/* * Copyright © 2011 Keith Packard * * 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 #endif #if HAS_GYRO #include #endif /* * Current sensor values */ #ifndef PRES_TYPE #define PRES_TYPE int32_t #define ALT_TYPE int32_t #define ACCEL_TYPE int16_t #endif __pdata uint16_t ao_sample_tick; /* time of last data */ __pdata pres_t ao_sample_pres; __pdata alt_t ao_sample_alt; __pdata alt_t ao_sample_height; #if HAS_ACCEL __pdata accel_t ao_sample_accel; #endif #if HAS_GYRO __pdata accel_t ao_sample_accel_along; __pdata accel_t ao_sample_accel_across; __pdata accel_t ao_sample_accel_through; __pdata gyro_t ao_sample_roll; __pdata gyro_t ao_sample_pitch; __pdata gyro_t ao_sample_yaw; __pdata angle_t ao_sample_orient; #endif __data uint8_t ao_sample_data; /* * Sensor calibration values */ __pdata pres_t ao_ground_pres; /* startup pressure */ __pdata alt_t ao_ground_height; /* MSL of ao_ground_pres */ #if HAS_ACCEL __pdata accel_t ao_ground_accel; /* startup acceleration */ __pdata accel_t ao_accel_2g; /* factory accel calibration */ __pdata int32_t ao_accel_scale; /* sensor to m/s² conversion */ #endif #if HAS_GYRO __pdata accel_t ao_ground_accel_along; __pdata accel_t ao_ground_accel_across; __pdata accel_t ao_ground_accel_through; __pdata int32_t ao_ground_pitch; __pdata int32_t ao_ground_yaw; __pdata int32_t ao_ground_roll; #endif static __pdata uint8_t ao_preflight; /* in preflight mode */ static __pdata uint16_t nsamples; __pdata int32_t ao_sample_pres_sum; #if HAS_ACCEL __pdata int32_t ao_sample_accel_sum; #endif #if HAS_GYRO __pdata int32_t ao_sample_accel_along_sum; __pdata int32_t ao_sample_accel_across_sum; __pdata int32_t ao_sample_accel_through_sum; __pdata int32_t ao_sample_pitch_sum; __pdata int32_t ao_sample_yaw_sum; __pdata int32_t ao_sample_roll_sum; static struct ao_quaternion ao_rotation; static struct ao_quaternion ao_pad_orientation; #endif static void ao_sample_preflight_add(void) { #if HAS_ACCEL ao_sample_accel_sum += ao_sample_accel; #endif ao_sample_pres_sum += ao_sample_pres; #if HAS_GYRO ao_sample_accel_along_sum += ao_sample_accel_along; ao_sample_accel_across_sum += ao_sample_accel_across; ao_sample_accel_through_sum += ao_sample_accel_through; ao_sample_pitch_sum += ao_sample_pitch; ao_sample_yaw_sum += ao_sample_yaw; ao_sample_roll_sum += ao_sample_roll; #endif ++nsamples; } static void ao_sample_preflight_set(void) { #if HAS_ACCEL ao_ground_accel = ao_sample_accel_sum >> 9; ao_sample_accel_sum = 0; #endif ao_ground_pres = ao_sample_pres_sum >> 9; ao_ground_height = pres_to_altitude(ao_ground_pres); ao_sample_pres_sum = 0; #if HAS_GYRO ao_ground_accel_along = ao_sample_accel_along_sum >> 9; ao_ground_accel_across = ao_sample_accel_across_sum >> 9; ao_ground_accel_through = ao_sample_accel_through_sum >> 9; ao_ground_pitch = ao_sample_pitch_sum; ao_ground_yaw = ao_sample_yaw_sum; ao_ground_roll = ao_sample_roll_sum; ao_sample_accel_along_sum = 0; ao_sample_accel_across_sum = 0; ao_sample_accel_through_sum = 0; ao_sample_pitch_sum = 0; ao_sample_yaw_sum = 0; ao_sample_roll_sum = 0; ao_sample_orient = 0; /* No rotation yet */ ao_quaternion_init_zero_rotation(&ao_rotation); /* Take the pad IMU acceleration values and compute our current direction */ ao_quaternion_init_vector(&ao_pad_orientation, ao_ground_accel_across - ao_config.accel_zero_across, ao_ground_accel_through - ao_config.accel_zero_through, -ao_ground_accel_along - ao_config.accel_zero_along); ao_quaternion_normalize(&ao_pad_orientation, &ao_pad_orientation); #endif nsamples = 0; } #if HAS_GYRO static void ao_sample_rotate(void) { #ifdef AO_FLIGHT_TEST float dt = (ao_sample_tick - ao_sample_prev_tick) / 100.0; #else static const float dt = 1/100.0; #endif float x = ao_mpu6000_gyro((float) ((ao_sample_pitch << 9) - ao_ground_pitch) / 512.0f) * dt; float y = ao_mpu6000_gyro((float) ((ao_sample_yaw << 9) - ao_ground_yaw) / 512.0f) * dt; float z = ao_mpu6000_gyro((float) ((ao_sample_roll << 9) - ao_ground_roll) / 512.0f) * dt; struct ao_quaternion rot; struct ao_quaternion point; /* The amount of rotation is just the length of the vector. Now, * here's the trick -- assume that the rotation amount is small. In this case, * sin(x) ≃ x, so we can just make this the sin. */ n_2 = x*x + y*y + z*z; n = sqrtf(n_2); s = n / 2; if (s > 1) s = 1; c = sqrtf(1 - s*s); /* Make unit vector */ if (n > 0) { x /= n; y /= n; z /= n; } /* Now compute the unified rotation quaternion */ ao_quaternion_init_rotation(&rot, x, y, z, s, c); /* Integrate with the previous rotation amount */ ao_quaternion_multiply(&ao_rotation, &ao_rotation, &rot); /* And normalize to make sure it remains a unit vector */ ao_quaternion_normalize(&ao_rotation, &ao_rotation); /* Compute pitch angle from vertical by taking the pad * orientation vector and rotating it by the current total * rotation value. That will be a unit vector pointing along * the airframe axis. The Z value will be the cosine of the * change in the angle from vertical since boost */ ao_quaternion_rotate(&point, &ao_pad_orientation, &ao_rotation); ao_sample_orient = acosf(rotz) * (float) (180.0/M_PI); } #endif static void ao_sample_preflight(void) { /* startup state: * * Collect 512 samples of acceleration and pressure * data and average them to find the resting values */ if (nsamples < 512) { ao_sample_preflight_add(); } else { #if HAS_ACCEL ao_accel_2g = ao_config.accel_minus_g - ao_config.accel_plus_g; ao_accel_scale = to_fix32(GRAVITY * 2 * 16) / ao_accel_2g; #endif ao_sample_preflight_set(); ao_preflight = FALSE; } } /* * While in pad mode, constantly update the ground state by * re-averaging the data. This tracks changes in orientation, which * might be caused by adjustments to the rocket on the pad and * pressure, which might be caused by changes in the weather. */ static void ao_sample_preflight_update(void) { if (nsamples < 512) ao_sample_preflight_add(); else if (nsamples < 1024) ++nsamples; else ao_sample_preflight_set(); } #if 0 #if HAS_GYRO static int32_t p_filt; static int32_t y_filt; static gyro_t inline ao_gyro(void) { gyro_t p = ao_sample_pitch - ao_ground_pitch; gyro_t y = ao_sample_yaw - ao_ground_yaw; p_filt = p_filt - (p_filt >> 6) + p; y_filt = y_filt - (y_filt >> 6) + y; p = p_filt >> 6; y = y_filt >> 6; return ao_sqrt(p*p + y*y); } #endif #endif uint8_t ao_sample(void) { ao_wakeup(DATA_TO_XDATA(&ao_sample_data)); ao_sleep((void *) DATA_TO_XDATA(&ao_data_head)); while (ao_sample_data != ao_data_head) { __xdata struct ao_data *ao_data; /* Capture a sample */ ao_data = (struct ao_data *) &ao_data_ring[ao_sample_data]; ao_sample_tick = ao_data->tick; #if HAS_BARO ao_data_pres_cook(ao_data); ao_sample_pres = ao_data_pres(ao_data); ao_sample_alt = pres_to_altitude(ao_sample_pres); ao_sample_height = ao_sample_alt - ao_ground_height; #endif #if HAS_ACCEL ao_sample_accel = ao_data_accel_cook(ao_data); if (ao_config.pad_orientation != AO_PAD_ORIENTATION_ANTENNA_UP) ao_sample_accel = ao_data_accel_invert(ao_sample_accel); ao_data_set_accel(ao_data, ao_sample_accel); #endif #if HAS_GYRO ao_sample_accel_along = ao_data_along(ao_data); ao_sample_accel_across = ao_data_across(ao_data); ao_sample_accel_through = ao_data_through(ao_data); ao_sample_pitch = ao_data_pitch(ao_data); ao_sample_yaw = ao_data_yaw(ao_data); ao_sample_roll = ao_data_roll(ao_data); #endif if (ao_preflight) ao_sample_preflight(); else { if (ao_flight_state < ao_flight_boost) ao_sample_preflight_update(); ao_kalman(); #if HAS_GYRO ao_sample_rotate(); #endif } #ifdef AO_FLIGHT_TEST ao_sample_prev_tick = ao_sample_tick; #endif ao_sample_data = ao_data_ring_next(ao_sample_data); } return !ao_preflight; } void ao_sample_init(void) { ao_config_get(); nsamples = 0; ao_sample_pres_sum = 0; ao_sample_pres = 0; #if HAS_ACCEL ao_sample_accel_sum = 0; ao_sample_accel = 0; #endif #if HAS_GYRO ao_sample_accel_along_sum = 0; ao_sample_accel_across_sum = 0; ao_sample_accel_through_sum = 0; ao_sample_accel_along = 0; ao_sample_accel_across = 0; ao_sample_accel_through = 0; ao_sample_pitch_sum = 0; ao_sample_yaw_sum = 0; ao_sample_roll_sum = 0; ao_sample_pitch = 0; ao_sample_yaw = 0; ao_sample_roll = 0; ao_sample_orient = 0; #endif ao_sample_data = ao_data_head; ao_preflight = TRUE; }