Colony

%Function which creates an occupancy grid map giving the probability of of there being an object

%given a series of measurements over the probability of there not being an object

%given the measurements.

%Input comes from 'filename' where each line contains 8 space-separated values

%Each line contains: x, y, theta, IR1, IR2, IR3, IR4, IR5 in that order

%Example line of input file:

%17 23 .45 -1 42 -1 -1 -1

%x and y are centimeters, theta is in radians

%IR values are the values seen by the robot, where -1 means that nothing is seen

%Output: graph of points seen by robot

%All output measurements are in millimeters

function arena = sensor_map(filename)

%aviobj = avifile('test.avi');

%aviobj.Quality = 80;

%aviobj.Compression = 'None';

%Vectors from center of bot to IR sensors

Bot_IR1 = [4.5,3.5];

Bot_IR2 = [7.5,0];

Bot_IR3 = [4.5,-3.5];

Bot_IR4 = [-4,-3.5];

Bot_IR5 = [-4,3.5];

Bot_IR = [Bot_IR1; Bot_IR2; Bot_IR3; Bot_IR4; Bot_IR5];

%Unit vectors with the same angle that the IR sensors are tilted at

Angle_IR1 = [.78,.63];

Angle_IR2 = [1,0];

Angle_IR3 = [.78,-.63];

Angle_IR4 = [0,-1];

Angle_IR5 = [0,1];

Angle_IR = [Angle_IR1; Angle_IR2; Angle_IR3; Angle_IR4; Angle_IR5];

%Define sensor model.

[sensor_model, udata, vdata] = model_sensor;

%Define map area

map_width = 1000;

map_height = 1000;

%xdata = [-1, 1] * map_width/2;

%ydata = [-1, 1] * map_height/2;

xdata = [-200, 800];

ydata = [-400, 300];

arena = ones(map_width,map_height);

%For now, read input in from a file

Data = dlmread(filename, ' ');

points = [];

%loop through each line of file

for i=25:size(Data, 1)

	display(i);

    row = Data(i, :);

    x = row(1);

    y = row(2);

    theta = row(3);

	row(4:8)

    for ir=1:5

		if (row(4:8) == [-1 -1 -1 -1 -1])

			break;

		end

		reading = row(ir+3);

        distance = reading * 0.1; %Scale by 0.1 since range is in mm.

        if reading ~= -1

			k_val = floor(distance);

			sensor_k = sensor_model(:,:,k_val);

			%Find vector of object relative to center of bot

        	ObjectVector = distance * Angle_IR(ir, :);

        	ObjectVector = ObjectVector + Bot_IR(ir, :);

			%rotate by theta

        	objTheta = atan2(ObjectVector(2), ObjectVector(1));

        	objTheta = objTheta + theta;

		else

			sensor_k = sensor_model(:,:,71);

			%Use the maximum length to clear an empty area.

        	ObjectVector = 80 * Angle_IR(ir, :);

        	ObjectVector = ObjectVector + Bot_IR(ir, :);

			%rotate by theta

        	objTheta = atan2(ObjectVector(2), ObjectVector(1));

        	objTheta = objTheta + theta;

		end

		dx = x + Bot_IR(ir,1);

		dy = y + Bot_IR(ir,2);

		translation_mat = [1, 0, 0;

						   0, 1, 0;

						  dx,dy, 1];

		rotation_mat = [cos(objTheta), sin(objTheta), 0;

					   -sin(objTheta), cos(objTheta), 0

						   		    0,			   0, 1];

		transformation_mat = rotation_mat * translation_mat;

		transformation = maketform('affine', transformation_mat);

		%Big time waster 1: TODO Speedups.

		sensor_k = imtransform(sensor_k, transformation,...

			'UData', udata, 'Vdata', vdata,...

			'XData', xdata, 'YData', ydata,...

			'Size', [map_width, map_height], 'FillValues', 1);

		%Big time waster 2: TODO Speedups.

		arena = arena.*sensor_k;

		%For when you want to show the image every round:

		image(arena.*20);

		drawnow;

		%frame = getframe;

		%aviobj = addframe(aviobj,frame.cdata);

    end

end

%aviobj = close(aviobj);