GB2489611A - Missile - Google Patents

Abstract

A missile 1 is has a fuselage 2 and at least two wings 3 as well as a control device steering the flight path and a drive device. The drive device has at least one jet engine 12, through which air flows, and is formed to produce variable drive thrust. The missile 1 is modular, with forward, drive and rear modules 31, 32, 33.

Description

SMALL MISSILE

BACKGROUND

The present invention relates to a small missile with a fuselage and at least two wings, as well as a control device steering the flight path and a drive device.

Small missiles with a total mass of, for example, up to kg, can be used for instance to carry a weapon under high safety requirements at high velocity and with high accuracy to a defined target. Such small missile, usually have a rocket engine operated by solid matter. For the missile to be controllable even in a slight air flow, i.e. at low speed, it is possible to provide thrusters in the flow channel of the solid-propellant engine. The high thermal loading due to the solid-propellant engine, however, causes the thrusters to become blunt within a very short time, namely a few seconds, which increases the flow resistance and reduces the manoeuvrability of the missile considerably.

DE 10 2007 012 799 B3, shows a small missile with propeller modules that are used for the driving and the control of the small missile. The relatively low thrust level and the accompanying low flight velocity of the known small missile are disadvantageous. This in turn brings about an increased susceptibility to disruptive forces from the environment, for example the wind force, which negatively influences manoeuvring accuracy.

THE INVENTION

It is desirable to create a small missile that avoids the disadvantages of a solid-propellant engine and can be guided to the target at high velocity, but still enables the user to reduce the velocity in order to intervene in the flight mission while the small missile is still in flight.

This invention is oonoerned with a jet-powered small missile as indicated in claim 1.

Missiles in accordance with the invention have a fuselage and at least two wings as well as a control device steering the flight path and a drive device, wherein the drive device has at least one jet engine, through which air flows, and capable of production of a variable drive thrust.

The missile is advantageously of modular design. Located in the front end module are, preferably, the seeker head, the gimbal system, the IMU, the UPS, the data link, the video transmission transmitter the flight guidance system and the weapon.

Arranged in the drive module are the energy supply and at least one drive device, i.e. the jet engine.

Located in the control module are servos, additional drive and control systems, the aerodynamic control surfaces and, if present, the jet deflection mechanisms.

The small missile has at least one jet engine through which air flows and which produces a thrust that can be varied during the flight phase. The user thereby has the opportunity to intervene in the mission still during the flight phase to re-identify the target, to mark it or to abort the mission in a safe mode. It is a significant advantage here that the drive thrust of missiles using the invention can be varied, so that due to which the velocity of the small missile can be reduced in the short term, for example to enable the user to transmit a new target to the small missile in the context of a new instruction process.

If the gunner does not succeed in determining a new target, he can abort the mission in a safe mode.

Compared with a propeller module, the jet engine has the advantage that the rotor of the jet engine is protected by the sheathing of the jet engine. The operating safety is thus increased, for example during launch of the missile.

Because of the sheathing of the at least one rotor, the thrust losses caused as a result of turbulence at the blade tips of the known propeller are avoided, so a much higher thrust level is achieved with the same diameter of rotor as in the known propeller.

Conversely, it is possible to provide a smaller cross-section of the rotor, with a smaller drag, which in turn increases the flight velocity of the missile. The jet engine can be a so-called COTS product, i.e. a jet engine that is readily available on the market, whereby development work for the engine is advantageously eliminated. Such an engine usually has a low net mass on account of the development work aiready done with the objective of reduced net mass. Variable ranges of the missile are possible by simple changes in the amount of stored drive energy carried with the missile, for example in the form of fuel or electrical energy, without causing large changes in the structure and algorithmics of the small missile.

The jet engine is preferably electric and/or fuel-operated.

The missile can have more than one such jet engine, possibly, for example in a more complex stage of development, combining four drives in the control module and one drive in the fuselage. In this case the drives in the control module can be electric and the drive in the fuselage can be fuel-operated.

To store the necessary energy, a commercially available accumulator battery or a fuel cell, for example, can be provided for the electrically operated jet engine. A so-called hybrid can likewise also be used for the electric variant. A fuel-operated generator, or a fuel-operated jet engine with generator, feeds its electrical energy according to the reguirements into an accumulator battery, while the fuel-operated variant has a tank for fuel.

The control device has preferably at least three external control surfaces actuatable by means of at least one actuator and/or a device for the deflection of drive thrust. It is possible to provide the missile with both control surfaces and a device for the deflection of drive thrust.

The control surfaces can be rotatable or pivotable lift surfaces in the form of so-called fins, mounted externally on the fuselage of the missile and serving to control the torques for adjustment of the position and of the transverse acceleration. The fins can be arranged here either as canard controllers ahead of the wings or as tail controllers also behind the wings. An embodiment with four fins, for example, has the advantage of redundancy, so that the small missile remains controllable even if one of the fins fails.

To be able to control the small missile even with a low air flow, additional control surfaces can be provided that serve to deflect the drive thrust laterally, so that the missile can also be launched from the ground, for example.

These alternative or additional control surfaces are arranged in the area behind the outlet opening of the jet engine. The fact that the jet engine is an electrically operated or a fuel-operated jet engine, whose outlet gases either have nearly ambient temperature or, although they have hot gas components, are at a much lower temperature than the outlet gases of a solid-propellant engine, means that the control surfaces lying in the drive jet of the jet engine are subject to much lower wear than those arranged in the outlet jet of a solid-propellant engine. The flow resistance thus remains small and the manoeuvrability of the missile according to the invention is maintained as far as the target.

It is preferably also provided according to the invention that the above-mentioned thrust-guiding control surfaces are connected detachably to the fuselage of the missile and can be discarded by remote control, for example. This advantageously allows the air flow of the outlet jet of the engine to be improved following the launch of the missile, since discarding of the thrust-guiding control surfaces means that foreign bodies acting having a restrictor effect are no longer present in the flow area of the outlet jet.

The fins can be controlled in a targeted manner here via a system of control actuators.

The flight control surfaces and/or thrust-guiding control surfaces can be actuated by means of an actuator, wherein it is preferably provided that they are actuatable in pairs by means of a respective actuator. This has the advantage of reducing the number of actuators required for control.

For deflection of the drive thrust preferably at least one jet engine is arranged movably relative to the fuselage and/or thrust-guiding control surfaces are arranged downstream of an outlet of the jet engine. The movable jet engine can be arranged preferably externally on the fuselage of the small missile and be provided rotatably about up to two axes. To this end, a cardanic suspension of the jet engine can be provided to control the torques for the adjustment of the position. The movement of the jet engine can be accomplished by two actuators, giving controllability of the small missile in the pitch and yaw axes even without air flow.

The jet engine, or one of the jet engines, is preferably arranged coaxially to the longitudinal centre axis of the fuselage, in a flow channel provided with at least one air iniet channel upstream of the jet engine, or parallel to the longitudinal centre axis of the fuselage, either fixedly or rotatably about at least one axis. In other words, the jet engine can be arranged either inside or outside the fuselage; with arrangements inside the fuselage, at least one air inlet channel is provided in the fuselage.

The air inlet channel has preferably at least one air intake surrounding the fuselage in the circumferential direction, at least in sections, so that several air intakes can be provided on the fuselage that surround the fuselage respectively at least in sections. They then emerge radially from the sheath ends forming the fuselage at least in sections and thus form an opening supplying the air flow from the environment of the fuselage to the intake of the jet engine in a controlled manner. The air intake can be arranged here in the axial direction of the fuselage both ahead of and behind the wings, depending on where the internally located jet engine is arranged in the axial longitudinal direction of the fuselage.

According to a further development of the invention, an outlet of the flow channel can be formed displaceably relative to the longitudinal centre axis of the fuselage.

The fluid flow emerging from the jet engine can be deflected, therefore, through the displaceable outlet for control of the small missile, providing sideways thrust.

It can also be provided according to the invention that the or each actuator is formed for actuating more than one control surface and/or thrust-guiding control surfaces.

This design makes it possible for actuation of control surfaces or thrust-guiding control surfaces to be carried out with a number of actuators that is smaller than the number of control surfaces and/or thrust-guiding control surfaces to be actuated.

In embodiments with at least one jet engine arranged externally on the fuselage, the jet engine can also be arranged pivotably relative to the fuselage by means of an actuator. In an embodiment with four externally arranged jet engines, say, the jet engines can also be linked mechanically to or mounted on the aerodynamic fins.

Finally, the or each wing can be arranged foldably on the fuselage or to be capable of folding away into the fuselage. This formation makes it possible for the small missile to be launched from a launch tube from a standing position, for example on the ground, or from a vehicle or from another aircraft.

In another embodiment, the control device has at least three control surfaces actuatable by means of at least one actuator, and at least one jet engine is linked mechanically to the control surfaces.

The small missile is further distinguished by a modular structure, wherein the missile consists of three main modules, the front end, a drive unit and a control unit.

Among other things, the use of a jet engine avoids the disadvantages of the solid-propellant engine described at the beginning, which are reproduced below: * a required secure bearing; * short service life due to the chemical disintegration of the fuel; * smoke signatures due to burn-off; * strong heat production and the accompanying load on adjacent components; * heavy and expensive insulation material; * many critical safety aspects for the gunner; * risk of explosion due to sensitivity to impacts; * a launch tube that protects the gunner from the exhaust plume; * difficulties when firing from closed spaces.

BRIEF DESCRIPTION OF THE DRAWING

Fig. 1 shows the basic layout of the small missiles with which the invention is concerned; Fig. 2 shows an embodiment with a jet engine arranged in the inside of the drive module and thrusters arranged behind it in the axial direction in the control module; Fig. 3 shows a variant similar to that according to Figure 2; Fig. 4 shows an embodiment with two jet engines arranged externally on the fuselage; Fig. 4A shows a front view of the small missile of Figure 4; Fig. 5 shows a missile similar to that of Figure 2, but having a jet engine arranged in the tail and four jet engines in the control module linked mechanically to the fins; Fig. 5A shows a front view of the small missile of Figure 5; Fig. 6 shows an alternative embodiment, with no central engine; Fig. 6A shows a front view of the small missile of Figure 6; and Fig. 7 shows a further alternative embodiment analogous to that of Figure 5.

DESCRIPTION OF EMBODIMENTS

The small missile 1 shown in Fig. 1 has a fuselage 2 containing a drive module and having at least two wings 3 arranged on its exterior. Four wings 3 in all are provided in the embodiment shown, which serve to generate lift.

If only two wings 3 are provided, the small missile must be guided to the target via a so-called "bank to turn" steering mode; in the case of at least three wings, the small missile can be guided to the target via a "skid to turn" mode. It should be noted here that in the embodiments shown, the geometry and the arrangement of the wings are only shown by way of example and for the sake of explanation, and the real geometry and arrangement are determined on the basis of dynamic, mechanical, structural and design aspects.

The material of the small missile as a whole can include metal components, a fibre-composite material, expanded polypropylene or other synthetic materials. The wings 3 are shown in all the embodiments illustrated in the drawing in the folded-out state, but it is envisaged in principle, if it is mechanically possible, to provide the wings 3, and the control surfaces or fins 4 provided in the area of the tail, to be able to fold away into the fuselage 2 or to fold or wrap around it. The small missile 1 can then be fired from a container or from a launch tube that can be ained.

The front area is the front end module 31. The nose of the small missile 1 has a radome 5, which reduces the air resistance of the small missile 1 and protects the sensor parts and control devices arranged behind it in the axial direction from environmental influences.

Arranged behind the radome 5 is preferably an imaging seeker head 6, which, uncoupled from the position of the small missile 1 by means of a gimbal platform system 7, can sight the target. A gimbal platform system 7 of this kind can be omitted if the field of sight of the seeker head 6 is suitably large or the small missile is envisaged to be fired from another missile from the air. In the latter case the high angles of attack normal at launch, at which the target typically disappears from the field of sight of the sensor, do not arise. The seeker head 6 can operate in the infrared range or also in the visible range. Instead of the imaging seeker head 6, a radar device or another non-imaging seeker device, such as a SAL (semi-active laser) can be provided. The information of the seeker head 6 is forwarded to the gimbal platform system 7 or another position-finding system, the task of which is to identify the target, track it and make prepared data available for a flight guidance system 8.

The missile 1 has a data link 9, with which data and commands from an operator station, not shown, can be transmitted to the small missile 1 and also telemetric data from the small missile 1 to the operator station.

Moreover, a video transmission transmitter 10 is also provided that makes it possible to transmit the images produced by the seeker head 6 to the operator station or a ground station. A user, who may be a gunner, can thereby change the sight direction by up to 90° both before the launch of the small missile 1 and even after the launch by means of the gimbal system 7 and the data link 9 and identify and mark a target.

Here a great advantage of missiles using the invention comes into play, namely the variable drive thrust of the jet engine used, because the time in which the above-mentioned instruction process has to take place can he extended by reducing the drive thrust of the jet engine, so that the gunner has more time.

The missile 1 has an Inertial Measurement Unit (IMU) 8, not shown in detail, which has three orthogonal yaw rate sensors and three orthogonal accelerometers as well as three magnetometers. The IMU 8 can be based on the technology of micro-electromechanical systems and has the task of supplying information to a subordinate position adjustment circuit for stabilization and making an inertial reference available to the bearing angle supplied by the direction finding.

A position determination can take place via a satellite-aided locating system with an aerial, likewise not shown, to keep the missile 1 on a previously calculated flight path. The missile 1 can thus be guided into a defined target area; as soon as the gunner sees the target of the imaging seeker head 6, he can identify the target and mark it. The target approach then commences, during which the small missile 1 assumes the further target tracking autonomously until collision occurs.

The missile 1 has a pitot tube 11, which is used to measure the air flow velocity and to determine the adaptive closed-loop gain for the above-mentioned flight guidance system 8.

Furthermore, the small missile 1 has a weapon 15. This can be both non-lethal (tear gas, stupefying gas, smoke grenades, stun grenades) and lethal (explosive) . It is used for example to fight people or lightly armoured vehicles.

The data of all sensor devices and information from the bidirectional data link 9 are processed in the flight guidance system 8 and this supplies the control commands for the jet engine or engines, which can be seen in greater detail with reference to the following examples.

Fig 2 shows the interior of a missile as envisaged, revealing a jet engine 12 located in the central section of the fuselage 12. Behind the engine are thrust-guiding control surfaces 14. The control commands supplied by the flight guidance system 8 are used also to activate actuators 13, which are used to actuate the control surfaces 4, the thrust-guiding control surfaces 14 and the rotary operation and position variation of the jet engine 12.

In the description of the embodiments of the small

missile 1 shown, similar components are designated with the same reference symbols, reference being made to the generic

description of Fig. 1 for their explanation.

The small missile 1 shown in Fig. 2 of the drawing has a funnel-shaped air intake 16 arranged ahead of the wings 3 in the axial or longitude direction of the fuselage 2.

This intake opens into an air inlet channel 17, with which air from the environment can be supplied to the jet engine 12.

The jet engine 12 is arranged in a flow channel 18 coaxial to the longitudinal centre axis of the fuselage 2. The embodiment shown in Fig. 2 concerns an electrically operated jet engine 12 with a tube-shaped casing ring 19, which encloses a rotor 20 and several propellers arranged thereon. The rotor 20 is driven by an electric motor (not shown) and thus accelerates the air flowing via the air intake 16. The enclosure formed by the casing ring 19 reduces thrust losses in the jet engine 12 that arise as a result of turbulence at the blade tips with a propeller engine.

The missile is modular, with a forward module 31 with the instrumentation, a drive module 32 and a control module 33 at the rear. The jet engine 12 is arranged in the drive module 32 of the missile 1, while the control takes place via devices in the rear control module 33; these devices are described below. An accumulator battery and/or fuel tank (not shown in detail in the drawings) can be provided as energy store and can be integrated into the structure of the fuselage 2 of the small missile.

By changing the casing cross-section, the pressure and the velocity of the flow can be adapted to the requirement of the driving motor. The speed of the motor is adjusted by a speed governor, not shown.

In addition to the control surfaces 4 arranged externally, the embodiment of the small missile 1 shown in Fig. 2 has internal thrust-guiding control surfaces 14, by means of which the air flow emerging from the jet engine 12 can be deflected to influence the flight path of the small missile 1. The air flowing through the air intake is supplied to the jet engine 12, accelerated there, and expelled through the flow channel arranged in the axial direction of the fuselage 2 behind the jet engine 12, and in this way produces a drive thrust for the small missile 1 in the longitudinal direction.

The internal thrust-guiding control surfaces 14 and shown in Fig. 2 have the advantage, moreover, that on account of their arrangement in the flow channel downstream of the jet engine 12 they ensure a good controllability even in the case of low air flow velocity of the small missile 1, as they act as thrusters in the fluid flow behind the jet engine 12. The control surfaces 14 are arranged in the flow channel well back in the vicinity of its end to achieve a deflection of the air jet without turbulence.

The control surfaces 14 lying internally can be discarded by remote control, for example, which has the advantage that when the small missile 1 has attained a sufficiently high velocity, the flow losses caused by the control surfaces 14 fall and a correspondingly high air flow of the control surfaces 14 lying externally ensures a good controllability of the small missile 1.

The control surfaces 4, 14 are activated in pairs respectively via respective actuators 13. The coordination of the actuators 13 is assumed by the flight guidance system 8.

The jet engine 12 shown in Fig. 3 of the drawing is a jet engine 12 operated using fuel, for example kerosene, which is supplied with air via air intakes 16. The intakes in this case are arranged around the circumference of the fuselage 2, behind the wings 3.

Whereas control of the torques for the position adjustment was achieved in the embodiment shown in Fig. 2 both via the control surfaces 4 lying externally and the thrust-guiding control surfaces 14 lying internally, in the embodiment shown in Fig. 3, this adjustment takes place only via the externally arranged control surfaces or fins 4.

In the embodiment shown in Fig. 3, the direction of the outlet channel 22 can be varied optionally by a mechanical gimbal device, which is not shown in the drawings.

For this purpose a flexible material can be used at the end area of the fuselage 2 in the area of the outlet channel 22, via the deflection of which a thrust vector control can be realized. Controllability of the small missile 1 can be achieved in this way in the pitch axis and yaw axis even without air flow velocity. To this end actuators, which are not shown in greater detail and which permit an adjustment of the outlet channel 22, can be provided on the small missile 1.

The embodiment of the small missile 1 shown in Figs. 4 and 4A has two jet engines 12 arranged externally on the fuselage 2, which engines can be attached to the fuselage 2 by means of a cardanic suspension 24 that is shown only schematically. The two jet engines 12 produce drive thrust and an emerging air flow, which flows via the control surfaces 4. Controllability of the small missile 1 is possible in this way in the pitch axis and yaw axis even when stationary or floating without air speed.

This kind of embodiment could also have four jet engines.

An example of a configuration of this kind is shown in Fig. 5. As well as a jet engine 12 arranged in the fuselage 2, the embodiment shown in Fig. 5 has four further jet engines 12 arranged respectively on the radial ends of the rear control surfaces or fins 4.

In Fig. 5, additional drive systems are provided on the fins that are linked mechanically to the fins. This has the advantage that the missile remains controllable due to this arrangement even when stationary. All embodiments shown have respectively four control surfaces 4 lying externally, in order to guarantee, even in the event of failure of one of the control surfaces, thanks to its redundancy, the controllability of the respective small missile 1 by the remaining three control surfaces 4 or fins.

Fig. 5 shows clearly the modular structure of the small missile according to the invention with a forward front end module, a central drive module and a control module provided in the tail area of the missile. The individual modules are shown separated from one another in the representation in Fig. 5, to be able to show the modules better. In the example in Fig. 5, the small missile is provided with a central jet engine 12 provided in the drive module as well as four jet engines 12A provided respectively at one end of the control surfaces 4, by means of which engines a thrust vector control is possible. In addition, the exhaust plume of the central jet engine 12 provided in the drive module can be deflected by a thrust-guiding control surface 14 provided in the exhaust channel 18 to control the small missile.

A further alternative modular embodiment of the small missile according to the invention is shown in Fig. 6.

According to this modified embodiment, a jet engine can be attached to each wing. Here too a forward front end module, a central drive module and a rear control module are provided. The central drive module is provided with four wings 3 arranged perpendicular to one another, at the wing roots of which in the fuselage a respective fuel tank 23 or accumulator battery is provided and at the respective free end of which a jet engine l2B is provided.

The control module is provided with four control surfaces 4 aligned in the same manner as the wings 3, which surfaces each lie at least with one control surface area in the exhaust plume of an assigned jet engine 12B and onto which and/or around which the respective exhaust plume flows.

A third variant of the modular structure of the small missile according to the invention is shown in Fig. 7.

Here also a forward front end module, a central drive module and a rear control module are provided once more.

The central drive module of this embodiment corresponds to the drive module of the embodiment according to Fig. 5, which module is provided with a central jet engine 12, with a fuel tank or accumulator battery 23' provided centrally in the fuselage. The rear control module corresponds in principle likewise to the control module of the embodiment from Fig. 5, wherein, however, no additional jet engines are provided at the free ends of the control surfaces 4 in the embodiment in Fig. 7. Control is achieved in this small missile thus only due to the aerodynamic effect acting on the control surfaces 4 and due to the deflection of the exhaust plume of the central jet engine 12 by means of the thrust-guiding control surface 14 in the exhaust flow channel 18.

The small missile according to the invention is distinguished by a high controllability about all three axes. A high roll controllability is important especially in the case of imaging seeker heads. In an embodiment of the small missile with a thrust vector control, a high controllability is possible even with a low or no air flow velocity. This facilitates an autonomous launch from the ground or a simple hover.

The stability of a missile relative to disturbances depends to a large extent on how great the disruptive forces are in relation to the control forces. To increase the stability of the missile, the velocity can he increased, in the present case the jet engine or engines used make it possible to increase the velocity significantly compared with a small missile operated by propeller drive, which can also be utilized in turn thereby to make the lift surfaces smaller. The area of the small missile that can be influenced by wind forces is thus reduced and thus its stability is increased in turn.

Reference symbols in the claims, the description and the drawings are only used for a better understanding of the invention and are not intended to restrict the protective scope. Features from one embodiment may be applied to other embodiments, where possible.

Reference numeral list 1 Small missile 2 Fuselage 3 Wing 4 Control surface Radome 6 Seeker head 7 Gimbal system 8 Flight guidance system and Inertial Measurement Unit and GPS 9 Data link Video transmission transmitter 11 Pitot tube 12 Jet engine 12A Jet engine 12B Jet engine 13 Actuator 14 Thrust-guiding control surface Weapon 16 Air intake 17 Air inlet channel 18 Flow channel 19 Casing ring Rotor 22 Outlet channel 23 Fuel tank/accumulator battery 23' Fuel tank/accumulator battery 24 Suspension 31 Front end module 32 Drive module 33 Control module