PL228118B1 - System and method for compensation of time delay in the firearm systems - Google Patents

Description

The present invention relates to a method for compensating for time delays in firearm systems that compensate for unknown time delays in an aiming transmission link between an target targeting unit (TSU) and the firearm system.

On the battlefield, it is essential to have the means to detect targets and to have the firepower necessary to attack targets and respond to attacks from a threatening enemy. Speed and mobility on the battlefield are also essential. For this purpose, firearms are installed on motor vehicles such as cars, commercial vehicles, helicopters, airplanes and the like. Although motor vehicles provide the necessary speed and mobility, they also present problems with accuracy.

The listed accuracy problems have a number of causes. First, shooting from a movable platform requires compensating the movement of said platform. For smooth movements it is relatively easy to compensate for platform movement, however, the platform hardly ever moves smoothly. The platform's smoothness is influenced by acceleration, deceleration, road unevenness, turbulence in the air and the like. In addition to the issues mentioned above, accuracy issues can be caused by time delays between systems on the platform. For example, an aircraft typically has an object targeting unit that tracks targets and a firearm system that provides firepower to the target. These systems are usually interconnected by a platform bus. Due to the time delays on the bus, the data generated by the target aiming unit cannot be simultaneously received by the firearm system. Since the time delay is very small (on the order of milliseconds), it seems that it can be ignored. However, when shot at long distances (from an aircraft, for example) these small time delays can cause large deviations from the target. Another problem with time delays between systems is that the time delay is mostly unknown. Therefore, it is almost impossible to introduce general compensation for time delays.

US Patent No. US2012246992 discloses rangefinders and targeting methods using bullet grouping.

Japanese Patent Document JP2011220625 discloses a missile guidance device providing a guidance control method that can guide a missile in a short time causing the missile to precisely hit the target, even with a short final guidance time in a missile aimed at an aircraft or the like.

An object of the invention is to provide a method for compensating for time delays in firearm systems which compensates for unknown time delays in the transmission link of the aiming line between the target targeting unit (TSU) and the firearm system.

A method of compensating for time delays in firearm systems to achieve the objectives of the present invention is illustrated in the accompanying figures, in which:

Figure 1 is a schematic representation of a time delay compensation system in firearm systems.

Figure 2 shows a flowchart of a method for compensating time delays in firearm systems.

The elements shown in the figures are designated by the following reference numerals:

1. Time delay compensation system in firearms systems

2. Platform

21. Firearms system

3. Object targeting unit

4. Indicating unit

5. Navigation unit

6. Rangefinder

7. Control unit

The novel time delay compensation system for firearms systems (1) generally comprises at least one platform (2) that carries the firearm system (21) providing the necessary firepower on the battlefield. In a preferred embodiment of the invention, the platform (2) is an aircraft, such as a helicopter. In order to track and capture targets, the platform (2) houses at least one target targeting unit (3). The firearm system (21) located on the platform targets the target using the information provided by the target targeting unit (3).

PL 228 118 B1

In order to determine where the firearm system (21) is aimed, at least one indicator unit (4) is provided on the platform (2). In a preferred embodiment of the invention, the indicating unit (4) is mounted on the barrel of at least one of the firearms of the firearm system (21). In this embodiment, the pointing unit (4) is a laser pointer. The platform (2) houses at least one navigation unit (5) which provides angular and linear velocity values for the platform (2). The inventive time delay compensation system in the firearm systems (1) further includes at least one rangefinder (6) that provides values for the distance of the platform (2) from the target. The inventive time delay compensation system for firearms systems (1) further comprises at least one control unit (7) that acquires data provided by the target targeting unit (3), navigation unit (5) and rangefinder (6) and performs operations on the target. obtained data. Operations performed on the acquired data may include but not be limited to mathematical, logical, and the like.

In a preferred embodiment of the invention, the navigation unit (5) is an inertial navigation unit.

In a preferred embodiment of the invention, the rangefinder (6) is a laser rangefinder.

The method (100) for compensating for delays in firearms systems includes the following steps:

- determination (101) of the aiming line in terms of azimuth, elevation angle and direct distance,

- converting (102) the azimuth, elevation and direct distance data determined in step 101 into Cartesian coordinates,

- obtaining (103) from the navigation unit (5) the rate of yaw, roll about the transverse axis and roll about the longitudinal axis of the platform (2),

- multiplying (104) the rates obtained in step 103 by the delay time (TDelay),

- applying (105) the 3-2-1 Euler transform to the data obtained in steps 102 and 104,

- obtaining (106) the speed of the platform (2) from the navigation unit (5),

- multiplication (107) of the platform speed (2) by the delay time (TDelay),

- subtracting (108) the data obtained in step 107 from the data obtained in step 105,

- converting (109) the result of step 108 into spherical coordinates,

- updating (110) the aiming line and the distance from the target.

In a preferred embodiment of the invention, the target targeting unit (3) comprises at least two encoders which provide data on the position of the target targeting unit (3) in terms of azimuth and elevation angle with respect to the platform (2). In this embodiment, a change in the targeting union due to platform movement (2) is compensated by using data received from the navigation unit (5).

In the time delay compensation method (100) in firearm systems, an aiming line at the object is obtained (101) in terms of azimuth, elevation angle and direct distance. In a preferred embodiment of the invention, the target line is obtained in terms of azimuth, elevation angle and distance, and these data are acquired over a lag time period. Once the target line is obtained, the values are converted (102) to Cartesian coordinates. Then, in step (103), the rates of pivoting, tilting about a transverse axis and tilting about a longitudinal axis of the platform (2) are obtained. The resulting rates of tilting, tilting about a transverse axis and tilting about a longitudinal axis are multiplied (104) then by the delay time (TDelay). The Eulerian angles for the rates of yawing, tilting about the transverse axis and tilting about the longitudinal axis are then calculated. In addition, the position of the target is obtained in Cartesian coordinates, and then these Cartesian coordinates are transformed (105) using at least one transformation. After transforming the data, the speed of the platform (2) is obtained in a step. The value of the platform speed (2) is obtained in Cartesian coordinates. The speed value is multiplied (107) then by the delay time (TDelay). The velocity value multiplied by the delay time (TDelay) is then converted to spherical coordinates and subtracted (108) from the coordinates obtained in step 105. Then the result is converted (109) to spherical coordinates. The aiming line and the distance to the target are updated (110) with respect to these coordinates.

In a preferred embodiment of the invention, the delay time (TDelay) is first approximated and then experimentally calibrated. The calibration process is performed as follows: when the platform (2) is hovering, grasps the target with the target targeting unit (3), the platform (2) is maneuvered in the yaw axis, while the ground crew observes the indicating unit (4).

PL 228 118 B1

If the indicating signal (which is a laser signal in the preferred embodiment) moves towards the platform (2), the TDelay increases. If the indicating signal moves in the direction opposite to platform (2), TDelay decreases. TDelay is set for the minimum movement of the pointing signal.

Claims (3)

A method for compensating time delays, characterized in that it comprises the steps of: - obtaining (101) the aiming line in terms of azimuth, elevation angle and direct distance, transforming (102) the obtained azimuth, elevation and distance data into Cartesian coordinates, - obtaining (103) the rates of roll, tilt and roll about the longitudinal axis of the platform (2) and the speed of the platform from the navigation unit (5), - multiplication (104), (105), (106), (107) of the obtained angular velocities and the speed of the platform (2) by the delay time (TDelay), thus determining the displacement and rotation angles of the platform (2) during the delay time, - subtracting (108) the displacement of the platform from the target aim line expressed in Cartesian coordinates and then multiplying the resulting target aim line expressed in Cartesian coordinates with the transformation matrix formed by the rotation angles, thus determining a corrected target line expressed in Cartesian coordinates, - converting (109) the corrected target line to an object expressed in Cartesian coordinates to spherical coordinates, thereby expressing the corrected target line to an object in terms of azimuth, elevation angle and direct distance, - updating (110) the aiming line and target distance, where the time delay first approximated and experimentally calibrated and the calibration process comprises steps; - blocking the aiming unit (3) at the object on the object when the platform (2) is hovering, - maneuvering the platform (2) on the yaw axis while the ground crew is watching the indicator unit (4); - increasing TDelay if the indicating signal is moving towards the platform (2), - decreasing TDelay if the indicating signal moves in the direction opposite to the platform (2), - establishing a TDelay for the minimum pointing signal movement. 2. The method of compensating for time delays according to claim 1, The method of claim 1, wherein the target line of sight and the distance to the object are obtained in terms of azimuth and elevation angle. 3. The method of compensating for time delays according to claim 1, The method of claim 2, wherein the target line of sight and the distance to the target are obtained with a period equal to the time delay.