Method and system for guiding ordnance to a target

Abstract

The present invention relates to a method for guiding ordnance (10) to a target (12), the method being implemented by a guidance system (14) comprising a laser illumination device (20) and a guidance device (22), the guidance device (22) being mounted on the ordnance (10), the guidance device (22) comprising a detection unit (30) for detecting laser spots, a computer (32) and a guidance unit (34), the method comprising the following steps: - indirectly designating the target (12) with the laser illumination device (20), the indirect designation being carried out by generating one or more laser spots (T), by means of the laser illumination device (20), in an area in proximity to the target (12) but not on the target (12), - detecting, by means of the detection unit (30), the one or more laser spots (T), - determining, by means of the computer (32), a positional datum of the target (12) depending on the one or more detected laser spots (T), and - determining, by means of the guidance unit (34), a guidance setpoint depending on the positional datum so as to guide the ordnance (10) to the target (12).

Description

[0001] DESCRIPTION

[0002] TITLE: Method and system for guiding a device onto a target

[0003] The present invention relates to a method for guiding a vehicle to a target. The present invention also relates to an associated guidance system. The present invention also relates to an associated assembly.

[0004] The terminal phase of a projectile's flight, such as a projectile or a drone, is defined as the final phase of its trajectory toward a target, typically beginning at an altitude of 2000 m and continuing until impact. In the case of a projectile, during this terminal phase, in the absence of guidance, the projectile's trajectory is ballistic, resulting in a low probability of impact.

[0005] One known strategy involves guiding a missile using a STANAG-coded laser with a wavelength of 1.06 pm to illuminate the target, thereby guiding the munition to the target using a four-quadrant silicon detector. However, this strategy has since been met with numerous detection and countermeasures from armored vehicle targets, significantly limiting its effectiveness, particularly against technologically advanced adversaries.

[0006] A second strategy is known: equipping a munition with an imaging system that can capture an image of the scene containing the target and, potentially, autonomously search for the target within that scene (an algorithm known as ATDR). However, this type of autonomous system is known to be limited in the size of addressable targets (due to a lack of resolution). It is also rarely compatible with day / night operations and presents a non-zero risk of error, which greatly reduces its practical use (no solution involving cannons, howitzers, mortars, or tanks is currently known for use in land combat).

[0007] A third, "dual-mode" strategy is also known, which involves equipping a munition with a four-quadrant detector and an imager. This solution relies on cross-referencing information from the two sensors to ensure guidance but, like the first strategy, requires laser illumination of the target with a STANAG code of 1.06 pm.

[0008] Therefore, there is a need for a solution to guide a vehicle to a target that reduces the risk of countermeasures hindering the vehicle's ability to reach the target, while remaining reliable and compatible with all types of targets. To this end, the invention relates to a method for guiding a vehicle to a target. The method is implemented by a system comprising a laser illumination device and a guidance device. The guidance device is mounted on the vehicle. The guidance device comprises a laser spot detection unit, a computer, and a guidance unit. The method comprises the following steps: indirect designation of the target by the laser illumination device, the indirect designation being achieved by generating one or more laser spots by the laser illumination device in an area near the target but not on the target; and detection, by the detection unit, of the laser spot(s).The determination, by the computer, of a target position data based on the detected laser spot(s), and the determination, by the guidance unit, of a guidance command based on the position data in order to guide the vehicle onto the target.

[0009] According to other advantageous aspects of the invention, the method comprises one or more of the following features, taken individually or in all technically possible combinations:

[0010] - the position data is the position, relative to the detected laser spot(s), of an area, called the area of ​​interest, in which the target is located, the position data being determined, by the computer, according to the position of the detected laser spot(s), the step of determining a guidance instruction including the search, by the computer, on the basis of an autonomous target search algorithm, of the target in the area of ​​interest, the guidance instruction being determined, by the computer, once the target has been identified;

[0011] - the position data includes one or more of the following information: the relative position of the target with respect to the detected laser spot(s), an absolute position of the target, a relative direction of the target with respect to the detected laser spot(s), and an absolute direction of the target;

[0012] - the position data includes at least the relative position of the target with respect to the detected laser spot(s), the indirect designation step including the generation of at least two laser spots by the laser illumination device, the position data being determined as a function of the relative position of the laser spots with respect to each other;

[0013] - the position data is determined on the basis of a mathematical operation whose antecedents are the relative positions of the laser spots with respect to each other, the mathematical operation being for example a calculation of the barycenter; - the detected laser spot or spots encodes, in a non-geometric way, at least one piece of information relating to the position of the target, the position data being determined according to the information encoded in a non-geometric way in the detected laser spot or spots;

[0014] - the information encoded in the laser task(s) is in the form of a temporal code and / or a spectral code;

[0015] - the detected laser spot or spots encodes, by its shape, at least one piece of information relating to the position of the target, the position data being determined according to the information encoded by the shape of the detected laser spot or spots.

[0016] The invention also relates to a system for guiding a craft onto a target, the guidance system being configured to implement a method as described above, the guidance system comprising: a laser illumination device, and a guidance device, the guidance device being mounted on the craft, the guidance device comprising a laser task detection unit, a computer and a guidance unit.

[0017] The invention also relates to an assembly comprising a device and a system for guiding the device to a target, the guidance system being as described above.

[0018] Advantageously, the whole thing is a projectile or a drone.

[0019] The invention will become clearer upon reading the following description, given solely by way of non-limiting example, and made with reference to the drawings in which:

[0020] [Fig. 1] Figure 1 is a schematic view of an example of a craft, a target, and a system for guiding the craft to the target.

[0021] [Fig. 2] Figure 2 is a flowchart of an example of the steps in a guidance process,

[0022] [Fig. 3] Figure 3 is a schematic view of an example of indirect target designation by a laser illumination device,

[0023] [Fig. 4] Figure 4 is a schematic view of another example of indirect target designation by a laser illumination device,

[0024] [Fig. 5] Figure 5 is a schematic view of an example of trajectory correction for a missile-type vehicle based on indirect target designation by a laser illumination device, so that the vehicle is guided to the target, and [Fig. 6] Figure 6 is a schematic view of another example of trajectory correction for a drone-type vehicle based on indirect target designation by a laser illumination device, so that the vehicle is guided to the target. A vehicle 10, a target 12, and a guidance system 14 are illustrated in the example in Figure 1.

[0025] Device 10 is, for example, a projectile (missile) or a drone. In particular, in the examples in Figures 1 and 5, device 10 is a missile-type projectile. In the example in Figure 6, device 10 is a drone.

[0026] Target 12 is, for example, a vehicle (naval, land, or air), a platform, a building, or a tactical deployment. In the examples in Figures 1 and 3 to 6, target 12 is a vehicle (battle tank).

[0027] The guidance system 14 is designed to guide the device 10 onto the target 12.

[0028] As illustrated by Figure 1, the guidance system 14 comprises a laser illumination device 20 and a guidance device 22.

[0029] The laser illumination device 20 is designed to send one or more laser beams near the target 12, allowing its indirect designation as will be described later. The laser illumination device 20 is thus designed to form one or more laser spots near the target 12.

[0030] Optionally, the laser illumination device 20 is suitable for adapting / modifying the spatial shape of each laser spot formed.

[0031] The laser illumination device 20 is advantageously mounted on an entity 24. Entity 24 is, for example, a drone, as in the examples in Figures 3 to 5. In another example, entity 24 is a control tower, as in the example in Figure 6. Alternatively, entity 24 is an operator or any other entity suitable for carrying the laser illumination device 20.

[0032] The guidance device 22 is mounted on the machine 10.

[0033] The guidance device 22 includes a laser task detection unit 30, a computer 32, and a guidance unit 34.

[0034] The laser spot detection unit 30 is suitable for detecting laser spots T on or near target 12.

[0035] The laser task detection unit 30 is, for example, suitable for operating in a semi-active mode.

[0036] The laser spot detection unit 30 is, for example, an imager. For example, the laser spot detection unit 30 is a 4-quadrant (4Q) photodiode sensor, a matrix imaging sensor, or an event matrix sensor.

[0037] The computer 32, for example, interacts with a computer program product comprising program instructions. The computer 32 includes, for example, a processor comprising a data processing unit, memory, and a data storage device. Alternatively, the computer 32 is in the form of an integrated circuit, such as an ASIC (application-specific integrated circuit), or in the form of a printed circuit board, such as an FPGA (field-programmable gate array).

[0038] The guidance unit 34 is designed to generate a guidance instruction so as to guide the vehicle 10 to the target 12. For this purpose, the guidance unit 34 includes, for example, a processor designed to generate the guidance instruction.

[0039] Advantageously, the guidance unit 34 is designed to control the trajectory in order to effectively guide the vehicle 10 in its terminal phase according to the generated guidance command. To this end, the guidance unit 34 includes, for example, at least one actuator, such as control surfaces or fins.

[0040] A method for guiding the craft 10 to the target 12, implemented by the guidance system 14, will now be described.

[0041] The method includes a step 100 of indirect designation of the target 12 by the laser illumination device 20. Indirect designation is achieved by generating one or more laser spots T, by the laser illumination device 20, in an area near the target 12 (but not on the target 12). By indirect designation, it is understood that the generated laser spot(s) T are not superimposed on the target 12. The area near the target 12 therefore designates an area in the vicinity of the target 12 (typically at a maximum of 5 meters, or even 10 meters), but not on the target 12.

[0042] Figure 3 illustrates an example of indirect illumination in which one laser spot T is generated. In the case of Figure 4, two laser spots T are generated.

[0043] The process includes a step 110 of detection, by the detection unit 30, of the generated laser spot(s) T.

[0044] For example, detection involves creating an image of the generated T laser spots.

[0045] The process includes a step 120 in which the computer 32 determines a position data point based on the detected laser spot(s) T. The position data point relates to the relative position of the target 12 with respect to the detected laser spot(s) T.

[0046] In a first embodiment, the position data is the position, relative to the detected laser spot(s) T, of an area, called the area of ​​interest, in which the target 12 is located. The position data is determined, by the computer 32, as a function of the position of the detected laser spot(s) T.

[0047] In this first embodiment, the step of determining a guidance instruction includes the search, by the computer 32, based on an autonomous target search algorithm (ATDR algorithm), for the target 12 in the area of ​​interest. The algorithm has, for example, been stored in a memory of the computer 32. The guidance instruction is determined by the computer 32 once the target 12 has been identified.

[0048] Thus, in this first embodiment, the laser designator T serves as a landmark (known beacon point) for long-range guidance before handing over to an imaging system with an ATDR algorithm that recognizes target 12 and issues commands to engage it. Given that a known limitation of onboard munitions imaging systems is their lack of resolution at long range and / or in low light, this simplifies the imaging process by only requiring it in the last few hundred meters of the trajectory. The ability to designate the sub-area (but not target 12) allows the sub-area of ​​interest to be filtered within the imaged area, increasing the reliability of the algorithms and reducing the detection requirements for target 12.

[0049] In a second embodiment, the position data is the relative position of the target 12 with respect to the detected laser spots T.

[0050] In particular, in the second embodiment, the indirect designation step includes the generation of at least two laser spots T by the laser illumination device 20.

[0051] The position data is then determined based on the relative position of the laser spots T with respect to each other.

[0052] In this second embodiment, the position data is, for example, determined on the basis of a mathematical operation whose antecedents are the relative positions of the laser spots T with respect to each other. The mathematical operation is, for example, a barycenter calculation. The weights of the different elements can be different in the barycenter calculation.

[0053] Optionally, the position data is also determined based on the shape of each laser spot. For example, specific shapes indicate distinct directions, target types, locations, or weightings during the mathematical operation.

[0054] This second embodiment has the advantage of being compatible with devices equipped with a four-quadrant photodiode.

[0055] In a third and fourth embodiment, the position data includes at least one or more of the following information: a relative position of the target 12 with respect to the detected laser spot(s), an absolute position of the target 12, a relative direction of the target 12 with respect to the detected laser spot(s), and an absolute direction of the target 12. In particular, in the third embodiment, the detected laser spot(s) T encodes at least one piece of information relating to the position of the target 12. Such information is encoded in a non-geometric way, that is to say that the encoding does not consist of the position or shape of the laser spot, but of additional information.

[0056] The position data is then determined based on the information encoded in the detected laser spot T(s).

[0057] The encoded information is, for example, an updated geographic coordinate (e.g., by a satellite positioning system) or a relative position indication (e.g., 20 m to the right of the task).

[0058] For example, the information encoded in each laser spot T is in the form of a time-domain code and / or a spectral code. For example, in the case of a time-domain code, the encoding conforms to a STANAG standard. Alternatively, the encoding differs from a STANAG code and, for example, has a higher frequency than a STANAG code, or a variable frequency.

[0059] Optionally, the position data is also determined based on the shape of each laser spot. For example, specific shapes indicate directions, target types, or locations.

[0060] In the fourth embodiment, the detected laser spot or spots T encodes by its shape at least one piece of information relating to the position of the target 12. The position data is therefore determined according to the information encoded by the shape of the detected laser spot or spots T.

[0061] The shapes can be of any type (disk, star, rectangle, or any other shape) and have, for example, been previously associated with spatial information.

[0062] Optionally, the shape of each detected laser spot also provides information on the type of target, or on distinct weightings during the mathematical operation of the second embodiment (in the case where the second and fourth embodiments are combined). The method includes a step 130 in which the guidance unit 34 determines a guidance instruction based on the position data so as to guide the craft 10 onto the target 12. For example, a trajectory correction of the craft 10 is determined so that the craft 10 aims at the target 12.

[0063] The guidance unit 34 then allows the vehicle 10 to be effectively guided onto the target 12. Figure 5 illustrates an example of how the trajectory of a projectile-type vehicle 10 is modified according to a guidance instruction. Figure 6 illustrates a similar example where the vehicle 10 is a drone.

[0064] Thus, the present method consists of not directly illuminating the target 12, but using the illumination of a nearby area to accompany the guidance process of the craft 10 towards the target 12.

[0065] In particular, indirect illumination makes it possible to avoid putting target 12 on alert and triggering countermeasures.

[0066] The present method and the guidance system 14 thus make it possible to guide a munition towards a target 12 to improve the Pkill (ability of the munition to neutralize the target 12) without triggering countermeasures which reduce the munition's ability to reach its target 12.

[0067] The present method and the guidance system 14 also allow information to be transmitted to the device 10 up to a few seconds before impact.

[0068] The solution is also compatible with all types of targets.

[0069] Finally, the first embodiment makes it possible to reduce the computational load of an imaging system aimed at detecting / recognizing targets 12 in a scene by a sub-zone designation.

[0070] Those skilled in the art will understand that the described embodiments can be combined provided they are technically compatible. This is particularly true for the second, third, and fourth embodiments.

Claims

9 DEMANDS 1. A method for guiding a vehicle (10) onto a target (12), the method being implemented by a guidance system (14) comprising a laser illumination device (20) and a guidance device (22), the guidance device (22) being mounted on the vehicle (10), the guidance device (22) comprising a laser spot detection unit (30), a computer (32), and a guidance unit (34), the method comprising the following steps: indirect designation of the target (12) by the laser illumination device (20), the indirect designation being performed by generating one or more laser spots (T) by the laser illumination device (20) in an area near the target (12) but not on the target (12), detection, by the detection unit (30), of the laser spot(s) (T), determination, by the computer (32), of a position data for the target (12) as a function of the laser spot(s). (T) detected, and the determination,by the guidance unit (34), a guidance instruction based on the position data so as to guide the device (10) onto the target (12).

2. A method according to claim 1, wherein the position data is the position, relative to the detected laser spot(s) (T), of an area, called the area of ​​interest, in which the target (12) is located, the position data being determined by the computer (32) as a function of the position of the detected laser spot(s) (T), the step of determining a guidance instruction comprising the search, by the computer (32), on the basis of an autonomous target search algorithm (12), for the target (12) in the area of ​​interest, the guidance instruction being determined by the computer (32) once the target (12) has been identified.

3. Method according to claim 1, wherein the position data comprises one or more of the following information: the relative position of the target (12) with respect to the detected laser spot(s) (T), an absolute position of the target (12), a relative direction of the target (12) with respect to the detected laser spot(s), and an absolute direction of the target (12).

4. A method according to claim 1 or 3, wherein the position data comprises at least the relative position of the target (12) with respect to the detected laser spot(s) (T), the indirect designation step comprising the generation of at least two laser spots (T) by the laser illumination device (20), the position data being determined as a function of the relative position of the laser spots (T) with respect to each other.

5. Method according to claim 4, wherein the position data is determined on the basis of a mathematical operation whose antecedents are the relative positions of the laser spots (T) with respect to each other, the mathematical operation being for example a barycenter calculation.

6. A method according to any one of claims 3 to 5, wherein the detected laser spot(T) encodes, in a non-geometric manner, at least one piece of information relating to the position of the target (12), the position data being determined as a function of the information encoded in a non-geometric manner in the detected laser spot(T).

7. Method according to claim 6, wherein the information encoded in the laser spot(T) is in the form of a time code and / or a spectral code.

8. A method according to any one of claims 3 to 7, wherein the detected laser spot or spots (T) encodes, by its shape, at least one piece of information relating to the position of the target (12), the position data being determined as a function of the information encoded by the shape of the detected laser spot or spots (T).

9. Guidance system (14) of a craft (10) on a target (12), the guidance system (14) being configured to implement a method according to any one of claims 1 to 8, the guidance system (14) comprising: a laser illumination device (20), and a guidance device (22), the guidance device (22) being mounted on the craft (10), the guidance device (22) comprising a laser spot detection unit (30), a computer (32) and a guidance unit (34).

10. Assembly comprising a device (10) and a guidance system (14) for the device (10) on a target (12), the guidance system (14) being according to claim 9.

11. Assembly according to claim 10, wherein the device (10) is a projectile or a drone.

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