50 results about "Spatial harmonics" patented technology

Techniques of making a recording of or transmitting a sound field from either multiple monaural or directional sound signals that reproduce through multiple discrete loud speakers a sound field with spatial harmonics that substantially exactly match those of the original sound field. Monaural sound sources are positioned during mastering to use contributions of all speaker channels in order to preserve the spatial harmonics. If a particular arrangement of speakers is different than what is assumed during mastering, the speaker signals are rematrixed at the home, theater or other sound reproduction location so that the spatial harmonics of the sound field reproduced by the different speaker arrangement match those of the original sound field. An alternative includes recording or transmitting directional microphone signals, or their spatial harmonic components, and then matrixing these signals at the sound reproduction location in a manner that takes into account the specific speaker arrangement. The techniques are described for both a two dimensional sound field and the more general three dimensional case, the latter based upon using spherical harmonics.

A dynamo electric machine includes a rotor having magnetic poles with permanent magnets and a stator having armature windings concentratedly wound around teeth. When the number of pole pairs of the magnetic poles of the rotor is P, diameter of the rotor is D (meters), and a spatial harmonic order of a predetermined harmonic component of an armature magnetomotive force of the rotor is N ((N=P to the 1.5^th power)×(N to the minus 4-th power)×(the square of P)×D<0.6 (in meters).

Method and apparatus are provided for displaying an image to a viewer with reduced visual artifacts. The apparatus comprises a display panel for forming the image using an array of pixels with distributed active regions, and a viewing arrangement optically situated between the display panel and the viewer for transferring the image formed on the display panel to the viewer with limited angular pixel subtense. The distributed active regions of the pixels are desirably divided into at least two simultaneously switched portions at least partly separated by or surrounding a significant portion of the non-switchable region. First order spatial harmonics and associated artifacts are reduced by the distributed apertures and second order and higher harmonics are reduced by limiting the pixel subtense angle seen by the viewer. A significant reduction in visual artifacts arising from the periodic structure of the display panel is obtained.

A structured illumination microscopy optical arrangement includes a projection path and an imaging path. The imaging path includes an imaging sensor and imaging optical elements. The projection path includes a light generator, a pattern generating element such as a spatial light modulator (SLM), and projection optical elements including an output lens and a projector artifact suppression element (PASE) located in the projection path between the SLM and the output lens. The PASE may include birefringent material which splits respective light rays of the structured illumination pattern source light to provide at least one replication of the structured illumination pattern with an offset transverse to the projection path. The offset replication of the structured illumination pattern increases the accuracy of the system by reducing spatial harmonic errors and spurious intensity variations due to projector pixel gap artifacts which may otherwise produce errors in resulting Z-height measurements.

A reluctance motor has: a stator provided with drive coils to which multiphase drive currents are inputted; and a rotor provided with a plurality of salient poles which receive primary rotating force when magnetic fluxes generated in the drive coils are interlinked with the rotor, and the rotor has: inductor pole coils which are placed on magnetic paths on which spatial harmonic components superimposed on the magnetic fluxes generated in the drive coils are interlinked with the rotor side so that induced currents can be generated in the inductor pole coils due to the spatial harmonic components of the magnetic fluxes; rectifier elements which rectify the induced currents generated in the inductor pole coils; and electromagnet coils as defined herein, and the inductor pole coils and the electromagnet coils do not serve for each other's purposes but are placed on the rotor individually.

The invention discloses a multi-phase single winding non-bearing motor driving system, which comprises a multi-phase alternating current motor, a multi-phase inverter, an inversion driving unit, a detection unit, a torque and rotary speed control unit, a suspended control unit and a comprehensive unit, wherein the multi-phase alternating current motor has a set of windings with phase number n>=5, a motor stator winding is formed by windings whose axial lines are separated in an angle of 2 pi/n, each phase winding simultaneously comprises odd spatial harmonics and even spatial harmonics, the torque and the suspended control of the multi-phase alternating current motor are respectively finished in different control freedom degrees, two groups of currents with different phase differences of adjacent phases are simultaneously electrified into the motor through the multi-phase inverter for respectively realizing the torque driving and the rotor suspension of the driving system. The motor driving system adopts a set of multi-phase motor windings and a set of multi-phase univertor, realizes the non-bearing operation of the driving system, and has the windings with simple structure, is much easier to embed wires than a traditional double-winding non-bearing motor, is easy to realize the large power driving, and has higher reliability.

The invention discloses an automobile Lundell motor AC-generator which comprises stator windings and a rectification circuit, wherein two sets of the stator windings which are of symmetrical triphase structures are isolated at an electrical degree of 30 degrees; the two sets of stator windings are connected by a star-shaped way, and two Y windings are output in series by respective rectifier bridges. The invention completely eliminates fifth time frequency harmonics, seventh time frequency harmonics, fifth spatial harmonics and seventh spatial harmonics in the air-gap field of the generator by adopting the structure of double-Y 30-degree stator windings, thereby reducing the torque pulsation of the generator, lowering electromagnetic noise, enhancing the efficiency and enabling the performance of the generator and a system to have a greater improvement.

The invention discloses an efficient terahertz artificial surface plasmon directional coupler and a coupling method. A metal cylindrical periodic array is coupled with an SSP waveguide, the terahertzwave transmitting the metal cylindrical periodic array generates a spectral folding effect, and abundant space harmonic waves are generated; when the tangential wave loss of the n-order space harmonicwave meets an SSP wave mismatching condition, an SSP mode is coupled on the surface of the SSP waveguide; through reasonable design of parameters, the conversion efficiency from a free space beam tothe SSP mode is improved, the coupling direction and the working frequency band of the plasmon can be freely regulated and controlled, and a powerful promotion effect on practical application of the SSP mode in the terahertz wave band is achieved; due to the fact that the coupler is of a full-metal structure, the loss of the coupler can be reduced; and meanwhile, the coupler is of a periodic cylindrical structure, and compared with a traditional coupler, the coupler is simple in structure and easy to process, low in cost and high in integration level, and can be widely applied to a terahertz communication system and an imaging system.

Methods and systems for solving measurement models of complex device structures with reduced computational effort and memory requirements are presented. The computational efficiency of electromagnetic simulation algorithms based on truncated spatial harmonic series is improved for periodic targets that exhibit a fundamental spatial period and one or more approximate periods that are integer fractions of the fundamental spatial period. Spatial harmonics are classified according to each distinct period of the target exhibiting multiple periodicity. A distinct truncation order is selected for each group of spatial harmonics. This approach produces optimal, sparse truncation order sampling patterns, and ensures that only harmonics with significant contributions to the approximation of the target are selected for computation. Metrology systems employing these techniques are configured to measure process parameters and structural and material characteristics associated with different semiconductor fabrication processes.

The invention discloses an axial gap rotation motor of a big electromagnetic torque winding excitation structure axial gap type rotary motor which is obtained through high order spatial harmonic flux generated by an armature coil. The axial gap rotation motor (100) has: two rotord (120,130) which performs rotation driving with an axis (101) as a center and a stator (110), the two sides of which in an axial direction are opposite to the rotors; the axial gap rotation motor (100) comprises a plurality of armature coils (11) which are configured at the circumference of the axis of the stator, multiple induction coils (21) and multiple excitation coils (22) which are arranged on the circumference of the two rotors, and a diode which perform rectification on the induction current generated by the induction coils in order to provide the excitation coil; the windings of the armature coils, the induction coils and the excitation coil are winding coils which are wound into an alpha coil on an iron core (15,25) in an axial direction.

A method for improving computation efficiency for diffraction signals in optical metrology is described. The method includes simulating a set of spatial harmonics orders for a grating structure. The set of spatial harmonics orders is truncated to provide a first truncated set of spatial harmonics orders based on a first pattern. The first truncated set of spatial harmonics orders is modified by an iterative process to provide a second truncated set of spatial harmonics orders based on a second pattern, the second pattern different from the first pattern. Finally, a simulated spectrum is provided based on the second truncated set of spatial harmonics orders.

The invention discloses an axisymmetric periodic permanent magnet focusing system with a prominent third spatial harmonics. The system comprises a plurality of permanent magnet focusing units with thelengths of L, each permanent magnet focusing unit comprises in order from left to right: a first magnetic pole (1); a first permanent magnet (2) having an N pole connected to the first magnetic pole(1); a second magnetic pole (3) connected to the S pole of the first permanent magnet (2); and a second permanent magnet (4) having an S pole connected to the second magnetic pole (3). The axisymmetric periodic permanent magnet focusing system with a prominent third spatial harmonics achieves the required peak axial magnetic field intensity Bm under the condition that the period L of the periodicpermanent magnet focusing system is not reduced, and simultaneously suppresses the fluctuation of the radius of an electron beam by utilizing the third spatial harmonics of the magnetic field distribution of the periodic permanent magnet focusing system on the axis, so that the aim of maintaining the stable passing of the electron beam is achieved.

The invention belongs to the technical field of motor analysis design, and discloses a method for analyzing magnetic potential of a non-sine power supply multiphase motor. The method includes the steps that the concepts of equivalent positive sequence currents and equivalent inverted sequence currents are imported, a synthetic forward circular rotating field and a synthetic inverted circular rotating field are seen as being generated by the equivalent positive sequence currents and the equivalent inverted sequence currents respectively, subharmonic currents are indicated as current phasors in an index mode, on the basis of magnetic potential equivalence, harmonic equivalent sequence currents corresponding to the subharmonic magnetic potential are acquired, and then corresponding space harmonic forward magnetic potential and inverted magnetic potential are directly solved. The method is based on the electro mechanics fundamental principles, the concept is clear, complex calculation of superposing the subharmonic magnetic potential of all phases in a traditional method is avoided, the method is suitable for analyzing the magnetic potentials of the multiphase motor under multiple working conditions, and when default phases or asymmetrical windings or asymmetrical currents or other failures occur, only corresponding elements in a current matrix or a winding spatial position matrix need to be changed.

A rotating induction machine, containing five or more different phases, having windings distributed according to a sinc function with a cutoff frequency allowing low-order spatial harmonics but preventing higher order spatial harnomics from flowing. In a preferred embodiment, the machine is connected to drive means capable of injecting third harmonic into the machine. In a further preferred embodiment, the windings are connected to the drive means with a mesh connection and the machine has five phases.

The invention provides a method for eliminating vibration of a PWM powered brushless direct current motor through frequency calculation. For the motor preliminarily designed in a electromagnetic scheme, spatial harmonic distribution of air gap flux density is firstly calculated, then the time harmonic wave change of the air gap flux density is calculated within a commutation period and is compared with the inherent vibration frequency of a motor iron core, and if the frequencies are similar, resonance is produced, the electromagnetic design scheme of the motor is needed to be optimized, and the frequencies are re-calculated till the vibrations produced by spatial harmonic flux density and harmonic wave flux density are not resonant with the iron core. The space and time changes of flux density causing motor vibration under the operating working condition of the motor are fully considered in the method, the accuracy of motor vibration calculation in a motor product development phase is improved, accordingly the success rate of motor design is improved, a development and trial-manufacturing period of the motor is shortened, and non-renewable resources including copper, iron, aluminum and the like are effectively saved.

The invention belongs to the technical field of acceleration tests, and particularly relates to a space driving mechanism harmonic reducer multi-performance parameter accelerated degradation test evaluation method, which comprises the steps of obtaining a performance degradation value of each tested sample at each degradation detection moment under each acceleration stress; carrying out normalization processing on each performance degradation value; carrying out uncertain process modeling on the performance degradation process under the acceleration stress level, and constructing a system degradation equation; establishing a relationship between the normalized performance degradation data and the reliability; performing comprehensive trade-off optimization on all unknown parameters of the system degradation equation by using an uncertainty statistical analysis method; and solving a system margin equation, an unreliability distribution function and a reliability measurement equation of a corresponding space harmonic reducer product by combining the threshold values of the performance parameters. According to the method, the problem of cognitive uncertainty quantification caused by a small number of test samples and limited performance detection times in a multi-performance parameter accelerated degradation test of the harmonic reducer is solved.

The present invention is a reluctance motor (10) that rotates as a result of the magnetic flux generated at the drive coil (14) of a stator (11) being interlinked with the rotor teeth (22) of a rotor (21). In the rotor, the key protrusion (119) of a rotor base material section (111) and the key protrusion (129) of a ring-shaped section (121) are fitted/affixed to a key groove (109) of a shaft (101), a core material section (112) that is integral to the rotor base material section is caused to be the rotor teeth provided with an electromagnet pole coil (28), the core material (25) is protected by a protruding piece (123) integral to the ring-shaped section, resulting in an inductor pole coil (27). By means of arranging in the direction of rotation in such an easy structure, it is possible to generate an induced current using the induction pole coil by means of the spatial harmonic component of the interlinked magnetic flux, and by supplying the result to the electromagnet pole coil as field magnet current, electromagnetic force is generated that assists in primary rotational force.