www.gusucode.com > 机器人工具箱 - robot源码程序 > robot\tr2eul.m
%TR2EUL Convert a homogeneous transform matrix to Euler angle form % % [PHI THETA PSI] = TR2EUL(M) % % Returns a vector of roll/pitch/yaw angles corresponding to M, either a rotation % matrix or the rotation part of a homogeneous transform. % The 3 angles correspond to rotations about the Z, Y and Z axes respectively. % % See also: EUL2TR, TR2RPY % 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 euler = tr2eul(m) s = size(m); if length(s) > 2, euler = []; for i=1:s(3), euler = [euler; tr2eul(m(:,:,i))]; end return end euler = zeros(1,3); % Method as per Paul, p 69. % phi = atan2(ay, ax) % Only positive phi is returned. if abs(m(1,3)) < eps & abs(m(2,3)) < eps, % singularity euler(1) = 0; sp = 0; cp = 1; euler(2) = atan2(cp*m(1,3) + sp*m(2,3), m(3,3)); euler(3) = atan2(-sp * m(1,1) + cp * m(2,1), -sp*m(1,2) + cp*m(2,2)); else euler(1) = atan2(m(2,3), m(1,3)); sp = sin(euler(1)); cp = cos(euler(1)); euler(2) = atan2(cp*m(1,3) + sp*m(2,3), m(3,3)); euler(3) = atan2(-sp * m(1,1) + cp * m(2,1), -sp*m(1,2) + cp*m(2,2)); end