Abstract: An adaptive control unit is described for receiving an analog input signal containing at least an indication of a parameter to be controlled to generate an analog output signal for control of the parameter. The analog input signal contains a fed back component resulting from the analog output signal. The adaptive control unit comprises an analog filter having an adjustable gain, a gain adjuster for adjusting the gain of the analog filter using a feedforward adjustment method, and a filter for compensating for the fed back component in the analog input signal.

Abstract: The present invention generally relates to proximity sensor monitors and proximity monitor systems incorporating proximity sensor monitors. A proximity sensor monitor measures the impedance or other electrical characteristics of a proximity sensor component to determine the presence of a target. The proximity sensor monitor performs this measurement independently of a separate proximity sensor. The proximity sensor monitor is configured to compensate for differences between the measurement frequency of the proximity sensor monitor and the driving frequency of the proximity sensor.

Abstract: A cable (7) is routed between a pair of links (1, 2) that are pivotally connected about a lateral pivot axis (4). A wound section (8) is provided in the cable with the winding axis coincident with the pivot axis of the links. The wound section (8) may be preformed. A cable protector (10, 11) is provided each end of the wound section (8) along the pivot axis (4) so as to constrain the adjacent end of the wound section (8) to be keyed with it and the adjacent link.

Abstract: An active tuned vibration absorber (100) is disclosed for reducing vibrations in a structure, the vibration absorber comprising: a mount (104) for attachment to the structure; a moveable mass (106); a spring arrangement (108) connected between the mass and the mount; an actuator arrangement (110) for applying a force between the mass and the mount; a first sensor (112) for providing a first measurement indicative of a force exerted between the structure and the mount; a second sensor (114) for providing a second measurement indicative of an acceleration of the structure at or proximate to the mount; and a control system (116) for generating an actuator driving signal for driving the actuator using the first and second measurement, wherein the control system is operable to generate the actuator driving signal to cause the first measurement and second measurement to conform to a target relationship.

Abstract: Apparatus for measurement of a DC voltage of a DC voltage source. An electrode forms a capacitive connection with the DC voltage source. A non-linear capacitor has a first node connected to the electrode. An initial voltage source is arranged to generate an initial voltage. A switch is arranged to selectively apply the initial voltage to a second node of the non-linear capacitor. A voltage sensor is arranged to measure the voltage of the second node of the non-linear capacitor and a processor is programmed to deduce the DC voltage of the DC voltage source by analysing the rate of decay of the measured voltage.

Abstract: A method is disclosed for controlling the distribution of power to a plurality of devices, the method being carried out during a plurality of time periods, and the method during each time period after the first comprising: determining (S700) an energy or power deficit for each device based on the difference between a target amount of energy or power and a measured amount of energy or power supplied to the device prior to the current time period; selecting (S702) at least one device in decreasing order of energy or power deficit, whereby priority is given to devices having the largest energy or power deficit or the smallest energy or power surplus, until the selection of any further devices will cause a total estimated power consumption of the selected devices during the time period to exceed a predetermined maximum power consumption; and supplying (S704) power to the or each selected device during the time period.

Abstract: A method of calibrating a heater system for heating a surface of a structure, the heater system including a heater element, a temperature sensor proximate the heater element for outputting a signal indicative of the temperature of the heater element, and a controller for controlling the supply of power to the heater element in dependence on the signal to maintain the temperature of the heater element at a first substantially constant temperature. The method comprises: immersing the structure in a fluid for maintaining the surface of the structure at a second substantially constant temperature; supplying an amount of power to the heater element; receiving the signal from the temperature sensor and determining a temperature at the temperature sensor; and determining a setpoint temperature for controlling the heater element in dependence on the signal and the second substantially constant temperature.

Abstract: An ice detection system, in particular a method, apparatus and controller for detecting icing conditions and the presence of ice formed on a structure. Also, a method, apparatus and controller to detect the prevailing environmental conditions to determine whether or not ice may form on a structure. Two heaters of an ice protection system (experiencing substantially the same environmental conditions) are driven to different temperatures (the first greater than or equal to 0° C., and the second less than 0° C.). A difference in the powers required to drive the two heaters indicates the prevailing environmental conditions. In another embodiment, a heater of an ice protection system is driven and the rate of change of surface temperature is measured over several periods. A substantial deviation from a rate of change of surface temperature, which indicates the presence of ice on the surface of the structure, is detected.

Abstract: An ice protection system for a structure having at least one surface to be protected from a range of icing conditions. The ice protection system includes at least one heater device, arranged in thermal contact with at least one surface to be protected; at least one temperature sensor for outputting at least one temperature signal, the sensor being in thermal contact with the heater device; and a control system for controlling the heat output of the heater device using the temperature signal. The control system is operable to control the heat output of the heater device in order to maintain the temperature of the heater device at a substantially constant temperature.

Abstract: A linkage guides a flexible cable between two structures. The linkage includes a proximal arm with a proximal pivot joint for coupling the proximal arm to a first one of the two structures; and a distal arm which is coupled to the proximal arm by one or more intermediate pivot joints. The distal arm is shaped to follow a three-dimensional curve along a majority of its length. Shaping the distal arm to form a three-dimensional curve along a majority of its length enables the distal arm to pass through a relatively small aperture as the linkage is adjusted between its retracted and extended positions. It also enables the proximal arm to move in a locus of movement which does not interfere with other system components. The linkage can be used to guide a flexible cable between any two structures, for instance a fixed aircraft wing and a slat.

Abstract: An ice detection system, in particular to a system for detecting icing conditions and a system for detecting the presence of ice formed on a structure, and the methods for doing the same. Two heaters of the ice protection system (experiencing substantially the same environmental conditions) are driven to different temperatures (the first greater than or equal to 0° C., and the second less than 0° C.). The difference in the powers required to drive the two heaters indicates the prevailing environmental conditions. A heater of the ice protection system is driven and the rate of change of surface temperature is measured over several periods. A substantial deviation from a rate of change of surface temperature, which indicates the presence of ice on the surface of the structure, is detected.

Abstract: A current measurement apparatus includes a shunt resistor (1) located between two terminal members (5, 6), each connected electrically to a respective end (4, 3) of the shunt resistor, and each extending over substantially the whole of an adjacent side face of the shunt resistor. Electrically insulating, thermally conductive material (8, 9) is provided between each side face of the shunt resistor (1) and the terminal members (5, 6), and serves to provide a thermal path for heat exchange between the shunt resistor and the terminals. The shunt resistor (1) is engineered to have the desired electrical properties, and the terminal members are connected by mechanical fasteners (13, 14) to ensure the required electrical properties without calibration. Measuring circuitry (15) is incorporated between the shunt resistor (1) and terminal members (5, 6).

Abstract: Each of a plurality of acoustic sensors (acoustically coupled to a structure for monitoring) is connected to a network bus system via a preamplifier for capturing, processing and reporting acoustic events in a structure, for example aircraft structures. Each of the preamplifiers processes the acoustic event signals received from the sensors when an acoustic emission resulting from an acoustic event (defect in a structure, impact on the structure etc), and passes digital processed signal data relating to the detected acoustic event to a Remote Data Concentrator over the network for collation. The collated data is then stored and/or further processed (at a later time or in near real-time) to determine the source and/or location of detected acoustic emissions in the structure.

Abstract: An adaptive control unit is described for receiving an analog input signal containing at least an indication of a parameter to be controlled to generate an analog output signal for control of the parameter. The analog input signal contains a fed back component resulting from the analog output signal. The adaptive control unit comprises an analog filter having an adjustable gain, a gain adjuster for adjusting the gain of the analog filter using a feedforward adjustment method, and a filter for compensating for the fed back component in the analog input signal.

Abstract: A towable buoy having a tow point for connection to a tow cable of a vessel, wherein the position of the tow point is translationally moveable with respect to the remainder of the buoy. Also, a method of operating the towable buoy.

Abstract: A method and system for detecting structural damage in a structure by detecting acoustic emissions from damage in a structure to obtain acoustic emission data, and processing the acoustic emission data in accordance with a model characterising acoustic paths. The model is built by inducing a plurality of types of acoustic emissions at each of a plurality of positions on a structure, the plurality of types of acoustic emissions corresponding to a respective plurality of types of structural damage. The acoustic emissions are detected using at least three sensors arranged on the structure, and the detected acoustic emissions are processed for each position to determine model data characterising effects on each type of acoustic emission from each position of acoustic paths between the positions and the sensors. The processed data is then stored as model data.

Abstract: A cable (7) is routed between a pair of links (1, 2) that are pivotally connected about a lateral pivot axis (4). A wound section (8) is provided in the cable with the winding axis coincident with the pivot axis of the links. The wound section (8) may be preformed. A cable protector (10, 11) is provided each end of the wound section (8) along the pivot axis (4) so as to constrain the adjacent end of the wound section (8) to be keyed with it and the adjacent link.

Abstract: A buoy is provided with first and second fixed hydrodynamic surfaces (15,16). When the buoy is towed through water by a tether (17), the first hydrodynamic surface (15) generates a downward force that reduces with increased speed through the water. The second hydrodynamic surface (16) generates an upward force that increases with increased speed through the water so that the buoy dives up to an upper critical speed through the water speed and rises beyond said upper critical speed through the water. The downward force of the first hydrodynamic surface (15) overcomes the buoyancy of the buoy at a lower critical speed through the water above, which the buoy dives. The hydrodynamic surface (15) comprises first fins (15) mounted on an outer casing (1) of the buoy and are spaced angularity and extend parallel to the center axis of the buoy which is substantially aligned with the direction of towing.

Abstract: A current measurement apparatus includes a shunt resistor (1) located between two terminal members (5, 6), each connected electrically to a respective end (4, 3) of the shunt resistor, and each extending over substantially the whole of an adjacent side face of the shunt resistor. Electrically insulating, thermally conductive material (8, 9) is provided between each side face of the shunt resistor (1) and the terminal members (5, 6), and serves to provide a thermal path for heat exchange between the shunt resistor and the terminals. The shunt resistor (1) is engineered to have the desired electrical properties, and the terminal members are connected by mechanical fasteners (13, 14) to ensure the required electrical properties without calibration. Measuring circuitry (15) is incorporated between the shunt resistor (1) and terminal members (5, 6).

Abstract: There is disclosed a printer, comprising a print unit for printing on a print medium; a print media reversal unit for reversing the print medium to allow double-sided printing onto the print medium; a memory unit for storing printer configuration data, the printer configuration data including data specifying whether or not the printer is permitted to operate in a double-sided printing mode; an input device for receiving an instruction to permit the operation of the printer in a double-sided printing mode; and a print controller for controlling the print unit and the print media rotation unit, the controller being programmed to operate the printer in either a single-sided or double-sided mode in dependence on the printer configuration data, and to update the printer configuration data appropriately in response to receiving the instruction to permit the operation of the printer in a double-sided printing mode.