METHOD FOR COORDINATING PROJECTILE IN A SALUD

Abstract

The invention relates to a method for coordinating projectiles in a salvo when combating a target with at least two projectiles where the projectiles comprise a zone tube and are arranged to be controlled and that the following method steps are included; i.) measuring the position of the target, ii.) predicting the future position of the target, iii.) firing a first projectile towards the future position of the target, iv.) firing a second projectile towards the future position of the target, v.) slowing the first projectile, vi.) detecting targets with a zone tube arranged in the first or second projectile, vii.) guiding projectiles towards the target. Furthermore, the invention consists of a fire control system for fire control towards targets comprising at least one sensor for measuring the position of the target as a function of time. Furthermore, the invention consists of a combat system comprising a launching device.

Description

The present patent application relates to a method for coordinating projectiles in a volley.BACKGROUND OF THE INVENTION, PROBLEM STATEMENT AND PRIOR ARTWhen engaging a moving or stationary target with unguided or guided projectiles fired from barreled weapons, the projectiles must be fired at the points where the target will be located when the projectiles reach it or at points close to where the target will be located. Such points, usually called forward points, must be predicted. To improve the impact on the target or to improve the probability of impact on the target, several projectiles can be coordinated to increase the possibility of impact on the target.An example of a method and device for coordinating multiple projectiles is given in patent RU2373485C2. The patent describes a system where multiple projectiles are fired in sequence with a leading projectile guiding subsequent projectiles.The problem with currently existing solutions according to the above-mentioned document is that the leading projectile controls subsequent projectiles, which means that the system is not based on autonomous projectiles, which makes the system sensitive to disturbances.Further problems that the present invention aims to solve will become apparent in connection with the following detailed description of the various embodiments.The purpose of the present invention is to improve the ability to combat a target by having multiple projectiles steer close to a target to achieve impact on the target.By firing a series of projectiles and slowing the projectiles that have been fired first, the projectiles can be brought close to the target at the same time. By having the projectiles equipped with guidance capabilities and zone tubes, the projectiles can detect a target and steer towards the target, and subsequent projectiles can either steer towards the preceding projectile or towards the target.The invention relates to a method for coordinating projectiles in a salvo when combating a target with at least two projectiles, where the projectiles comprise a zone tube and are arranged to be guided, where the following method steps are included: i.) measuring the position of the target, ii.) predicting the future position of the target, iii.) firing a first projectile towards the future position of the target, iv.) firing a second projectile towards the future position of the target, v.) slowing the first projectile, vi.) detecting targets with a zone tube arranged in the first or second projectile, vii.) guiding projectiles towards the target.According to further aspects of the method for coordinating projectiles in a salvo when engaging a target;that additional projectiles are fired at the target.that the zone tube is arranged to distinguish between projectiles and targets ahead.that subsequent projectiles steer towards the preceding projectiles if no target is detected.that the first projectile is slowed down by;i.) that the first projectile is provided with at least one braking surface,ii.) that the initial velocity of the first projectile is adjusted,iii.) that the first projectile is designed to have higher air resistance than subsequent projectiles.that the braking surface arranged in the projectile is extendable and retractable to change the braking effect acting on the projectile.Furthermore, the invention consists of a fire control system for fire control against a target comprising at least one sensor for measuring the target's position as a function of time where the method for fire control as above is applied.Furthermore, the invention consists of a combat system comprising a launcher where a fire control system according to the above is applied.According to further aspects for a control system;that the launcher is a barrel-based cannon system.ADVANTAGES AND EFFECTS OF THE INVENTIONThe advantage of the present invention is that a target can be engaged with greater probability. Since multiple projectiles can be brought to be cooperatively and / or synergistically arranged in the vicinity of the target, the probability that the target will be engaged by the projectiles increases. Relatively conventional methods allow a smaller number of projectiles to be used to engage a target.To increase the effectiveness of the target, several projectiles can be coordinated close to each other by braking the projectiles, where each projectile has a partially different braking effect. When the projectiles are arranged close to each other, the possibility of detecting the target can increase, which increases the possibility of acting against the target.When the projectiles are arranged close together, subsequent projectiles can follow the preceding projectiles. Since the sensors in the projectiles preferably do not have a long range, due to cost and size limitations in the projectile, it is advantageous if the distance between the projectiles is relatively short so that the sensors in subsequent projectiles can detect the preceding projectiles and steer towards the preceding projectiles.LIST OF FIGURESThe invention will be described in more detail below with reference to the accompanying figures in which:Fig. 1 shows a flow chart of a method for fire control against a target according to an embodiment of the invention.Fig. 2 shows a block diagram of a device for combating targets according to an embodiment of the invention.Fig. 3a shows three projectiles directed at a target in a first position according to an embodiment of the invention.Fig. 3b shows three projectiles directed at a target in a second position according to an embodiment of the invention.Fig. 3c shows three projectiles aimed at a target in a third position according to an embodiment of the invention.Fig. 3d shows three projectiles directed at a target in a fourth position according to an embodiment of the invention.A launcher, also called a cannon, howitzer, or gun, such as a ship's gun, is intended to use a propellant to fire, or launch, a projectile. Preferably, a propellant, such as gunpowder, is initiated in a part of the cannon, often a chamber specially adapted for this. Initiation occurs by igniting the propellant, for example with a primer or a igniter in an ammunition unit, which is initiated by impact. Other methods of igniting the propellant can be by laser or electrical energy igniting the propellant. The propellant burns at high speed and produces a large amount of gas, which creates a gas pressure in the chamber that drives the projectile out of the firing barrel of the launcher. The propellant is adapted to generate, to the greatest extent possible, a constant pressure on the projectile throughout the entire course of the barrel, as the projectile moves in the barrel, which creates a high velocity on the projectile when the projectile leaves the muzzle.Projectiles, such as various types of grenades, in most cases include some form of action part and some form of fuse that initiates the action part. Fuses can be of different types where impact is common for projectiles that are intended to explode upon contact with an object. Other types of fuses are, for example, time tubes where the projectile is arranged to explode at a certain predetermined time and zone tubes where the projectile is arranged to explode when an object comes within a certain distance from the projectile. Zone tubes are preferably used when combating aircraft, while time tubes and impact can be used when combating a large number of different objects. It is advantageous to combine different types of fuse functions in the same fuse, so that if a fuse with the function of a zone tube does not detect any object, the projectile explodes after a certain time, etc. In the present invention, zone tubes with a function to measure objects in the vicinity of the projectile are preferably used. Zone tubes can be based on operating in different electromagnetic ranges with different performance and properties, commonly zone tubes are arranged for operation in a low-frequency electromagnetic range, also called near field. Furthermore, zone tubes can be arranged to operate in a higher frequency range and then work preferably in far field. Furthermore, zone tubes can be arranged with optical transmitter and receiver.The action part preferably comprises some form of explosive and some form of fragmentation casing that encloses the explosive. Furthermore, various forms of control means, such as fins, can be arranged either in the fuse or on the projectile body. The fuse can be programmed electrically, for example by contacting the fuse or with inductive / capacitive programming to make the fuse carry out a certain task or fulfill a certain function. The fuse can also communicate wirelessly, for example by radio or optical communication, in order to change the function of the fuse during the projectile's journey towards the target.An attacking guided vehicle or other target may intend to damage an attack target or a protected object depending on the perspective from which the attack target or protected object is viewed. Combating the target means affecting the target so that it can no longer damage the protected object towards which the target is traveling.A system designed to combat targets using gun weapons and unguided or steerable projectiles can be considered to consist of three parts; fire control, weapons and projectiles. In the following, such a system will be referred to as gun-barrel air defense. Unguided projectiles mean various forms of projectiles such as grenades and rockets intended to be used to combat targets. In the case that guided projectiles are used, projectiles with guidance capabilities are used, to which additional systems for communication to the steerable projectiles can be added. The steerable projectiles can also be autonomous and arranged with, for example, homing devices to steer themselves towards the target. Furthermore, targets can be combated with missiles. In the described invention, guided projectiles arranged with zone tubes that act autonomously are preferably used, which is why the projectile does not include a device for communication.A fire control system that is part of a gun-barrel air defense system includes one or more sensors and several methods for handling and evaluating sensor data. The sensor(s) that are part of, and used by, the fire control system will hereinafter be referred to as a sight.Refined information from the sight is used to control the alignment of both the sight and the weapon.A control can be considered to consist of a number of activities. Some activities must be carried out in sequence while others can be carried out in parallel.In figure 1, a flow chart for a method in a fire control system 1 is described. When a combat operation is initiated, start 2 in figure 1, the sight is directed towards the target to be combated. This is usually made possible by an external unit, for example a reconnaissance radar, continuously supplying information about the target's position as a function of time. The external unit can, for example, be arranged on the platform where the firing system is arranged, for example a ship. This external unit is called the pointing unit. The method is called pointing 3.In parallel with aiming the sight at the target, the gun barrel, or the firing device, can be aimed at a pre-calculated forward point whose position is based on data from the pointing unit. In this way, the time for gun barrel aiming is reduced when a more accurate forward point has been calculated because the pre-calculated forward point will be close to the more accurate, later, calculated forward point.Completed alignment means that the sight may be able to measure the target's position itself. However, it is not certain that the sight will be able to detect the target immediately - even though it is correctly aimed. In the event that the target gets closer and closer, the probability that the sight will be able to detect the target increases. The event that occurs when this happens is called target acquisition. Target acquisition is the beginning of a new sequence called target tracking 4. The sight then controls its own line of sight so that the line of sight follows the target.Once target tracking 4 has been established, target acquisition 5 begins. The sight now attempts to measure both direction and range to the target. It is not guaranteed that the sight can measure range to the target immediately when a target acquisition 5 is initiated. However, sooner or later the sight will begin to deliver range data . In the meantime, the target position and the preliminary forward point can be calculated by combining the angle data from the sight and the range data from the pointing device.When the sight can finally generate both direction and range data, no guidance data is needed to control the sight and gun barrel. However, guidance data can be used for other purposes.When the sight measures the target's position, during target acquisition 5, it usually does so at a higher frequency and with better accuracy than the pointing sensor can achieve. This is the fundamental reason why two types of sensors are used, reconnaissance sensors and fire control sensors.Measurement data is used for an Estimation of the target's position and velocity 6. By utilizing knowledge of the position of the protected object that the target may be intended to hit, the target's trajectory can be predicted with greater accuracy. The target's current position and velocity can be estimated from the raw data, for example in the manner already described.Estimating the target's trajectory involves predicting how the target will move through the air from a given starting point with a certain initial speed and direction.To estimate the target's trajectory, one can use principles from classical mechanics and physics, especially in areas such as kinematics and dynamics. A common method for doing this is to use equations of motion under constant acceleration (Newton's second law), but other methods can also be applied, such as various forms of Kalman filters.The Kalman filter is a mathematical algorithm used to estimate the future state of a system based on a series of measurements and previous state estimates. It is particularly useful when dealing with systems where measurements are associated with noise and where a more accurate and robust estimate of the system's state is desired.The Kalman filter is often based on a state model, a measurement model, a state prediction, and measurement updates. First, the system must be described with a state model, which means that the state of the system (e.g., position, velocity) is represented with a mathematical model. This model can contain information about how the system is expected to behave over time. Then, a measurement model is needed that describes how the measurements are performed in relation to the state of the system, including uncertainty and noise in the measurements. Based on the current state assessment and the measurement model, the Kalman filter can predict, predict, with a state prediction, the future state of the system. After new measurements have been obtained, the Kalman filter updates its estimate of the system's state based on the new measurements, measurement updates, and compares them with the predicted state assessment. This process combines the information from the new measurement with the predicted state assessment to generate a more accurate estimate of the system's state. The Kalman filter is particularly powerful because it can handle both system dynamics and measurement noise effectively. By repeatedly updating and improving its estimate, it can provide a very robust and stable estimate of the system state even in the presence of noise and uncertainties. It is widely used in various fields such as signal processing, navigation, robotics, and autonomous control.The Kalman filter is specifically designed to easily identify the projectile and target ahead because the projectile and target ahead move at very different speeds and directions, which is reflected in the Kalman filter's model structure.To begin estimating the trajectory of a projectile, one usually needs to know the initial conditions, including the target's initial position, velocity, and direction, as well as environmental conditions, including air resistance, gravitational acceleration, and any other external forces that may affect the target's motion. With this data, one can then use various models and equations to calculate the target's position and velocity at different times along its trajectory. It is important to note that for more accurate estimates, advanced methods and simulations can be used that take into account complex factors such as the effects of air resistance, variations in gravitational acceleration, and other external forces. In addition, one can also include factors such as assumptions about the target's control laws.At a certain point in time, a choice can be made to Combat Target 7. If the target is not combated, the method can be repeated from step 4, target tracking, until a better time is available to combat the target.If the choice is made to combat targets, projectiles can be fired at the target, as shown in Firing projectiles at the target 8. It is also possible to improve information about the target's trajectory in various ways before firing, for example by estimating the target's acceleration.The first projectile is either provided with at least one braking surface so that subsequent projectiles can approach the first projectile in a position close to the target area, or the initial velocity of the first projectile is adapted so that subsequent projectiles can approach the first projectile in a position close to the target area, or the first projectile is designed to have a higher air resistance than subsequent projectiles so that subsequent projectiles can approach the first projectile in a position close to the target area.Braking the projectile is shown in method step Braking the first projectile 9.A projectile can be designed with brake flaps or other deployable and possibly retractable braking device that can be deployed in the projectile's path and provide a braking effect on the projectile. Preferably, the brake flaps are arranged so that the braking effect only affects the speed of the projectile and not the radial path of the projectile. Alternatively, the projectile can be fired with a lower initial velocity so that subsequent projectiles can approach the first projectile, for example by adapting the charge with which the first projectile is fired. Alternatively, the first projectile can be arranged with an aerodynamic property which causes the projectile to be slowed. For example, a number of projectiles, for example five projectiles, can be arranged with different aerodynamic designs so that the first projectile has the highest air resistance, the second projectile the second highest air resistance, the third projectile the third highest air resistance, the fourth projectile the second lowest air resistance and the fifth projectile the lowest air resistance so that all projectiles can be coordinated within a target area.In method step Detect target 10, the zone tube arranged in the projectile can detect a target, preferably it is the first fired projectile that detects the target, but in the event that the first projectile does not detect the target, subsequent projectiles can detect the target.When the first projectile has detected the target, the projectile is guided towards the target with guidance elements arranged in the projectile, for example fins, which is indicated in the method step Guide towards target 11.In one embodiment, the first projectile initiates bursting of subsequent projectiles based on sensor data acquired in the first projectile, such as an indication that targets are near the present zone tube in the first projectile. When subsequent projectiles, with the zone tubes, identify that the preceding projectiles have burst, subsequent projectiles can be initiated to jointly or near jointly burst.A gun barrel air defense system 20, as shown in Figure 2, includes a fire control 21, one or more weapons 26 and projectiles 27 that can be fired at targets. The system 20 receives guidance from an external reconnaissance sensor 22, which can search very large volumes with great depth at the expense of accuracy and measurement frequency. The gun barrel air defense system 20 includes a fire control sensor 23 that, after guidance, can measure the position of the individual target in a small sector with limited depth but with high accuracy and high measurement frequency. The calculation unit 25 is used to calculate the forward points that the weapons 26 are to be aimed at. The fire control 21 may also include a protection object database 24 that contains positions for a plurality of protection objects that may be in the immediate area around the gun barrel air defense system 20. The weapons 26 and projectiles 27 may also consist of missiles.Figure 3a shows three projectiles 101, 102, 103 fired at a target 110 in a first position. The first projectile 101 was fired before projectile 102, after projectile 102 projectile 103 was fired from a launcher.In Figure 3b, the three projectiles 101, 102 and 103 have approached the target and are in a second position. Projectile 102 is approaching projectile 101 so that the projectiles can be coordinated in target area A. The first projectile 101 has identified target 110 as the projectile approaches target 110 in target area A.In Figure 3c, the three projectiles 101, 102 and 103 have approached the target 110 and are in a third position. Projectile 101 and projectile 102 are approaching the target 110 and projectile 101 is in target area A. The zone tube in projectile 102 has identified projectile 101 and is heading towards projectile 101.In Figure 3d, the three projectiles 101, 102 and 103 have entered target area A and are in a fourth position. Projectiles 101, 102 and 103 are relatively close to each other and relatively close to target 110. At a certain point in time, the impact part of projectile 101 explodes, followed by projectile 102 and then projectile 103. The impact from the projectiles will act synergistically against the target and in target area A by distributing shrapnel in target area A and acting against target 110.The invention is not limited to the embodiments specifically shown but can be varied in various ways within the scope of the claims.It is understood, for example, that the number of sensors, launchers, or systems of elements and details included in the method for fire control against a target is adapted to the weapon system(s), platform, and other design features that currently exist.It is understood that the above-described method of fire control against targets can be applied to in principle all unguided or guided vehicles and systems including aircraft, unmanned aerial vehicles and missiles, land vehicles, surface ships or underwater vehicles that are possible to measure.

Claims

1. Method for coordinating projectiles in a salvo when combating a target with at least two projectiles, where the projectiles comprise a zone tube and are arranged to be controlled, characterized in that the following method steps are included;i.) measure the target's position,ii.) predict the target's future position, iii.) fire a first projectile at the target's future position,iv.) fire a second projectile at the target's future position,v.) slow down the first projectile,vi.) detect targets with a zone tube arranged in the first or second projectile,vii.) directs projectiles towards the target.

2. Method for coordinating projectiles in a volley according to claim 1, characterized in that additional projectiles are fired at the target.

3. Method for coordinating projectiles in a volley according to claim 1, characterized in that the zone tube is arranged to distinguish between projectiles in front and targets.

4. Method for coordinating projectiles in a volley according to claim 1, characterized in that subsequent projectiles steer towards preceding projectiles if no target is detected. Method for coordinating projectiles in a volley according to any of the above claims characterized in that the first projectile is slowed by;i.) that the first projectile is provided with at least one braking surface,ii.) that the initial velocity of the first projectile is adjusted,iii.) that the first projectile is designed to have higher air resistance than subsequent onesprojectiles.

6. Method for coordinating projectiles in a salvo according to claim 5, characterized in that the braking surface arranged in the projectile is deployable and retractable in order to change the braking effect acting on the projectile.

7. Fire control system for fire control against a target comprising at least one sensor for measuring the target's position as a function of time, characterized in that a method for coordinating projectiles in a salvo according to any one of claims 1 to 6 is applied.

8. Control system including aA launcher characterized in that a fire control system according to claim 7 is applied.

9. Combat system according to claim 8, characterized in that the launching device is a barrel-based cannon system.