * ao_error_h +
206 (int32_t) AO_BOTH_K11_10 * ao_error_a) / (65536.0 * 16.0));
209 (int32_t) AO_BOTH_K00_10 * ao_error_h +
210 (int32_t) AO_BOTH_K01_10 * ao_error_a;
212 (int32_t) AO_BOTH_K10_10 * ao_error_h +
213 (int32_t) AO_BOTH_K11_10 * ao_error_a;
215 (int32_t) AO_BOTH_K20_10 * ao_error_h +
216 (int32_t) AO_BOTH_K21_10 * ao_error_a;
219 if (ao_flight_debug) {
220 printf ("correct speed %g + (%g * %g) + (%g * %g) = %g\n",
221 ao_k_speed / (65536.0 * 16.0),
222 (double) ao_error_h, AO_BOTH_K10_100 / 65536.0,
223 (double) ao_error_a, AO_BOTH_K11_100 / 65536.0,
225 (int32_t) AO_BOTH_K10_100 * ao_error_h +
226 (int32_t) AO_BOTH_K11_100 * ao_error_a) / (65536.0 * 16.0));
230 (int32_t) AO_BOTH_K00_100 * ao_error_h +
231 (int32_t) AO_BOTH_K01_100 * ao_error_a;
233 (int32_t) AO_BOTH_K10_100 * ao_error_h +
234 (int32_t) AO_BOTH_K11_100 * ao_error_a;
236 (int32_t) AO_BOTH_K20_100 * ao_error_h +
237 (int32_t) AO_BOTH_K21_100 * ao_error_a;
242 ao_kalman_correct_accel(void)
244 ao_kalman_err_accel();
246 if (ao_sample_tick - ao_sample_prev_tick > 5) {
247 ao_k_height +=(int32_t) AO_ACCEL_K0_10 * ao_error_a;
248 ao_k_speed += (int32_t) AO_ACCEL_K1_10 * ao_error_a;
249 ao_k_accel += (int32_t) AO_ACCEL_K2_10 * ao_error_a;
252 ao_k_height += (int32_t) AO_ACCEL_K0_100 * ao_error_a;
253 ao_k_speed += (int32_t) AO_ACCEL_K1_100 * ao_error_a;
254 ao_k_accel += (int32_t) AO_ACCEL_K2_100 * ao_error_a;
257 #endif /* HAS_ACCEL */
264 if (ao_flight_state <= ao_flight_coast) {
266 ao_kalman_correct_accel();
268 ao_kalman_correct_both();
272 ao_kalman_correct_baro();
273 ao_height = from_fix(ao_k_height);
274 ao_speed = from_fix(ao_k_speed);
275 ao_accel = from_fix(ao_k_accel);
276 if (ao_height > ao_max_height)
277 ao_max_height = ao_height;
278 #ifdef AO_FLIGHT_TEST
279 ao_sample_prev_tick = ao_sample_tick;