AUTONOMOUS OPTRONIC MODULE FOR GEOLOCATED TARGET POINTING FOR A PORTABLE SYSTEM, AND CORRESPONDING SYSTEM

Abstract

Disclosed is an autonomous visual pointing module producing location information about a target aimed at by a user and intended to be installed on portable equipment to form a portable and autonomous visual target pointing system, the target location information being at least the target heading. The module includes: —an autonomous power supply, —control, calculation and user-interfacing electronic circuits, —a motion sensor including an inertial navigation system, INS, or an attitude heading reference system, AHRS, including gyrometers and accelerometers, —a satellite geolocation receiver, GNSS, for providing the module location in real type and continuously, —an optronic unit including a set of optical sensors of the viewfinder and/or camera type, for visually pointing the module to the aimed-at target, and a rangefinder for determining the distance between the target and the module. The gyrometers are of the fibre-optic type.

Claims

1. An autonomous visual pointing module (1) producing location information about a target aimed at by a user and intended to be installed on portable equipment (11) to form a portable and autonomous visual target pointing system, the target location information being at least the target heading, the module including: an autonomous power supply (3), control, calculation and user-interfacing electronic circuits (4), a motion sensor including an inertial navigation system, INS, (6) providing the module location and heading, or an attitude heading reference system, AHRS, providing only the heading, a satellite geolocation receiver, GNSS, (5) for providing the module location in real time and continuously, and for hybridizing the inertial sensors, an optronic unit including a set of optical sensors of the viewfinder (14) and/or camera (7) type, for visually pointing the module to the aimed-at target, and a rangefinder (9) for determining the distance between the target and the module, wherein the motion sensor includes gyrometers and accelerometers, and wherein the gyrometers are of the fibre-optic, FOG, or ring-laser, RLG, or hemispherical-resonator, HRG, type, making it possible to autonomously determine the North direction.

2. The module (1) according to claim 1, further comprising a pedometer and wherein the inertial navigation system, INS, or the attitude heading reference system, AHRS, is further hybridized with the pedometer.

3. The module (1) according to claim 2, further comprising an attachment device (8) for attaching the module to the portable equipment (11) and wherein the attachment device is configured to be attached to an attachment rail of the equipment.

4. The module (1) according to claim 3, further comprising a user direct-sight optical viewfinder and at least one target viewing camera producing images, said at least one camera allowing a viewing of the target at least in daylight.

5. The module (1) according to claim 4, wherein said at least one camera (7) further allows a viewing of the target by night.

6. The module (1) according to claim 5, wherein the module includes: either two cameras, a first one for viewing the target in daylight and a second one for viewing the target by night, the second camera being chosen among the light-intensifying camera or the only infrared-sensitive cameras, or a single camera for viewing the target in daylight combined with a target illuminator for lighting the target by night in order to allow its viewing, or a single, only infrared-sensitive camera for viewing the target both in daylight and by night.

7. The module (1) according to claim 1, further comprising at least one camera (7) producing images of the aimed-at target and at least one viewer (2) for displaying said images, said at least one viewer being integrated to the module and/or arranged remote from the module.

8. The module (1) according to claim 4, further comprising a wireless data communication device (13) for transmitting the target location information and the images of the aimed-at target in the case where the module includes at least one camera (7).

9. The module (1) according to claim 1, wherein the module has a level of uncertainty that is lower than or equal to 2 mrad rms for the heading and a level of accuracy for the location corresponding to that of the satellite geolocation receiver, GNSS, (5).

10. The module (1) according to claim 1, wherein the module has a weight lower than five kilograms.

11. A system consisted of an autonomous visual pointing module (1) attached to portable equipment (11), wherein the module is configured according to claim 1 and the portable equipment (11) is a portable weapon, said weapon being intended to at least remotely neutralize a targeted objective.

12. The module (1) according to claim 6, further comprising at least one camera (7) producing images of the aimed-at target and at least one viewer (2) for displaying said images, said at least one viewer being integrated to the module and/or arranged remote from the module.

13. The module (1) according to claim 12, further comprising a wireless data communication device (13) for transmitting the target location information and the images of the aimed-at target in the case where the module includes at least one camera (7).

14. The module (1) according to claim 13, wherein the module has a level of uncertainty that is lower than or equal to 2 mrad rms for the heading and a level of accuracy for the location corresponding to that of the satellite geolocation receiver, GNSS, (5).

15. The module (1) according to claim 14, wherein the module has a weight lower than five kilograms.

16. The module (1) according to claim 1, further comprising has fibre-optic gyrometers with coils diameters of 50 mm or less.

17. The module (1) according to claim 15, further comprising has fibre-optic gyrometers with coils diameters of 50 mm or less.

18. The module (1) according to claim 1, further comprising an attachment device (8) for attaching the module to the portable equipment (11) and wherein the attachment device is configured to be attached to an attachment rail of the equipment.

19. The module (1) according to claim 1, further comprising a user direct-sight optical viewfinder and at least one target viewing camera producing images, said at least one camera allowing a viewing of the target at least in daylight.

20. The module (1) according to claim 2, further comprising a user direct-sight optical viewfinder and at least one target viewing camera producing images, said at least one camera allowing a viewing of the target at least in daylight.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0132] FIG. 1 is a schematic illustration of a first example of module according to the invention, including a means for the removable attachment to an assault rifle,

[0133] FIG. 2 is a schematic illustration of a second example of module according to the invention, including a means for the removable attachment to an assault rifle,

[0134] FIG. 3 shows the application of a module according to the invention in a dedicated system in the form of a rifle,

[0135] FIG. 4 is a generic schematic illustration of the interconnections between the different main elements of the module, and

[0136] FIG. 5 shows a module according to the invention in the form of a viewfinder that can be attached to a rifle.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0137] The following description in relation with the appended drawings, given by way of non-limitative examples, will allow a good understanding of what the invention consists of and of how it can be implemented.

[0138] In the first example of FIG. 1, the pointing module 1 is provided with a quick attachment device 8 for a quick and accurate mounting on portable equipment that is here an assault rifle 11, the mounting being symbolized by the arrow 10 between the module 1 and an assault rifle 11. This attachment device 8 is compatible with a rail of the Picatinny rail type. The attachment device 8 hence allows a quick and accurate attachment of the module on a weapon or on any other equipment pre-fitted with a Picatinny rail or that will have been fitted with such a rail for the attachment of the module. The attachment device 8 can further include mechanical adjustment means so that the module sight allows using the module as the own sighting means of the weapon or equivalent.

[0139] The rechargeable battery 3 powers the module 1 in such a way as to make it energetically self-sufficient. The camera 7, here of the infrared type, makes it possible to view the target and its environment both in daylight and by night. A crosshair allows defining a reference line of sight of the target in the field of observation of the camera 7. The infrared camera 7 can be cooled or non-cooled. The infrared camera 7 can allow an observation in the SWIR, MWIR and/or LWIR bands.

[0140] The module 1 includes an inertial navigation system, INS, 6 hybridized with a satellite geolocation receiver, GNSS, 5, which allow, in electronic circuits forming a calculator 4, to permanently calculate the location of the module 1 and the target direction or heading. The satellite geolocation receiver 5 may be of the GPS type.

[0141] The inertial navigation system, INS, includes internal calculation means, in particular with a Kalman filter, and means for data exchange with other sensors and, in particular, for receiving location data produced by the satellite geolocation receiver, GNSS, 5. Due to the combination of the data from the inertial navigation system, INS, 6 and from the satellite geolocation receiver, GNSS, 5, as well as other data from other sensors (for example, a pedometer, accelerometers . . . ) and to the use of a Kalman filter, the calculated location information remain optimum for almost all the operation conditions met, for example, in case of GSNN signal loss, it is possible to continue obtaining location information even if they are less accurate than if all the sensors were still working.

[0142] The inertial system that is implemented, preferably of the FOG type, has a size lower than 100 mm×100 mm×100 mm and the optical fibre loops have diameters of 50 mm or less. This inertial system is hybridized with a satellite geolocation receiver or “Global Navigation Satellite System” (GNSS). The inertial system has a level of uncertainty lower than or equal to 2 mrad rms for the heading and, for the location, a level of accuracy corresponding to that of the satellite geolocation receiver.

[0143] If the signal of the satellite geolocation receiver 5 is received nominally, the location of the module 1 is known with an accuracy of less than 5 m. With an inertial navigation system, INS, 6 of the FOG type, based on an optical fibre coil of 50 mm diameter, the heading is known with an accuracy better than 2 mils. In case of loss of the satellite geolocation receiver 5 signal and in a “purely inertial” mode, the operator heading and location values provided by the module 1 will be all the more degraded since the signal loss duration is long and since the module 1 has been moved during this time.

[0144] The module 1 also includes a laser rangefinder 9 that, when it is activated towards the target, allows determining the module-target distance. There hence exists in this exemplary embodiment a means for activating the rangefinder 9.

[0145] A calculator 4 operates to calculate information about the target absolute or relative location, which can be provided to the operator, including the target location coordinates, from module location, target heading and target distance data.

[0146] The module implements at least one Kalman filter to process the data coming from the various sensors (gyrometers, accelerometers, satellite geolocation receiver, pedometer . . . ) available in the considered version of the module (of the INS or AHRS type, with or without a satellite geolocation receiver, with or without a pedometer . . . ). The Kalman filter may be implemented in the inertial navigation system, INS, or in the attitude heading reference system, AHRS, and/or, in the calculation means of the control, calculation and interfacing electronic circuits, these latter being connected to the various sensors of the module to recover therefrom the produced data and to process these data.

[0147] Hence, for example, the implementation of a Kalman filter in the inertial navigation system, INS, allows mutualizing the advantages of the INS system and of the GNSS receiver: the possible slow drift of the INS system can be corrected by the GNSS receiver data and, in case of loss of the GNSS receiver data, the location information can continue to be calculated thanks to the only INS system. By way of illustration, if the GNSS receiver data are of good quality, it will be mainly the GNSS receiver data that will be used to determine the location information. If the GNSS receiver data become unavailable, the INS system operates to continue providing location information whose quality will deteriorate over the duration of the GNSS data flow loss. In this example, the location information may be absolute and continue to be absolute despite the GNSS data flow loss.

[0148] On the other hand, in the case where the motion sensor is an attitude heading reference system, AHRS, the correct reception of the GNSS data is indispensable to obtain absolute location information because these latter are produced only by the GNSS receiver, the AHRS system being unable to substitute for it. However, in case of GNSS data flow loss, the module can be used to provide the heading thanks to the AHRS system and the distance to the target if the rangefinder is installed in the module. In this latter case, the target location information is relative and is hence provided with reference/respect to the module. Thus, in the case where the motion sensor is an attitude heading reference system, AHRS, the target location information can switch between absolute locations (GNSS data available) or relative locations (GNSS data not available).

[0149] It is to be noted that, if the inertial navigation system is not hybridized with any speed sensor, it will undergo a drift during the displacements of the module. In such a case, it is preferable to regularly recalibrate the module. It is also possible to perform regular Zero-Velocity Updates (ZUPT).

[0150] The target location information can hence be absolute or relative and can hence correspond to one or several of: the target location coordinates, the target-module distance, the module location coordinates, the target heading. This or these piece(s) of information are provided to the operator on a viewer or display screen 2 that moreover allows viewing the scene with the target, the line of sight being shown as a crosshair, one or the useful pieces of information, including the location, the heading, the distance as well as the coordinates of the target for a module including a satellite geolocation receiver, GNSS, or GPS, and a rangefinder.

[0151] This information is provided to the operator directly on the module or remotely by wired or wireless connection, for example on a “connected” viewfinder, which allows the operator to view at the same time the scene, the target, the line of sight (crosshair), and the location, heading, distance and coordinates of the target.

[0152] In an alternative embodiment, the rangefinder 9 that is of the laser type further allows providing the relative speed of the target.

[0153] In an alternative embodiment shown in FIG. 2, a direct optical viewfinder 14 allows the operator 12 to view the target and its environment in daylight. A crosshair allows defining a reference line of sight of the target in the field of observation of the viewfinder 14. The inertial navigation system 6 hybridized with a geolocation receiver 5, for example of the GPS type, allows the calculator 4 to permanently calculate the module location and the target heading. In this case where there is no camera, the remotely provided information includes no image of the target, the target being only visible live on the module by means of the direct optical viewfinder 14. It can be planed to provide the information calculated by the calculator in the direct optical viewfinder using a direct display system, for example a liquid-crystal display, or by injection using a light information injection prism or plate through which the target can be seen. As hereinabove, the module 1 of FIG. 2 includes an attachment device compatible with a Picatinny rail for a quick and accurate mounting of the module on portable equipment that is here an assault rifle 11.

[0154] In still another alternative embodiment shown in FIG. 3, the module has been incorporated into equipment imitating a weapon and that serves only to point a target and to obtain target location information. It can even be considered that the module itself a weapon imitation. In this latter case, the module does not necessarily need a device for attachment to equipment. The pointing module can hence take the form of an assault rifle as in FIG. 3, or a handgun, or a viewfinder, integrating in particular the inertial and viewing modules.

[0155] The assault rifle module 15 of FIG. 3 includes a rear part 16 adapted to be raised on a shoulder and a front part 17. The elements constituting the assault rifle module 15 of FIG. 3 are distributed therein in such a way as to balance it. Thus, the battery 3 that supplies the module so as to make it energetically self-sufficient is arranged towards the front 17 at the lower part. The infrared camera 7 that allows viewing the target and its environment both in daylight and by night is arranged towards the front 17 at the upper part. If a laser rangefinder 9 is installed as in this example, it is also towards the front 17 and at the upper part of the module 15.

[0156] A crosshair makes it possible to define a reference line of sight of the target in the field of observation of the infrared camera 7. The infrared camera 7 can be cooled or not-cooled. The infrared camera 7 can allow an observation in the SWIR, MWIR and/or LWIR bands. The navigation system hybridized with a GPS receiver allows permanently calculating the operator location and the target heading.

[0157] The assault rifle module 15 also includes a satellite geolocation receiver 5, herein GNSS, arranged in an intermediate position along the module and upwards. The inertial navigation system 6 is also arranged in an intermediate position along the module. A radiocommunication module 13, for example Wi-Fi®, is also installed in the module, as well as the calculator 4 that allows controlling all the elements of the module, calculating the information based on the data produced by the different sensors and interfacing with the user. For the interfacing, it is in particular provided a viewer or a display screen 2 for displaying the information calculated and/or simply acquired by the sensors, as well as a trigger 18, intended for example to trigger information acquisitions and calculations when the operator has the target in sight and wants to obtain the desired information about it. As an alternative, the trigger 18 can for example serve to start the module for the target acquisition and to stop it, or to simply start it if an automatic shutdown is provided. The acquisitions and calculations on demand make it possible to reduce the power consumption of the module.

[0158] It is to be noted that, as long as the module has to be usable for target pointing, it is necessary that certain elements of the module continue to operate, and notably the inertial navigation system, in particular if doubt exists about the availability of the satellite geolocation receiver.

[0159] The main elements of the module are schematically illustrated in FIG. 4, in which it can be seen that the battery 3 powers the satellite geolocation receiver 5, the inertial navigation system, INS, 6, the laser rangefinder 9, the camera 7, the calculator 4 and the display screen by means of the camera 7 that sends it current in addition to the image data. The inertial navigation system, INS, 6, the laser rangefinder 9 and the camera 7 are grouped within an opto-mechanical harmonization area schematically illustrated by a boxed area in this FIG. 4. The data of the satellite geolocation receiver 5 are combined to those of the inertial navigation system 6, then sent to the calculator 4. The calculator also receives data from the laser rangefinder 9. It is understood that the module can be configured differently as regards data exchanges: the calculator can receive directly and separately the data from the satellite geolocation receiver 5, the inertial navigation system 6 and the laser rangefinder 9 and ensure the hybridization.

[0160] In FIG. 5, the module 1 is this time in the form of a viewfinder that can be attached to a rifle or another portable piece of equipment. At the upper part of the module 1 is arranged the satellite geolocation receiver 5, GNSS. At the front of the module 1, the optical elements are visible with the infrared camera 7 and the laser rangefinder 9 because their respective removable protective covers 19 have been open. To trigger the measurements and the provision of information about the aimed-at target location, a control button 18 is accessible on the module 1.

[0161] Thus, it has been seen that it is possible to make the module in various ways and that the elements that compose it can be chosen as a function of the needs. Preferably, modules with INS are made in order to benefit from the advantages of the inertial system but, in other versions, it is possible to only use an attitude heading reference system, AHRS, instead of the INS.