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
25 #include <ao_quaternion.h>
29 * Current sensor values
33 #define PRES_TYPE int32_t
34 #define ALT_TYPE int32_t
35 #define ACCEL_TYPE int16_t
38 __pdata uint16_t ao_sample_tick; /* time of last data */
39 __pdata pres_t ao_sample_pres;
40 __pdata alt_t ao_sample_alt;
41 __pdata alt_t ao_sample_height;
43 __pdata accel_t ao_sample_accel;
46 __pdata accel_t ao_sample_accel_along;
47 __pdata accel_t ao_sample_accel_across;
48 __pdata accel_t ao_sample_accel_through;
49 __pdata gyro_t ao_sample_roll;
50 __pdata gyro_t ao_sample_pitch;
51 __pdata gyro_t ao_sample_yaw;
52 __pdata angle_t ao_sample_orient;
53 __pdata angle_t ao_sample_orients[AO_NUM_ORIENT];
54 __pdata uint8_t ao_sample_orient_pos;
57 __data uint8_t ao_sample_data;
60 * Sensor calibration values
63 __pdata pres_t ao_ground_pres; /* startup pressure */
64 __pdata alt_t ao_ground_height; /* MSL of ao_ground_pres */
67 __pdata accel_t ao_ground_accel; /* startup acceleration */
68 __pdata accel_t ao_accel_2g; /* factory accel calibration */
69 __pdata int32_t ao_accel_scale; /* sensor to m/s² conversion */
73 __pdata accel_t ao_ground_accel_along;
74 __pdata accel_t ao_ground_accel_across;
75 __pdata accel_t ao_ground_accel_through;
76 __pdata int32_t ao_ground_pitch;
77 __pdata int32_t ao_ground_yaw;
78 __pdata int32_t ao_ground_roll;
81 static __pdata uint8_t ao_preflight; /* in preflight mode */
83 static __pdata uint16_t nsamples;
84 __pdata int32_t ao_sample_pres_sum;
86 __pdata int32_t ao_sample_accel_sum;
89 __pdata int32_t ao_sample_accel_along_sum;
90 __pdata int32_t ao_sample_accel_across_sum;
91 __pdata int32_t ao_sample_accel_through_sum;
92 __pdata int32_t ao_sample_pitch_sum;
93 __pdata int32_t ao_sample_yaw_sum;
94 __pdata int32_t ao_sample_roll_sum;
95 static struct ao_quaternion ao_rotation;
99 extern uint8_t ao_orient_test;
103 ao_sample_preflight_add(void)
106 ao_sample_accel_sum += ao_sample_accel;
108 ao_sample_pres_sum += ao_sample_pres;
110 ao_sample_accel_along_sum += ao_sample_accel_along;
111 ao_sample_accel_across_sum += ao_sample_accel_across;
112 ao_sample_accel_through_sum += ao_sample_accel_through;
113 ao_sample_pitch_sum += ao_sample_pitch;
114 ao_sample_yaw_sum += ao_sample_yaw;
115 ao_sample_roll_sum += ao_sample_roll;
122 ao_sample_set_all_orients(void)
125 for (i = 0; i < AO_NUM_ORIENT; i++)
126 ao_sample_orients[i] = ao_sample_orient;
127 ao_sample_orient_pos = 0;
131 ao_sample_set_one_orient(void)
133 ao_sample_orients[ao_sample_orient_pos] = ao_sample_orient;
134 ao_sample_orient_pos = (ao_sample_orient_pos + 1) % AO_NUM_ORIENT;
138 ao_sample_compute_orient(void)
140 /* Compute pitch angle from vertical by taking the pad
141 * orientation vector and rotating it by the current total
142 * rotation value. That will be a unit vector pointing along
143 * the airframe axis. The Z value will be the cosine of the
144 * change in the angle from vertical since boost.
146 * rot = ao_rotation * vertical * ao_rotation°
147 * rot = ao_rotation * (0,0,0,1) * ao_rotation°
148 * = ((a.z, a.y, -a.x, a.r) * (a.r, -a.x, -a.y, -a.z)) .z
150 * = (-a.z * -a.z) + (a.y * -a.y) - (-a.x * -a.x) + (a.r * a.r)
151 * = a.z² - a.y² - a.x² + a.r²
153 * rot = ao_rotation * (0, 0, 0, -1) * ao_rotation°
154 * = ((-a.z, -a.y, a.x, -a.r) * (a.r, -a.x, -a.y, -a.z)) .z
156 * = (a.z * -a.z) + (-a.y * -a.y) - (a.x * -a.x) + (-a.r * a.r)
157 * = -a.z² + a.y² + a.x² - a.r²
161 rotz = ao_rotation.z * ao_rotation.z - ao_rotation.y * ao_rotation.y - ao_rotation.x * ao_rotation.x + ao_rotation.r * ao_rotation.r;
163 ao_sample_orient = acosf(rotz) * (float) (180.0/M_PI);
165 #endif /* HAS_GYRO */
168 ao_sample_preflight_set(void)
171 ao_ground_accel = ao_sample_accel_sum >> 9;
172 ao_sample_accel_sum = 0;
174 ao_ground_pres = ao_sample_pres_sum >> 9;
175 ao_ground_height = pres_to_altitude(ao_ground_pres);
176 ao_sample_pres_sum = 0;
178 ao_ground_accel_along = ao_sample_accel_along_sum >> 9;
179 ao_ground_accel_across = ao_sample_accel_across_sum >> 9;
180 ao_ground_accel_through = ao_sample_accel_through_sum >> 9;
181 ao_ground_pitch = ao_sample_pitch_sum;
182 ao_ground_yaw = ao_sample_yaw_sum;
183 ao_ground_roll = ao_sample_roll_sum;
184 ao_sample_accel_along_sum = 0;
185 ao_sample_accel_across_sum = 0;
186 ao_sample_accel_through_sum = 0;
187 ao_sample_pitch_sum = 0;
188 ao_sample_yaw_sum = 0;
189 ao_sample_roll_sum = 0;
190 ao_sample_set_all_orients();
192 struct ao_quaternion orient;
194 /* Take the pad IMU acceleration values and compute our current direction
197 ao_quaternion_init_vector(&orient,
198 (ao_ground_accel_across - ao_config.accel_zero_across),
199 (ao_ground_accel_through - ao_config.accel_zero_through),
200 (ao_ground_accel_along - ao_config.accel_zero_along));
202 ao_quaternion_normalize(&orient,
207 struct ao_quaternion up = { .r = 0, .x = 0, .y = 0, .z = 1 };
209 if (ao_config.pad_orientation != AO_PAD_ORIENTATION_ANTENNA_UP)
212 /* Compute rotation to get from up to our current orientation, set
213 * that as the current rotation vector
215 ao_quaternion_vectors_to_rotation(&ao_rotation, &up, &orient);
218 printf("\n\treset\n");
221 ao_sample_compute_orient();
222 ao_sample_set_all_orients();
229 #define TIME_DIV 200.0f
232 ao_sample_rotate(void)
234 #ifdef AO_FLIGHT_TEST
235 float dt = (int16_t) (ao_sample_tick - ao_sample_prev_tick) / TIME_DIV;
237 static const float dt = 1/TIME_DIV;
239 float x = ao_convert_gyro((float) ((ao_sample_pitch << 9) - ao_ground_pitch) / 512.0f) * dt;
240 float y = ao_convert_gyro((float) ((ao_sample_yaw << 9) - ao_ground_yaw) / 512.0f) * dt;
241 float z = ao_convert_gyro((float) ((ao_sample_roll << 9) - ao_ground_roll) / 512.0f) * dt;
242 struct ao_quaternion rot;
244 ao_quaternion_init_half_euler(&rot, x, y, z);
245 ao_quaternion_multiply(&ao_rotation, &rot, &ao_rotation);
247 /* And normalize to make sure it remains a unit vector */
248 ao_quaternion_normalize(&ao_rotation, &ao_rotation);
251 if (ao_orient_test) {
252 printf ("rot %d %d %d orient %d \r",
259 ao_sample_compute_orient();
260 ao_sample_set_one_orient();
265 ao_sample_preflight(void)
269 * Collect 512 samples of acceleration and pressure
270 * data and average them to find the resting values
272 if (nsamples < 512) {
273 ao_sample_preflight_add();
276 ao_accel_2g = ao_config.accel_minus_g - ao_config.accel_plus_g;
277 ao_accel_scale = to_fix_32(GRAVITY * 2 * 16) / ao_accel_2g;
279 ao_sample_preflight_set();
280 ao_preflight = FALSE;
285 * While in pad mode, constantly update the ground state by
286 * re-averaging the data. This tracks changes in orientation, which
287 * might be caused by adjustments to the rocket on the pad and
288 * pressure, which might be caused by changes in the weather.
292 ao_sample_preflight_update(void)
295 ao_sample_preflight_add();
296 else if (nsamples < 1024)
299 ao_sample_preflight_set();
304 static int32_t p_filt;
305 static int32_t y_filt;
307 static gyro_t inline ao_gyro(void) {
308 gyro_t p = ao_sample_pitch - ao_ground_pitch;
309 gyro_t y = ao_sample_yaw - ao_ground_yaw;
311 p_filt = p_filt - (p_filt >> 6) + p;
312 y_filt = y_filt - (y_filt >> 6) + y;
316 return ao_sqrt(p*p + y*y);
324 ao_wakeup(DATA_TO_XDATA(&ao_sample_data));
325 ao_sleep((void *) DATA_TO_XDATA(&ao_data_head));
326 while (ao_sample_data != ao_data_head) {
327 __xdata struct ao_data *ao_data;
329 /* Capture a sample */
330 ao_data = (struct ao_data *) &ao_data_ring[ao_sample_data];
331 ao_sample_tick = ao_data->tick;
334 ao_data_pres_cook(ao_data);
335 ao_sample_pres = ao_data_pres(ao_data);
336 ao_sample_alt = pres_to_altitude(ao_sample_pres);
337 ao_sample_height = ao_sample_alt - ao_ground_height;
341 ao_sample_accel = ao_data_accel_cook(ao_data);
342 if (ao_config.pad_orientation != AO_PAD_ORIENTATION_ANTENNA_UP)
343 ao_sample_accel = ao_data_accel_invert(ao_sample_accel);
344 ao_data_set_accel(ao_data, ao_sample_accel);
347 ao_sample_accel_along = ao_data_along(ao_data);
348 ao_sample_accel_across = ao_data_across(ao_data);
349 ao_sample_accel_through = ao_data_through(ao_data);
350 ao_sample_pitch = ao_data_pitch(ao_data);
351 ao_sample_yaw = ao_data_yaw(ao_data);
352 ao_sample_roll = ao_data_roll(ao_data);
356 ao_sample_preflight();
358 if (ao_flight_state < ao_flight_boost)
359 ao_sample_preflight_update();
365 #ifdef AO_FLIGHT_TEST
366 ao_sample_prev_tick = ao_sample_tick;
368 ao_sample_data = ao_data_ring_next(ao_sample_data);
370 return !ao_preflight;
378 ao_sample_pres_sum = 0;
381 ao_sample_accel_sum = 0;
385 ao_sample_accel_along_sum = 0;
386 ao_sample_accel_across_sum = 0;
387 ao_sample_accel_through_sum = 0;
388 ao_sample_accel_along = 0;
389 ao_sample_accel_across = 0;
390 ao_sample_accel_through = 0;
391 ao_sample_pitch_sum = 0;
392 ao_sample_yaw_sum = 0;
393 ao_sample_roll_sum = 0;
397 ao_sample_orient = 0;
398 ao_sample_set_all_orients();
400 ao_sample_data = ao_data_head;