%JACOBN Compute manipulator Jacobian in end-effector frame%%	JN = JACOBN(ROBOT, Q)%% Returns a Jacobian matrix for the robot ROBOT in pose Q.%% The manipulator Jacobian matrix maps differential changes in joint space% to differential Cartesian motion of the end-effector (end-effector coords).% 		dX = J dQ%% This function uses the technique of% 	Paul, Shimano, Mayer% 	Differential Kinematic Control Equations for Simple Manipulators% 	IEEE SMC 11(6) 1981% 	pp. 456-460%% For an n-axis manipulator the Jacobian is a 6 x n matrix.%% See also: JACOB0, DIFF2TR, TR2DIFF% Copyright (C) 1999-2008, 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 J = jacobn(robot, q)	n = robot.n;	L = robot.link;		% get the links	J = [];	U = robot.tool;	for j=n:-1:1,		if robot.mdh == 0,			% standard DH convention			U = L{j}( q(j) ) * U;		end		if L{j}.RP == 'R',			% revolute axis			d = [	-U(1,1)*U(2,4)+U(2,1)*U(1,4)				-U(1,2)*U(2,4)+U(2,2)*U(1,4)				-U(1,3)*U(2,4)+U(2,3)*U(1,4)];			delta = U(3,1:3)';	% nz oz az		else			% prismatic axis			d = U(3,1:3)';		% nz oz az			delta = zeros(3,1);	%  0  0  0		end		J = [[d; delta] J];		if robot.mdh ~= 0,			% modified DH convention			U = L{j}( q(j) ) * U;		end	end