Moving vehicle classifier with iterative deconvolver estimator

Claim 1

A method for classifying a moving vehicle which produces a source signal propagating along at least two signal paths, each path having an impulse response duration, the method comprising the steps of: (a) sensing, at a minimum of one locations remote from the vehicle, a set of at least two received input signals propagated from the source signal along a minimum of two signal paths, and preprocessing such signals into input signal vectors xO, yO, . . . , zO, one vector from each sensor; (b) collecting samples from each received input signal; (c) for the set of received input signals: (1) forming each of the received input signals into blocks of M+N-1 contiguous samples, where M is the duration of the source signal and N is the longest impulse response duration of any path, M and N both being measured in sampling intervals; (2) measuring the energy of each block; (3) selecting a block which has the most energy; and (4) storing the input signal vectors, xO, yO, . . . , zO, received during said most energy block; (d) combining a plurality of components of the input signal vectors, xO, yO, . . . , zO, by a root-sum-square technique, thereby producing a zeroth M+N-1 sample unconstrained reference signal vector, rO; and setting an index i to have a value equal to one; (e) selecting an (i-1)st unconstrained reference signal vector, r(i-1), for use in an ith iteration; (f) forcing to zero all values of the (i-1)st unconstrained reference signal vector, r(i-1), except those which exceed a computed threshold, thereby producing an ith zeroed signal vector; (g) discarding N-1 end samples of the ith zeroed signal vector such that the remaining M contiguous samples have more energy than any other grouping of M contiguous samples, thereby forming an ith constrained source signal vector, si; (h) forming an tth constrained source signal matrix, [Si], from the ith constrained source signal vector, si, by setting each element of the ith constrained source signal matrix, [Si], at row p and column n to zero if n is greater than p or p is greater than M-1+n, otherwise setting that element equal to the (p-n)th element of the corresponding ith constrained source signal vector, si; (i) premultiplying the ith constrained source signal matrix, [Si], by its transpose to form an ith product matrix, then postmultiplying the inverse of the ith product matrix by the transpose of the ith constrained source signal matrix, [Si], to form a pseudoinverse of the ith constrained source signal matrix, [Si]; (j) postmultiplying the pseudoinverse by each of the received input signal vectors, xO, yO . . . zO, to form an ith set of signal path impulse response estimation vectors, ci, di, . . . , ei; (k) forming an tth set of signal path estimation matrices, [Ci], [Di], . . . , Ei, from the corresponding signal path impulse response estimation vectors, ci, di, . . . , ei, by setting each element of the ith signal path estimation matrices, [Ci], [Di9 . . . , Ei, at row p and column m to zero if m is greater than p or p is greater than N-1+m, otherwise setting that element equal to the (p-m)th entry of the corresponding signal path impulse response estimation vector, ci, di, . . . , ei; (l) generating an tth set of input signal estimate vectors, xi, yi, . . . , zi, of the corresponding values of the input signal vectors, xO, yO, . . . , zO, by a step selected from the group consisting of the steps of: (1) postmultiplying the ith constrained source signal matrix, [Si], by the corresponding signal path impulse response estimation vectors, ci, di, . . . , ei; and (2) postmultiplying the corresponding ith set of signal path estimation matrices, [Ci], [Di], . . . , Ei, by the ith constrained source signal vector, si; (m) obtaining an ith unconstrained reference signal vector, ri, by postmultiplying the inverse of an ith matrix [Mi] by a vector vi; the ith matrix [[]Mi] consisting of the sum of all ith signal path estimation matrices, [Ci], [Di]. . . , Ei, premultiplied by their respective transposes; and the vector vi consisting of the sum of all ith signal path estimation matrix transposes postmultiplied by their respective input signal vectors, xO, yO, . . . , zO; (n) generating a first group of ith iteration estimation errors by subtracting from the input signal vectors, xO, yO . . . , zO, the corresponding input signal estimate vectors, xi, yi, . . . , zi; (o) computing a first evaluation of estimator ith iteration performance by summing the squares of all scalar components of the first group of ith iteration estimation errors; (p) generating a second group of ith iteration estimation errors by subtracting from the input signal vectors, xO, yO . . . , zO, the corresponding ith signal path estimation matrices, [Ci], [Di]. . . , Ei, each postmultiplied by the ith unconstrained reference signal vector, ri; (q) computing a second evaluation of estimator ith iteration performance by summing the squares of all scalar components of said second group of ith iteration estimation errors; (r) terminating the procedure if at least one of the first and second evaluations of the ith iteration performance indicate no further reduction in estimation errors, otherwise incrementing the value of i by one and repeating steps (e) through (r); (s) selecting the ith constrained source signal vector, si, as the deconvolved source signal; and (t) transferring the deconvolved source signal to an analysis apparatus.

Claim 2

A method for classifying a moving vehicle which produces a source signal propagating along at least two signal paths, each path having an impulse response duration, the method comprising the steps of: (a) sensing, at a minimum of one locations remote from the vehicle, a set of at least two received input signals propagated from the source signal along a minimum of two signal paths, and preprocessing such signals into input signal vectors xO, yO, . . . , zO, one vector from each sensor; (b) collecting samples from each received input signal; (c) for the set of received input signals: (1) forming each of the received input signals into blocks of M+N-1 contiguous samples, where M is the duration of the source signal and N is the longest impulse response duration of any path, M and N both being measured in sampling intervals; (2) measuring the energy of each block; (3) selecting a block which has the most energy; and (4) storing the input signal vectors, xO, yO, . . . , zO, received during said most energy block; (d) combining a plurality of components of the input signal vectors, xO, yO, . . . , zO, by a root-sum-square technique, thereby producing a zeroth M+N-1 sample unconstrained reference signal vector, rO; and setting an index i to have a value equal to one; (e) selecting an (i-1)st unconstrained reference signal vector, r(i-1), for use in an ith iteration; (f) forcing to zero all values of the (i-1)st unconstrained reference signal vector, r(i-1), except those which exceed a computed threshold, thereby producing an ith zeroed signal vector; (g) discarding N-1 end samples of the ith zeroed signal vector such that the remaining M contiguous samples have more energy than any other grouping of M contiguous samples, thereby forming an ith constrained source signal vector, si; (h) forming an tth constrained source signal matrix, [Si], from the ith constrained source signal vector, si, by setting each element of the ith constrained source signal matrix, [Si], at row p and column n to zero if n is greater than p or p is greater than M-1+n, otherwise setting that element equal to the (p-n)th element of the corresponding ith constrained source signal vector, si; (i) premultiplying the ith constrained source signal matrix, [Si], by its transpose to form an ith product matrix, then postmultiplying the inverse of the ith product matrix by the transpose of the ith constrained source signal matrix, [Si], to form a pseudoinverse of the ith constrained source signal matrix, [Si]; (j) postmultiplying the pseudoinverse by each of the received input signal vectors, xO, yO . . . zO, to form an ith set of signal path impulse response estimation vectors, ci, di, . . . , ei; (k) forming an tth set of signal path estimation matrices, [Ci], [Di], . . . , Ei, from the corresponding signal path impulse response estimation vectors, ci, di, . . . , ei, by setting each element of the ith signal path estimation matrices, [Ci], [Di9 . . . , Ei, at row p and column m to zero if m is greater than p or p is greater than N-1+m, otherwise setting that element equal to the (p-m)th entry of the corresponding signal path impulse response estimation vector, ci, di, . . . , ei; (l) generating an tth set of input signal estimate vectors, xi, yi, . . . , zi, of the corresponding values of the input signal vectors, xO, yO, . . . , zO, by a step selected from the group consisting of the steps of: (1) postmultiplying the ith constrained source signal matrix, [Si], by the corresponding signal path impulse response estimation vectors, ci, di, . . . , ei; and (2) postmultiplying the corresponding ith set of signal path estimation matrices, [Ci], [Di], . . . , Ei, by the ith constrained source signal vector, si; (m) obtaining an ith unconstrained reference signal vector, ri, by postmultiplying the inverse of an ith matrix [Mi] by a vector vi; the ith matrix [[]Mi] consisting of the sum of all ith signal path estimation matrices, [Ci], [Di]. . . , Ei, premultiplied by their respective transposes; and the vector vi consisting of the sum of all ith signal path estimation matrix transposes postmultiplied by their respective input signal vectors, xO, yO, . . . , zO; (n) generating a first group of ith iteration estimation errors by subtracting from the input signal vectors, xO, yO . . . , zO, the corresponding input signal estimate vectors, xi, yi, . . . , zi; (o) computing a first evaluation of estimator ith iteration performance by summing the squares of all scalar components of the first group of ith iteration estimation errors; (p) generating a second group of ith iteration estimation errors by subtracting from the input signal vectors, xO, yO . . . , zO, the corresponding ith signal path estimation matrices, [Ci], [Di]. . . , Ei, each postmultiplied by the ith unconstrained reference signal vector, ri; (q) computing a second evaluation of estimator ith iteration performance by summing the squares of all scalar components of said second group of ith iteration estimation errors; (r) terminating the procedure if at least one of the first and second evaluations of the ith iteration performance indicate no further reduction in estimation errors, otherwise incrementing the value of i by one and repeating steps (e) through (r); (s) selecting the ith constrained source signal vector, si, as the deconvolved source signal; and (t) transferring the deconvolved source signal to an analysis apparatus.