METHOD AND APPARATUS FOR PASSIVE DETERMINATION OF TARGET DATA

• US 20110310703A1
• Filed: 06/16/2011
• Published: 12/22/2011
• Est. Priority Date: 06/19/2010
• Status: Active Grant

• Current Assignee: Atlas Elektronik GmbH (Thyssenkrupp AG)
• Original Assignee: Atlas Elektronik GmbH (Thyssenkrupp AG)
• Inventors: STEIMEL, Ulrich
• Granted Patent: US 8,804,459 B2
• Time in Patent Office: Days
• US Class Current: 367/99
• CPC Class Codes: G01S 3/8083 determining direction of source
• CPC Class Codes: G01S 3/8086 determining other position line of source

Abstract

A method and apparatus for passive determination of target data (R, K, V) associated with a target from measured and estimated bearing angles. The measured bearing angles (4) are determined by a sonar receiving installation (2) by directionally selective reception of sound waves which are emitted or sent from a target, and the estimated bearing angles are determined from estimated positions of the target. The bearing angle differences from estimated and measured bearing angles are minimized iteratively over a plurality of processing cycles, and a position of the target, on which the minimum is based, is determined as the optimized solution (12). Furthermore, limit values (10) are defined for the target data (R, K, V) to be determined, in order to exclude unrealistic target data as solutions. However, because the optimized solution (12) from the optimization method (6) does not converge with the actual solution if the limit values (10) are chosen erroneously, an error handling process (14) for identification and correction of incorrect limit values (10) is carried out.

Claims

1. Method for passive determination of target data (R, K, V) associated with a target, in particular of a target range (R), a target course (K) and/or a target velocity (V), from bearing angles (4), which are measured by means of an arrangement of water-borne sound sensors of a sonar receiving installation (2) by directionally selective reception of sound waves emitted or sent from the target, and from estimated bearing angles, which are determined from estimated positions of the target, with bearing angle differences from the measured bearing angles (4) and the estimated bearing angles being iteratively minimized over a plurality of processing cycles by means of at least one optimization method (6), referred to in the following text as a CTMA method, and with an estimated position of the target, on which the minimum is based, being determined as an optimized CTMA solution (12), from the temporary target data (R, K, V), and with the CTMA method (6) taking account of predetermined limit values (10) for the target data (R, K, V) to be determined, during the optimization process,

characterized in that

an error handling process (14) is carried out for identification and correction of incorrect limit values (10), which process has the following steps:

a) limit values (10) are checked for possible errors by means of a plausibility test module (38) carrying out a plausibility test for identification of incorrect limit values (10) and

b) i) if at least one incorrect limit value (10) is identified;

one, a plurality or all of the limit values (10) are changed using predetermined rules by means of a correction module (40), and the CTMA method (6) and the error handling process (14) are carried out again, taking account of the changed limit values (20) for determination of new temporary target data (R, K, V) and

ii) if no incorrect limit value (10) is identified;

the optimized CTMA solution (12) from the CTMA method (6) is output, and/or the target data (R, K, V) which has been determined from the CTMA solution (12) and is assumed to be correct is output.

2. Method according to claim 1,

characterized in that

the method additionally has the following steps:

a) a further optimization method (26) is carried out, referred to in the following text as a TMA method, for determination of further temporary target data (R_TMA, K_TMA, V_TMA) from an optimized TMA solution (28) of the TMA method (26), with the estimated position of the target, on which the minimum determined by the TMA method (26) is based, being determined as the optimized TMA solution (28),

b) this temporary target data (R_TMA, K_TMA, V_TMA) is compared with the limit values (10) in order to check whether the temporary target data (R_TMA, K_TMA, V_TMA) is within a solution space which is covered by the limit values (10), and

c)i) if no temporary target data item (R_TMA;

K_TMA;

V_TMA) is identified outside the solution space;

the TMA solution (28) is output, and/or the target data (R, K, V) which has been determined from the TMA solution (28) and is assumed to be correct is output, and

ii) if at least one temporary target data item (R_TMA;

K_TMA;

V_TMA) is identified outside the solution space;

the CTMA method (6) is started and the error handling process (14) for identification and correction of incorrect limit values (10) is carried out.

3. Method according to claim 2,

characterized in that

a convergence time of the TMA method (26) is determined, with the CTMA solution (12) from the CTMA method (6) being output for the situation in which the CTMA method (6) is carried out until the convergence time is reached, and/or the target data (R, K, V) which was determined from the CTMA solution (12) and is assumed to be correct is output without previously carrying out the error handling process (14), and

after reaching the convergence time of the TMA method (26), the error handling process (14) for identification and correction of incorrect limit values (10) is carried out.

4. Method according to claim 3,

characterized in that

the CTMA solution (12) from the CTMA method (6) and/or the target data (R, K, V) which has been determined from the CTMA solution (12) and is assumed to be correct are/is output visually until the convergence time is reached, and the limit values (10) are changed by means of an input device (8).

5. Method according to claim 1,

characterized in that

a residue test (42) and/or an edge test (44) are/is carried out for the plausibility test (38) for identification of incorrect limit values (10).

6. Method according to claim 5,

characterized in that a residue factor (Q) is determined for the residue test (42), with the residue factor (Q) being determined from the respective solutions of the optimization methods using at least two optimization methods, in particular a TMA method (26) and a CTMA method (6), and with the residue factor (Q) being compared with at least one predetermined threshold value for identification of incorrect limit values (10).

7. Method according to claim 5,

characterized in that,

for the edge test (44) for identification of incorrect limit values (10), the limit values (10) and/or a variable which is derived from the limit values (10), in particular state restrictions, are/is compared with the CTMA solution (12) from the CTMA method (6), and/or the temporary target data (R, K, V) which has been obtained from the CTMA solution (12).

8. Method according to claim 1,

characterized in that

the correction of the incorrect limit values (10) by means of the correction module (40) has the following steps:

a) when either at least one incorrect limit value (10) or an incorrect, changed limit value (20) is identified, one, a plurality or all of the limit values (10;

20) and/or an associated limit value interval which has the limit value (10;

20) are/is changed, and the CTMA method (6) and the error handling process (14) are carried out once again in the current processing cycle, taking account of the changed limit values,

b) when at least one incorrect, changed limit value (20) is identified again, step a) is repeated in the current processing cycle,

c) when at least one incorrect, changed limit value (20) is identified again, and after step a) has been carried out a plurality of times, the CTMA method (6) and the error handling process (14) are carried out again in the current processing cycle, taking account of predetermined minimum limit values, or

the CTMA method (6) and the error handling process (14) are carried out again in the next processing cycle, with bearing angles (4) being measured again, and taking account of predetermined limit values (10).

9. Method according to claim 1,

characterized in that

a target manoeuvre while carrying out the CTMA method (6) is taken into account by the CTMA method (6) calculating two target legs, with the original limit values (10) being taken into account for the original target leg, and with new limit values being defined for the new target leg.

10. Apparatus for passive determination of target data (R, K, V) associated with a target, in particular of a target range (R), a target course (K) and/or a target velocity (V), from bearing angles (4), which can be measured by means of an arrangement of water-borne sound sensors of a sonar receiving installation (2) by directionally selective reception of sound waves emitted or sent from the target, and from estimatable bearing angles, which can be determined from estimated positions of the target, with bearing angle differences from the measured bearing angles (4) and the estimated bearing angles being iteratively minimized over a plurality of processing cycles by means of at least one optimization method (6), referred to in the following text as a CTMA method, and with an estimated position of the target, on which the minimum is based, can be determined as an optimized CTMA solution (12), from the temporary target data (R, K, V), and with the CTMA method (6) can be taken into account of predetermined limit values (10) for the target data (R, K, V) to be determined, during the optimization process, in particular for carrying out a method according to claim 1,

characterized by

an error handling device (14) which is designed to identify and to correct incorrect limit values (10), with the error handling device (14) having a plausibility test module (38) and a correction module (40),

the plausibility test module (38), which is designed to identify incorrect limit values (10),

the correction module (40), which is designed to correct incorrect limit values (10), and

an output unit (24) for outputting the optimized CTMA solution (12) from the CTMA method (6) and/or for outputting the target data (R, K, V) which can be determined from the CTMA solution (12) and is assumed to be correct, for the situation in which no incorrect limit values (10) can be identified by means of the plausibility test module (38).

11. Apparatus according to claim 10,

characterized in that

the plausibility test module (38) has a residue test module (42) and/or an edge test module (44), with the residue test module (42) and the edge test module (44) being designed to identify incorrect limit values.

12. Apparatus according to claim 10,

characterized by

a test device (30), which is designed to test whether temporary target data (R_TMA, K_TMA, V_TMA) which can be determined from an optimized solution (28) of a further optimization method (26), referred to in the following text as a TMA method, is within a solution space which can be covered by the limit values (10), in which case the estimated position of the target on which the minimum which can be determined by the TMA method (26) is based can be determined as the optimized TMA solution (28).

13. Apparatus according to claim 12,

characterized by

a convergence phase detector (78), which is designed to determine a convergence time of the TMA method (26).

14. Apparatus according to claim 10,

characterized by means for carrying out one, a plurality of or all of the method steps according to claim 1.

15. Computer program, which has computer program code means which are suitable for carrying out the method according to claim 1 when the program is run on a computer.