www.gusucode.com > 机器人工具箱 - robot源码程序 > robot\tr2diff.m
%TR2DIFF Convert a transform difference to differential representation % % D = TR2DIFF(T) % D = TR2DIFF(T1, T2) % % First form converts a homogeneous transform representing an % infinitessimal motion to a 6-element differential representation. % Such a homogeneous transform has a rotational submatrix that is, % approximately, skew symmetric. % % Second form returns the 6-element differential motion required to move % from T1 to T2 in base coordinates. % % See also: DIFF2TR. % 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 d = tr2diff(t1, t2) if nargin == 1, d = [ t1(1:3,4); 0.5*[t1(3,2)-t1(2,3); t1(1,3)-t1(3,1); t1(2,1)-t1(1,2)]]; else d = [ t2(1:3,4)-t1(1:3,4); 0.5*( cross(t1(1:3,1), t2(1:3,1)) + ... cross(t1(1:3,2), t2(1:3,2)) + ... cross(t1(1:3,3), t2(1:3,3)) ... )]; end