Scoring of simulated weapons fire with sweeping fan-shaped beams

• US 4,218,834 A
• Filed: 02/22/1979
• Issued: 08/26/1980
• Est. Priority Date: 03/02/1978
• Status: Expired due to Term

• Current Assignee: Saab-Scania Aktiebolag
• Original Assignee: Saab-Scania Aktiebolag
• Inventors: Robertsson, Hans R.
• Primary Examiner(s): Buczinski, S. C.
• Application Number:
  US06/014,115
• Time in Patent Office: 551 Days
• Field of Search: 35/25, 273/102.2 R, 273/102.2 B, 356/4, 356/5, 356/152, 250/199, 250/203 R, 89/41 L, 364/423, 235/412
• US Class Current: 434/21
• CPC Class Codes: F41G 3/265 with means for selecting or varying the shape or the direction of the emitted beam
• CPC Class Codes: F41G 3/2688 using target range measurement, e.g. with a laser rangefinder

Abstract

For scoring of simulated firing of a weapon, having flatwise-angularly sweeping beams of radiation, emitted at the weapon location during a period beginning at or about the instant of simulated firing are used for measuring the position of a target retroreflector in range and in functions of azimuth and elevation. During the same period a calculation is made of the instantaneous positions in range, and in functions of azimuth and elevation, of an imaginary projectile fired from the weapon at the firing instant under conditions then existing, and the relationship is ascertained between the imaginary projectile and each beam in its angular position at interception by the retroreflector. At a scoring instant, when weapon-to-reflector distance equals weapon-to-projectile distance, or when the projectile is at a predetermined elevation relative to the reflector, scoring is based on the relationship of projectile to angular beam position at that instant. Scoring results can be displayed at the weapon location and/or transmitted to the target in beam modulation for evaluation of hit effect at the target.

Claims

1. A method of scoring simulated firing of a weapon against a target which comprises a reflector whereby radiation such as that of a laser is reflected back in the direction opposite to the one from which it arrived at the reflector, said method being characterized by:

A. beginning at the instant of simulated firing of the weapon, generating at the weapon location a calculated trajectory output which substantially signifies the position that a hypothetical projectile would have in its trajectory at successive instants if it had been fired from the weapon at the instant of simulated firing and which comprises

(1) calculated range magnitudes related to the location of the weapon at said instant, and

(2) other calculated position magnitudes which are related to a predetermined axis extending from the weapon generally in a direction in which the trajectory is oriented;

B. emitting radiation from the weapon location in the form of at least two fan-shaped beams, each having a long cross-section dimension which increases with increasing distance from the weapon location and a narrow cross-section dimension transverse to said long dimension,

(1) said long dimension of every beam at an angle to that of every other beam, and

(2) each of said at least two beams being swept angularly, substantially transversely to its said long dimension, across a solid angle space which has the weapon location at its apex;

C. each time radiation of a beam in its sweep is returned to the weapon location by reflection from said reflector, generating at the weapon location a measured output which comprises

(1) a range magnitude

(a) which is determined on the basis of time elapsed between emission of radiation and detection of the reflection thereof at the weapon location and

(b) which is a function of the distance between the reflector and the weapon location and is thus comparable with said measured range magnitude, and

(2) a beam angle magnitude which is a function of the then-existing angular position of the beam and which is related to said axis and is thus comparable with at least one of said other calculated position magnitudes; and

D. from time to time comparing one of said measured magnitudes with the comparable calculated magnitude so that when a predetermined relationship between the compared magnitudes is found to exist, the remaining calculated magnitudes can be compared for scoring purposes with the remaining measured magnitudes.

2. The method of claim 1 wherein said one measured magnitude and said one calculated magnitude that are compared are range magnitudes.

3. The method of claim 1 wherein said one measured magnitude and said one calculated magnitude that are compared are elevation magnitudes.

4. The method of claim 1 wherein the comparison of said one measured magnitude with said comparable calculated magnitude takes place at the weapon location.

5. The method of claim 1 wherein a detector of beam radiation is located adjacent to the reflector, further characterized by:

E. encoding in modulation of each beam, during a time when reflection of its radiation returned from the reflector is detected at the weapon location, information corresponding to the relationships between functions of said measured magnitudes and said calculated magnitudes so that scoring can take place at the reflector position.

6. The method of claim 5 wherein said sweep cycle has a predetermined duration, further characterized by:

F. at the reflector position, accepting information concerning relationships between said magnitudes only upon the condition that such information is detected in the modulation of every beam during a predetermined period having a duration not less than that of a sweep cycle during which every beam makes at least one sweep.

7. The method of claim 1, further characterized by:

modifying one of said outputs during said period to compensate for departures of the weapon location and the weapon barrel axis orientation from their conditions at the instant of simulated firing.

8. The method of claim 1 wherein rapid firing of the weapon is simulated by generation, during a period following initiation of simulated firing, of a plurality of calculated trajectory outputs which begin successively and certain of which begin to be generated while generation of another continues, and wherein reflections of radiation may be received at the weapon location from a plurality of reflectors during said period, further characterized by:

(1) at the weapon location comparing each of the calculated range magnitudes with each of the measured range magnitudes; and

(2) as the calculated range magnitude of each of said trajectory outputs comes into equality with a measured range magnitude, generating an output which signifies the relationship between said other calculated position magnitudes of that trajectory output and the then-existing beam angle magnitudes.

9. Apparatus for scoring results obtained in simulated firing with a weapon that has a barrel and a firing mechanism, said apparatus being of the type comprising a radiation emitter at the weapon location, a target that comprises a reflector whereby radiation is reflected back in the direction opposite to that from which it arrived, and a radiation detector, said apparatus being characterized by:

A. beam forming means at the weapon location, operatively associated with said radiation emitter, for forming emitted radiation into a plurality of fan-shaped beams, each of which is elongated in one direction transverse to its direction of propagation and each of which has its said long dimension at an angle to that of every other beam;

B. beam sweep means operatively associated with said radiation emitter and with said beam forming means and arranged to sweep each beam angularly, substantially transversely to its said dimension, in a regular relationship to the sweep of every other beam, so that the beams collectively have a regular sweep cycle;

C. control means at the weapon location, having an input connection with said firing mechanism and having output connections with said radiation emitter and with said beam sweep means, for initiating a period of repeated sweep cycles upon simulated firing of the weapon;

D. said detector being at the weapon location and being arranged to detect beam radiation reflected back to said location;

E. target range measurement means at said weapon location, connected with said radiation emitter and said detector, for producing during each sweep cycle a target range output which corresponds to a function of the distance between the target and the weapon location;

F. beam position measurement means at said weapon location, connected with said detector and with said beam sweep means, for producing during each sweep cycle beam position outputs corresponding to functions of the angular position of each beam in its sweep at the instant when beam radiation, reflected back from the reflector, is detected at the weapon location;

G. imaginary projectile trajectory output means at the weapon location, having an input connection with said control means, for generating

(1) a projectile range output corresponding to the distance between the weapon location and the instantaneous position that a real projectile would have in its trajectory if it had been fired from the weapon at the instant of simulated firing, and

(2) projectile position outputs corresponding to functions of the instantaneous position of said projectile in relation to said angular positions of the beams; and

H. comparison means at the weapon location, connected with said measurement means and with said trajectory output means to receive their outputs and compare them with one another, said comparison means being arranged to produce a scoring output at a scoring instant when there is a predetermined relationship between one of said outputs of the measurement means and a corresponding one of said projectile outputs, which scoring output signifies a relationship between the imaginary projectile and the target at said scoring instant.

10. The apparatus of claim 9, further characterized by:

I. means at the weapon location, connected with said comparison means, for modulating the beams with information corresponding to said scoring output;

J. another detector adjacent to said reflector; and

K. display means connected with said other detector for producing at the target at perceptible output appropriate to the information with which the beams are modulated.

11. The apparatus of claim 10, further characterized by:

L. logic circuit means connected between said other detector and said display means, said logic circuit means being arranged to pass information corresponding to said scoring output from said other detector to said display means only upon the condition that every beam is modulated with such information during a predetermined time interval having a duration at least equal to that of said sweep cycle.

12. The apparatus of claim 9, further characterized by:

I. display means at the weapon location, connected with said comparison means, for producing at the weapon location a perceptible output appropriate to said scoring output.