73 results about "Tangent function" patented technology

A lighting device for streets, paths, and the like, includes a lighting unit containing a lighting element and a lens arranged in front of the lighting element in the main emission direction to produce a specified light distribution characteristic. The lens includes a light entrance surface on a light entrance side facing the lighting element and a light exit surface on a light exit side facing away from the lighting element, at which surfaces the light is refracted. The light entrance surface and / or the light exit surface of the lens is shaped in a direction transverse to the optical axis of the lighting element in such a way that the luminous intensity of the coupled out light, starting from a center plane that intersects with the optical axis, rises with an increasing emission angle from the optical axis at least partially according to a tangent function.

A method for detecting an edge and generating an interpolated edge pixel at a target pixel position between two lines of an interlace scan image first determines gradient intensities in the horizontal and vertical directions and then calculates the angle of the edge by comparing the gradient intensities. The interpolated pixel value is calculated from samples in the interlace scan image that lie along the identified angle and are proximate to the target pixel position. The method represents the gradient strengths and the difference between them as bit strings; locates the most significant non-zero bit in the larger gradient value; divides the value of the corresponding bit position in the difference string, and a predetermined number of following positions, by increasing powers of 2; sums the results; subtracts the sum from 1.0 and uses the inverse tangent function to calculate the angle of the edge.

The invention relates to the field of solar photovoltaic power generation and discloses a particle swarm optimization based control method and device of photovoltaic maximum power point tracking. A duty ratio of a converter is used as particles, the particles are initialized and uniformly dispersed at possible extreme value points, inertia weight and learning factor are adjusted linearly, an anti-tangent function is introduced to modify conventional particle swarm speed updating, and speed of each particle is limited solely. Convergence rate of a particle swarm algorithm is increased, oscillation during tracking is reduced, and new maximum power points can be quickly tracked during shadow changing.

Circuitry for computing a tangent function of an input value includes first look-up table circuitry that stores pre-calculated tangent values of a limited number of sample values, circuitry for inputting bits of the input value of most significance as inputs to the first look-up table circuitry to look up one of the pre-calculated tangent values as a first intermediate tangent value, circuitry for calculating a second intermediate tangent value from one or more ranges of remaining bits of the input value, and circuitry for combining the first intermediate tangent value and the second intermediate tangent value to yield the tangent function of the input value.

The invention provides a refined processing method for temperature forecast data of a numerical forecasting grid point. The refined processing method specifically comprises the steps of obtaining experimental data after system initialization; reading longitude and latitude coordinates of an observation point and four grid points around, the live temperature data of the observation point and the temperature forecast values of the four grid points around; carrying out error analysis and data sieving; then calculating an error arithmetic mean value of each of the 24 solar terms and a sliding mean value of a same forecast time error of continuous three days; carrying out inverse tangent function optimization processing for the obtained values; then obtaining a weight coefficient of influences from the two errors abovementioned to the forecast result; then calculating sequentially based on a set sequence to obtain a set of an error sliding mean value of each observation point, a solar term error mean value and a weight coefficient; carrying out amended calculation for the temperature data of the numerical forecasting grid point in the county territory represented by each observation point by using the result abovementioned; and finally carrying out refined interpolation calculation, daily maximum temperature calculation and daily minimum temperature calculation for an appointed coordinate point by using the amended data.

In the system, relations between transmittance and wavelength of two optical elements are sine function with error and cosine function with error respectively. Through processing optical signal power of two optical elements and monitoring end received by detector obtain lookup table about two transmittances and ratio as well as arc tangent function value phi (lambda) of the said ratio and standard wavelength. The said lookup table is stored into memory in demodulation system so as to realize system calibration. Through processing optical signal power of optical fiber grating sensor received by detector obtains the said two transmittances and ratio. Using lookup table in system memory obtains two or more phase values and wavelength values. Then, using linear or non-linear interpolation obtains wavelength value, which is converted to a measured sensing value. The invention possesses features of super high demodulation speed, wide demodulation range, high resolution and low cost.

The invention is suitable for the technical field of the computer, and provides a sentiment classification method and system. The method comprises the following steps: according to a rhetorical structure theory, analyzing a text to be classified to obtain a rhetorical structure parse tree; obtaining the initial vector of each node in the rhetorical structure parse tree, wherein the node comprises an input gate, an output gate, a memory cell, a hiding state and a forgetting gate; according to the hyperbolic curve tangent function value of the output gate and the memory cell of the node, carrying out dot product to obtain the hiding state of the node; and according to the hiding state of the node, carrying out sentiment classification on a classifier function. The text to be classified is constructed into the rhetorical structure parse tree, each layer in the rhetorical structure parse tree is provided with two node fragments, each node is provided with an own forgetting gate, child node information is selected through the forgetting gate in a learning process, a cell state is continuously updated, unimportant information is abandoned, core contents are added, and semantic feature expression is improved so as to improve classification accuracy.

The invention provides a single-ended vector BOTDA (Brillouin Optical Time Domain Analysis) dynamic strain measurement method, and a measurement apparatus thereof. The single-ended vector BOTDA dynamic strain measurement method comprises utilizing one composite optical signal to realize incidence from one end of a sensor fibre, wherein the back Rayleigh scattering light generated from the microwave modulation pulse substrate light in the sensor fibre is used as the probe light; the sensor pulse light generated from the microwave modulation pulse substrate light in the sensor fibre is used as the pump light; generation of the probe light and pump light are affected by the stimulated Brillouin scattering; the local oscillator light and the probe light carrying the stimulated Brillouin scattering information perform beat frequency in a photoelectric detector and extract the in-phase and quadrature components in an electric signal; the quotient of the in-phase and quadrature components and the phase shift of the stimulated Brillouin scattering has the relationship of arc tangent function so that a phase shift value is obtained; and finally according to the corresponding relationship curve stored in the computer between the phase shift and the dynamic strain, the corresponding dynamic strain value is obtained through modulation. As a nondestructive single-ended structure is introduced into a vector BOTDA, the single-ended vector BOTDA dynamic strain measurement apparatus is simple in structure and convenient for application, and is high in the response frequency band width and the measurement accuracy, and can improve the stability and reliability of a dynamic strain measurement system.

The invention belongs to the field of electric system state monitoring, and particularly relates to a voltage sag detecting method suitable for a dynamic voltage restorer. The method includes the steps of establishing phase shifting components through the three selected detection points which include the front detection point, the middle detection point and the rear detection point and are arranged at equal intervals, obtaining a d-axis DC component and a q-axis DC component of a fundamental wave through a Butterworth low-pass filter after alpha beta-d q conversion is conducted on the detection points and a middle sampling point, conducting quadratic sum addition on the d-axis DC component and the q-axis DC component and calculating through a root-mean-square to obtain a voltage amplitude, conducting arc-tangent function operation on the quotient obtained by dividing the q-axis DC component by the d-axis DC component, and obtaining a phase jump angle through the difference between the phase detection value at the earlier moment and the phase detection value at the later moment. By means of the method, the certain white noise resistance is still achieved while the real-time requirement is met, and the method is quite suitable for detecting voltage sags in the dynamic voltage restorer.

The invention discloses an all-round trigonometric function demonstrating and shape drawing instrument mainly composed of a support, a movable drawing board, a disk gear bank and a sliding-block linkage mechanism. A demonstrating device, a converting mechanism and a shape drawing mechanism are arranged on the support. The demonstrating device is connected with the shape drawing mechanism through a connection rope. The components are combined in different assembly modes. People just need to rotate a handle on a driving wheel, all the trigonometric function relationships such as the sine function relationship, the cosine function relationship, the tangent function relationship, the cotangent function relationship and the cosecant function relationship can be demonstrated visually, continuous accurate functional shapes can be drawn on a drawing board, a piece of paper and any fixed planes, compound-form trigonometric-function-like relationships such as the variable-period trigonometric-function-like relationship, the variable-amplitude trigonometric-function-like relationship and the variable-initial-phase trigonometric-function-like relationship can also be demonstrated by simply adjusting the structure and changing the connection mode, and corresponding shapes can also be drawn. The all-round trigonometric function demonstrating and shape drawing instrument is simple in structure, flexible in operation, convenient to use, wide in application range and low in cost and has complete functions.

The invention belongs to the technical field of ultrasonic inspection. The invention aims at providing a color ultrasonic Doppler blood flow speed estimation method which has less resource consumption and is accurate and reliable. The color ultrasonic Doppler blood flow speed estimation arc tangent optimization algorithm is characterized by comprising the following steps of: making an LUT (look-up table) table in an LUT method; looking up the LUT table as 0<=c<1; firstly calculating and then looking up the LUT table and finally outputting as 1<=c< infinity; and in a similar way, transforming arc tangent operation in a value range of -pi to pi of a blood flow mean velocity arc tangent function, wherein V is average blood flow speed; A is an imaginary part of a self correlation function; and B is a real part of the self correlation function. The invention is mainly applied to ultrasonic inspection blood flow speed estimation.

A double correcting software PLL in the field of signal processing technology. The processes are as follows: base on the standard signal, utilize the output of parallel double low pass filter to get resection tangent function to correct frequency; base on the output signal of the frequency correcting tache, use he output of parallel double low pass filter to get resection tangent function to correct phase; design low pass filter to assure PLL's tracking speed and precision; adopt TM320C2407DSP to program and speed up the calculation. This invention adopts simple loop control, has high stability and fast tracking speed. The temporary state response time is less than 20ms. It precisely and quickly measures the voltage, base wave frequency and phase of the current of the electric system. It supplies the synchronous signals to the non-power compensator, the filter and micro-computer protective device.

The invention discloses an SDFT fundamental positive sequence component phase synchronization method and a phase synchronization system. The method comprises steps: analog signals for three-phase power grid AC voltage are discretized, discrete data are obtained through sampling in a fixed period, Clark transform is carried out on the discrete data, and transform data are obtained; according to a sampling sequence and an overlapped period, single-point DFT calculation is carried out on the transform data to obtain a correction result for an ith point, wherein the correction result for the ith point is the accumulated value between the DFT calculation result for the ith point and the correction result for an (i-1)th point; N-point recursive SDFT calculation is carried out on the transform data in the fixed period to obtain a calculation result in the current period; when i is smaller than N, the calculation result in the current period is outputted; when i is equal to N, the correction result for the ith point serves as the calculation result in the current period to be outputted; according to the calculation result outputted in the current period, an arc-tangent function is used for acquiring a fundamental positive sequence component phase angle. Thus, the problem of stability caused by recursive iterative cumulative errors can be eliminated.

The invention relates to an arc-tangent function data structure and an establishment method, and a function value acquisition method and device. The arc-tangent function data structure comprises N fitting straight lines and an arc-tangent function value lookup table; the N fitting straight lines are used for conducting linear fitting on arc-tangent functions corresponding to first N intervals respectively, and the arc-tangent function value lookup table is used for storing a function value of the arc-tangent function of an (N+1)th interval. According to the arc-tangent function data structure and the establishment method, the usage of the storage space can be reduced, the value range of the arc-tangent function can be quickly determined by adopting the function value acquisition method and device, the required computing times and the number of required arithmetic units are reduced, the computing time is reduced, the hardware resources are saved, and the consumption of system resources is lowered.

The invention discloses an angle detection tool and a detection method thereof and belongs to the technical field of angle detection. The angle detection tool is simple and convenient to operate and low in cost. Components are irregular in shape and need measuring continuously in narrow and small space, and rotation angles of two components are measured in specific conditions of rotation around a fixed shaft and the like. The angle detection tool comprises a fixing device, and one end of the fixing device is connected with a screw through threads. The detection method using the angle detection tool includes that the fixing device is fixed on a fixing part of a measured component, so that the screw at one end of the fixing device is vertical to the upper surface of the fixing part of the measured component; the screw is rotated, so that the end portion of the screw is contacted with the rotating part of the measured component; the stretched length of the screw and the distance between the screw and a rotation shaft are read; and an included angle between the rotating part and the fixing part is determined according to an arc-tangent function.

The invention discloses a sectional table look-up based arc-tangent function realization method and device. The realization method includes: determining an arc-tangent function lookup table according to the size of inputted data; determining an index value according to a high value of the inputted data, determining an angle compensation value according to a low value of the inputted data, and determining initial angle and compensation slope in the lookup table according to the index value; determining arc-tangent angle according to the initial angle, compensation slope and angle compensation value so as to realize the arc-tangent function. Through the realization method and device, the technical problem about how to realize the arc-tangent function of infinite interval is solved, calculation in the angle solving process of the arc-tangent function is reduced, calculation cost is reduced under the condition that data accuracy is assured, and limited storage space is saved.

The invention discloses a levelness detection device, which comprises a transparent cuboid base and is characterized in that a sealed water storage chamber is arranged in the base; water is stored in the water storage chamber; a sealed left scale chamber and a sealed right scale chamber are respectively arranged on two sides of the water storage chamber; both the left scale chamber and the right scale chamber are cavities, and scales are arranged on the surfaces of the left scale chamber and the right scale chamber; the upper part of the left scale chamber is communicated with the upper part of the right scale chamber through an upper communicating pipe; and the lower parts of the left scale chamber and the right scale chamber are connected with the water storage chamber through a lower communicating pipe. In the levelness detection device, by utilizing the difference between water levels in the left scale chamber and the right scale chamber and the distance between the left scale chamber and the right scale chamber, the tangent function of an inclined angle of a surface to be detected can be obtained so as to calculate and obtain the inclined angle. The levelness detection device has the advantages of simple structure, direct display and the like.

The invention provides a double-shield TBM shield body jamming prediction method and system. The method comprises the following steps that tunneling parameters are obtained in real time through an on-site TBM upper computer; the single-tool thrust and propelling speeds of the tunneling parameters of the first n parameters at the current time are selected; through a sliding average window, the sliding averages of the n single-tool thrust and propelling speeds are obtained correspondingly; through a double-curve tangent function, real-time characteristic indexes are obtained, and each link of accumulated characteristic parameters are calculated through accumulating summation; accumulated characteristic indexes are compared with preset alarm warning values, and if the accumulated characteristic indexes are larger than the preset alarm warning values, information is sent to the TBM upper computer for alarm; and a pre-warning system comprises a data obtaining unit, a model calculating unit,a pre-warning display unit and a jamming alarm module. According to the double-shield TBM shield body jamming prediction method and system, jamming indexes are obtained through the tunneling parameters, real-time alarm of double-shield TBM jamming can be achieved, and the loss, caused by the jamming accident, of manpower, financial resources and materials is avoided.

The invention relates to an island detection method based on reactive current and voltage frequency feedback. Phase-locked loop control is adopted, so that a phase-locked angle can be obtained; phasedifference exists between the phase-locked angle and the voltage phase angle of a power grid; a relation among reactive current, active current and voltage frequency are obtained according to a relation between the power of a load and the output power of an inverter under a steady state after the power outage of the power grid; positive feedback between the frequency and given reactive current isachieved through a tangent function; the voltage frequency deviates towards the same direction all the time through the positive feedback, so that the phase difference can be eliminated; when the power of the power grid is normal, the voltage frequency of a common point is stabilized at 50Hz or has very small fluctuation, the disturbance of applied reactive current is very small, and influence onthe power factor of a system is relatively small; and if an island condition appears in the power grid, the positive feedback between the reactive current and the frequency enables the frequency to quickly change towards one direction until island protection is triggered. The method has the advantages of small influence and high efficiency.

The invention relates to a method for measuring a horizontal angle of a nozzle of a four-corner tangential burner. The nozzle of the burner is provided with a reflective plate, the reflective plate isparallel to a plane in which the nozzle of the burner is, a light source is arranged at a position of an opposite angle of the nozzle of the burner, light emitted by the light source is reflected bythe reflective plate and then falls onto a first protective wall, a distance between a light falling point and a second protective wall is measured, and an included angle between the nozzle of the burner and the second protective wall is calculated through an arc-tangent function. The method for measuring the horizontal angle of the nozzle of the four-corner tangential burner measures accurately,is convenient to operate in the site, is easy to implement in the site, is simple and flexible, and is low-cost. The light source and the reflective plate are easy to obtain, and the arrangement is flexible.

A system is provided for preventing gear hopout in a tooth clutch in a vehicle transmission, the tooth clutch including an engaging sleeve having sleeve clutch teeth. The tangent function for at least one of driving back-taper angle and braking back-taper angle is larger than the average value of clutch coefficient of friction and spline coefficient of friction multiplied by the sum of unity and the ratio of clutch teeth pitch diameter and spline teeth pitch diameter.

The New Trigonometer is a genuine device used to compute the sine, cosine, and tangent of angles. Consequently, the device could also be used to calculate the reciprocal sine, cosine, and tangent functions. Modern calculators can easily compute the above mathematical functions, thus the importance of this device is not in its ability to do such calculation. On contrast, the New Trigonometer has many aspects of novelty, which need to be protected. Indeed, it adds to the conventional protractor three new components: the Tangent Calculator, the Sin / Cos Calculator and the Angle Tracking Device. Moreover, these components are assembled in a genuine way, which makes the new trigonometer a tangible reflection of the trigonometric circle. Thus, the New Trigonometer becomes a significant educative tool for the students due to its illustrative characteristics, and a useful measurement tool in carpentry due to its holistic features and ease of use.

The invention relates to a self-adaptive estimating method for the position of a rotor of a non-inductive permanent magnet synchronous motor. The method includes the following steps of firstly, designing a continuous self-adaptive sliding-mode observer for observing the counter electromotive force of the motor, and selecting the gain of the self-adaptive sliding-mode observer; secondly, using theobservation value of the continuous self-adaptive sliding-mode observer for extracting a quasi-flux-linkage signal containing the rotor position and speed direction; thirdly, designing a lock phase ring of speed information on the basis of a tangent function, and obtaining the rotor position information from the quasi-flux-linkage model signal. Compared with the prior art, the method has the advantages that the structure is clear, parameter selection is simple and convenient, and the position information estimation accuracy in the forward rotation and backward rotation of the motor can be kept.

A method for determining the radiation distance of a phototherapeutic apparatus features that two visual laser devices are obliquely installed at both sides of light source and the distance between said two laser devices can be calculated according to the distance between skin and phototherapeutic apparatus and the included angle between said two laser devices by tangent function.

The invention relates to the air-conditioning control technique, and discloses a control method for improving the compensation control accuracy of a motor dead zone, which solves the acquisition problem of an arc tangent angle while improving the acquiring accuracy of the arc tangent angle so as to improve the compensation accuracy of the dead zone. The method comprises the steps of establishing a high-accuracy arc tangent data look-up table for a single-chip microcomputer to acquire the compensation data of the dead zone and compensate the dead zone, wherein the high-accuracy arc tangent data look-up table is subdivided into 2n parts based on 0-45 degree tangent function values and tangent values in each part are set apart; determining an angle value corresponding to each tangent function value and amplifying the angle value; rounding the amplified angle value and storing the rounded value in the ROM of the single-chip microcomputer for the single-chip microcomputer to inquire and use. According to the invention, generally, n is larger than or equal to 8, and m is larger than or equal to 16. The above method is used for controlling the permanent-magnet brushless direct current motor of an air conditioner.

The invention provides a construction method of a distance measurement model, a distance measurement method and device and an automatic driving system, which are applied to a binocular camera with symmetrical and inclined optical axes, and the construction method comprises the following steps of: obtaining a tangent function formula of alpha and beta based on a baseline distance B of the binocularcamera, a measured distance Z, a distance Z0 from an optical axis intersection point of the binocular camera to an X-axis and a tangent function. Alpha is an included angle between a left camera or aright camera of the binocular camera and a Y axis, and beta is an included angle between a connecting line from a measured point W to a left camera optical center or a right camera optical center ofthe binocular camera and the Y axis; according to the invention, according to the actual relationship between the intersection point of optical axis of binocular camera and a measured point, the tangent function formulas of alpha and beta are used to calculate a ranging model of the binocular camera with symmetrical and inclined optical axes. According to the invention, each parameter in the distance measurement model is acquired during calibration of the binocular camera through the construction of the distance measurement model of the binocular camera with symmetrical and inclined optical axes, so that the binocular camera can rapidly and accurately measure the distance in the later using process.

The invention discloses a method for building flood loss model. The method includes selecting curve tangent functions to be used as standard S-type functions and ultimately creating a flood loss function by means of translation and generalization processing. An x in the flood loss function is an independent variable and represents hazard intensity; an a in the flood loss function is a sensitivity coefficient; an S in the flood loss function is a maximum loss coefficient; an xD in the flood loss function is a horizontal-axis value corresponding to a turning point D in a loss curve. The method has the advantages that the physical quantity flood loss models with physical mechanisms are built, accordingly, the subjectivity due to the fact that loss is expressed in currency amounts can be avoided, and reliable and credible results can be obtained; flood loss can be quickly evaluated by the aid of regression equations of physical quantities and total loss, and accordingly the novel method can be used for evaluating the flood loss; parameters are determined on the basis of a process for measuring data and analyzing numerical values, accordingly, the key parameter determination objectivity can be guaranteed, and the method can be popularized in regions with similar characteristics and future flood loss prediction.

The New Trigonometer is a device used to compute the trigonometric sine, cosine and tangent of angles. Consequently, the device could also be used to calculate the reciprocal sine, cosine, and tangent functions. The device constitutes of a protractor and a graduated ruler attached thereof. An arm is pivotally joined to the center of protractor and a second graduated ruler is pivotally joined to the arm in a way, which makes the New Trigonometer a reflection of the trigonometric circle.

The invention discloses a calculation method of an object directional positioning angle of an aerial remote sensor, and relates to a calculation method of an object directional positioning angle. The calculation method solves the problem that a tangent function has a monotonic increase characteristic thus a high-accuracy object directional positioning angle is obtained difficultly through a traditional table look-up way. The calculation method comprises the following steps of converting geographic coordinates of an object needing to be photographed into aerial carrier coordinates through a coordinate conversion method, and based on a aerial carrier coordinate system, calculating to obtain an object directional positioning angle through an arctan function calculation method. The calculation method realizes a rapidity and an accuracy of arctan function calculation results, and provides a fast table look-up way comprising that tangent values corresponding to all angles are arranged in a table according to an arrangement of even angle increasing to form multiple ordered tables and an object directional positioning angle needing to be photographed is obtained through a sequential search method and a binary search method. The calculation method reduces a calculation time and realizes a rapidity and an accuracy of calculation of an object directional positioning angle of an aerial remote sensor.

The invention discloses a micro-doppler radar human body action classification method of convolutional neural network, which comprises an original data processing process and a deep convolutional neural network, and is characterized in that the output of the original data processing process is connected to the deep convolutional neural network; the original data processing process is a one-dimensional convolution process; wherein the one-dimensional convolution process comprises a first 1D convolution layer representing a real part, a second 1D convolution layer representing an imaginary part,a first merging layer, a second merging layer, a total merging layer, a mapping layer and an active layer; wherein the first merging layer after the first 1D convolution layer is used for calculatingthe square of a real part, and the second merging layer after the second 1D convolution layer is used for calculating the square of an imaginary part; wherein the total merging layer sums the squarevalue of the real part and the square value of the imaginary part, the mapping layer is used for calculating a normalized square root value, and the active layer has an arc tangent function for nonlinear transformation. The input of the network is an original radar signal, the output of the network is an action category, and the end-to-end learning advantage in the neural network is fully exerted.