From 68ab69de010adbe37b37558824ca013ecd0d569a Mon Sep 17 00:00:00 2001 From: Lorenz Meier Date: Sat, 20 Jul 2013 13:47:51 +0200 Subject: moved commander to C++, preparation for better gyro scale calibration respecting the current attitude for more accurate results --- src/modules/commander/accelerometer_calibration.c | 453 ---------------------- 1 file changed, 453 deletions(-) delete mode 100644 src/modules/commander/accelerometer_calibration.c (limited to 'src/modules/commander/accelerometer_calibration.c') diff --git a/src/modules/commander/accelerometer_calibration.c b/src/modules/commander/accelerometer_calibration.c deleted file mode 100644 index bc9d24956..000000000 --- a/src/modules/commander/accelerometer_calibration.c +++ /dev/null @@ -1,453 +0,0 @@ -/**************************************************************************** - * - * Copyright (C) 2013 PX4 Development Team. All rights reserved. - * Author: Anton Babushkin - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions - * are met: - * - * 1. Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * 2. Redistributions in binary form must reproduce the above copyright - * notice, this list of conditions and the following disclaimer in - * the documentation and/or other materials provided with the - * distribution. - * 3. Neither the name PX4 nor the names of its contributors may be - * used to endorse or promote products derived from this software - * without specific prior written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS - * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT - * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS - * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE - * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, - * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, - * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS - * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED - * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT - * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN - * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. - * - ****************************************************************************/ - -/** - * @file accelerometer_calibration.c - * - * Implementation of accelerometer calibration. - * - * Transform acceleration vector to true orientation, scale and offset - * - * ===== Model ===== - * accel_corr = accel_T * (accel_raw - accel_offs) - * - * accel_corr[3] - fully corrected acceleration vector in body frame - * accel_T[3][3] - accelerometers transform matrix, rotation and scaling transform - * accel_raw[3] - raw acceleration vector - * accel_offs[3] - acceleration offset vector - * - * ===== Calibration ===== - * - * Reference vectors - * accel_corr_ref[6][3] = [ g 0 0 ] // nose up - * | -g 0 0 | // nose down - * | 0 g 0 | // left side down - * | 0 -g 0 | // right side down - * | 0 0 g | // on back - * [ 0 0 -g ] // level - * accel_raw_ref[6][3] - * - * accel_corr_ref[i] = accel_T * (accel_raw_ref[i] - accel_offs), i = 0...5 - * - * 6 reference vectors * 3 axes = 18 equations - * 9 (accel_T) + 3 (accel_offs) = 12 unknown constants - * - * Find accel_offs - * - * accel_offs[i] = (accel_raw_ref[i*2][i] + accel_raw_ref[i*2+1][i]) / 2 - * - * Find accel_T - * - * 9 unknown constants - * need 9 equations -> use 3 of 6 measurements -> 3 * 3 = 9 equations - * - * accel_corr_ref[i*2] = accel_T * (accel_raw_ref[i*2] - accel_offs), i = 0...2 - * - * Solve separate system for each row of accel_T: - * - * accel_corr_ref[j*2][i] = accel_T[i] * (accel_raw_ref[j*2] - accel_offs), j = 0...2 - * - * A * x = b - * - * x = [ accel_T[0][i] ] - * | accel_T[1][i] | - * [ accel_T[2][i] ] - * - * b = [ accel_corr_ref[0][i] ] // One measurement per axis is enough - * | accel_corr_ref[2][i] | - * [ accel_corr_ref[4][i] ] - * - * a[i][j] = accel_raw_ref[i][j] - accel_offs[j], i = 0;2;4, j = 0...2 - * - * Matrix A is common for all three systems: - * A = [ a[0][0] a[0][1] a[0][2] ] - * | a[2][0] a[2][1] a[2][2] | - * [ a[4][0] a[4][1] a[4][2] ] - * - * x = A^-1 * b - * - * accel_T = A^-1 * g - * g = 9.80665 - * - * @author Anton Babushkin - */ - -#include "accelerometer_calibration.h" -#include "commander_helper.h" - -#include -#include -#include -#include -#include -#include -#include - - -#include -#include -#include -#include -#include -#include -#include - -int do_accel_calibration_measurements(int mavlink_fd, float accel_offs[3], float accel_scale[3]); -int detect_orientation(int mavlink_fd, int sub_sensor_combined); -int read_accelerometer_avg(int sensor_combined_sub, float accel_avg[3], int samples_num); -int mat_invert3(float src[3][3], float dst[3][3]); -int calculate_calibration_values(float accel_ref[6][3], float accel_T[3][3], float accel_offs[3], float g); - -void do_accel_calibration(int mavlink_fd) { - /* announce change */ - mavlink_log_info(mavlink_fd, "accel calibration started"); - - /* measure and calculate offsets & scales */ - float accel_offs[3]; - float accel_scale[3]; - int res = do_accel_calibration_measurements(mavlink_fd, accel_offs, accel_scale); - - if (res == OK) { - /* measurements complete successfully, set parameters */ - if (param_set(param_find("SENS_ACC_XOFF"), &(accel_offs[0])) - || param_set(param_find("SENS_ACC_YOFF"), &(accel_offs[1])) - || param_set(param_find("SENS_ACC_ZOFF"), &(accel_offs[2])) - || param_set(param_find("SENS_ACC_XSCALE"), &(accel_scale[0])) - || param_set(param_find("SENS_ACC_YSCALE"), &(accel_scale[1])) - || param_set(param_find("SENS_ACC_ZSCALE"), &(accel_scale[2]))) { - mavlink_log_critical(mavlink_fd, "ERROR: setting offs or scale failed"); - } - - int fd = open(ACCEL_DEVICE_PATH, 0); - struct accel_scale ascale = { - accel_offs[0], - accel_scale[0], - accel_offs[1], - accel_scale[1], - accel_offs[2], - accel_scale[2], - }; - - if (OK != ioctl(fd, ACCELIOCSSCALE, (long unsigned int)&ascale)) - warn("WARNING: failed to set scale / offsets for accel"); - - close(fd); - - /* auto-save to EEPROM */ - int save_ret = param_save_default(); - - if (save_ret != 0) { - warn("WARNING: auto-save of params to storage failed"); - } - - mavlink_log_info(mavlink_fd, "accel calibration done"); - tune_positive(); - } else { - /* measurements error */ - mavlink_log_info(mavlink_fd, "accel calibration aborted"); - tune_negative(); - } - - /* exit accel calibration mode */ -} - -int do_accel_calibration_measurements(int mavlink_fd, float accel_offs[3], float accel_scale[3]) { - const int samples_num = 2500; - float accel_ref[6][3]; - bool data_collected[6] = { false, false, false, false, false, false }; - const char *orientation_strs[6] = { "x+", "x-", "y+", "y-", "z+", "z-" }; - - /* reset existing calibration */ - int fd = open(ACCEL_DEVICE_PATH, 0); - struct accel_scale ascale_null = { - 0.0f, - 1.0f, - 0.0f, - 1.0f, - 0.0f, - 1.0f, - }; - int ioctl_res = ioctl(fd, ACCELIOCSSCALE, (long unsigned int)&ascale_null); - close(fd); - - if (OK != ioctl_res) { - warn("ERROR: failed to set scale / offsets for accel"); - return ERROR; - } - - int sensor_combined_sub = orb_subscribe(ORB_ID(sensor_combined)); - while (true) { - bool done = true; - char str[80]; - int str_ptr; - str_ptr = sprintf(str, "keep vehicle still:"); - for (int i = 0; i < 6; i++) { - if (!data_collected[i]) { - str_ptr += sprintf(&(str[str_ptr]), " %s", orientation_strs[i]); - done = false; - } - } - if (done) - break; - mavlink_log_info(mavlink_fd, str); - - int orient = detect_orientation(mavlink_fd, sensor_combined_sub); - if (orient < 0) - return ERROR; - - sprintf(str, "meas started: %s", orientation_strs[orient]); - mavlink_log_info(mavlink_fd, str); - read_accelerometer_avg(sensor_combined_sub, &(accel_ref[orient][0]), samples_num); - str_ptr = sprintf(str, "meas result for %s: [ %.2f %.2f %.2f ]", orientation_strs[orient], accel_ref[orient][0], accel_ref[orient][1], accel_ref[orient][2]); - mavlink_log_info(mavlink_fd, str); - data_collected[orient] = true; - tune_neutral(); - } - close(sensor_combined_sub); - - /* calculate offsets and rotation+scale matrix */ - float accel_T[3][3]; - int res = calculate_calibration_values(accel_ref, accel_T, accel_offs, CONSTANTS_ONE_G); - if (res != 0) { - mavlink_log_info(mavlink_fd, "ERROR: calibration values calc error"); - return ERROR; - } - - /* convert accel transform matrix to scales, - * rotation part of transform matrix is not used by now - */ - for (int i = 0; i < 3; i++) { - accel_scale[i] = accel_T[i][i]; - } - - return OK; -} - -/* - * Wait for vehicle become still and detect it's orientation. - * - * @return 0..5 according to orientation when vehicle is still and ready for measurements, - * ERROR if vehicle is not still after 30s or orientation error is more than 5m/s^2 - */ -int detect_orientation(int mavlink_fd, int sub_sensor_combined) { - struct sensor_combined_s sensor; - /* exponential moving average of accel */ - float accel_ema[3] = { 0.0f, 0.0f, 0.0f }; - /* max-hold dispersion of accel */ - float accel_disp[3] = { 0.0f, 0.0f, 0.0f }; - /* EMA time constant in seconds*/ - float ema_len = 0.2f; - /* set "still" threshold to 0.1 m/s^2 */ - float still_thr2 = pow(0.1f, 2); - /* set accel error threshold to 5m/s^2 */ - float accel_err_thr = 5.0f; - /* still time required in us */ - int64_t still_time = 2000000; - struct pollfd fds[1] = { { .fd = sub_sensor_combined, .events = POLLIN } }; - - hrt_abstime t_start = hrt_absolute_time(); - /* set timeout to 30s */ - hrt_abstime timeout = 30000000; - hrt_abstime t_timeout = t_start + timeout; - hrt_abstime t = t_start; - hrt_abstime t_prev = t_start; - hrt_abstime t_still = 0; - - unsigned poll_errcount = 0; - - while (true) { - /* wait blocking for new data */ - int poll_ret = poll(fds, 1, 1000); - if (poll_ret) { - orb_copy(ORB_ID(sensor_combined), sub_sensor_combined, &sensor); - t = hrt_absolute_time(); - float dt = (t - t_prev) / 1000000.0f; - t_prev = t; - float w = dt / ema_len; - for (int i = 0; i < 3; i++) { - accel_ema[i] = accel_ema[i] * (1.0f - w) + sensor.accelerometer_m_s2[i] * w; - float d = (float) sensor.accelerometer_m_s2[i] - accel_ema[i]; - d = d * d; - accel_disp[i] = accel_disp[i] * (1.0f - w); - if (d > accel_disp[i]) - accel_disp[i] = d; - } - /* still detector with hysteresis */ - if ( accel_disp[0] < still_thr2 && - accel_disp[1] < still_thr2 && - accel_disp[2] < still_thr2 ) { - /* is still now */ - if (t_still == 0) { - /* first time */ - mavlink_log_info(mavlink_fd, "still..."); - t_still = t; - t_timeout = t + timeout; - } else { - /* still since t_still */ - if ((int64_t) t - (int64_t) t_still > still_time) { - /* vehicle is still, exit from the loop to detection of its orientation */ - break; - } - } - } else if ( accel_disp[0] > still_thr2 * 2.0f || - accel_disp[1] > still_thr2 * 2.0f || - accel_disp[2] > still_thr2 * 2.0f) { - /* not still, reset still start time */ - if (t_still != 0) { - mavlink_log_info(mavlink_fd, "moving..."); - t_still = 0; - } - } - } else if (poll_ret == 0) { - poll_errcount++; - } - if (t > t_timeout) { - poll_errcount++; - } - - if (poll_errcount > 1000) { - mavlink_log_info(mavlink_fd, "ERROR: failed reading accel"); - return -1; - } - } - - if ( fabs(accel_ema[0] - CONSTANTS_ONE_G) < accel_err_thr && - fabs(accel_ema[1]) < accel_err_thr && - fabs(accel_ema[2]) < accel_err_thr ) - return 0; // [ g, 0, 0 ] - if ( fabs(accel_ema[0] + CONSTANTS_ONE_G) < accel_err_thr && - fabs(accel_ema[1]) < accel_err_thr && - fabs(accel_ema[2]) < accel_err_thr ) - return 1; // [ -g, 0, 0 ] - if ( fabs(accel_ema[0]) < accel_err_thr && - fabs(accel_ema[1] - CONSTANTS_ONE_G) < accel_err_thr && - fabs(accel_ema[2]) < accel_err_thr ) - return 2; // [ 0, g, 0 ] - if ( fabs(accel_ema[0]) < accel_err_thr && - fabs(accel_ema[1] + CONSTANTS_ONE_G) < accel_err_thr && - fabs(accel_ema[2]) < accel_err_thr ) - return 3; // [ 0, -g, 0 ] - if ( fabs(accel_ema[0]) < accel_err_thr && - fabs(accel_ema[1]) < accel_err_thr && - fabs(accel_ema[2] - CONSTANTS_ONE_G) < accel_err_thr ) - return 4; // [ 0, 0, g ] - if ( fabs(accel_ema[0]) < accel_err_thr && - fabs(accel_ema[1]) < accel_err_thr && - fabs(accel_ema[2] + CONSTANTS_ONE_G) < accel_err_thr ) - return 5; // [ 0, 0, -g ] - - mavlink_log_info(mavlink_fd, "ERROR: invalid orientation"); - - return -2; // Can't detect orientation -} - -/* - * Read specified number of accelerometer samples, calculate average and dispersion. - */ -int read_accelerometer_avg(int sensor_combined_sub, float accel_avg[3], int samples_num) { - struct pollfd fds[1] = { { .fd = sensor_combined_sub, .events = POLLIN } }; - int count = 0; - float accel_sum[3] = { 0.0f, 0.0f, 0.0f }; - - while (count < samples_num) { - int poll_ret = poll(fds, 1, 1000); - if (poll_ret == 1) { - struct sensor_combined_s sensor; - orb_copy(ORB_ID(sensor_combined), sensor_combined_sub, &sensor); - for (int i = 0; i < 3; i++) - accel_sum[i] += sensor.accelerometer_m_s2[i]; - count++; - } else { - return ERROR; - } - } - - for (int i = 0; i < 3; i++) { - accel_avg[i] = accel_sum[i] / count; - } - - return OK; -} - -int mat_invert3(float src[3][3], float dst[3][3]) { - float det = src[0][0] * (src[1][1] * src[2][2] - src[1][2] * src[2][1]) - - src[0][1] * (src[1][0] * src[2][2] - src[1][2] * src[2][0]) + - src[0][2] * (src[1][0] * src[2][1] - src[1][1] * src[2][0]); - if (det == 0.0f) - return ERROR; // Singular matrix - - dst[0][0] = (src[1][1] * src[2][2] - src[1][2] * src[2][1]) / det; - dst[1][0] = (src[1][2] * src[2][0] - src[1][0] * src[2][2]) / det; - dst[2][0] = (src[1][0] * src[2][1] - src[1][1] * src[2][0]) / det; - dst[0][1] = (src[0][2] * src[2][1] - src[0][1] * src[2][2]) / det; - dst[1][1] = (src[0][0] * src[2][2] - src[0][2] * src[2][0]) / det; - dst[2][1] = (src[0][1] * src[2][0] - src[0][0] * src[2][1]) / det; - dst[0][2] = (src[0][1] * src[1][2] - src[0][2] * src[1][1]) / det; - dst[1][2] = (src[0][2] * src[1][0] - src[0][0] * src[1][2]) / det; - dst[2][2] = (src[0][0] * src[1][1] - src[0][1] * src[1][0]) / det; - - return OK; -} - -int calculate_calibration_values(float accel_ref[6][3], float accel_T[3][3], float accel_offs[3], float g) { - /* calculate offsets */ - for (int i = 0; i < 3; i++) { - accel_offs[i] = (accel_ref[i * 2][i] + accel_ref[i * 2 + 1][i]) / 2; - } - - /* fill matrix A for linear equations system*/ - float mat_A[3][3]; - memset(mat_A, 0, sizeof(mat_A)); - for (int i = 0; i < 3; i++) { - for (int j = 0; j < 3; j++) { - float a = accel_ref[i * 2][j] - accel_offs[j]; - mat_A[i][j] = a; - } - } - - /* calculate inverse matrix for A */ - float mat_A_inv[3][3]; - if (mat_invert3(mat_A, mat_A_inv) != OK) - return ERROR; - - /* copy results to accel_T */ - for (int i = 0; i < 3; i++) { - for (int j = 0; j < 3; j++) { - /* simplify matrices mult because b has only one non-zero element == g at index i */ - accel_T[j][i] = mat_A_inv[j][i] * g; - } - } - - return OK; -} -- cgit v1.2.3