enterdelays.m

基于声源的方向定位程序

function [m1,m2,d,useful] = enterDelays(arr, c, tolerance, limits)
%enterDelays	Enter a set of inter-phone delays for use in localization.
%
% [m1,m2,d,useful] = enterDelays(arr, c, tolerance, limits)
%    Have the user enter a set of inter-phone delays.  As each is entered,
%    display its hyperbola.  The values can be either seconds or milliseconds;
%    the program guesses about which it might be, and gives the user a chance
%    to correct the guess.
%
%
% Required input arguments:
%    arr	[2xN]     x- and y-positions, m
%    c		[scalar]  speed of sound, m/s (~343 in air, ~1500 in seawater)
% Optional input arguments:
%    tolerance	[scalar]  error in time delays, s
%    limits	[1x4]     axes limits of plot, m [xMin xMax yMin yMax]
%
% Values entered when this function executes:
%    - number of inter-phone delays
%    - for each inter-phone delay: which two phones are involved, and 
%      the delay value
%
% Outputs:
%    m1		[1xM]  first phone number of each pair
%    m2		[1xM]  second phone number of each pair
%    d		[1xM]  arrival-time delay between phone 1 and phone 2, seconds;
%		       d > 0 if the sound reached phone 1 first, < 0 if phone 2
%                      first (this is the negative of Canary's correlation 
%                      offset value)
%    useful	[1xM]  whether each phone pair value is less than max possible 
%                      delay

global previousM1 previousM2 previousD scale scaleText

if (nargin < 3), tolerance = []; end
if (nargin < 4), limits    = []; end

checkScale('init')
plotPhones(arr, limits);	% turns hold on

if (~exist('previousM1')), previousM1 = []; end
if (isempty(previousM1))
  n = input('Number of inter-phone delays? ');
else
  n = input('Number of inter-phone delays? [enter NaN to use previous set] ');
end
if (isnan(n))

  % Use previous values.
  m1 = previousM1;
  m2 = previousM2;
  d  = previousD;

else

  % Get new values from user.
  d    = zeros(1,n);
  m1   = zeros(1,n);
  m2   = zeros(1,n);
  maxD = zeros(1,n);
  
  for i = 1:n
    m1(i) = input('Between phone # ');
    m2(i) = input('    and phone # ');
    maxDelay = norm(arr(:,m1(i)) - arr(:,m2(i))) / c;

    d(i) = -input(sprintf('    max delay is %g, actual delay%s is? ', ...
	maxDelay * scale, scaleText));
    checkScale(d(i));

    if (~isempty(tolerance)), t = tolerance; 
    else t = defaultTolerance(d);
    end
    PlotHyperbolas(d(i) / scale, t, arr, m1(i), m2(i), c, limits);
  end
  
  d = d / scale;
  previousM1 = m1;
  previousM2 = m2;
  previousD = d;
end  

hold off
clf

useful = PlotHyperbolas(d, tolerance, arr, m1, m2, c, limits);