/* goto.c */ /* asserv - Position & speed motor control on a ATmega128. {{{ * * Copyright (C) 2005 Nicolas Schodet * * Robot APB Team/Efrei 2005. * Web: http://assos.efrei.fr/robot/ * Email: robot AT efrei DOT fr * * 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 2 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. * * }}} */ /** Destination position, f24.8. */ int32_t goto_x, goto_y; /** Destination angle, f8.24. */ int32_t goto_a; /** Destination epsillon. */ int32_t goto_eps = 20L << 8; /* +AutoDec */ /* -AutoDec */ /** Update the speed according to the desired destination. */ static inline void goto_update (void) { int32_t dx, dy, c, s, dl, da; /* Project in the robot base. */ dx = goto_x - postrack_x; /* f24.8 */ dy = goto_y - postrack_y; if (dx < goto_eps && dx > -goto_eps && dy < goto_eps && dy > -goto_eps) { speed_left_aim = 0; speed_right_aim = 0; } else { c = dsp_cos (postrack_a); s = dsp_sin (postrack_a); dl = dsp_mul_f824 (dx, c) + dsp_mul_f824 (dy, s); da = dsp_mul_f824 (dy, c) - dsp_mul_f824 (dx, s); /* Convert da into a arc. This is a rough aproximation. */ //da = da * postrack_footing / 2 / (dl >> 8); speed_distance (dl, da); } }