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197results about How to "Simple algorithm" patented technology

Online monitoring and early warning system for vibration of intelligent motor

The invention relates to an online monitoring and early warning system for vibration of an intelligent motor, which belongs to the field of intelligent motor monitoring. The system comprises a vibration sensor, a processing and analysis module, a calendar module, a storage module, a communication module, a field alarming module and a portable device. the vibration sensor measures the real-time vibration data of the motor, the data are transmitted to the processing and analysis module, the operation and the working state of the motor are analyzed and judged in combination of data measured by an electric parameter measuring module and a rotation speed measuring module, and in view of abnormal vibration features under different load rates, field alarming or early warning to the portable device is carried out. Besides, early warning is also carried out for the changing trend of the vibration frequency and the changing trend of the amplitude. The system can realize online vibration monitoring and early warning when the motor is abnormal or in an abnormal working state, timely finding and timely processing are carried out, expanding of motor fault can be effectively avoided, the maintenance efficiency is greatly improved, the structure is simple, the cost is low, the measurement is accurate, and the system can be widely applied to intelligent and online vibration monitoring on middle and small-sized motors.
Owner:HARBIN UNIV OF SCI & TECH +2

Device and method for eliminating grid-connected current zero-crossing distortion of unipolar control single-phase grid-connected inverter

The invention discloses a device and a method for eliminating the grid-connected current zero-crossing distortion of a unipolar control single-phase grid-connected inverter, which belong to the field of transformation of electrical energy and aim to solve the problem of the grid-connected current zero-crossing distortion of the conventional unipolar control single-phase grid-connected inverter. The method provided by the invention comprises the following steps of: 1, obtaining an instantaneous value ig of a grid-connected current and the instantaneous value e of a power grid voltage, and setting the amplitude Im<*> of a given grid-connected current of an input signal; 2, obtaining the instantaneous value ig<*> of the given grid-connected current, comparing the ig<*> with the ig, and generating two paths of switching signals as control signals of a second bridge arm; 3, obtaining a phase difference; and 4, commonly inputting a sine value of a current phase angle of the power grid voltage and the phase difference obtained by the step 3 into a switching signal generation module, and generating the two paths of switching signals as the control signals of a first bridge arm to realize closed loop control over the grid-connected current and eliminate the grid-connected current zero-crossing distortion of the conventional unipolar control single-phase grid-connected inverter.
Owner:HARBIN INST OF TECH

Laser phase ranging module

The present invention relates to a laser ranging technology and provides a laser phase ranging module. The laser phase ranging module includes a laser emitting assembly, an echo receiving and pre-processing assembly, a local receiving and pre-processing assembly and an FPGA processor; the FPGA processor generates two clock frequencies f1 and f2 by using a phase-locked loop, and a square wave signal with a measurement ruler frequency fs is generated through frequency division based on the clock frequency f1, and the square wave signal is transmitted to the laser emitting assembly; the laser emitting assembly emits laser to a target; echoes reflected by the target are processed by the echo receiving and pre-processing assembly, and then, square waves A of which the frequency is fs can be outputted; the local receiving and pre-processing assembly partially leads in the emitted laser and performs the same pre-processing as the echo receiving and pre-processing assembly on the led-in laser, and then outputs square waves B; and the FPGA processor synchronously reads the square waves A and the square waves B through using the clock frequency f2 and calculates out the distance of the target through data processing. According to the laser phase ranging module, frequency mixing processing is not required, and one measurement ruler can be adopted to realize remote precise ranging. The laser phase ranging module is suitable for single-point ranging and multi-path simultaneous ranging equipment.
Owner:UNIV OF ELECTRONIC SCI & TECH OF CHINA

Wind power plant flexible direct current grid connection subsynchronous oscillating current detection and suppression method

The invention provides a wind power plant flexible direction current grid connection subsynchronous oscillating current detection and suppression method. According to the detection method, through subsynchronous dq rotational coordinate transformation, three-phase currents on the converter valve side of the wind power plant side are transformed to a two-phase dq rotational coordinate system from a three-phase abc stationary coordinate system, and then subsynchronous frequency current components are obtained through filtering of a low-pass filter. The suppression method includes the steps that according to the magnitude of subsynchronous frequency current components output by a wind power plant, a converter on the wind power plant side generates corresponding subsynchronous frequency voltage components on the alternating current side, and then current components which are the same as the subsynchronous frequency current components output by the wind power plant in magnitude and opposite to the subsynchronous frequency current components output by the wind power plant in direction are generated, the subsynchronous frequency current components are offset by the current components, and then subsynchronous oscillating currents are suppressed. According to the suppression method, a control system of a wind power plant unit does not need to be changed, no hardware device needs to be additionally arranged, the amplitude of the subsynchronous frequency current components in alternating currents can be reduced as much as possible within the alternating current voltage allowance fluctuation range, the method is simple, and the calculated quantity is small.
Owner:SHANGHAI JIAO TONG UNIV

DSP (Digital Signal Processor)-based rice weed recognition system and method

The invention belongs to the technical field of agriculture, in particular relating to a DSP (Digital Signal Processor)-based rice weed recognition system and method. The DSP-based rice weed recognition system consists of an image acquiring module, a rice weed recognition module and an image displaying module, wherein the image acquiring module and the image displaying module are connected with the rice weed recognition module respectively by virtue of an I2C (inter-integrated circuit) bus and a BNC (Bayonet Nut Connector) data bus; the image acquiring module consists of a CCD (charge-coupled device) camera supporting high-definition image and an SAA7115 decoding chip of Philips, the image displaying module consists of a Gadmei PL7006 liquid crystal television used for displaying a television signal, and the rice weed recognition module consists of a DM642DSP image processing chip, and expanding SDRAM (synchronous dynamic random access memory) and SAA7121 (system application architecture 7121) decoding chips. According to the invention, the real-time recognition of weeds in rice fields can be realized, and the system miniaturization and portability can lead the system to be capable of being flexibly arranged on rice planting field equipment, and improving the practical application range of the system.
Owner:CHINA NAT RICE RES INST

Wireless sensor network node self-positioning method based on mobile anchor node

The invention relates to the technical field of wireless sensors, and discloses a wireless sensor network node self-positioning method based on a mobile anchor node, which is used for solving a problem of high complexity when a mobile anchor node positioning method is adopted. The method comprises the following steps of: building a two-dimensional rectangular plane coordinate system by aiming at a monitoring area so as to locate a sensor network monitoring area in a first quadrant completely and position an initial position of the anchor node in the origin of coordinates. The anchor node does not move when positioning broadcasting location information at interval or positioning the broadcasting location information, all the unknown nodes can receive the location information through rotating a directional antenna and store the received location information and signal strength, and the location information with the largest signal strength is selected as the available self-positioning data after the unknown nodes do not receive the location information. All the unknown nodes receive different location information for at least two times along with the movement of the anchor node, and a self position is computed through utilizing the selected available self-positioning data.
Owner:广西农垦昌菱农场有限公司

Doppler distorted acoustic signal correction method based on microphone array

The invention discloses a Doppler distorted acoustic signal correction method based on a microphone array. The Doppler distorted acoustic signal correction method can correct Doppler distortion in the acoustic signal detected by a rail edge acoustic diagnosis system, and accurate diagnosis of train bearing faults can be achieved. The Doppler distorted acoustic signal correction method comprises carrying out Hilbert transformation to a detection signal, obtaining a complex signal, windowing the complex signal, obtaining a signal segment, calculating the acceptance angle corresponding to each signal segment, constructing a resampling time sequence in dependence on the relationship between the emission time and the reception time, carrying out cubic spline difference value resampling to a signal acquired a microphone in the center of the array, carrying out Hibert transformation and fast Fourier transform to a correction signal, and carrying out diagnosis. Compared with a conventional method based on a single microphone, the Doppler distorted acoustic signal correction method based on the microphone array is advantaged in that the algorithm is simple, the calculated amount is low, prior knowledge is not needed, noise robustness is good and the like, and the Doppler distorted acoustic signal correction method has obvious advantages in practical application.
Owner:UNIV OF SCI & TECH OF CHINA

LED lighting-based color measurement multispectral imaging system

The invention provides an LED lighting-based color measurement multispectral imaging system. The system comprises a main control computer and a closed light box; the top of the light box is provided with a digital camera; the bottom of the light box is provided with an LED light group control device, a drawer type bearing stage and an LED light group; a measured object is arranged on the drawer type bearing stage; and the main control computer controls the spectral power distribution of the LED light group to be in a reciprocal relation with the spectral sensitivity curve of the digital camera, drives the LED lamp group control device to turn on a corresponding LED lights and control the lighting degrees of the LED lights, and controls the digital camera to shoot the image of the measured object when the LED lights are turned on and extracts camera response to perform calculation so as to obtain the spectral reflectance of each pixel of the measured object. With the LED lighting-based color measurement multispectral imaging system of the present invention adopted, conventional limitations can be broken. The LED lighting-based color measurement multispectral imaging system is applied to fields where a conventional color measurement instrument cannot be used.
Owner:WENZHOU UNIVERSITY
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