31results about How to "Large distortion" patented technology

An electric power assist device can be compactly disposed with ease in an electric power steering system for a vehicle. The electric power steering system for a vehicle includes: a steering wheel; a steering column incorporating therein a steering shaft connected to the steering wheel and extending downward to the front; and an electric power assist device for assisting a steering torque of the steering wheel. Here, an input shaft and an output shaft of the electric power assist device are connected to the lower end of the steering shaft and the input shaft of the steering gear device, respectively, via universal joints.

A phosphomolybdate has the molecular formula of K4M5P4Mo4HO27, and has the powder frequency-doubling intensity the same as that of KDP; when M is K, the phosphomolybdate is potassium hydrogen phosphomolybdate, the crystal belongs to a tetragonal system, the space group is I-4c2, unit cell parameters comprise a=9.670 angstroms, c=29.335 angstroms, alpha=beta=gamma=90 DEG and Z=4, and the unit cell volume is V=2743.1 cubic angstroms; when M is Rb, the phosphomolybdate is rubidium potassium hydrogen phosphomolybdate, the crystal also belongs to a tetragonal system, the space group is I-4c2, unit cell parameters comprise a=9.768 angstroms, c=29.635 angstroms, alpha=beta=gamma=90 DEG and Z=4, and the unit cell volume is V=2827.7 cubic angstroms; the two crystals are both grown by a fluxing agent spontaneous nucleation method or a fluxing agent top seed crystal method; the two crystals both have the nonlinear optical effect, and are incongruent melting compounds; and the two crystals as nonlinear optical crystals from infrared band to ultraviolet band can be used for preparation of a laser output frequency conversion laser device or used for preparation of a generator for generating a second, third, fourth or fifth harmonic generation harmonic to a laser beam with the wavelength of 1064 nm.

The invention discloses a near infrared optical lens. The near infrared optical lens comprises right eyeglasses successively arranged from an object side to an image side, wherein the first eyeglass is crescent-shaped, has negative focal power and has a convex surface oriented towards the object side; the second eyeglass is crescent-shaped, has negative focal power and has a convex surface oriented towards the object side; the third eyeglass is biconvex-shaped and has positive focal power; the fourth eyeglass is crescent-shaped, has positive focal power and has a convex surface oriented towards the image side; a doublet is formed by combining the fifth eyeglass with the sixth eyeglass; a seventh eyeglass is biconvex-shaped and has positive focal power; and the eighth eyeglass is crescent-shaped, has positive focal power and has a convex surface oriented towards the object side. The near infrared optical lens, through adoption of different eyeglass combinations and utilization of focal power distribution, has good performance of wide aperture, large visual angle and small distortion, and can effectively realize a heat difference elimination effect by use of a full glass structure.

The invention relates to a high-pixel macro-focus high-zoom-ratio zooming optical system. A first lens unit, a second lens unit, a third lens unit, a fourth lens unit and a fifth lens unit are arranged in sequence between a shot object and an image surface; the first lens unit is fixed relative to the image surface; the second lens unit can move forwards and backwards relative to the image surface along an objective image; the third lens unit is fixed relative to the image surface; the focal length of the first lens unit is positive; and the focal length of the second lens unit is negative. Due to the adoption of the high-pixel macro-focus high-zoom-ratio zooming optical system, the problems of long focusing distance, small focusing range, low resolution, low zoom ratio, large size and the like are solved.

The invention discloses a positioning method and a device for distribution network line fault points based on a double sampling rate. Phase correlation calculation is carried out on phase current waveforms acquired by a low sampling rate measuring apparatus. A recording function of a high sampling rate measuring apparatus is started when a fault occurs. Phase current waveforms acquired by the highsampling rate measuring apparatus are processed by a short-time Fourier transform. Accurate positioning is carried out on the fault points according to a D-type traveling wave method. According to the positioning method and the device for the distribution network line fault points based on the double sampling rate, the correlation coefficient calculation is carried out on waveform data, so as tosolve the unreliable problem of the traditional amplitude triggering recording wave; correlation calculation is only carried out on low sampling rate data, so as to reduce the calculation amount and improve the fault recording triggering speed; and meanwhile, a sampling time window of the high sampling rate measuring apparatus is small, so as to not rely on the large storage capacity and reduce the cost of distribution network detection equipment.

The invention relates to a small-distortion, small-volume, high-illumination and high-resolution optical system, which solves the problems of large distortion, large volume, small illumination, low resolution and the like, and comprises a first lend, a second lens, a third lens and a fourth lens, wherein the first lens, the second lens, the third lens and the fourth lens are arranged sequentially; an aperture is arranged between the third lens and the fourth lens; the first and third lenses are spherical lenses; the second and fourth lenses are non-spherical lenses; the first and third lensesare made of glass; and the second and the fourth lenses are made of plastic. The optical system is mainly used in the fields such as monitoring, photographic and vehicle-mounted systems.

The invention discloses a method for measuring the three-dimensional shape of a large-curvature mirror surface based on the phase deflection of a curved screen. Firstly, a measurement system is built, and then system parameters are calibrated. After obtaining corresponding parameters through a reference plane mirror, the measured mirror surface is used to replace the reference plane mirror to solve The height information of the measured mirror surface. This measurement method establishes a direct calculation formula for the height of a large curvature mirror surface based on the phase deflection of the curved surface, avoids the complicated gradient integration and numerical analysis process, and can realize the depth measurement of the discontinuous mirror surface. This measurement method uses the curved screen as the structured light source for the phase deflection technique for the first time, which expands the range of the measurement field, expands the measurement height field and gradient field of the mirror measurement phase deflection technique, and realizes the effect of measurement field amplification.

The invention discloses an ultra-high-definition internal focusing virtual reality optical system. The system comprises an aperture (100), and a first lens (1), a second lens (2), a third lens (3), a fourth lens (4) and a display screen (200) are sequentially arranged behind the aperture (100); the first lens (1) adopts a bi-convex aspherical lens, the second lens (2) adopts a crescent-shaped aspherical lens, the third lens (3) adopts a bi-convex aspherical lens, and the fourth lens (4) adopts a crescent-shaped aspherical lens; the first lens (1) and the second lens (2) are bound together through optical glue to form a glued lens set (300), and the glued surface bends towards the aperture (100). The ultra-high-definition internal focusing virtual reality optical system is simple in structure, high in definition, large in view field angle and wide in application range.

The invention discloses a double-sampling-rate distribution network line fault point accurate positioning method based on singular value decomposition and a device thereof. The method comprises the steps of performing phase correlation calculation on a phase current waveform which is acquired by low-sampling-rate measuring equipment, starting a wave recording function of high-sampling-rate measuring equipment when occurrence of a fault is determined, then processing the phase current waveform which is acquired by the high-sampling-rate measuring equipment, and performing accurate positioning on the fault point according to a D-type traveling wave method. According to the method and the device, through performing correlation coefficient calculation on the waveform data, a problem of low reliability in traditional amplitude triggered wave recording is settled. Furthermore correlation calculation is only performed on the low-sampling-rate data, thereby effectively reducing calculation amount and increasing fault wave recording triggering speed. Furthermore the utilized high-sampling-rate measuring equipment has a small sampling time window and does not depend on a high storage capacity, thereby effectively reducing cost of distribution network testing equipment.

The invention provides an on-orbit calibration device and on-orbit calibration method for pointing precision of a remote sensor. The device includes a calibration processing module, a filter component, and an imaging component, wherein the filter component is mounted on the imaging component to filter out the light sources outside the range of a calibration source spectrum, and only enable a calibration light source passing through the optical path system of the remote sensor to be calibrated to pass through; the imaging area of the imaging component includes a calibration area and an imagingarea, the calibration area is located at the edge of the imaging area, the surface of the calibration area is installed with the filter component, and the calibration area receives an optical signal of the calibration light source passing through the filter component, converts the optical signal into an electrical signal, and outputs the electrical signal to the calibration processing module; theimaging area receives the optical signal of an observation target, converts the optical signal of the observation target into an electrical signal, and outputs the electrical signal to an external digital transmission subsystem; and the calibration processing module determines the position coordinate of the calibration light source on the imaging component according to the electrical signal of thecalibration light source, and completes the on-orbit calibration of the pointing accuracy of the remote sensor. The on-orbit calibration device and on-orbit calibration method for pointing precisionof the remote sensor have the advantages of compact structure, convenient installation and high reliability.

The invention relates to a high-resolution, low-distortion day and night dual-purpose fixed-focus lens. The optical system is provided with a front group A with a negative focal power, a diaphragm C with a positive focal power, and a rear group with a positive focal power in sequence along the incident direction of light. group, the front group A is sequentially provided with a negative crescent lens A-1, a negative crescent lens A-2, a biconcave lens A-3, and a negative crescent lens A-4 and a negative crescent lens A-5. The first cemented group, the rear group B is sequentially provided with a biconcave lens B-1, a second cemented group closely connected by a negative crescent lens B-2 and a negative crescent lens B-3, and a biconvex lens B-4. The lens has the advantages of high resolution, large relative aperture, day and night confocal, and low distortion. It can not only image clearly in daytime lighting environment, but also can image clearly at night with infrared supplementary light in extremely low illumination environment.

The present invention relates to the field of optical instruments, and in particular to an 8K ultra-clear zoom visible light TV camera lens, wherein the front fixed group is composed of a positive first double-convex lens, a first negative meniscus lens and a first glued group in which the first positive meniscus lens is in close contact. , the second positive meniscus lens, and the third positive meniscus lens; the variable power group is composed of the second negative meniscus lens, the second cemented group of the first biconcave lens and the second biconvex lens, and the third negative meniscus lens The compensation group is composed of the fourth positive meniscus lens, the fourth negative meniscus lens and the third double-convex lens in close contact with the third cemented group, and the fourth double-convex lens; the rear fixed group is composed of the fifth positive meniscus lens The fourth cemented group in which the lens is in close contact with the second biconcave lens, the sixth positive meniscus lens, the fifth cemented group in which the fifth negative meniscus lens is in close contact with the fifth biconvex lens, the sixth negative meniscus lens, and the seventh negative meniscus lens lens, the eighth negative meniscus lens and the sixth double-convex lens in close contact with the sixth cemented group. The lens has the characteristics of large target area, large aperture, and small distortion, and can match 8K (40 million pixels) ultra-high-definition cameras.

The invention relates to a twisting box-shaped member and a manufacture process thereof and belongs to the technical field of steel structures. The twisting box-shaped member comprises a top plate, a base plate and a rectangular box, wherein the rectangular box is enclosed by webs, and the cross section of the rectangular box is an isosceles trapezoid. More than one cross partition plate is arranged on the rectangular box. The twisting box-shaped member is large in twisting range, reasonable in design and firm in structure.

The invention discloses an optical system of a depth camera. The optical system comprises six lenses that are arranged successively along the optical axis from object space to image space. The first lens has a crescent shape with a negative focal power and a convex surface of the first lens faces the object space; the second lens has a crescent shape with a negative focal power and a convex surface of the second lens faces the object space; the third lens has a biconvex shape with a positive focal power; the fourth lens has a biconcave shape with a negative focal power; the fifth lens has a biconvex shape with a positive focal power; and the sixth lens has a biconvex shape with a positive focal power. According to the optical system of the depth camera, with different lens combination units and focal-power distribution, excellent performances of large aperture, large view angle, and low distortion are realized; and on the basis of the glass-plastic mixing structure, athermalization and low manufacturing cost can be effectively considered.