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author | Lorenz Meier <lm@inf.ethz.ch> | 2013-09-01 00:10:06 +0200 |
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committer | Lorenz Meier <lm@inf.ethz.ch> | 2013-09-01 00:10:06 +0200 |
commit | 4b018e74a9c22ae4b0a87466392d79409108c1b3 (patch) | |
tree | f357ea38f49653a585d297b67bff8d4c3c23b491 /src/modules/systemlib/geo/geo.c | |
parent | a1c4c0fd787401f8ed332fa974a88a74ae079383 (diff) | |
parent | ccc5bef3af2852172b18f33edaffb809a0a1ffcb (diff) | |
download | px4-firmware-4b018e74a9c22ae4b0a87466392d79409108c1b3.tar.gz px4-firmware-4b018e74a9c22ae4b0a87466392d79409108c1b3.tar.bz2 px4-firmware-4b018e74a9c22ae4b0a87466392d79409108c1b3.zip |
Merge branch 'master' of github.com:PX4/Firmware
Diffstat (limited to 'src/modules/systemlib/geo/geo.c')
-rw-r--r-- | src/modules/systemlib/geo/geo.c | 438 |
1 files changed, 0 insertions, 438 deletions
diff --git a/src/modules/systemlib/geo/geo.c b/src/modules/systemlib/geo/geo.c deleted file mode 100644 index 6463e6489..000000000 --- a/src/modules/systemlib/geo/geo.c +++ /dev/null @@ -1,438 +0,0 @@ -/**************************************************************************** - * - * Copyright (C) 2012 PX4 Development Team. All rights reserved. - * Author: Thomas Gubler <thomasgubler@student.ethz.ch> - * Julian Oes <joes@student.ethz.ch> - * Lorenz Meier <lm@inf.ethz.ch> - * - * 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 geo.c - * - * Geo / math functions to perform geodesic calculations - * - * @author Thomas Gubler <thomasgubler@student.ethz.ch> - * @author Julian Oes <joes@student.ethz.ch> - * @author Lorenz Meier <lm@inf.ethz.ch> - */ - -#include <systemlib/geo/geo.h> -#include <nuttx/config.h> -#include <unistd.h> -#include <pthread.h> -#include <stdio.h> -#include <math.h> -#include <stdbool.h> - - -/* values for map projection */ -static double phi_1; -static double sin_phi_1; -static double cos_phi_1; -static double lambda_0; -static double scale; - -__EXPORT void map_projection_init(double lat_0, double lon_0) //lat_0, lon_0 are expected to be in correct format: -> 47.1234567 and not 471234567 -{ - /* notation and formulas according to: http://mathworld.wolfram.com/AzimuthalEquidistantProjection.html */ - phi_1 = lat_0 / 180.0 * M_PI; - lambda_0 = lon_0 / 180.0 * M_PI; - - sin_phi_1 = sin(phi_1); - cos_phi_1 = cos(phi_1); - - /* calculate local scale by using the relation of true distance and the distance on plane */ //TODO: this is a quick solution, there are probably easier ways to determine the scale - - /* 1) calculate true distance d on sphere to a point: http://www.movable-type.co.uk/scripts/latlong.html */ - const double r_earth = 6371000; - - double lat1 = phi_1; - double lon1 = lambda_0; - - double lat2 = phi_1 + 0.5 / 180 * M_PI; - double lon2 = lambda_0 + 0.5 / 180 * M_PI; - double sin_lat_2 = sin(lat2); - double cos_lat_2 = cos(lat2); - double d = acos(sin(lat1) * sin_lat_2 + cos(lat1) * cos_lat_2 * cos(lon2 - lon1)) * r_earth; - - /* 2) calculate distance rho on plane */ - double k_bar = 0; - double c = acos(sin_phi_1 * sin_lat_2 + cos_phi_1 * cos_lat_2 * cos(lon2 - lambda_0)); - - if (0 != c) - k_bar = c / sin(c); - - double x2 = k_bar * (cos_lat_2 * sin(lon2 - lambda_0)); //Projection of point 2 on plane - double y2 = k_bar * ((cos_phi_1 * sin_lat_2 - sin_phi_1 * cos_lat_2 * cos(lon2 - lambda_0))); - double rho = sqrt(pow(x2, 2) + pow(y2, 2)); - - scale = d / rho; - -} - -__EXPORT void map_projection_project(double lat, double lon, float *x, float *y) -{ - /* notation and formulas accoring to: http://mathworld.wolfram.com/AzimuthalEquidistantProjection.html */ - double phi = lat / 180.0 * M_PI; - double lambda = lon / 180.0 * M_PI; - - double sin_phi = sin(phi); - double cos_phi = cos(phi); - - double k_bar = 0; - /* using small angle approximation (formula in comment is without aproximation) */ - double c = acos(sin_phi_1 * sin_phi + cos_phi_1 * cos_phi * (1 - pow((lambda - lambda_0), 2) / 2)); //double c = acos( sin_phi_1 * sin_phi + cos_phi_1 * cos_phi * cos(lambda - lambda_0) ); - - if (0 != c) - k_bar = c / sin(c); - - /* using small angle approximation (formula in comment is without aproximation) */ - *y = k_bar * (cos_phi * (lambda - lambda_0)) * scale;//*y = k_bar * (cos_phi * sin(lambda - lambda_0)) * scale; - *x = k_bar * ((cos_phi_1 * sin_phi - sin_phi_1 * cos_phi * (1 - pow((lambda - lambda_0), 2) / 2))) * scale; // *x = k_bar * ((cos_phi_1 * sin_phi - sin_phi_1 * cos_phi * cos(lambda - lambda_0))) * scale; - -// printf("%phi_1=%.10f, lambda_0 =%.10f\n", phi_1, lambda_0); -} - -__EXPORT void map_projection_reproject(float x, float y, double *lat, double *lon) -{ - /* notation and formulas accoring to: http://mathworld.wolfram.com/AzimuthalEquidistantProjection.html */ - - double x_descaled = x / scale; - double y_descaled = y / scale; - - double c = sqrt(pow(x_descaled, 2) + pow(y_descaled, 2)); - double sin_c = sin(c); - double cos_c = cos(c); - - double lat_sphere = 0; - - if (c != 0) - lat_sphere = asin(cos_c * sin_phi_1 + (x_descaled * sin_c * cos_phi_1) / c); - else - lat_sphere = asin(cos_c * sin_phi_1); - -// printf("lat_sphere = %.10f\n",lat_sphere); - - double lon_sphere = 0; - - if (phi_1 == M_PI / 2) { - //using small angle approximation (formula in comment is without aproximation) - lon_sphere = (lambda_0 - y_descaled / x_descaled); //lon_sphere = (lambda_0 + atan2(-y_descaled, x_descaled)); - - } else if (phi_1 == -M_PI / 2) { - //using small angle approximation (formula in comment is without aproximation) - lon_sphere = (lambda_0 + y_descaled / x_descaled); //lon_sphere = (lambda_0 + atan2(y_descaled, x_descaled)); - - } else { - - lon_sphere = (lambda_0 + atan2(y_descaled * sin_c , c * cos_phi_1 * cos_c - x_descaled * sin_phi_1 * sin_c)); - //using small angle approximation -// double denominator = (c * cos_phi_1 * cos_c - x_descaled * sin_phi_1 * sin_c); -// if(denominator != 0) -// { -// lon_sphere = (lambda_0 + (y_descaled * sin_c) / denominator); -// } -// else -// { -// ... -// } - } - -// printf("lon_sphere = %.10f\n",lon_sphere); - - *lat = lat_sphere * 180.0 / M_PI; - *lon = lon_sphere * 180.0 / M_PI; - -} - - -__EXPORT float get_distance_to_next_waypoint(double lat_now, double lon_now, double lat_next, double lon_next) -{ - double lat_now_rad = lat_now / 180.0d * M_PI; - double lon_now_rad = lon_now / 180.0d * M_PI; - double lat_next_rad = lat_next / 180.0d * M_PI; - double lon_next_rad = lon_next / 180.0d * M_PI; - - - double d_lat = lat_next_rad - lat_now_rad; - double d_lon = lon_next_rad - lon_now_rad; - - double a = sin(d_lat / 2.0d) * sin(d_lat / 2.0d) + sin(d_lon / 2.0d) * sin(d_lon / 2.0d) * cos(lat_now_rad) * cos(lat_next_rad); - double c = 2.0d * atan2(sqrt(a), sqrt(1.0d - a)); - - const double radius_earth = 6371000.0d; - return radius_earth * c; -} - -__EXPORT float get_bearing_to_next_waypoint(double lat_now, double lon_now, double lat_next, double lon_next) -{ - double lat_now_rad = lat_now * M_DEG_TO_RAD; - double lon_now_rad = lon_now * M_DEG_TO_RAD; - double lat_next_rad = lat_next * M_DEG_TO_RAD; - double lon_next_rad = lon_next * M_DEG_TO_RAD; - - double d_lat = lat_next_rad - lat_now_rad; - double d_lon = lon_next_rad - lon_now_rad; - - /* conscious mix of double and float trig function to maximize speed and efficiency */ - float theta = atan2f(sin(d_lon) * cos(lat_next_rad) , cos(lat_now_rad) * sin(lat_next_rad) - sin(lat_now_rad) * cos(lat_next_rad) * cos(d_lon)); - - theta = _wrap_pi(theta); - - return theta; -} - -// Additional functions - @author Doug Weibel <douglas.weibel@colorado.edu> - -__EXPORT int get_distance_to_line(struct crosstrack_error_s * crosstrack_error, double lat_now, double lon_now, double lat_start, double lon_start, double lat_end, double lon_end) -{ -// This function returns the distance to the nearest point on the track line. Distance is positive if current -// position is right of the track and negative if left of the track as seen from a point on the track line -// headed towards the end point. - - float dist_to_end; - float bearing_end; - float bearing_track; - float bearing_diff; - - int return_value = ERROR; // Set error flag, cleared when valid result calculated. - crosstrack_error->past_end = false; - crosstrack_error->distance = 0.0f; - crosstrack_error->bearing = 0.0f; - - // Return error if arguments are bad - if (lat_now == 0.0d || lon_now == 0.0d || lat_start == 0.0d || lon_start == 0.0d || lat_end == 0.0d || lon_end == 0.0d) return return_value; - - bearing_end = get_bearing_to_next_waypoint(lat_now, lon_now, lat_end, lon_end); - bearing_track = get_bearing_to_next_waypoint(lat_start, lon_start, lat_end, lon_end); - bearing_diff = bearing_track - bearing_end; - bearing_diff = _wrap_pi(bearing_diff); - - // Return past_end = true if past end point of line - if (bearing_diff > M_PI_2_F || bearing_diff < -M_PI_2_F) { - crosstrack_error->past_end = true; - return_value = OK; - return return_value; - } - - dist_to_end = get_distance_to_next_waypoint(lat_now, lon_now, lat_end, lon_end); - crosstrack_error->distance = (dist_to_end) * sin(bearing_diff); - - if (sin(bearing_diff) >= 0) { - crosstrack_error->bearing = _wrap_pi(bearing_track - M_PI_2_F); - - } else { - crosstrack_error->bearing = _wrap_pi(bearing_track + M_PI_2_F); - } - - return_value = OK; - - return return_value; - -} - - -__EXPORT int get_distance_to_arc(struct crosstrack_error_s * crosstrack_error, double lat_now, double lon_now, double lat_center, double lon_center, - float radius, float arc_start_bearing, float arc_sweep) -{ - // This function returns the distance to the nearest point on the track arc. Distance is positive if current - // position is right of the arc and negative if left of the arc as seen from the closest point on the arc and - // headed towards the end point. - - // Determine if the current position is inside or outside the sector between the line from the center - // to the arc start and the line from the center to the arc end - float bearing_sector_start; - float bearing_sector_end; - float bearing_now = get_bearing_to_next_waypoint(lat_now, lon_now, lat_center, lon_center); - bool in_sector; - - int return_value = ERROR; // Set error flag, cleared when valid result calculated. - crosstrack_error->past_end = false; - crosstrack_error->distance = 0.0f; - crosstrack_error->bearing = 0.0f; - - // Return error if arguments are bad - if (lat_now == 0.0d || lon_now == 0.0d || lat_center == 0.0d || lon_center == 0.0d || radius == 0.0d) return return_value; - - - if (arc_sweep >= 0) { - bearing_sector_start = arc_start_bearing; - bearing_sector_end = arc_start_bearing + arc_sweep; - - if (bearing_sector_end > 2.0f * M_PI_F) bearing_sector_end -= M_TWOPI_F; - - } else { - bearing_sector_end = arc_start_bearing; - bearing_sector_start = arc_start_bearing - arc_sweep; - - if (bearing_sector_start < 0.0f) bearing_sector_start += M_TWOPI_F; - } - - in_sector = false; - - // Case where sector does not span zero - if (bearing_sector_end >= bearing_sector_start && bearing_now >= bearing_sector_start && bearing_now <= bearing_sector_end) in_sector = true; - - // Case where sector does span zero - if (bearing_sector_end < bearing_sector_start && (bearing_now > bearing_sector_start || bearing_now < bearing_sector_end)) in_sector = true; - - // If in the sector then calculate distance and bearing to closest point - if (in_sector) { - crosstrack_error->past_end = false; - float dist_to_center = get_distance_to_next_waypoint(lat_now, lon_now, lat_center, lon_center); - - if (dist_to_center <= radius) { - crosstrack_error->distance = radius - dist_to_center; - crosstrack_error->bearing = bearing_now + M_PI_F; - - } else { - crosstrack_error->distance = dist_to_center - radius; - crosstrack_error->bearing = bearing_now; - } - - // If out of the sector then calculate dist and bearing to start or end point - - } else { - - // Use the approximation that 111,111 meters in the y direction is 1 degree (of latitude) - // and 111,111 * cos(latitude) meters in the x direction is 1 degree (of longitude) to - // calculate the position of the start and end points. We should not be doing this often - // as this function generally will not be called repeatedly when we are out of the sector. - - // TO DO - this is messed up and won't compile - float start_disp_x = radius * sin(arc_start_bearing); - float start_disp_y = radius * cos(arc_start_bearing); - float end_disp_x = radius * sin(_wrapPI(arc_start_bearing + arc_sweep)); - float end_disp_y = radius * cos(_wrapPI(arc_start_bearing + arc_sweep)); - float lon_start = lon_now + start_disp_x / 111111.0d; - float lat_start = lat_now + start_disp_y * cos(lat_now) / 111111.0d; - float lon_end = lon_now + end_disp_x / 111111.0d; - float lat_end = lat_now + end_disp_y * cos(lat_now) / 111111.0d; - float dist_to_start = get_distance_to_next_waypoint(lat_now, lon_now, lat_start, lon_start); - float dist_to_end = get_distance_to_next_waypoint(lat_now, lon_now, lat_end, lon_end); - - - if (dist_to_start < dist_to_end) { - crosstrack_error->distance = dist_to_start; - crosstrack_error->bearing = get_bearing_to_next_waypoint(lat_now, lon_now, lat_start, lon_start); - - } else { - crosstrack_error->past_end = true; - crosstrack_error->distance = dist_to_end; - crosstrack_error->bearing = get_bearing_to_next_waypoint(lat_now, lon_now, lat_end, lon_end); - } - - } - - crosstrack_error->bearing = _wrapPI(crosstrack_error->bearing); - return_value = OK; - return return_value; -} - -__EXPORT float _wrap_pi(float bearing) -{ - /* value is inf or NaN */ - if (!isfinite(bearing) || bearing == 0) { - return bearing; - } - - int c = 0; - - while (bearing > M_PI_F && c < 30) { - bearing -= M_TWOPI_F; - c++; - } - - c = 0; - - while (bearing <= -M_PI_F && c < 30) { - bearing += M_TWOPI_F; - c++; - } - - return bearing; -} - -__EXPORT float _wrap_2pi(float bearing) -{ - /* value is inf or NaN */ - if (!isfinite(bearing)) { - return bearing; - } - - while (bearing >= M_TWOPI_F) { - bearing = bearing - M_TWOPI_F; - } - - while (bearing < 0.0f) { - bearing = bearing + M_TWOPI_F; - } - - return bearing; -} - -__EXPORT float _wrap_180(float bearing) -{ - /* value is inf or NaN */ - if (!isfinite(bearing)) { - return bearing; - } - - while (bearing > 180.0f) { - bearing = bearing - 360.0f; - } - - while (bearing <= -180.0f) { - bearing = bearing + 360.0f; - } - - return bearing; -} - -__EXPORT float _wrap_360(float bearing) -{ - /* value is inf or NaN */ - if (!isfinite(bearing)) { - return bearing; - } - - while (bearing >= 360.0f) { - bearing = bearing - 360.0f; - } - - while (bearing < 0.0f) { - bearing = bearing + 360.0f; - } - - return bearing; -} - - |