EP2053343A2

EP2053343A2 - A user deployable grenade system, grenade and command unit for use in such a system

Info

Publication number: EP2053343A2
Application number: EP08167165A
Authority: EP
Inventors: Nicholas Charles Lee
Original assignee: Roke Manor Research Ltd
Current assignee: Roke Manor Research Ltd
Priority date: 2007-10-24
Filing date: 2008-10-21
Publication date: 2009-04-29
Also published as: GB2454040B; GB0810080D0; GB0720975D0; GB2454040A

Abstract

A grenade for use in a user deployable grenade (1) system includes a camera (11) for providing a field of view about the grenade which is transmitted to a command unit (15). The command unit (15) is carried by a user (14) and it includes a display. The user views on the display (17) the images transmitted from the grenade. If hostile forces are present, the user may enter a command to the command unit which is transmitted to the grenade resulting in its detonation.

Description

This invention relates to a user deployable grenade.
A conventional "hand-grenade" is a hand-deployed explosive device which is fused by a user by removal of a pin.
The device is then thrown into a target area and explodes. Their indiscriminate nature can lead to unwanted injury or death. For example, the grenade may fall short causing casualties amongst friendly forces or civilians when it explodes.
According to the invention there is provided a grenade as recited in claim 1.
By providing a visual output to be displayed to a user, the user can check the target area before detonating the grenade. Thus, if civilians or friendly troops are in the target area the user will refrain from sending the command signal.
By use of an ovoid shape and the optical arrangement a low centre of gravity is achieved giving excellent self righting properties without the need for additional assistance.
In addition to this primary advantage, the grenade may provide a surveillance device.
The grenade may be split into two parts a sensor module including the camera and a payload module containing for example the explosive and an initiator. This confers the advantage that a modular approach may be adapted. This will allow the explosive part to have different forms perhaps providing offensive and defensive explosive variations with different shrapnel effects. Other modules may provide a stun grenade, smoke, gas or incendiary effects. Different sensor modules may provide different fields of view or day or night capabilities although it is preferred that a module has both capabilities. This will be particularly advantageous where the grenade is to be used in urban warfare since it may be used in the open in daylight or within darkened buildings. A night capability will also be of use in caves and tunnels.
A further advantage will also be now apparent. If the grenade is deployed and there are no hostile forces in the target area, a decision will be taken not to explode the grenade. The grenade may then be retrieved for further use.
Additional command signals may be provided for example to render the grenade safe.
The communication link is preferably an encrypted link for security. It may be wire, optical fibre or a wireless link. The wireless link may be infra red, acoustic or radio.
The display may be wrist or helmet mounted or handheld. The display may be arranged to minimise light leakage.
The grenade may be deployed by the user throwing it or it may be deployed by use of an extendible rod attached to the grenade by a threaded hole formed in the grenade.
The explosive part may include wire or other shrapnel material. The shrapnel may be explosively formed by shaped charge or the "Munroe" effect by, for example, providing a dimpled casing to the explosive part.
The control unit may relay camera information to another unit and also relay commands from that unit to the grenade.
A specific embodiment of the invention will now be described, by way of example only, with reference to the drawings of which:

Figures 1 to 3 show a grenade system, grenade and command unit in accordance with an embodiment of the invention.

As is shown in figure 1, a grenade 1 is generally an ovoid shape and comprises an explosive module 2 being the prolate of the ovoid and a camera module 3 being the oblate of the ovoid. The two parts are assembled together by mutually engaging threaded portions not shown at junction 4. The weight distribution of the various components is arranged to provide a Centre of Gravity CG as shown in the oblate.
The explosive module 2 is formed from a steel casing 5 cast to have fragmentation bumps on the inner surface to assist in the production of shrapnel. This module is an offensive fragmentation grenade module.
The casing 5 is filled with a RDX/TNT explosive 6 and an electrical detonator 7.
The electrical detonator 7 is linked to the camera module 3 by wire 7a. This wire 7a is attached to a spring-loaded contact to permit relative rotational movement during assembly of the modules.
The camera module 3 comprises a clear polycarbonate shell 8 By virtue of the shape and the weight distribution to give the indicated centre of gravity the grenade self rights itself when thrown to land on surface 9. Polycarbonate is preferred since it is strong and light.
Within the polycarbonate shell 8 is located a printed circuit board 10 and the control electronics to be described later.
A CMOS colour camera 11 is provided mounted on the printed circuit board with its active sensor surface directed upwards to receive light from a lens (not shown) at the upper end of camera unit and a pair of mirrors forming a catadioptric optical arrangement. Mirror 12 is a primary light gathering mirror which has a 360 degree field of view. The gathered light is reflected to a secondary mirror 13 which reflects it down through a hole in the primary mirror to the camera 11. The mirrors are formed by vapour deposition onto curved plastics material substrates. The electronic components mounted on the printed circuit board 10 include a battery, camera, transmitter receiver sections, a coil antenna and a firing circuit to provide the required power to the detonator 7 when initiated.
It will be seen that the choice of mirror arrangement provides a folded optical path which results in a short moment arm for the mass that is formed by the mirrors and the polycarbonate shell 8. This ensures that there is a low centre of gravity within the oblate and in conjunction with the ovoid shape ensure rapid self-righting of the grenade when it lands after being thrown and is thus advantageous. This avoids the need for any righting mechanism such as spring loaded arms or the like. It will be appreciated that the speed and reliability of the self-righting is highly advantageous in conflict.
The grenade 1 has a size permitting its deployment by hand. The user 14 (not to scale) wears a command unit 15 on the user's forearm. A secure radio link 19 exists between the grenade 1 and the command unit 15.
The command unit 15 is shown in greater detail in figure 2 and it includes an on-off switch 16 for switching on a battery power supply (not shown) to power up the command unit. It also includes a touch sensitive screen 17 with two main display areas. In the first area 18 a set of menu options are presented and in the second area 19 three camera outputs are provided from three separate grenades. These images are unwrapped 360 degree views from the cameras in each grenade. To initiate the payload of a grenade firstly one of the images is selected. This results in the image being highlighted by changing its visual significance. In this case the size is increased to take up substantially all of the display area. Tapping the image again results in the payload being initiated. (It will be appreciated that other sequences may be used to initiate the payload.)
Figure 3 shows a block diagram of the command unit circuitry. A receiver and transmitter section 30 receives transmissions and passes them to a decoder 31 which applies a decryption algorithm. The decoded and decrypted data is passed to a control processor 33. This determines whether or not the transmission is a command signal from another control unit or camera output. Camera output is passed to image processing 32. The image processing 32 performs an unwrapping process which converts the wrapped 360 degree image provided by the camera into a rectilinear unwrapped image. This is passed to the display driver 36 and a video store 34. The video store 34 may be accessed via a port and connector arrangement 35 to allow downloading of the video information for review at a later time.
The display driver 36 puts the image into a form suitable for being displayed on display 37.
The display 37 is a touch sensitive screen which allows inputs as earlier described to be made. It couples the inputs to a command processor 38 which interprets the commands and provides command signals to the encoder 39. The encoder 39 encrypts the command and passes it to the transmitter receiver section 30 for transmission.
It will be seen that in figure 1 another control unit operated by a further person may be used to send commands to the first unit. In essence it is possible for the first unit to act as a relay in both directions. This means that a grenade may be initiated from another command point. It will also be appreciated that with a suitable negotiation protocol it will be possible for a command to initiate the payload to be authorised by another user or for a collective decision to be made.
In use, the user 14 deploys the grenade 1 into a target area by throwing the grenade 1. The camera 11 provides an output representative of the imaged target area which is transmitted over the secure communications link. The image is displayed on display 17 and the user 15 may then decide whether or not to enter the activation sequence. If the sequence is entered a command signal is transmitted over the communications link. This is received by the grenade 1 and the detonator 7 initiated to explode the explosive 6.
It will be appreciated that the grenade also provides a surveillance device in the target area. The camera part may also be provided with a microphone to enable sound to be detected and transmitted to the receiver.
A threaded hole is provided in the casing of the explosive part to permit threaded engagement of a rod. The rod is then used to deploy the grenade in a more controlled manner than by throwing. This part of the casing may be machined to provide a planar facet to assist further in the self righting of the grenade.
Whilst a two part arrangement is shown it will be possible to provide a one part arrangement.
The imaging information provided by the camera is processed to convert the 360° image into a form such as a panorama which is readily discernable. This conversion may take place at the grenade instead of at the command unit as described.
The grenade may be provided with a number of different payloads.
In the described embodiment the payload is initiated immediately but it may also be delayed by the use of a timer.

Claims

A user-deployable system comprising: a grenade having a camera with a sensor and lens for viewing at least a part of a target area when the grenade is deployed and to produce a camera output representative thereof, a transmitter for transmitting the camera output to a command unit separate to the grenade which command unit comprising means to present the camera output, a receiver at the grenade for receiving a user input command signal from the command unit and responsive thereto to activate a payload of the grenade wherein a catadioptric optical arrangement formed by the lens and mirrors is provided to provide a field of view to the camera about the grenade which grenade having a shape and a centre of gravity which assists the righting of the grenade into an upright position when deployed.
A user deployable grenade for use in the system of claim 1 wherein the field of view is substantially 360 degrees.
A user deployable grenade as claimed in claim 2 wherein the grenade is an ovoid having one axis of symmetry.
A user deployable grenade as claimed in claim 3 wherein the centre of gravity of the grenade lies within an oblate of the ovoid.
A user deployable grenade as claimed in claim 4 in which oblate is provided with a substantially planar facet.
A user deployable grenade as claimed in claim 4 or 5 wherein the optical arrangement comprises at least a primary convex mirror and a secondary convex mirror located in a prolate of the ovoid.
A user deployable grenade as claimed in claim 6 wherein the primary mirror gathers light from the field of view and directs it to the secondary mirror and wherein the secondary mirror directs the light through the primary mirror to the camera.
A user deployable grenade as claimed in claim 6 or 7 wherein at least the prolate is formed of a transparent material.
A user deployable grenade as claimed in claim 8 wherein the transparent material is a plastics material.
A user deployable grenade as claimed in any preceding claim wherein the oblate of the grenade is user separable from the prolate.
A user deployable grenade as claimed in claim 10 wherein the prolate includes the payload nodule of the grenade.
A user deployable grenade as claimed in any preceding claim wherein the payload module comprises at least one of the following group of payloads: an offensive fragmentation grenade; a defensive fragmentation grenade; a stun grenade; a smoke grenade; a tear gas grenade and an inert grenade.
A user-deployable grenade as claimed in any preceding claim wherein the prolate comprises a camera module user separable from the oblate.
A user-deployable grenade as claimed in any preceding claim comprising a microphone to detect sound when the grenade is deployed to provide a signal representing the sound to the camera output.
A user-deployable grenade as claimed in any preceding claim wherein the camera has a day and night capability.
A grenade as claimed in any preceding claim wherein the payload is activated after a delay from receipt of the signal.
A user-deployable grenade substantially as hereinbefore described with reference to, and as illustrated by, the drawings.
A command unit for use in a system as claimed in claim 1 comprising:
a receiver to receive transmitted camera output;

means to present to the user the received camera output;

a command input for user input of a command signal;

a transmitter for transmitting the command signal to the grenade to detonate the grenade.
A command unit as claimed in claim 18 wherein the means to present comprises at least one of a visual display and a speaker.
A command unit as claimed in any preceding claim including an image processor for processing the received camera output to display a rectilinear image.
A command unit as claimed in claim 20 wherein the image processor processes the received camera output to display an unwrapped substantially rectilinear image.
A command unit as claimed in any preceding claim wherein the camera outputs of a plurality of grenades may be presented to the user.
A command unit as claimed in claim 22 wherein respective command signals may be transmitted to respective grenades individually or collectively.
A command unit as claimed in any preceding claim comprising a touch sensitive display for presenting the camera output to a user and to enable the input of command signals.
A command unit as claimed in claim 24 wherein the command signal is transmitted following a command input sequence comprising : selecting a grenade by touching a displayed output for that grenade amongst a displayed set of outputs; emphasising the selected grenade output and in response to a user selection of the emphasised selected grenade output transmitting the command signal.
A command unit as claimed in any preceding claim wherein the unit includes a transmitter for relaying the camera output to a second command unit.
A command unit as claimed in claim 26 wherein the second command unit includes a command signal transmitter which transmits the command signal to initiate the grenade either directly to the grenade or by relay from the first command unit.
A command unit as claimed in any preceding claim comprising a recorder for recording the camera output.