摘要:
A technique for correcting wavefront aberrations introduced by large primary optical elements in portions of the electromagnetic spectrum. The aberrations of the primary element are first transferred to a beacon beam and this aberrated beam is interfered with a reference beam in a holographic medium. These beams are then turned off and a beam from a distant object, containing the same aberrations, is allowed to diffract from the hologram. The diffracted beam from the hologram contains the image of the distant object with aberrations removed. Use of this technique permits the construction of large optical elements inexpensively, since surface tolerances of the elements can be substantially relaxed.
摘要:
Apparatus, and a corresponding method for its use, for producing a phased array of high-energy laser beams from multiple laser amplifiers. A reference beam produced by a master oscillator senses phase and piston errors in a primary mirror array, and is divided into multiple probe beams, each of which makes multiple passes of its own laser amplifier. The multiple probe beams are together focused into a single phase conjugation cell, which not only produces phase-conjugated reflected beams, to effect compensation for various phase aberrations, but also locks all of the reflected beams together in phase. An arrangement of a birefringent wedge and a quaterwave plate for each of the beams prevents the reflected beams from returning to the master oscillator and facilitates combining of the reflected beams for output as a cophasal array. In a preferred embodiment of the invention, this is accomplished by using the birefringent wedges to deflect each retro-reflected phase-conjugated beam onto the appropriate portion of a monolithic secondary mirror, and then to the primary mirror array.
摘要:
In one aspect, a hydraulic system including a reservoir, a hydraulic device, a first sensor, a second sensor and a controller is described. The reservoir is connected to the hydraulic device for supplying hydraulic fluid to and from the hydraulic device. The first sensor is adapted for measuring a first volume of the hydraulic fluid in the reservoir. The second sensor is connected to the hydraulic device such that at least one parameter being indicative for a second volume of the hydraulic fluid in the hydraulic device is measurable. The controller is adapted for calculating the second volume of the hydraulic fluid based on the at least one parameter. The controller is adapted for determining a leakage of hydraulic fluid in the hydraulic system based on the first volume and the second volume.
摘要:
In one aspect, a hydraulic system including a reservoir, a hydraulic device, a first sensor, a second sensor and a controller is described. The reservoir is connected to the hydraulic device for supplying hydraulic fluid to and from the hydraulic device. The first sensor is adapted for measuring a first volume of the hydraulic fluid in the reservoir. The second sensor is connected to the hydraulic device such that at least one parameter being indicative for a second volume of the hydraulic fluid in the hydraulic device is measurable. The controller is adapted for calculating the second volume of the hydraulic fluid based on the at least one parameter. The controller is adapted for determining a leakage of hydraulic fluid in the hydraulic system based on the first volume and the second volume.
摘要:
A device is provided for the adjustment of the pitch of a rotor blade of a wind turbine. The device includes a pitch actuator and a fixing device. The pitch actuator includes a tube. The fixing device includes a first and a second ring-like element, each of which is arranged at the tube and each of which is supported towards a respective stopper assigned to the tube, and a clamping means which press the first and the second ring-like element in such a way towards the respective stopper that the fixing device and the tube are substantially non-relocatable relatively to each other.
摘要:
A device and corresponding method for optical phase conjugation using a stimulated Brillouin scattering (SBS) medium and resulting in a reduction in the (SBS) threshold level. An incident light beam is brought to a first focus in the SBS medium, and light transmitted through the first focus is brought to a second focus in the SBS medium. Light transmitted through the second focus is brought to a third focus, and so forth through N foci in the medium. The effective SBS threshold level is inversely proportional to the number of foci N, which may be located in separate SBS cells, or may be in a single cell through which multiple passes are made by means of appropriate reflective optics. Laser sources operating in multiple longitudinal modes are handled by spacing the foci at an intergral multiple of the laser resonant cavity length.
摘要:
Disclosed is a wind turbine with a nacelle and a rotor, the rotor including a number of blades and a hub, the nacelle and the hub being connected with each other in an interface region, the wind turbine further including a transport system for transporting hydraulic and/or pneumatic fluid from the nacelle into the hub. The transport system includes a rotary unit as a connection through which the fluid passes and a part of which rotates in operation together with the hub which rotary unit is positioned in the hub at a position distanced from the interface region facing away from the nacelle, the transport system further including a pipe system leading from the interface region into the hub to the rotary unit and being fixed in its position. The disclosure also concerns a method of construction of such wind turbine.
摘要:
A device is provided for the adjustment of the pitch of a rotor blade of a wind turbine comprising a pitch actuator acting on an adjusting plane for the adjustment of the pitch and a fixing device to which the pitch actuator is attached, the fixing device comprises a first and a second bearing shaft allowing a pendulum motion of the pitch actuator wherein both the first and the second bearing shaft are arranged respectively under a certain tilt angle relatively to the adjusting plane which tilt angle is respectively substantially different from 0° or 90°.
摘要:
A device is provided for the adjustment of the pitch of a rotor blade of a wind turbine. The device includes a pitch actuator and a fixing device. The pitch actuator includes a tube. The fixing device includes a first and a second ring-like element, each of which is arranged at the tube and each of which is supported towards a respective stopper assigned to the tube, and a clamping means which press the first and the second ring-like element in such a way towards the respective stopper that the fixing device and the tube are substantially non-relocatable relatively to each other.
摘要:
A direct drive wind turbine with a nacelle and a rotor including a hub, the nacelle and the hub connected in an interface region. The wind turbine includes a transport system for transporting hydraulic and/or pneumatic fluid from the nacelle into the hub. The transport system includes a rotary unit through which the fluid passes. A part of the rotary unit rotates in operation together with the hub. The rotary unit is positioned in the hub at a position distanced from the interface region facing away from the nacelle. Further disclosed are a transport system and a method of construction of such a direct drive wind turbine.