2012-04-10 05:39:41 +02:00
|
|
|
/**
|
|
|
|
|
******************************************************************************
|
|
|
|
|
*
|
|
|
|
|
* @file paths.c
|
|
|
|
|
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2012.
|
|
|
|
|
* @brief Library path manipulation
|
|
|
|
|
*
|
|
|
|
|
* @see The GNU Public License (GPL) Version 3
|
|
|
|
|
*
|
|
|
|
|
*****************************************************************************/
|
|
|
|
|
/*
|
|
|
|
|
* 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; either version 3 of the License, or
|
|
|
|
|
* (at your option) any later version.
|
|
|
|
|
*
|
|
|
|
|
* 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
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#include "pios.h"
|
|
|
|
|
#include "paths.h"
|
|
|
|
|
|
|
|
|
|
/**
|
|
|
|
|
* @brief Compute progress along path and deviation from it
|
|
|
|
|
* @param[in] start_point Starting point
|
|
|
|
|
* @param[in] end_point Ending point
|
|
|
|
|
* @param[in] cur_point Current location
|
|
|
|
|
* @param[out] status Structure containing progress along path and deviation
|
|
|
|
|
*/
|
|
|
|
|
void path_progress(float * start_point, float * end_point, float * cur_point, struct path_status * status)
|
|
|
|
|
{
|
|
|
|
|
float path_north, path_east, diff_north, diff_east;
|
|
|
|
|
float dist_path2;
|
|
|
|
|
float dot;
|
|
|
|
|
float normal[2];
|
|
|
|
|
|
|
|
|
|
// Distance to go
|
|
|
|
|
path_north = end_point[0] - start_point[0];
|
|
|
|
|
path_east = end_point[1] - start_point[1];
|
|
|
|
|
|
|
|
|
|
// Current progress location relative to start
|
|
|
|
|
diff_north = cur_point[0] - start_point[0];
|
|
|
|
|
diff_east = cur_point[1] - start_point[1];
|
|
|
|
|
|
|
|
|
|
dot = path_north * diff_north + path_east * diff_east;
|
|
|
|
|
dist_path2 = path_north * path_north + path_east * path_east;
|
|
|
|
|
|
2012-04-10 09:49:19 +02:00
|
|
|
if(dist_path2 < 1e-3) {
|
|
|
|
|
status->fractional_progress = 1;
|
|
|
|
|
status->error = 0;
|
|
|
|
|
status->correction_direction[0] = status->correction_direction[1] = 0;
|
|
|
|
|
status->path_direction[0] = status->path_direction[1] = 0;
|
|
|
|
|
return;
|
|
|
|
|
}
|
|
|
|
|
|
2012-04-10 05:39:41 +02:00
|
|
|
// Compute the normal to the path
|
|
|
|
|
normal[0] = -path_east / sqrtf(dist_path2);
|
|
|
|
|
normal[1] = path_north / sqrtf(dist_path2);
|
|
|
|
|
|
|
|
|
|
status->fractional_progress = dot / dist_path2;
|
|
|
|
|
status->error = normal[0] * diff_north + normal[1] * diff_east;
|
|
|
|
|
|
|
|
|
|
// Compute direction to correct error
|
|
|
|
|
status->correction_direction[0] = -status->error * normal[0];
|
|
|
|
|
status->correction_direction[1] = -status->error * normal[1];
|
|
|
|
|
|
|
|
|
|
// Compute direction to travel
|
|
|
|
|
status->path_direction[0] = path_north / sqrtf(dist_path2);
|
|
|
|
|
status->path_direction[1] = path_east / sqrtf(dist_path2);
|
|
|
|
|
|
|
|
|
|
status->error = fabs(status->error);
|
|
|
|
|
}
|
|
|
|
|
|
