Abstract: A functional rotor, desirably but not necessarily a Savonius, helical, or other vertical axis wind turbine rotor, has other functions in addition to driving a useful driven mechanism (such as an electricity or hydrogen generator, pump, etc.). The rotor has exterior rotating surface areas and at least one of design, aesthetic, holographic, reflective, and informational elements on those areas that create the illusion of movement distinct from the rotation of the rotor itself. The elements may be substantially vertical holographic material or reflective material stripes alternating with non-holographic or non-reflective stripes, or at least one of design and aesthetic elements disposed to create a spiral movement illusion. The elements may be selected and positioned so that a message or design is completed in the viewer's eye only upon rotation of the surface areas. The rotor may simulate a praxinoscope, phenakistascope, or zoetrope.

Abstract: A wind turbine generator generates power through rotation of a rotor to which a plurality of blades are pivotally coupled and includes a pitch-angle control section that outputs a pitch-angle command value that indicates the amount of change in the pitch angle of each of the blades, hydraulic cylinders each of which changes the pitch angle of the corresponding blade based on the corresponding pitch-angle command value output from the pitch-angle control section, and load measurement sections that measure blade-root loads. A set value indicating that wind received by the wind turbine generator has a biased wind speed distribution is set in advance in the pitch-angle control section. Only when a calculated pitch-angle command value exceeds the set value, the pitch-angle control section outputs a pitch-angle command value beyond pitch command limit values.

Abstract: A method for monitoring blade frequencies of a wind turbine and a monitoring system for performing the method are provided. An accelerometer or G-sensor is placed into a nacelle of a wind turbine and thereby measuring the vibrations of the nacelle. To extract the vibration signals originating from each blade, the vibration signals are combined with the measuring signals from the azimuth angle sensor (rotating angle), which is normally used for pitch control. To further extract each blade frequency a Fast Fourier Transformation is used on the modulated G-sensor signals. To further monitor a severe and alarming change in each blade frequency, each blade frequency is compared to the other blade frequencies and an alarm is set when a given level is reached.

Abstract: Disclosed is a method of reducing a structural unbalance in a wind turbine rotor with pitch control and a control device for performing the method are provided. The method comprises the steps of: detecting a magnitude of the structural unbalance and its phase in relation the rotor's azimuth (?) on the basis of a measurement of the rotor's azimuth (?) and a measurement of the rotor speed or the generator speed (?), establishing individual pitch angle offsets for each blade of the rotor on the basis of the magnitude and the phase, and adding the individual pitch angle offsets to the respective pitch angles of the blades of the rotor.

Abstract: An electric fan includes a fan shaft driven by a fan motor supported by a motor support. An oscillating device includes a rotational shaft connected to the motor support for driving the motor support to oscillate. A transmission gear has an axle connected to the rotational shaft and a gear wheel mounted around the axle and driven by a synchronous motor. An oscillating angle limiting switch detects a rotational angle of the rotational shaft and the gear wheel and sends a signal indicative of the rotational angle. A circuit board has a processor coupled to the oscillating angle limiting switch and receives the signal. A comparing program compares the rotational angle indicated by the signal with a selected one of a plurality of preset rotational angles. The synchronous motor is driven when the rotational angle indicated by the signal is equal to the selected preset rotational angle.

Abstract: A wind turbine and a method of controlling yawing of a wind turbine are provided. A nacelle is mounted rotatable around a first axis by an adjustable yaw angle and a hub is mounted rotatable around a rotational axis. The hub includes a blade rotating around the rotational axis, the blade defining a rotor plane perpendicular to the rotational axis. A channel of the wind turbine has an opening, the opening being located at a predefined distance to the rotor plane. At least one component of incoming wind is guided through the opening and into the channel as air flow. A measuring device is provided for measuring the air flow, the measuring device being connected to a controller. The controller detects a yaw angle error between a direction of the incoming wind and the rotational axis, the yaw angle error being used to adjust the yaw angle of the nacelle.

Abstract: Described is a rotor blade for a wind power installation having a rotor blade leading edge. A deposit sensor device is arranged in the region of the rotor blade leading edge. That deposit sensor device has a transmitter for the wireless transmission of signals by way of a transmission link and a receiver for receiving the signals wirelessly transmitted by way of the transmission link. Deposits on the surface can be detected in the region of the transmission link on the basis of the signals transmitted by way of the transmission link.

Abstract: The invention relates to a method for detecting icing and other loadings on blades of wind turbines. Advantageously, the method utilizes existing wind turbine actuators, for example pitch actuators, far excitation of blade vibrations. Vibration sensors on the blade such as strain sensors or accelerometers measure the blade vibrations excited in response to the actively excised vibrations. By comparing the measured response with previously obtained reference responses, it is possible to determine if blade icing is present.

Abstract: The invention provides a method and system of detecting ice or other foreign matter on a wind turbine blade or damage to a wind turbine blade. The method in one aspect comprises: measuring twisting torque on the blade about its longitudinal axis to provide a detected torque signal; comparing a value based on the detected torque signal with a comparison value, the comparison value derived from one or more measured parameters having a predetermined relationship with the twisting torque about the longitudinal axis of the blade when the blade is operating under normal operating conditions; and determining that ice or other foreign matter is on the blade or that the blade is damaged if the value based on the detected torque signal differs from the comparison value by more than a predetermined amount. Wind turbine blades are designed such that any change in the shape of the blade reduces twisting torque on the blades significantly.

Abstract: The invention provides a wind turbine blade comprising a first shell, having a first bonding region, and a second shell having a second bonding region, wherein the second bonding region of the second shell is bonded to the first bonding region of the first shell; and a temperature sensor positioned between the first bonding region and the second bonding region. Having a temperature sensor positioned within the turbine blade, in the region at which the two shells of the turbine blade are bonded together, allows for accurate determination and control of the temperature of the critical bonding regions during blade manufacture. The temperature sensor may be used during the service life of the wind turbine blade to detect delamination of the wind turbine blade.

Abstract: A wind turbine condition monitoring system and method are disclosed where the wind turbines include a tower, a gearbox coupled to the tower, and turbine blades coupled to the gearbox. The monitoring system includes blade sensors coupled to the blades, a hub node coupled to the gearbox and a controller. The controller is in communication with the hub node and blade sensors, and determines blade positions based on blade sensor readings. The blade sensors and hub node can include multi-axis accelerometers. The controller can wirelessly communicate with the blade sensors directly or through the hub node. Using position information, shadowing areas with obstructed communication can be avoided, node separation can be accounted for to reduce power requirements and/or interference from multiple transmitters can be avoided during node communications.

Abstract: The method consists in depositing, by alumina spraying, an electrically insulating sublayer on the substrate, then in placing the sensor on the electrically insulating sublayer and finally in depositing, by alumina spraying, a cover layer on the sensor and the electrically insulating sublayer. It further includes, before the cover layer is deposited, a step in which an impermeable and thermally insulating cement is applied locally on wires of the sensor.

Abstract: A system and method capable of performing online corrosion monitoring of a component installed in a gas turbine. A sensing device is located so that electrodes thereof are exposed to an operating environment within the gas turbine section containing the component. The electrodes are formed of a material so that the component and electrodes similarly respond to corrosive agents within the gas turbine section. The electrodes are electrically insulated from each other and each electrode is operable as an anodic electrode or a cathodic electrode, depending on the extent of corrosion thereat, so that each electrode has an electrical potential value, voltages exist across the electrodes, electric currents flow between the electrodes, and the electrical potential/current values correspond to corrosion behaviors at the anodic electrodes.

Abstract: The invention relates to a fairing adapted to be mounted on a wind turbine blade (2), wherein the outer surface of said fairing is arranged so as to reduce, when mounted on the blade, the aerodynamic drag in a flapwise (z) direction of the blade. In this way a reduction of the exciter power required in a flatwise fatigue test of the blade is achieved.

Abstract: The risk of an extreme gust of wind hitting a wind turbine is estimated by gathering data from one or more sensors for use as training data. This data is acquired over a period of time and is converted in to a feature vector for a given time period by a statistical measure. A number of feature zones are formed, each zone relating to a different estimate of risk with each feature vector being assigned to a risk category. The risk category is defined with reference to the value of one or more chosen turbine parameters at the time the data was acquired. The feature zones are formed from from a measure of distance such as the mean and co-variance of feature vectors from within a given category. Live data is processed by measuring the mahalonobis distance from the feature vector of the live data to the centre of each zone and the risk of an extreme gust is assessed as that of the feature zone to which the mahalonobis distance is lowest.

Abstract: The invention relates to a wind turbine, comprising a tower, a nacelle, at least one blade with a tip end and a root end and monitoring means for monitoring the surface condition of the blade, wherein said monitoring means are located at the tower or at the nacelle and wherein said monitoring means are adapted to monitor the surface condition of at least substantially one entire side of the blade from its tip end to its root end.

Abstract: A monitoring system and associated operational method are operatively configured with a wind turbine for detecting separation of shell members along an edge of a wind turbine rotor blade. The system includes any configuration of sensors disposed within an internal cavity of the rotor blade, with the sensor oriented relative to a leading or trailing edge of the blade and configured to detect a physical characteristic within the blade that is indicative of onset of a separation between the shell members along the monitored edge. A controller is configured to receive signals from the sensor and to initiate an automatic response to a detected separation.

Abstract: A method for estimating an operating temperature of component in turbo machinery includes providing body detachably affixed to component, operating machinery, stopping operation of machinery, and removing body. The method includes obtaining concentration profile by determining final concentration of at least one species in first material and in second material, and determining a transient concentration of at least one species between first material and second material. The method includes determining an operating temperature by correlating concentration profile to corresponding operating temperature for system. A system including body is also provided. Body includes at least one species, a first material having a starting first concentration of the species, a second material arranged to permit migration of the species from first material to second material. Species migrates from first material to second material during operation of turbo machinery allowing body to estimate temperature during operation.

Abstract: An object is to provide a wind turbine and an apparatus and method for detecting damage to a wind-turbine-blade skin, which can reduce the workload of workers who are in charge of inspection for damage to a wind-turbine-blade skin. Provided is an apparatus for detecting damage to a wind-turbine-blade skin that detects damage to the skin of a wind turbine blade having a hollow structure, the apparatus including a pressure sensor that measures the internal pressure of the wind turbine blade; and a nacelle-side control unit that detects damage based on the pressure measured by the pressure sensor.

Abstract: A method for attaching a connector to deposited material includes the steps of depositing material on a substrate using a thin- or thick-film deposition process and attaching at least one connector to the deposited material using a high energy beam welding process.

Abstract: A method is disclosed for calibrating a wind turbine sensor placed on a component of a wind turbine and where the wind turbine is of the type having a rotor with at least one pitchable wind turbine blade. The method comprises pitching one or more of the blades according to a predetermined pitch movement and detecting the response signal from the wind turbine sensor at least partly caused by the pitch movement. From this is then determined a characteristic sensor response value which upon comparison to a predetermined sensor calibration parameter forms the basis for a calibration of the wind turbine sensor if needed. The characteristic sensor response value may be determined from the pitch movement having been performed a number of times over a longer period of time. The invention further relates to a control system and a wind turbine configured for performing the method.

Abstract: An aerodynamically shaped profile member for aircraft and wind power stations includes, for example, phased-array ultrasonic generator arrangement arranged therein. During operation of the profile member, the ultrasonic generator emits ultrasonic waves in a targeted manner in multiple directions to determine a profile of the thickness of an ice layer on the surface of the aerodynamic profile. The structure may be, for example, a composite fiber material arranged around a foam core, with the ultrasonic generator arrangement being laminated into the composite fiber material. For measurement of the ice thickness, ultrasonic waves are transmitted in a targeted manner to different positions of the surface of the aerodynamic profile, and the ultrasonic waves reflected on the interfaces of the ice layer are detected. At least one region of the surface is scanned by means of the targeted ultrasonic waves, to determine an ice thickness profile.

Abstract: A rotary blade rotating hub mounted rotating assembly vibration control system including a first imbalance mass concentration rotor, a second imbalance mass concentration rotor, a third imbalance mass concentration rotor, and a fourth imbalance mass concentration rotor. The first imbalance mass concentration rotor has a first imbalance mass concentration rotor center axis rotation centered on the rotating assembly center rotation axis. The second imbalance mass concentration rotor has a second imbalance mass concentration rotor center axis rotation centered on the rotating assembly center rotation axis. The third imbalance mass concentration rotor has a third imbalance mass concentration rotor center axis rotation centered on the rotating assembly center rotation axis. The fourth imbalance mass concentration rotor has a fourth imbalance mass concentration rotor center axis rotation centered on the rotating assembly center rotation axis.

Abstract: A system for detecting loads in a wind turbine is disclosed. In one aspect, the system may generally include a shaft and first and second pillow blocks receiving portions of the shaft. The second pillow block may be spaced axially apart from the first pillow block. Additionally, the system may include at least one sensor configured to indirectly detect loads transmitted through at least one of the first pillow block and the second pillow block.

Abstract: A method for operating a wind turbine having at least one blade includes determining an ambient air operating envelope and controlling a power output of the wind turbine at least partially based on the determined ambient air operating envelope. Determining an ambient air operating envelope includes measuring at least one of an ambient air temperature, an ambient air pressure, an ambient air humidity, and wind turbine power output. The method also includes comparing at least one of a measured ambient air temperature, a measured ambient air humidity and a measured ambient air pressure to predetermined ambient air temperature, pressure and humidity values. The method further includes referencing the predetermined ambient air temperature, pressure and humidity values to at least one operational parameter of the wind turbine. The method also includes determining if an existing wind turbine power output is within a range associated with the determined ambient air operating envelope.

Abstract: A wind turbine for generating electrical power, the turbine having a rotor assembly comprising a hub, a rim and a plurality of blade members extending between the hub and rim, and at least two anemometers mounted at stationary locations relative to the rotor assembly or on the rotor assembly itself, wherein the pitch of individual blade members is adjustable in response to differences in wind speed detected by the anemometers as the rotor assembly rotates.

Abstract: A wind turbine rotor blade is disclosed that includes a body extending between a blade root and a blade tip. The body may include a pressure side and a suction side extending between a leading edge and a trailing edge and may define an outer surface. In addition, an ultraviolet light-reflective tape may be disposed on the outer surface of the body.

Abstract: The invention relates to a method for the operation of a wind power plant (11) with a rotor (10) and a rotating apparatus (20, 22, 24) connected with the rotor (10), wherein a rotor speed (nR) and a rotating apparatus speed (n) are interrelated via a specifiable transmission ratio, wherein the rotating apparatus speed (n) is determined, and wherein a rotational speed measurement value (rpmi) is captured for the determination of the rotating apparatus speed (n). The method according to the invention is characterized in that the rotational speed measurement value (rpmi) is corrected with an intermittently variable correction value (rpmi,c) so that the determined rotating apparatus speed (rpmi,f) results, and wherein the determined rotating apparatus speed (rpmi,f) is fed as the actual value into a regulation apparatus (36) of the wind power plant (11).

Abstract: Embodiments of the invention provide methods, systems, and apparatus for determining a property of wind approaching a wind turbine. A light detection and ranging equipment may emit pulsed radiation into oncoming wind to detect properties of the wind at a plurality of predefined locations. A property of the wind approaching the wind turbine may be determined based on the property of wind measured at at least two predefined locations.

Abstract: An apparatus, for example for a pitch change mechanism, includes a cylinder having a magnetic portion defining an annular array of features extending parallel to the longitudinal axis of the cylinder, the cylinder rotating in use and able to translate longitudinally. There is a sensing arrangement including a stationary magnetised core and two coils connected in series and wound around the core. In use, the cylinder rotates and current is induced in the coils. Monitoring equipment is arranged to calculate rotational speed of the cylinder from the frequency of the current and to calculate longitudinal position from the relative amplitude of the current in each coil. Also a method.

Abstract: A watercraft propulsion device includes an engine, a drive shaft, a propeller shaft, a shift mechanism, an operation force transmitting mechanism, and a magnetostrictive sensor. The drive shaft transmits power from the engine. The propeller shaft is rotationally driven by power transmitted from the drive shaft. The shift mechanism changes a rotation direction of power transmitted from the drive shaft to the propeller shaft. The operating force transmitting mechanism connects to the shift mechanism and transmits a shift operation force to the shift mechanism to cause the shift mechanism operate. The magnetostrictive sensor detects a load acting on the operation force transmitting mechanism.

Abstract: The fan has an arrangement for monitoring the ageing of at least one of its bearing, the arrangement including a reference ambient temperature sensor and a processing circuit for comparing the temperature difference between the temperature measured by the temperature sensor or by each temperature sensor fitted directly on the corresponding bearing and the temperature measured by the reference temperature sensor with a first predetermined value.

Abstract: A fan test system includes a control module. The control module includes a temperature-speed table storing standard speeds at different temperatures of a fan, a counter loaded with a default value, and a fan speed control unit setting the time interval for obtaining the actual speed of a fan corresponding to a certain temperature. The fan speed control unit obtains the actual speed of the fan at every interval time, and determines whether the speeds obtained at predetermined continuous interval times are equal. The fan speed control unit obtains the standard speed of the fan according to the certain temperature if the speeds are equal. It indicates the fan is qualified in response to the actual speed being equal to the standard speed.

Abstract: A wind energy power plant optical vibration sensor is described, using two light sources 15, 16 that emit light at different respective frequencies. The light from the first light source falls on a surface 44 of the wind energy power plant at a detection site. Movements in the surface result in changes to the phase of the light reflected back from the surface which can be detected by mixing the first light with the light emitted from the second light source. The difference in frequencies between the two light sources results in a beating of the resulting interference signal, whereas movements in the sensor surface result in changes in the phase timing and frequency of the beats.

Abstract: Embodiments of the present application can provide systems and methods for mode shape identification of turbine buckets. According to one embodiment, a system can be provided. The system can include a turbine bucket having numerous trigger patterns disposed at a distal end of the turbine bucket. A sensor is disposed adjacent to the distal end of the turbine bucket for detecting the trigger patterns. The trigger patterns are patterned to identify at least one mode shape of the turbine bucket.

Abstract: A system is provided for transmitting data between a first component and a second component, which rotates relative to the first component. The system includes a first coupling element of limited angular extent mounted to the first component, and a second coupling element of limited angular extent mounted to the second component. The first and second coupling elements come into angular alignment once per revolution of the second component relative to the first component. The system further includes a first transceiver connected to the first coupling element, and a second transceiver connected to the second coupling element. The first and second transceivers are configured to detect the angular alignment of the first and second coupling elements. The first and second transceivers are further configured to transmit data between the first and second transceivers via the first and second coupling elements when the angular alignment is detected.

Abstract: The present invention relates to a method and a system for operating a Wind Turbine (WTG), which WTG comprises a rotor comprising at least two blades, which blades are pitch regulated, where the rotor is connected to a shaft, which shaft is supported by bearings, and which shaft drives at least one generator, where the WTG uses a load regulation system for regulating the individual pitch of at least two blades. The object of the invention is to compensate for asymmetric load on the rotor in a wind turbine, a second object is to reduce wearing at shaft bearings in the wind turbine, and a third object is to increase the power production of a wind turbine. This can be achieved if the load regulation system measures the actual rotor load by at least one displacement sensor, which displacement sensor is measuring the bending of the main shaft, where the load regulation system based on the shaft bending regulates the individual pitch of the blades for compensating asymmetric load at the rotor.

Abstract: The present disclosure relates to a method for operating a wind turbine with the steps: detection of the values of predetermined operating parameters by means of suitable sensors, detection of at least one predetermined initial condition, comparison of the detected values to stored values of the operating parameters. The disclosure further relates to a wind turbine for implementing the method. Therefore, the object of the present disclosure is, to be able to adapt the operation of a wind turbine to changes using a method of the type named above, such that when the detected parameter values deviate from the stored parameter values, as a function of the initial condition, either the stored parameter values are adapted to the detected parameter values or the operation of the wind turbine is influenced as a function of the detected parameter values.

Abstract: A creep indication system and a method for determining a creep amount are disclosed. The system includes a first creep indicating member on a first rotating component and a second creep indicating member on a second rotating component. The second creep indicating member has at least one different creep characteristic from the first creep indicating member. The system further includes at least one measurement device configured to measure a change in radial position of at least one of the first creep indicating member or the second creep indicating member. The method includes measuring a first creep amount of a first creep indicating member and measuring a second creep amount of a second creep indicating member. The method further includes estimating a temperature of a rotating component using the first creep amount and the second creep amount.

Abstract: A method of operating a wind turbine having at least one rotor blade and an active flow control (AFC) system is provided. The at least one rotor blade has at least one aperture defined through a surface thereof, and the AFC system is configured to modify aerodynamic properties of the rotor blade by ejecting gas through the aperture. The method includes operating the wind turbine in a normal mode, determining whether an estimated insect density value surrounding the wind turbine is above an insect density threshold value based on a measured environmental condition, and changing a mode of the wind turbine from the normal mode to a cleaning mode different than the normal mode based on the estimated insect density value. The cleaning mode includes adjusting at least one operation parameter of the wind turbine based on the estimated insect density value such that fouling of the aperture is reduced.

Abstract: A device for detecting a shaft rupture in a rotor of a turbine, in particular a medium-pressure turbine, of a gas turbine, in particular of an aircraft engine, at least one stator-side sensor element being positioned downstream from the turbine, in particular in the area of a stator-side blade ring of another turbine, in particular a low-pressure turbine, and, in case of a shaft rupture of the rotor of the turbine, a radially externally situated segment of a last (seen in the direction of flow) rotor-side blade ring of the turbine working together with the, or with each, sensor element to generate an electrical signal corresponding to the shaft rupture.

Abstract: A wind turbine and methods for controlling wind turbine thrust are disclosed. In one embodiment, the method includes measuring a tilt angle of a wind turbine in a loaded position using a measuring device. The wind turbine includes a tower, a nacelle mounted on the tower, a rotor coupled to the nacelle, and a plurality of rotor blades coupled to the rotor. The method further includes comparing the tilt angle to a predetermined tilt angle for the wind turbine and, if the tilt angle exceeds the predetermined tilt angle, adjusting a pitch of at least one of the plurality of rotor blades such that the tilt angle is less than or equal to the predetermined tilt angle.

Abstract: A lubrication system and wind turbine are provided having one or more input ports in a component and one or more output ports in the component. An expandable lubrication receptacle is connected to the one or more output ports, and the expandable lubrication receptacle is configured for receiving a lubrication medium from the component.

Abstract: A method of validating a wind turbine including a rotor includes intentionally inducing a loading imbalance to the rotor. The method also includes measuring the loading imbalance induced to the rotor, transmitting a signal representative of the measured loading imbalance to a calibration module, and at least one of detecting an error and calibrating at least one component of the wind turbine based on the signal.

Abstract: A method is disclosed for inspecting a weld joining a first rotor disk made of nickel alloy and having an inner surface and an outer surface concentric with the rotor's longitudinal axis to a second rotor disk having an inner surface and an outer surface concentric with the rotor's longitudinal axis. The weld made of nickel alloy fills a radial gap between the rotor disks, and has a dissimilar microstructure to either of the rotor disks. The method includes forming at least one slot in the first rotor disk extending through either the inner surface or the outer surface of the first rotor disk terminating in the first rotor disk; and passing an inspection signal from the first slot to the weld to inspect the weld for defects.

Abstract: An arrangement with a nacelle and with at least one instrument of a wind turbine is disclosed. The instrument is connected with a rod. A channel penetrates the wall of the nacelle. The channel interacts with the rod in a way that the rod and its assigned instrument are moved through the channel between a first and a second position. The instrument is positioned inside the nacelle at the first position for installation and/or service purposes, while the instrument is positioned outside the nacelle at the second position for operation purposes of the instrument.

Abstract: A blade monitoring system is provided for inspecting the condition of at least one turbine blade of a wind turbine generator. The wind turbine blade condition monitoring system includes a wind turbine which has at least one blade mounted on a hub, the hub mounted to a nacelle body along an axis of rotation, the nacelle being supported on a tower. A storage location is connected to at least one of the nacelle body and the tower and includes an opening. A storage door is mounted to and selectively covers the opening, acting to enclose the storage location. The blade monitoring system also includes imaging equipment for imaging the at least one blade and a conveyance system. The conveyance system is mounted to at least one of the nacelle body and the tower and is connected to the imaging equipment. The conveyance system conveys the imaging equipment from within the storage location through the opening in a direction generally parallel to a longitudinal axis of the at least one blade.

Abstract: The invention relates to a sensor system and method for detecting deformation in a wind turbine rotor blade, and particularly to a temperature compensated system and method. A first optic fiber 22b is attached to the rotor blade such that deformation of the component acts on the first optical fiber and causes the optical path length of the fiber to change. A second optic fiber 27 is mounted loosely in the wind turbine component in such a way that it is not subject to deformation. A light source 10, a light detector 11, and a controller 12 input light into the two optical fibers and receive signals from them. Based on the detected light, the controller can determine the optical path length based on the light signals. In different embodiments, the light source varies the input wavelength over a range of wavelengths, provides a multi wavelength light signal, such as a white light source, or inputs a pulsed light signal.

Abstract: Disclosed is a method of capturing 3D data of one or more airborne. At least one image of the one or more airborne particles is taken by a plenoptic camera of which the geometry and the optical properties of its optics are known, and the distance of a plane of focus with at least one selected particle of the one or more airborne particles from a defined reference location is determined by use of the captured image together with the known optical properties and the known geometry of the optics of the plenoptic camera.

Abstract: A method for acoustically monitoring a wind turbine, in particular for monitoring the existence of loose objects inside the wind turbine is provided. A sound generated in a rotating part of the wind turbine is monitored during operation of the wind turbine which sound is analyzed with respect to specific parameter values of the sound within at least one specific frequency range and if such specific parameter values are detected, a signal for possible further actions is generated. An acoustic monitoring system for a wind turbine and a re-equipment kit are also disclosed.