How can I find the intersection point of Hough Lines for vision based navigation?

The following coding has been used to find the hough lines in a corridor for a vision based navigating robot. It is required to find the coordinates of the intersection points of the hough lines to obtain the heading for the robot (Vanishing point theorem). I am unaware of the functions/algorithm used to obtain the heading of the robot. Following is the coding used to find the hough lines. An image of the Hough Line output is attached with this.

gblock=imread('gblock2.jpg');
%Convert the image to Grayscale
I=rgb2gray(gblock);
figure(1),imshow(I);title('Grayscale Image');pause;
x= I;
%Generate Histogram
imhist(x); pause;
%Perform Median Filtering
x = medfilt2(x);
%Convert Grayscale image to Binary
threshold=98;%assign a threshold value
x(x<threshold)=0;
x(x>=threshold)=1; 
x=logical(x);%convert image to binary compared to threshold
%Perform Median Filtering
im2=medfilt2(x);
figure(1),imshow(im2);title('filtered image');pause;
%Edge Detection
a=edge(im2,'sobel');
imshow(a); title('Edge Detection');pause
%Horizontal Edge Detection
BW=edge(im2,'sobel',(graythresh(I)*0.3),'horizontal');
imshow(BW)
pause;
%Hough Transform
[H,theta,rho] = hough(BW);
figure, imshow(imadjust(mat2gray(H)),[],'XData',theta,'YData',rho,...
'InitialMagnification','fit');
xlabel('\theta (degrees)'), ylabel('\rho');
axis on, axis normal, hold on;
colormap(hot)

% Finding the Hough peaks (number of peaks is set to 10)
P = houghpeaks(H,10,'threshold',ceil(0.2*max(H(:))));

x = theta(P(:,2));
y = rho(P(:,1));
plot(x,y,'s','color','black');
pause;
%Fill the gaps of Edges and set the Minimum length of a line
lines = houghlines(BW,theta,rho,P,'FillGap',170,'MinLength',350);

figure, imshow(gblock), hold on
max_len = 0;
for k = 1:length(lines)
xy = [lines(k).point1; lines(k).point2];

plot(xy(:,1),xy(:,2),'LineWidth',2,'Color','red');
% Plot beginnings and ends of lines
plot(xy(1,1),xy(1,2),'x','LineWidth',2,'Color','yellow');
plot(xy(2,1),xy(2,2),'x','LineWidth',2,'Color','green');
end
pause;