Abstract:
An apparatus, and a method performed by the apparatus, are disclosed wherein the apparatus can be mounted on an unmanned vehicle and arranged to act upon a payload. The payload can be mounted on the unmanned vehicle and, under an action of the apparatus, is able to be activated. The method can include receiving an activation instruction from an entity remote from the unmanned vehicle; determining whether or not the received activation instruction is valid by performing a validation process; and in response to determining that the received activation instruction is valid, activating the payload. In response to determining that the received activation instruction is not valid, activation of the payload may be prevented or opposed.

Description:
FIELD OF THE INVENTION 
     The present invention relates to apparatus for use on unmanned vehicles. 
     BACKGROUND 
     Unmanned aircraft are powered aerial vehicles that do not carry a human operator. They may fly autonomously or be piloted remotely. 
     A data link employed to facilitate communication between an unmanned aircraft and its operator, e.g. a satellite data-link, may have uncertain performance, availability, and integrity. 
     In manned armed aircraft, the weapon control is typically performed by the airborne operator. The airborne operator interprets relevant Rules of Engagement to ensure weapons release is authorised. Typically, the weapon is released using a control sequence to release a series of electro-mechanical safety critical switches. The control sequence is usually performed on the aircraft. The data-link employed within a manned aircraft for the control of the weapon systems is typically robust, reliable, and of high integrity relative to a data link used for communication between an unmanned aircraft and its operator. 
     SUMMARY OF THE INVENTION 
     In a first aspect, the present invention provides a method performed by apparatus, the apparatus being mounted on an unmanned vehicle and arranged to act upon a payload, the payload being mounted on the unmanned vehicle and, under an action of the apparatus, able to be activated, the method comprising receiving an activation instruction from an entity, the entity being remote from the unmanned vehicle, determining whether or not the received activation instruction is valid by performing a validation process, and in response to determining that the received activation instruction is valid, activating the payload. 
     The method may further comprise, in response to determining that the received activation instruction is not valid, preventing or opposing the activation of the payload. 
     The apparatus may comprise, or has access to, validation information, and the validation process may comprise comparing the received activation instruction to the validation information. 
     The activation instruction may comprise a code, and the validation information may be a further code, the further code being stored in the apparatus. 
     The activation instruction may comprise an indication of a time that the activation instruction was sent from the entity to the unmanned vehicle, and the validation process may comprise determining that the activation instruction is not valid if a time period between the indicated time and a time that the validation process is performed is longer than a pre-determined threshold. 
     The apparatus and the entity may each comprise multiple codes, each code being related to a payload activation event. Once completed, information pertaining to each payload activation event may be stored in the apparatus. The information may comprise valid, actioned codes. An event history may, thus, be generated and the next anticipated code may readily be identified. Time synchronisation data may be provided to and stored in each of the entity and the apparatus. Time synchronisation data may be used in combination with the event history to enable system re-synchronisation to be performed. System re-synchronisation may be required following a period of degradation in data communications between the apparatus and the entity, for example a UAV and its ground station. 
     The activation instruction may comprise an indication of the next anticipated valid code. The validation process may comprise comparing the received anticipated code with the corresponding code stored in the apparatus. 
     The method may further comprise receiving target details from a further entity, the further entity being remote from the unmanned vehicle, and, using the received target details, facilitating a payload controller to direct the payload towards the target. 
     The further entity may be the entity. 
     The method may further comprise measuring a parameter of an area of terrain, the area of terrain comprising a target, and providing, for use by the entity, the measurements of the parameter. 
     The step of measuring may be performed using at least one of a visible light detecting camera, an infra-red camera, a ultra-violet camera or a radar sensor. 
     The method may further comprise, in response to activating the payload, providing for the entity an indication that the payload has been activated. 
     The unmanned vehicle may be an aircraft. 
     The payload may be a weapon. 
     The method may further comprise, if in response to activating the payload the payload fails to be activated, providing for use by the entity an indication that the payload has failed to be activated. 
     In a further aspect, the present invention provides apparatus mounted on an unmanned vehicle and arranged to act upon a payload, the payload being mounted on the unmanned vehicle and, under an action of the apparatus, able to be activated, the apparatus being arranged to receive an activation instruction from an entity, the entity being remote from the unmanned vehicle, determine whether or not the received activation instruction is valid by performing a validation process, and, in response to determining that the received activation instruction is valid, activate the payload. 
     In a further aspect, the present invention provides a program or plurality of programs arranged such that when executed by a computer system or one or more processors it/they cause the computer system or the one or more processors to operate in accordance with the method of any of the above aspects. 
     In a further aspect, the present invention provides a machine readable storage medium storing a program or at least one of the plurality of programs according to the above aspect. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic illustration (not to scale) of an example scenario in which an aircraft implements an embodiment of an aircraft weapon system; 
         FIG. 2  is a schematic illustration (not to scale) of the aircraft; 
         FIG. 3  is a schematic illustration (not to scale) of an embodiment of the weapon system of the aircraft; and 
         FIG. 4  is a process flow chart showing certain steps of a process for implementing the weapons system to attack the target. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a schematic illustration (not to scale) of an example scenario in which an aircraft  2  implements an embodiment of an aircraft weapon system. 
     In this scenario, the aircraft  2  is an unmanned aircraft (UAV). 
     In this scenario, the aircraft  2  has been launched under the control of a ground station  4 . 
     In this scenario, the ground station  4  is located on the ground  6 . 
       FIG. 1  shows the aircraft  2  airborne (i.e. after its launch from the ground  6 ). 
     In this scenario, the aircraft  2  is launched under the control of the ground station  4  with an intention of attacking (using a weapon launched from the aircraft  2  as described in more detail later below) a target  8 . 
     In this embodiment, the aircraft  2  follows a pre-programmed navigation route. The aircraft  2  does not deviate from this route unless the aircraft  2  is commanded to “loiter” by the ground station  4 , the aircraft is commanded to “return” by the ground station, or the aircraft  2  experiences a communications failure (in which case the aircraft  2  returns to the ground  6 ). 
     In this scenario, the target  8  is located on the ground  6 . Also, the target  8  is located at a position on the ground  6  that is remote from the ground station  4 . 
     In this scenario, the aircraft  2  and the ground station  4  are in two-way communications. The aircraft  2  and the ground station  4  communicate via a communications satellite, hereinafter referred to as “the satellite  10 ”. The two-way communication of the aircraft  2  and the ground station  4  is represented in  FIG. 1  by dotted two-headed arrows. Also, the two-way communication of the aircraft  2  and the ground station  4  is described in more detail later below with reference to  FIG. 4 . 
       FIG. 2  is a schematic illustration (not to scale) of the aircraft  2 . 
     In this example, the aircraft  2  comprises a transceiver  12  and a weapon system  14 . 
     In this example, messages received by the aircraft  2  from the ground station  4  (via the satellite  10 ) are received by the transceiver  12 . Furthermore, in this embodiment messages sent by the aircraft  2  to the ground station  4  (via the satellite  10 ) are sent by the transceiver  12 . 
     In this example, the transceiver  12  is connected to the weapon system  14  such that messages received at the transceiver  12  from the ground station  4  (via the satellite  10 ) are sent from the transceiver  12  to the weapon system  14 . Furthermore, the transceiver  12  is connected to the weapon system  14  such that messages may be sent from the weapon system  14  to the transceiver, which may then be sent from the transceiver  12  to the ground station  4  (via the satellite  10 ). 
     In this embodiment, the aircraft  2  comprises an Armament Control Safety Break (not shown in the Figures) which provides an additional safety interlock whilst the aircraft  2  is on the ground  6 . 
       FIG. 3  is a schematic illustration (not to scale) of an embodiment of the weapon system  14  of the aircraft  2 . 
     In this embodiment, the weapon system  14  comprises a sequencer  16  and a weapon  18 . 
     In this embodiment, the sequencer  16  is fitted in the aircraft such that, when certain criteria are satisfied (i.e. when certain messages have been received by the aircraft  2  from the ground station  4 ) the sequencer  16  controls the power, pre-launch, and firing commands to the weapon  18 . 
     The sequencer  16  is connected to the weapon  18  such that the weapon  18  can be powered and controlled by the sequencer  16 . 
     In this embodiment, prior to the launch of the aircraft  2  (i.e. prior to the aircraft  2  taking off from the ground  6 ) a pre-determined “firing code” is stored in the sequencer  16 , e.g. by hardwiring the code into a storage device which is connected to a port on the sequencer  16 . The same code is also stored in a further storage device which is kept by mission crew at the ground station  4 . This firing code is used to initiate the firing of a weapon from the aircraft  2  as described in more detail later below with reference to  FIG. 4 . 
     Alternatively, the firing code could by synchronised between the ground station  4  and the sequencer  16  by transmitting the firing code via the satellite  10 , whilst the aircraft  2  is on the ground. 
     In this example, the ground station  4  and the sequencer  16  are time synchronised using an incrementing time code, transmitted with the firing code from the ground via the satellite  10  and the transceiver  12 . The firing code should comprise sufficient digits to satisfy the safety requirements of the system. 
     A new/different firing code is used for each new aircraft sortie. 
     Multiple firing codes may be stored in the sequencer  16  to enable many different events to be instructed by the ground station  4  within a single sortie. The multiple firing codes may be transmitted from the ground station  4  via the satellite  10  and transceiver and stored in the sequencer  16 . 
     The process by which the sequencer  16  powers, controls and fires the weapon  18  is described in more detail later below with reference to  FIG. 4 . 
     In this embodiment, the weapon  18  is a relatively lightweight, precision strike, low collateral damage weapon. However, in other embodiments the weapon is a different type of weapon, or other type of payload. For example, in other embodiments, the weapon is a different type of lethal effector, such as an unpowered laser guided bomb. In other embodiments, the weapon may use any appropriate method to be guided to the target, e.g. a beam rider method, or the weapon may detect reflected laser light on the ground and steer towards that. In other embodiments the payload may be a non-lethal effector, e.g. a communications jamming device, a locator beacon, or equipment for friendly ground-based troops. 
       FIG. 4  is a process flow chart showing certain steps of a process for implementing the weapons system  14  to attack the target  8 . 
     In this embodiment, the aircraft  2  is airborne following its launch from the ground  6 , as described above with reference to  FIG. 1 . 
     At step s 2 , as the aircraft  2  flies above the ground  6 , images of the ground  6  are captured by the aircraft  2  using an aircraft-mounted camera (not shown in the Figures). 
     At step s 4 , the captured images of the ground  6  are relayed from the transceiver  12  of the aircraft  2  to the ground station  4 . In this embodiment, these images are sent via the satellite  10 . 
     At step s 6 , the camera images received at the ground station  4  are displayed (on a screen) to a human operator at the ground station  4 . 
     At step s 8 , the operator identifies the target  8  within the displayed images. 
     At step s 10 , the operator sends details about the target  8  (e.g. a global position of the target  8 ) from the ground station  4  to the aircraft  2 . 
     In this embodiment, these target details are sent via the satellite  10 . 
     At step s 12 , the firing code that is stored at the ground station  4  is sent from the ground station  4  to the aircraft  2  by the operator. 
     In this embodiment, the ground station&#39;s firing code is sent via the satellite  10 . 
     In this embodiment, the ground station&#39;s firing code is transmitted to the aircraft  2  at the same time as the target details are transmitted to the aircraft  2  (as described above at step s 10 ). However, in other embodiments, the firing code and the target details are sent to the aircraft  2  at different respective times. 
     At step s 14 , the ground station&#39;s firing code and the target details received at the transceiver  12  of the aircraft  2  is transmitted to the sequencer  16  of the weapon system  14 . 
     In this embodiment the time between the ground station&#39;s firing code and target details being sent from the ground station  4 , and the time these signals are received at the sequencer  16  is typically less than 10 seconds. Preferably, the time delay in this communication is less than 10 seconds, for example, less than 1 second. In other embodiments, for example, when multiple satellite links are used in the communications path, the delay is greater than 10 seconds. 
     At step s 16 , it is determined whether the firing code received by the aircraft  2  from the ground station  4  is valid. 
     In this embodiment, the sequencer  16  checks the validity of the ground station&#39;s firing code. 
     As described above, a firing code is stored in a storage device which is connected to a port on the sequencer  16 . This stored firing code is compared to the firing code received by the aircraft  2  from the ground station  4  to determine the validity of the firing code received from the ground station  4 . 
     In this embodiment, if the firing code received from the ground station  4  is identical to the firing code stored at the sequencer  16 , the received code is determined to be valid. 
     However, if the firing code received from the ground station  4  is not identical to the firing code stored at the sequencer  16 , the received code is determined to be invalid. 
     Also, in this embodiment the sequencer  16  is arranged to only process a valid firing code if the code carries a recent time code. In this embodiment, a valid code is rejected by the sequencer  16 , i.e. declared “invalid”, if it has been delayed by a pre-determined time period, for example, greater than the maximum expected communication delay. This tends to alleviate problems caused by the firing code command being kept in the aircraft data buffer for several minutes prior to it being processed by the sequencer  16 . For example, the problem of the weapon  18  receiving a significantly delayed power and trigger command tends to be reduced. 
     In practice, it tends to be very unlikely that there is a significant delay in processing the firing code. In this embodiment, a misfire (Hang-Up) is assumed to have occurred if there is a firing delay longer than the maximum expected communication delay. 
     If, at step s 16 , it is determined by the sequencer  16  that firing code received by the aircraft  2  from the ground station  4  is valid, the process proceeds to step s 18 . 
     However, if, at step s 16 , it is determined by the sequencer  16  that firing code received by the aircraft  2  from the ground station  4  is not valid, the process proceeds to step s 22 . 
     At step s 18 , the target details transmitted to the sequencer  16  at step s 14  are transmitted from the sequencer  16  to the weapon  18 . 
     In this embodiment, the determination that the firing code is valid and the transmission of the target details from the sequencer  16  to the weapon  18  is performed in less than 30 ms. 
     At step s 20 , the weapon  18  is launched from the aircraft  2 . 
     In this embodiment, after launch the weapon  18  is controlled in a conventional manner dependent on the type of weapon. 
     In this embodiment, if a weapon misfire (Hang-Up) occurs during firing, the weapon system  14  reports this via the transceiver  12  to the ground station  4 . This report is sent via satellite  10 . 
     The aircraft-mounted camera may be used to advantageously provide a visual aid for confirming if the weapon  18  has successfully fired. 
     After performing step s 20 , the process for implementing the weapons system  14  to attack the target  8  ends. 
     Returning now to step s 16 , if at this step it is determined by the sequencer  16  that firing code received by the aircraft  2  from the ground station  4  is invalid, the process proceeds to step s 22 . 
     At step s 22 , after an invalid code is received by the sequencer  16 , the sequencer  16  ignores the firing code and target details are not provided to the weapon  18  via the sequencer  16 . 
     At step s 24  the weapon system  14  reports via the transceiver  12  to the ground station  4  that an invalid firing code has been received. This report is sent via satellite  10 . 
     After step s 24 , the process for implementing the weapons system  14  ends. 
     Thus, a process for implementing the weapons system  14  to attack the target  8  is provided. 
     Once a valid action or event has been completed, the ground station  4  may send an indication of the next anticipated valid firing code to the sequencer  16  (e.g. via the satellite  10  and transceiver  12 ). The sequencer  16  may return a confirmation of the anticipated next valid firing code to the ground station  4 . 
     If degradation in the communication link occurs, say, due to a temporary loss of or problem with the satellite connection, the data transmitted by the ground station to the transceiver (or by the transceiver to the ground station) may be corrupted. The ground station  4  may then request that the firing code and time synchronisation data for the last successfully completed action be transmitted by the sequencer  16  via the transceiver  12  and satellite  10  to the ground station  4 , such that end-to-end re-synchronisation of the ground station  4  and the sequencer  16  can be achieved. 
     An advantage provided by the above described system and method is that failure modes of the system tend to be easy to identify and plan for. 
     The following information details certain possible failure modes of the above described system, and certain actions that may be performed in the event of those failures occurring. 
     A first failure mode is where the weapon  18  misfires as result of sequencer  16  not relaying codes to the weapon  18  (i.e. there is fault in the sequencer  16 ). The weapon system  14  reports via the transceiver  12  to the ground station  4  that a misfire has occurred. Any relevant data on this misfire may also be reported to the ground station  4 . This report is sent via the satellite  10 . 
     A second failure mode is where the weapon  18  misfires e.g. as a result of a failure of the release mechanism for releasing the weapon  18  from the aircraft  2 . In other words, the weapon is initiated, but not fired. In this event, the weapon system  14  reports via the transceiver  12  to the ground station  4  that a misfire has occurred. Any relevant data on this misfire may also be reported to the ground station  4 . This report is sent via the satellite  10 . 
     A further advantage of the above described system and method is that a fully autonomous vehicle is used to launch payloads at a target. Thus, a human operator on the vehicle (i.e. a pilot) is not used, and the risks to such an operator are negated. Nevertheless, in the event of an emergency, manual control of the aircraft may be reverted to. 
     A further advantage of the above described system is that the aircraft can be fitted with a variety of different payloads depending on the requirements of the scenario. 
     A further advantage of the above described system is that the aircraft tends to be inherently stable in all three axes (roll, pitch, and yaw). 
     The above described system and method tends to provide for real time monitoring of the state of the weapon on the aircraft. 
     The satellite link between the ground station and the aircraft advantageously tends to provide for Beyond Line Of Sight (BLOS) communication. In other embodiments, a different type of data link, e.g. a Line Of Sight (LOS) data link, is used instead of or in addition to the BLOS data link. 
     A further advantage provided by the above described system and method is that end-to-end control of the weapon system tends to be maintained even when the data link employed (between the ground station and the aircraft) has uncertain performance, availability, and integrity. 
     Apparatus, for implementing the arrangement described above with reference to  FIGS. 1-3 , and performing the method steps described above with reference to  FIG. 4 , may be provided by configuring or adapting any suitable apparatus, for example one or more computers or other processing apparatus or processors, and/or providing additional modules. The apparatus may comprise a computer, a network of computers, or one or more processors, for implementing instructions and using data, including instructions and data in the form of a computer program or plurality of computer programs stored in or on a machine readable storage medium such as computer memory, a computer disk, ROM, PROM etc., or any combination of these or other storage media. 
     It should be noted that certain of the process steps depicted in the flowchart of  FIG. 4  and described above may be omitted or such process steps may be performed in differing order to that presented above and shown in  FIG. 4 . Furthermore, although all the process steps have, for convenience and ease of understanding, been depicted as discrete temporally-sequential steps, nevertheless some of the process steps may in fact be performed simultaneously or at least overlapping to some extent temporally. 
     In the above embodiments, the aircraft weapon system is implemented in the particular scenario described above with reference to  FIG. 1 . However, in other embodiments the aircraft weapon system is implemented in a different scenario. For example, in other embodiments a scenario in which the weapon system is implemented may comprise a different number of aircraft, ground stations, satellites, and/or targets that interact in the same or a different appropriate way to that described above. 
     In the above embodiments, the autonomous vehicle used to deliver the payload is an aircraft. However, in other embodiments the vehicle is a different type of autonomous vehicle, for example, an autonomous land-based or water-based vehicle. 
     In the above embodiments, communications between the ground station and the aircraft are via a single satellite. However, in other embodiments the ground station and the vehicle communicate in a different way, for example, via a different number of satellites, or directly, or using an airborne relay. 
     In the above embodiments, the aircraft follows a pre-programmed navigation route. However, in other embodiments the vehicle may follow a different type of route, for example a series of way-points may be uploaded to the aircraft while the aircraft is airborne, or the aircraft may determine its own route. 
     In the above embodiments, the firing code is stored in a storage device which is connected to a port on the sequencer. The same code is also stored at the ground station. The firing code may be stored in computer memory of the respective sequencer and ground station. However, in other embodiments a different appropriate system is implemented to provide relatively secure and robust way in which the sequencer (or equivalent) can validate firing codes and target details. For example, in other embodiments two respective firing codes can be relayed to the aircraft from two respective ground stations. The sequencer (or equivalent) may compare the two received codes in order to validate an attack instruction. 
     In the above embodiments, the ground station is located on the ground. However, in other embodiments, the ground station, i.e. a location that the operator that controls the aircraft&#39;s weapon systems is at, is located at a different location remote from the aircraft, e.g. in a different aircraft or other vehicle. 
     In the above embodiments, an aircraft-mounted camera is used to capture images of the ground for use by the operator at the ground station. However, in other embodiments, a different type of sensor (mounted on the aircraft or remote from the aircraft) is used to provide data to the operator for the purpose of target selection. For example, a visible light-detecting camera, an infra-red camera, a ultra-violet camera, a radar sensor, etc. may be used.