Automatic correction of aiming in firing at moving targets

• US 4,402,250 A
• Filed: 02/26/1981
• Issued: 09/06/1983
• Est. Priority Date: 06/29/1979
• Status: Expired due to Fees

• Current Assignee: Hollandse Signaalappareten BV
• Original Assignee: Hollandse Signaalapparaten BV (Thales SA)
• Inventors: Baasch, Hans-Friedrich
• Primary Examiner(s): BENTLEY, STEPHEN
• Application Number:
  US06/243,959
• Time in Patent Office: 922 Days
• Field of Search: 89/41 E, 89/41 EA, 89/41 AA, 89/41 L, 89/41 SW, 235/411, 235/412, 235/413, 235/414, 235/415, 235/416, 235/417, 343/7 G, 364/423
• US Class Current: 89/41.11
• CPC Class Codes: F41G 5/08 Ground-based tracking-systems for aerial targets

Abstract

In a method for automatically measuring aiming errors and correcting aiming values in the aiming and firing of ballistic weapons at moving targets the continuously supplied direction values (A'"'"', E'"'"'+σ) of a target position measurement, corrected for daily influences and for the superelevation, are compared with the aiming values (α+ε) of at least one gun (2) in a series of successive time intervals after storage of the gun aiming values (α+ε) in a memory (3) for a period corresponding with the instantaneous time of flight of the projectile (τ).

Claims

1. A method for correcting aiming errors of a ballistic weapon which is aimed at a moving target in response to changing azimuth values α

and elevation values ε

received from a fire control device, said method comprising the steps of;

(a) continually storing the instantaneous azimuth and elevation values received by the ballistic weapon;

(b) measuring the present azimuth A and elevation E of the target;

(c) computing a corrected azimuth A'"'"' and elevation E'"'"'+σ

of a position at which a projectile fired by the ballistic weapon should have been aimed to account for meteorological influences and superelevation;

(d) computing a projectile'"'"'s time of flight τ

to said position from the ballistic weapon;

(e) comparing the corrected azimuth A'"'"' and elevation E'"'"'+σ

with the respective azimuth value α and

elevation value ε

which was stored for a period corresponding to the time of flight τ

, and determining differences representing aiming errors Δ

α and

Δ

ε

, respectively; and

(f) adjusting the aim of the ballistic weapon to correct for the errors Δ

α and

Δ

ε

.

2. A method as in claim 1 wherein the interval between successive comparisons of the corrected azimuth A'"'"' and elevation E'"'"'+σ

with the respective azimuth value α and

elevation value ε

is equal to the computed time of flight τ

.

3. A method as in claim 1 wherein the interval between successive comparisons of the corrected azimuth A'"'"' and elevation E'"'"'+σ

with the respective azimuth value α and

elevation value ε

is less than the computed time of flight τ

.

4. A method as in claim 1, 2 or 3 where said differences are statistically processed to produce said aiming errors.

5. A method as in claim 4 employing programmable digital signal processing to effect said statistical processing.

6. An apparatus for correcting aiming errors of a ballistic weapon adapted for aiming at a moving target in response to changing azimuth values α

and elevation values ε

, said apparatus comprising;

(a) a fire control device for supplying the values α and

ε

to the ballistic weapon, said device including means for measuring the present azimuth A and elevation E of the target, means for computing a corrected azimuth A'"'"' and elevation E'"'"'+σ

of a position at which a projectile fired by the ballistic should have been aimed to account for meteorological influences and superelevation, and means for computing the time of flight τ

of said projectile from the ballistic weapon to said position;

(b) an aiming value memory for storing the instantaneous azimuth and elevation values supplied to the ballistic weapon;

(c) a timing means for effecting reading out from the memory the azimuth value α and

elevation value ε

which was stored for a period corresponding to the time of flight τ

;

(d) an error processing unit for receiving the corrected azimuth A'"'"' and elevation E'"'"'+σ

computed by the fire control device and comparing them with the respective azimuth value α and

elevation value ε

read out from memory, and determining differences corresponding to aiming errors Δ

α and

Δ

ε

, respectively; and

(e) means for adjusting the aim of the ballistic weapon in response to Δ

α and

Δ

ε

to correct for said aiming errors.

7. An apparatus as in claim 6 where the timing means comprises:

(a) means for producing an initiation signal S;

(b) a timing element triggered by the initiation signal S for producing a time value t representative of the time elapsed since triggering; and

(c) a comparator for comparing the time value t with the computed time of flight τ and

, upon equivalence, producing a signal C for resetting the time element and reading out from memory the azimuth value α and

the elevation value ε

corresponding to the corrected azimuth A'"'"' and elevation E'"'"'+σ

then being received by the error processing unit.

8. An apparatus as in claim 6 where the timing means comprises:

(a) means for producing an initiation signal S;

(b) a first timing element triggered by the initiation signal S for producing a time value t respresentative of the time elapsed since triggering;

(c) a second timing element triggered by the initiation signal S for repeatedly producing a signal S'"'"' at intervals Δ

t after triggering, each signal S'"'"' effecting storage in the memory of the values α and

ε

then being supplied to the ballistic weapon;

(d) a time register for producing a signal representing Δ

t each time a signal C is applied thereto;

(e) a subtractor coupled to the first timing element and the time register for decreasing the time value t by Δ

t each time the signal C is applied to the time register; and

(f) a comparator for comparing the time value t with the computed time of flight τ and

, upon equivalence, producing said signal C, effecting reading out from memory the azimuth value α and

the elevation value ε

corresponding to the corrected azimuth A'"'"' and elevation E'"'"'+σ

then being received by the error processing unit.

9. An apparatus as in claim 6 where the timing means comprises:

(a) means for producing an initiation signal S;

(b) a first timing element triggered by the initiation signal S for producing a time value t representative of the time elapsed since triggering;

(c) a dividing network for determining a fractional value kτ

from the computed time of flight τ

;

(d) a time memory for storing the instantaneous value kτ

when the initiation signal S is produced, and for producing the stored value kτ

each time a signal C is applied thereto;

(e) a subtractor coupled to the first timing element and the time memory for decreasing the time value t by kτ

each time the signal C is applied to the time memory;

(f) a first comparator for comparing the time value t with the computed time of flight τ and

, upon equivalence, producing the signal C;

(g) a second timing element triggered by the initiation signal S, for producing a continually increasing time value which is repeatedly reset to zero by a signal S'"'"'; and

(h) a second comparator for comparing the time value produced by the second timing element with the fractional value kτ

determined by the dividing network and, upon equivalence, producing the signal S'"'"';

each signal S'"'"' effecting storage in the aiming value memory of the values α and

ε

then being supplied to the ballistic weapon, and each signal C effecting reading out from the aiming memory the azimuth value and the elevation corresponding to the corrected azimuth A'"'"' and elevation E'"'"'+σ

then being received by the error processing unit.