Abstract: A folded optical arrangement for use in a look-through display to transmit an image from an image plane to a user's eye, the arrangement providing a folded optical transmission path and comprising: an optical system having a first optical element comprising a first plurality of optically powered surfaces; and a second optical element comprising at least one optically powered surface, the optical system configured to receive light forming the image from an image source, and to focus the light to have an apparent optical focus between a predetermined distance and optical infinity and output the light; wherein the first plurality of optically powered surfaces and the at least one optically powered surface of the second optical element are arranged to define a plurality of interfaces along the folded optical path and wherein a refractive index change at each interface is predetermined to control the direction of light passing through the or each interface; and wherein one surface of the first optical element and

Abstract: A lightweight end cap for an ammunition cartridge, said end cap having a central axis along its axial length, with a first radius; wherein said end cap further comprises a swept volume rebate; having a second radius less than the first radius, wherein the second radius is at least 10% smaller than the first radius, and wherein the swept volume rebate extends along at least 10% of the axial length of said end cap, wherein the end cap further comprises an extractor groove suitable for receiving an ejection mechanism.

Abstract: A method for generating a measure for insertion loss of an antenna structure comprising a radome defining a cavity to receive an antenna array. The method may comprise partitioning a user define geometry, which includes shape and dimensions, of the radome into a mesh comprising a first set of discrete geometric and topological cells, determining, for each cell, angles of incidence of electromagnetic radiation emitted from respective antenna elements of the antenna array for each scan angle of interest, the angles of incidence of electromagnetic radiation for a cell defining a distribution for that cell, on the basis of the distribution for a cell, assigning each cell to a zone of a set of zones for the radome, generating a measure of the insertion loss for each zone, and using the corresponding measure of insertion loss for a zone, selecting a structural configuration for the zone.

Abstract: A folded optical arrangement for use in a view-through display to transmit an image from an image source to a user's eye, the arrangement providing a folded optical transmission path and comprising: an optical system having a first optical element comprising a first plurality of optically powered surfaces; and a second optical element comprising at least one optically powered surface, the optical system configured to receive light forming the image from an image source, and to present a virtual image of the image source to the user with an apparent focus between a predetermined distance and optical infinity; wherein the first plurality of optically powered surfaces and the at least one optically powered surface of the second optical element are arranged to define a plurality of interfaces along the folded optical path and wherein a refractive index change at each interface is predetermined to control the direction of light passing through the or each interface; and wherein one surface of the first optical ele

Abstract: According to some examples, a non-incendiary projectile comprises a housing defining an internal cavity, and an energy harvesting structure comprising a first part and a second part, the first part provided on an inner surface of the housing, the second part provided in the internal cavity, the second part further comprising a rotation damping system configured to regulate a rate of rotation of the second part in a rotational direction about a flight axis defined by the housing.

Abstract: In some examples, an apparatus comprises a first working fluid circuit comprising a first working fluid, a heat exchanger fluidly coupled to and in thermal communication with the first working fluid circuit, the heat exchanger to transfer thermal energy from a heat source stream to the first working fluid within the first working fluid circuit, a recuperator fluidly coupled to and in thermal communication with the first working fluid circuit and disposed downstream of the heat exchanger, a first condenser fluidly coupled to and in thermal communication with the first working fluid circuit and disposed downstream of the recuperator, a second working fluid circuit comprising a second working fluid, the second working fluid circuit coupled to and in thermal communication with the first condenser, a second condenser fluidly coupled to and in thermal communication with the second working fluid circuit and disposed downstream of the first condenser, and a third working fluid circuit comprising a third working fluid

Abstract: A vehicle control system (110) for use with at least one fluidic control effector (102) for a vehicle, the vehicle control system (110) comprising a controller (110), wherein the controller is configured to: receive a vehicle control input indicating a demanded vehicle manoeuvre, wherein the input is further configured to receive condition data; determine a fluid mass-flow for the at least one fluid control effector based on the received vehicle control input and the condition data, wherein the relationship between the fluid mass-flow and the vehicle control input is substantially non-linear; and output data relating to the determined fluid mass-flow to effect the demanded vehicle manoeuvre, wherein the fluid mass-flow is determined to provide a substantially linear relationship between the vehicle control input and the effected demanded vehicle manoeuvre.

Abstract: According to the present invention there is provided a vibration control system comprising: a resonator comprising: a base attachable to an external body; a control element; and one or more connection elements each having a resilient portion, wherein the control element is resiliently connected to the base by the one or more connection elements such that relative movement between the control element and the base is facilitated by the one or more connection elements; and a driving mechanism, wherein the resonator comprises at least a part of the driving mechanism.

Abstract: According to the present invention there is provided a resonator comprising: a base attachable to an external body; a control element; and one or more connection elements each having a resilient spiral portion, wherein the control element is resiliently connected to the base by the one or more connection elements such that relative movement between the control element and the base is facilitated by the one or more connection elements.

Abstract: In some examples, an acoustic absorbing structure comprises a surface comprising an array of apertures, each aperture defining an opening for a corresponding channel, each channel forming a non-resonant acoustic attenuation structure with an axially decreasing cross-section over at least a portion of the length of the channel.

Abstract: A cooling system (100) for removing heat from a heat source (1000) fluid cooling circuit (1100). The cooling system (100) comprises a first fluid manifold (200) for flow of a heat transfer fluid, the first fluid manifold (200) comprising a flow inlet (210) and a flow outlet (212); a heat exchanger (310) and a heat sink unit (410) each in heat transfer communication with the first fluid manifold (200). In a first mode of operation, heat transfer fluid enters the flow inlet (210) and part of the heat transfer fluid flow is controlled to be in heat transfer communication with the heat exchanger (310), and the remainder of the heat transfer fluid flow is controlled to be in heat transfer communication with the heat sink unit (410). In a second mode of operation, heat transfer fluid enters the flow inlet (210) and all of the heat transfer fluid flow is controlled to first be in heat transfer communication with the heat sink unit (410) and then in heat transfer communication with the heat exchanger (310).

Abstract: A corrosion sensor is described. The corrosion sensor comprises a substrate 10 and a patterned conductive layer provided on the substrate 10, wherein the conductive layer defines: a common terminal; a set of terminals, including a first terminal and a second terminal; and a set of sensing elements, including a first sensing element and a second sensing element; wherein respective sensing elements of the set thereof are electrically coupled to the common terminal and to respective terminals of the set thereof, such that the respective terminals of the set thereof are specific to the respective sensing elements of the set thereof.

Abstract: A method of providing secure communication between first and second devices comprises the first device and the second device connecting to a server via a secure communication channel. Encryption keys for the devices are generated and data relating to the encryption keys are exchanged via the server in the secure communication channel. A peer-to-peer connection for exchanging data is generated using encrypted connection information for the devices.

Abstract: A robot cell, having a cell floor defining an array of nodes corresponding with a predetermined two-dimensional coordinate system and defining a volume for receiving a workpiece W therein and accessible by a human operator, is described. The robot cell comprises: a set of robots, including a first robot, having respective bases, end effectors and working envelopes and defining respective three-dimensional coordinate systems, located according to the array of nodes; a set of detectors, including a first detector, configured to detect respective locations and/or bearings of the set of robots using a set of targets disposed on and/or in the cell floor; a safety system, configured to alert the human operator; and a controller, communicatively coupled to the set of robots and to the set of detectors, configured to control movement of the set of robots using the detected respective locations and/or bearings of the set of robots.

Abstract: The invention relates to a system and method for detecting anomalous system behaviour. The system comprises a plurality of sensors and a trained autoencoder. The method of training comprises: obtaining training data and test data comprising multiple data records for at least one engineering asset which corresponds to the engineering asset whose behaviour is to be classified, wherein the data records comprise a plurality of sensor readings for the engineering asset; fitting the autoencoder to the obtained training data; running the test data through the encoder of the fitted autoencoder to obtain encodings of the test data; generating a plurality of data sets from the obtained encodings, wherein the generated plurality of data sets include under-represented data sets; cloning the fitted autoencoder to create a cloned autoencoder for each of the generated plurality of data sets; and aggregating the cloned autoencoders to form an over-arching autoencoder.

Abstract: There is provided a projectile, a system and a related method of operation of a projectile comprising: a front ogive section; an aft section; and a control module; wherein the front ogive section is rotatably connected to the aft section by a coupling device, the front ogive section further comprising an asymmetric surface such that the asymmetric surface exerts an imbalance upon the projectile, where in use, the angular rotation of the front ogive section can be selectively adjusted relative to the aft section by commands from the control module to the coupling device influencing a helical trajectory of the projectile in flight thereby causing a change in direction thereby steering the projectile towards a target.

Abstract: A system to determine a temperature corrected pressure of a medium in a pressure transducer is disclosed. The system comprises a first circuitry to obtain a first value related to a vibration frequency of the vibration of a pressure sensitive vibration member; a second circuity to obtain a second value related to a vibration amplitude of the vibration of the vibration member; and a third circuity to use the first value and the second value to determine the temperature corrected pressure of the medium based on a predetermined relationship between the vibration frequency and the vibration amplitude.

Abstract: Apparatus (100) for use in space, the apparatus (100) comprising: a feedstock storage module (108) for storing a feedstock; a heating module (110) coupled to the feedstock storage module (108) and configured to heat the feedstock; an extrusion nozzle (112) coupled to the heating module (110) and configured to extrude heated feedstock from the apparatus (110); and one or more thrusters (118) configured to provide a propulsive force to the apparatus (100).

Abstract: There is disclosed a rotorcraft comprising: an array of lift devices; a pilot housing; connecting lines attaching the pilot housing to the array of lift devices; and an actuator interface at the pilot housing such that the pilot can 5 steer the rotorcraft.

Abstract: A jet engine exhaust assembly 20 is disclosed. The exhaust assembly comprises a double-walled exhaust duct 22 comprising an inner wall defining the inner profile of the duct and an outer wall spaced apart from the outer surface of said inner wall to define a cooling space 21 therebetween. The double-walled exhaust duct 20 is a structural load bearing component.