www.gusucode.com > 机器人工具箱 - robot源码程序 > robot\tr2rpy.m
%TR2RPY Convert a homogeneous transform matrix to roll/pitch/yaw angles % % [R P Y] = TR2RPY(M) % % Returns a vector of roll/pitch/yaw angles corresponding to M, either a rotation % matrix or the rotation part of a homogeneous transform. % part of the homogeneous transform TR. The angles correspond to rotations % about the X, Y and Z axes respectively. % % See also: RPY2TR, TR2EUL % Copyright (C) 1993-2008, by Peter I. Corke % % This file is part of The Robotics Toolbox for Matlab (RTB). % % RTB is free software: you can redistribute it and/or modify % it under the terms of the GNU Lesser General Public License as published by % the Free Software Foundation, either version 3 of the License, or % (at your option) any later version. % % RTB 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 Lesser General Public License for more details. % % You should have received a copy of the GNU Leser General Public License % along with RTB. If not, see <http://www.gnu.org/licenses/>. function rpy = tr2rpy(m) s = size(m); if length(s) > 2, rpy = []; for i=1:s(3), rpy = [rpy; tr2rpy(m(:,:,i))]; end return end rpy = zeros(1,3); rpy(1) = atan2(-m(2,3), m(3,3)); % roll % compute sin/cos of roll angle sr = sin(rpy(1)); cr = cos(rpy(1)); rpy(2) = atan2(m(1,3), cr * m(3,3) - sr * m(2,3)); % pitch rpy(3) = atan2(-m(1,2), m(1,1)); % yaw