JPH0552926A - Adaptive phasing method - Google Patents

Abstract

PURPOSE:To continuously search a target signal without missing the target signal even when a sensor becomes defective. CONSTITUTION:When one of sensors 1-1 to 1-N becomes defective, a sensor abnormality detector 15 detects the abnormality of the sensor which forms a null beam by means of a constraint matrix multiplier 6. A bound matrix controller 16 reconstructs the constraint matrix of the multiplier 6 by dividing the weight of a constraint coefficient of the sensor which is discriminated as abnormal into a plurality of weight coefficients and adding the divided weights to the weight coefficient which is discriminated as normal, and at the same time, making the weight coefficient of the abnormal sensor to '0'.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a sensor array composed of a plurality of sensors in a sonar or the like to estimate the direction of a target and the like. The present invention relates to an adaptive phasing method for extracting only the signal.

[0002]

2. Description of the Related Art Conventionally, as this type of adaptive phasing method,
For example, some documents were described in the following documents.

I-E-Trans Actions on Antennas and Propagation
(IEEE TRANSACTIONS ON ANTENNAS AND PROPAGAtion
), AP-30 [1] (1982-1) (US) L.A.
J. Griffiths, et al, “An Alternative Approach Linear Constrained Adaptive Bean Forming (An Alter
native Approch to Linear Constrained AdaptiveBeamf
ormig) "P.27-34 The adaptive phasing method described in this document is an adaptive phasing method using a constraint matrix, and its contents will be described with reference to FIG.

FIG. 2 is a functional block diagram showing an example of the configuration of an adaptive phasing device for carrying out the conventional adaptive phasing method described in the above document.

This adaptive phasing device includes a plurality of sensors 1-1.
.. 1-N, the output side of each sensor 1-1 to 1-N has a delay circuit 2-1 to 2-2.
The adder 4 is connected via -N and the multipliers 3-1 to 3-N, and the subtractor 5 is connected to the output side thereof. On the output side of each of the delay circuits 2-1 to 2-N, a beam having zero sensitivity in the phasing direction by multiplying the output by a constraint matrix (this is a null beam).
A constraint matrix multiplier (hereinafter referred to as BM multiplier) 6 for creating a plurality of beams is connected.

An adder 8 is connected to the output side of the BM multiplier 6 via a plurality of adaptive filters (hereinafter referred to as ADF) 7-1 to 7-L, and the output of the adder 8 is the subtractor 5 It is connected to the. The output side of the subtractor 5 has ADFs 7-1 to
7-L feedback connection and output terminal 9
It is connected to the.

FIG. 3 shows each ADF 7-1 to 7-L in FIG.
3 is a functional block diagram showing a configuration example of FIG.

This ADF has a plurality of stages of delay elements 11-1 to 11-P which sequentially delay the output of the BM multiplier 6, and a plurality of coefficient units 12-0 to 12-0 on its input / output side. 12-
P is connected, and the adder 13 is further connected to the output side thereof.

Next, a conventional adaptive phasing method using the adaptive phasing device of FIGS. 2 and 3 will be described.

First, the sensor array 1 of FIG. 2 converts the received acoustic signal into an electric signal and outputs it to the delay circuits 2-1 to 2-N. The delay circuits 2-1 to 2-N perform phasing by delaying the input acoustic signal by the delay time based on the phasing direction, and the phasing result is multiplied by the multiplier 3-1.
To 3-N and BM multiplier 6, respectively. The multipliers 3-1 to 3-N multiply the phasing results from the delay circuits 2-1 to 2-N by a shading coefficient and output the result to the adder 4. In the adder 4, the multipliers 3-1 to 3-3-
By adding the results of N, a beam having the maximum sensitivity in the phasing direction is formed, and the result is output to the subtractor 5.

The BM multiplier 6 includes delay circuits 2-1 to 2-N.
By performing a matrix operation of the phasing result and the constraint matrix based on the following equation (1),
L null beams having zero sensitivity in the phasing direction are created and the results are output to the ADFs 7-1 to 7-L, respectively.

[0012]

[Equation 1]

Here, the constraint matrix B is a 0th-order constraint, 1
Arbitrary restraints such as the following restraints can be applied. For example,
Wal when the number of sensors N = 8 and the number of null beams L = 6
A block matrix of 0th order constraint using the sh function is given by the following equation (2).

[0014]

[Equation 2]

The ADF 7-1 shown in FIG. 3 is a BM multiplier 6
The first null beam output from the above is input to the delay element 11-1 and the coefficient unit 12-0. In the delay element 11-1,
The first null beam output is delayed for a fixed time and is given to the delay element 11-2 and the coefficient unit 12-1. Similarly, the delay elements 11-2 to 11-P process the same. The coefficient units 12-0 to 12-P perform the multiplication process of the following Expression (3). Ya _ji (k) = Y _ji (k) · W _ji (k) (3) where i = 0, 1, 2, ..., P, j = 1, 2, ..., L Y _ji (k ); Output of delay element 11-i at time k Output of BM multiplier 6 when i = 0 W _ji (k); Weighting coefficient at time k The result of multiplication processing by equation (3) is sent to adder 13. Then, the adder 13 adds the results of Ya _{10 to} Ya _1P ,
It outputs to the adder 8 of FIG. Other ADF7-2 to 7-L
Is the same processing. The adder 8 has ADFs 7-1 to 7-
The output of L is added, and the result is output to the subtracter 5.

The subtractor 5 subtracts the output from the adder 4 and the output from the adder 8 and outputs the subtraction result to the output terminal 9 and the ADFs 7-1 to 7-N. Coefficient multipliers 12-0 to 12-12 in the respective ADFs 7-1 to 7-N
-P uses the output z (k) from the subtracter 5 and is based on the following equation (4), and the weighting coefficient W _ji (k
+1) is updated. W _ji (k + 1) = W _ji (k) + μ · Y _ji (k) · z (k) (4) where μ; convergence coefficient z (k); output of adaptive phasing process at time k

[0017]

However, in the conventional method, when a sensor forming a null beam fails and outputs 0, for example, the BM multiplier 6 multiplies the constraint matrix. , Including fault sensor nu
The ll beam has a finite sensitivity in the phasing direction.
Therefore, the ADFs 7-1 to 7-L operate so as to remove the signal received from the phasing direction and have a problem of missing the target signal, which is difficult to solve.

The present invention provides an adaptive phasing method that solves the problem of the prior art that the target signal is lost when a sensor failure occurs.

[0019]

In order to solve the above-mentioned problems, the first invention performs phasing on a signal received by a sensor array composed of a plurality of sensors, and performs phasing on the phasing result. A plurality of null beams having zero sensitivity in the phasing direction are created by multiplying the constraint matrix, and the phasing result and the null beam are used to perform the adaptive signal processing to arrive from a direction other than the phasing direction. In the adaptive phasing method for adaptively removing the signal to be used, the following means are taken.

That is, the n
The abnormality of the sensor forming the null beam is detected, and the weighting coefficient of the constraint matrix is used to calculate the sum of the weighting coefficient values of the sensors determined to be abnormal by the sensor abnormality detection processing. Divide into multiple weighting factors so that they have the same value. Then, this divided weighting factor is added to the weighting factor for the sensor determined to be normal for each null beam, and the weighting factor for the sensor determined to be abnormal is set to 0, whereby the constraint matrix I am trying to reconstruct.

In the second aspect of the present invention, signals received by a sensor array composed of a plurality of sensors are phased and the phasing result is multiplied by a constraint matrix to obtain zero sensitivity in the phasing direction. Multiple beams with null beam
In the adaptive phasing method for creating a signal and adaptively removing signals arriving from other than the phasing direction by adaptive signal processing using the phasing result and the null beam, the following means are taken. ..

That is, the sensor forming the null beam is divided into a plurality of groups for each null beam, and in each null beam, there is zero sensitivity in the phasing direction for each group. The constraint matrix is formed so as to be formed, and the abnormality of the sensor forming the null beam is detected by the sensor abnormality detection processing. If the sensor abnormality detection processing determines that the sensor in the group is abnormal, the constraint coefficient in the group is set to 0 to reconstruct the constraint matrix. ing.

[0023]

According to the first aspect of the present invention, the adaptive phasing method is configured as described above. Therefore, when a sensor malfunctions, the sensor malfunction detection process detects the malfunction of the sensor forming the null beam. Done. Then, the weight of the constraint coefficient for the sensor determined to be abnormal is divided into a plurality of weight coefficients, the divided weight is added to the weight coefficient determined to be normal, and the weight coefficient for the abnormal sensor is 0. Then, the constraint matrix is reconstructed. As a result, even if the sensor fails, detection of the target signal can be continued without missing the target signal.

According to the second invention, the constraint matrix is divided into a plurality of groups for each null beam. When a sensor malfunctions, the sensor abnormality detection process detects the abnormality of the sensor forming the null beam, and the constraint coefficient in the group is set to 0.
The constraint matrix is reconstructed. Accordingly, even if the sensor fails, the detection of the target signal can be continued with relatively simple control without losing the target signal. Therefore, the above problem can be solved.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment FIG. 1 is a functional block diagram of an adaptive phasing device for carrying out an adaptive phasing method showing a first embodiment of the present invention. Elements common to and are assigned common reference numerals.

In this adaptive phasing device, the conventional delay circuit 2
The sensor abnormality detector 15 is connected to the output side of -1 to 2-N, the BM controller 16 is further connected to the output side thereof, and the BM multiplier 6 is controlled by the output of the BM controller 16. Is becoming

The sensor abnormality detector 15 includes a delay circuit 2-1.
It has a function of detecting an abnormality sensor based on the outputs of 2 to 2-N and giving the detection result to the BM controller 16.
The BM controller 16 calculates a constraint matrix based on the detection result of the sensor abnormality detector 15, and calculates it by the BM multiplier 6
It has a function to give to.

FIG. 4 is a block diagram showing a configuration example of the sensor abnormality detector in FIG. This sensor abnormality detector is
It has a plurality of power calculators 21-1 to 21-N for calculating an instantaneous power from the outputs of the delay circuits 2-1 to 2-N, and the power calculator 21 is provided on each output side thereof. -1 to 21-
An integrator 22-1 for obtaining a long-time integration power from the output of N
22-N are respectively connected.

On the output side of each of the integrators 22-1 to 22-N, a comparison process with a predetermined threshold is performed on the long-time integration power output from the integrators 22-1 to 22-N. The comparators 23-1 to 23-N are connected to each other, and the output side thereof is connected to the abnormal sensor determiner 24 that extracts the abnormal sensor and outputs the abnormal sensor number to the BM controller 16 of FIG. ing.

Next, an adaptive phasing method using the above-mentioned adaptive phasing device will be described. First, the sensor array 1 of FIG. 1 converts the received acoustic signal into an electric signal and outputs it to the delay circuits 2-1 to 2-N. Each delay circuit 2-
1 to 2-N perform phasing by delaying the sensor output by a delay time based on the phasing direction, and the phasing result is obtained by each of the multipliers 3-1 to 3-N and the BM multiplier 6, And sensor abnormality detector 15 respectively.

Each of the multipliers 3-1 to 3-N has a corresponding delay circuit 2
The phasing results from -1 to 2-N are multiplied by a shading coefficient and output to the adder 4. The adder 4 adds the multiplication results of the multipliers 3-1 to 3-N to form a beam having the maximum sensitivity in the phasing direction, and outputs the result to the subtractor 5.

The BM multiplier 6 includes delay circuits 2-1 to 2-N.
Based on the equation (1), the phasing result is obtained by performing a matrix operation of the phasing result and the constraint matrix output from the BM controller 16 to obtain a null beam having zero sensitivity in the phasing direction. L-frames are created and the results are used for each ADF7-
Output to 1 to 7-L.

Each ADF 7-1 to 7-L has a BM multiplier 6
Filtering processing is performed using the L null beam outputs from the above, and the result is output to the adder 8. The adder 8 adds the outputs of the ADFs 7-1 to 7-L and outputs the result to the subtractor 5.

The subtractor 5 subtracts the output from the adder 4 and the output from the adder 8 and outputs the subtraction result to the output terminal 9
And output to each ADF 7-1 to 7-L. Coefficient multiplier 12 in each ADF 7-1 to 7-L shown in FIG.
−0 to 12-P uses the output z (k) from the subtractor 5 and the weighting coefficient W _{ji at} time k + 1 is calculated by the equation (4).
Update (k + 1).

On the other hand, the sensor abnormality detector 15 detects the abnormality sensor using the outputs from the delay circuits 2-1 to 2-N, and outputs the result to the BM controller 16.

That is, in the sensor abnormality detector 15 shown in FIG. 4, the outputs from the delay circuits 2-1 to 2-N are input to the power calculators 21-1 to 21-N. The power calculators 21-1 to 21-N perform square processing on the outputs from the delay circuits 2-1 to 2-N, respectively.
Instantaneous power is calculated, and the result is calculated for each integrator 22-1 to 2-2.
Output to 2-N.

Each of the integrators 22-1 to 22-N performs an integration process on the instantaneous powers from the power calculators 21-1 to 21-N to obtain a long-time integral power, and each comparison is performed. Bowl 23
Output to -1 to 23-N. Comparators 23-1 to 23-N
Is the long-term integration power from the integrators 22-1 to 22-N.
On the other hand, a comparison process with a predetermined threshold value is performed, and the result is sent to the abnormality sensor determiner 24. Abnormal sensor determiner 24
Outputs an abnormal sensor number to the BM controller 16 in FIG. 1 based on the comparison result of the comparators 23-1 to 23-N.

The BM controller 16 is a sensor abnormality detector 15
Based on the abnormal sensor number from, the weighting coefficient of the constraint matrix relating to the abnormal sensor is extracted, and the value of the sum is divided into a plurality of weights so as to be equal to the value of the extracted weighting coefficient. Is added to the weighting coefficient determined to be normal.

For example, if it is determined that the k-th sensor 1-k is abnormal in the equation (2), B1k, B2
The values of the weighting factors of k, B3k, B4k, B5k, B6k are extracted. Although various methods of dividing into a plurality of weights can be considered, here, a method of dividing the weight coefficient by the normal number of sensors will be described. The number of normal sensors is abnormal sensor 1
When −k is one, it becomes N−1, and therefore each element of the constraint matrix can be calculated by the following equation (5).

[0040]

[Equation 3]

The BM controller 16 outputs the constraint matrix calculated by the equation (5) to the BM multiplier 6.

In this first embodiment, the sensors 2-1 to 2-2 are provided.
-If a failure occurs in N, the sensor abnormality detector 15 and B
The M controller 16 divides the weight of the constraint coefficient for the sensor determined to be abnormal into a plurality of weight coefficients, adds the divided weight to the weight coefficient determined to be normal, and determines the weight coefficient for the abnormal sensor. Set to 0. Therefore, it is possible to continue the target detection without losing the target signal at the time of sensor failure and without significant deterioration in performance.

[0043] In a second embodiment adapted phasing method of the second embodiment, performs the adaptive phased using an adaptive phased device composed of FIGS. 1 and 4, BM multiplier of FIG. 1 6, the processing contents of the ADFs 7-1 to 7-L and the BM controller 16 are different from those of the first embodiment.

That is, in this adaptive phasing method, when the sensor array 1 receives an acoustic signal, based on the reception result, the delay circuits 2-1 to 2-N, the multipliers 3-1 to 3-N, and the adder. 4 performs the same operation as in the first embodiment. Delay circuit 2
When the outputs of −1 to 2-N are sent to the BM multiplier 6, the B
Similar to the first embodiment, the M multiplier 6 creates L null beams having zero sensitivity in the phasing direction and outputs the results to the ADFs 7-1 to 7-L.

Here, the constraint matrix B is divided into a plurality of groups for each null beam, and the sum of the weighting factors is set to 0 for each group.
When the block matrix of 0th order constraint using the Walsh function of the equation (2) is used, it can be divided into groups such as the following equation (6). First null beam: (B11, B15), (B12, B16), (B13, B17), (B14, B18) Second null beam: (B21, B23), (B22, B24), (B25, B27), (B26, B28) 3rd null beam: (B31, B34), (B32, B33), (B35, B38), (B36, B37) 4th null beam: (B41, B42), ( B43, B44), (B45, B46), (B47, B48) 5th null beam: (B51, B58), (B52, B57), (B53, B56), (B54, B55) 6th null beam : (B61, B67), (B62, B68), (B63, B65), (B64, B66) ・ ・ ・ (6) In (6), the parentheses indicate the group. Are divided so that the sum of the weights becomes zero.

Then, as in the first embodiment, the ADF7
-1 to 7-L perform filtering processing using L null beam outputs from the BM multiplier 6,
Since the result is output to the adder 8, the adder 8
The addition processing of the outputs of DF7-1 to 7-L is performed and the addition result is output to the subtractor 5.

The subtractor 5 subtracts the output from the adder 4 and the output from the adder 8 and outputs the result to the output terminal 9 and the ADFs 7-1 to 7-L. Each ADF7-1
The coefficient units 12-0 to 12-P in ~ 7-L use the output z (k) from the subtracter 5 and, like the first embodiment,
From the equation (4), the weighting factor W _ji (k
+1) is updated.

On the other hand, the sensor abnormality detector 15 is the first
In the same manner as in the above embodiment, the output of each delay circuit 2-1 to 2-N is used to detect the abnormal sensor, and the detection result is
Output to the M controller 16. Different from the first embodiment, the BM controller 16 reconfigures the constraint matrix for the abnormal sensor number from the sensor abnormality detector 15 by setting the weighting coefficient in the group including the abnormal sensor number to 0. The result is output to the BM multiplier 6. For example, in the example of equation (6),
If it is determined that the third sensor 1-3 is abnormal, (B
13, B17), (B21, B23), (B32, B33), (B43, B44), (B53, B56), (B
63, B65) is set to 0.

In the second embodiment, the constraint matrix is divided into a plurality of groups for each null beam, and when a failure occurs in the sensors 1-1 to 1-N, the group is divided. The constraint coefficient in the loop is 0. Therefore, the sensors 1-1 to 1
Even if -N fails, the performance is slightly deteriorated as compared with the first embodiment by the relatively simple control as compared with the first embodiment, but the target signal is lost without significant deterioration of the performance. Without this, the detection of the target signal can be continued.

The present invention is not limited to the above embodiment,
Various modifications are possible. Examples of such modifications include the following. (A) In the first and second embodiments, ADFs 7-1 to 7-L
Is configured in the time domain, the output of the sensor array 1 is converted into a signal in the frequency domain by a frequency analysis means such as FFT, and the phasing device and the ADF are configured in the frequency domain. The same effect can be obtained.

(B) In the first and second embodiments, the inputs to the sensor abnormality detector 15 are delay circuits 2-1 and 2-1 for phasing.
Although the output is −N, the same effect can be obtained by using the output of the sensor array 1 before phasing.

(C) In the first and second embodiments, an example of adaptive phasing processing for one phasing azimuth has been described. However, by providing the above configuration in K stages in parallel, a standby search in a certain angle range is performed. It can also be used as a treatment.

(D) In the first and second embodiments, the sensors 1-1 to 1-N and the null beam used to form the beam having the maximum sensitivity in the phasing direction are prepared. Although the same sensor is used as the sensor, a part of the sensors 1-1 to 1-N used to form the former beam constitutes a sensor that creates a null beam. Alternatively, another sensor may be used.

(E) In the equation (5) of the first embodiment, the case where one sensor is abnormal is shown, but the case where a plurality of sensors are abnormal can be similarly expanded. Further, in the formula (5), the weighting factor for the abnormal sensor is divided into a plurality of weights by dividing the weighting factor by the number of normal sensors, but the sum of the divided weights is equal to the weight of the original abnormal sensor. However, any division method may be used. (F) In the equation (6) of the second embodiment, the group is composed of two constraint matrix elements. However, if there are two or more group elements to be divided, any number is possible. You may comprise.

(G) The devices of the first and second embodiments may be composed of individual circuits using integrated circuits, or may be composed of a digital signal processor (DSP) or the like.

[0056]

As described in detail above, according to the first aspect of the present invention, when a sensor malfunctions, the weight of the constraint coefficient relating to the sensor judged to be abnormal is divided into a plurality of weight coefficients. Since the divided weights are added to the weight coefficient determined to be normal, and the weight coefficient relating to the abnormal sensor is set to 0, even if the sensor fails, the target signal can be obtained without significant deterioration in performance. The detection of the target signal can be continued without being lost.

According to the second aspect of the present invention, the constraint matrix is divided into a plurality of groups for each null beam, and when the sensor fails, the constraint coefficient in the group is set to 0. Therefore, even if the sensor fails, it is possible to continue the detection of the target signal with a relatively simple control without losing the target signal and without losing the target signal.

[Brief description of drawings]

FIG. 1 is a functional block diagram of an adaptive phasing device for implementing an adaptive phasing method according to a first embodiment of the present invention.

FIG. 2 is a functional block diagram of an adaptive phasing device for implementing a conventional adaptive phasing method.

FIG. 3 is a functional block diagram of the ADF in FIG.

4 is a configuration block diagram of a sensor abnormality detector in FIG. 1. FIG.

[Explanation of symbols]

 1 Sensor Array 1-1 to 1-N Sensor 2-1 to 2-N Delay Circuit 3-1 to 3-N Multiplier 4,8 Adder 5 Subtractor 6 BM Multiplier 7-1 to 7-L ADF 15 Sensor abnormality detector 16 BM controller

Claims (2)

[Claims] 1. A null array having zero sensitivity in a phasing direction by phasing signals received by a sensor array composed of a plurality of sensors and multiplying the phasing result by a constraint matrix. In the adaptive phasing method that creates multiple beams and adaptively removes signals arriving from other than the phasing direction by adaptive signal processing using the phasing result and the null beam, The abnormality of the sensor forming the null beam is detected, and the weight coefficient of the constraint matrix is the sum of the weight coefficient values of the sensors determined to be abnormal by the sensor abnormality detection process. Value is divided into a plurality of weighting factors, and the divided weighting factors are added to the weighting factors related to the sensor judged to be normal for each null beam, and it is judged as abnormal. An adaptive phasing method characterized in that the constraint matrix is reconstructed by setting a weighting coefficient for the disconnected sensor to 0. 2. A null sensor having zero sensitivity in a phasing direction by performing phasing on a signal received by a sensor array composed of a plurality of sensors and multiplying the phasing result by a constraint matrix. In the adaptive phasing method, in which a plurality of beams are created, and signals arriving from directions other than the phasing direction are adaptively removed by adaptive signal processing using the phasing result and the null beam, The sensor to be formed is divided into a plurality of groups for each Nalvem, and each group is divided into each group.
A constraint matrix is constructed so that zero sensitivity is formed in the phasing direction for each group, and the sensor abnormality detecting process detects the abnormality of the sensor forming the null beam, and the sensor abnormality detecting process performs the group abnormality detection. An adaptive phasing method, characterized in that, when it is determined that the sensor inside is abnormal, the constraint matrix in the group is set to 0 to reconstruct the constraint matrix.