function robot = get_Kinematics(robot, opt)
if(opt.Isreal)
    switch opt.KM_method
        case 'SCREW'
            thetalist = robot.theta;
            Slist = robot.slist;
            % TODO:move to lib
            for j = 1:length(thetalist)
                T=robot.Home.M(:,:,j);
                for i = j: -1: 1
                    T = MatrixExp6(VecTose3(Slist(:, i) * thetalist(i))) * T;
                end
                robot.TW(:,:,j) = T;
            end
            for i = 1:size(thetalist)
                if i == 1
                    robot.T(:,:,i) = robot.TW(:,:,i);
                else
                    robot.T(:,:,i) = TransInv(robot.TW(:,:,i-1))*robot.TW(:,:,i);
                end
            end
            robot.Fkine = robot.TW(:,:,end);
        case 'SDH'
            theta = robot.theta;
            alpha = robot.alpha;
            a = robot.a;
            d = robot.d;
            robot.Fkine = eye(4,4);
            ndof = length(theta); % special for MDH
            % init transform matrix
            robot.R = zeros([3,3,ndof]);
            robot.t = zeros([3,1,ndof]);
            robot.T = zeros([4,4,ndof]);
            for i = 1:ndof
                robot.R(:,:,i) = [cos(theta(i)) -sin(theta(i))*cos(alpha(i)) sin(theta(i))*sin(alpha(i));...
                                  sin(theta(i)) cos(theta(i))*cos(alpha(i)) -cos(theta(i))*sin(alpha(i));...
                                  0 sin(alpha(i)) cos(alpha(i))];
                robot.t(:,:,i) = [a(i)*cos(theta(i));a(i)*sin(theta(i));d(i)];
                Transform = eye(4,4);
                Transform(1:3,1:3) = robot.R(:,:,i);
                Transform(1:3,4) = robot.t(:,:,i);
                robot.T(:,:,i) = Transform;
                robot.Fkine = robot.Fkine*robot.T(:,:,i);
            end
        case 'MDH'
            theta = robot.theta;
            alpha = robot.alpha;
            a = robot.a;
            d = robot.d;
            robot.Fkine = eye(4,4);
            ndof = length(theta); % special for MDH
            % init transform matrix
            robot.R = zeros([3,3,ndof]);
            robot.t = zeros([3,1,ndof]);
            robot.T = zeros([4,4,ndof]);
            for i = 1:ndof
                robot.R(:,:,i) = [cos(theta(i)) -sin(theta(i)) 0;...
                    sin(theta(i))*cos(alpha(i)) cos(theta(i))*cos(alpha(i)) -sin(alpha(i));...
                    sin(theta(i))*sin(alpha(i)) cos(theta(i))*sin(alpha(i)) cos(alpha(i))];
                robot.t(:,:,i) = [a(i);-d(i)*sin(alpha(i));d(i)*cos(alpha(i))];
                Transform = eye(4,4);
                Transform(1:3,1:3) = robot.R(:,:,i);
                Transform(1:3,4) = robot.t(:,:,i);
                robot.T(:,:,i) = Transform;
                robot.Fkine = robot.Fkine*robot.T(:,:,i);
            end
        otherwise
            disp('Bad opt.KM_method!')
            return;
    end
else
    switch opt.KM_method
        case 'SDH'
        case 'MDH'
            theta = robot.theta;
            alpha = robot.alpha;
            a = robot.a;
            d = robot.d;
            robot.Fkine = eye(4,4);
            ndof = length(theta); % special for MDH
            % init transform matrix
            robot.R = sym(zeros([3,3,ndof]));
            robot.t = sym(zeros([3,1,ndof]));
            robot.T = sym(zeros([4,4,ndof]));
            for i = 1:ndof
                robot.R(:,:,i) = [cos(theta(i)) -sin(theta(i)) 0;...
                    sin(theta(i))*cos(alpha(i)) cos(theta(i))*cos(alpha(i)) -sin(alpha(i));...
                    sin(theta(i))*sin(alpha(i)) cos(theta(i))*sin(alpha(i)) cos(alpha(i))];
                robot.t(:,:,i) = [a(i);-d(i)*sin(alpha(i));d(i)*cos(alpha(i))];
                Transform = sym(eye(4,4));
                Transform(1:3,1:3) = robot.R(:,:,i);
                Transform(1:3,4) = robot.t(:,:,i);
                robot.T(:,:,i) = Transform;
                robot.Fkine = robot.Fkine*robot.T(:,:,i);
            end
        otherwise
            disp('Bad opt.KM_method!')
            return;
    end
end