Abstract:For white light interference method of composite fiber pearl pressure sensor spectral reflectance is complex, its accurate demodulation are susceptible to light source spectrum is unstable and the influence of factors such as noise problem, by theoretical analysis, confirmed the reflection spectral envelope signal from the sensor is sensitive to pressure air chamber, the frequency of cycle is directly proportional to the cavity length,the extraction method of compound fiber pearl pressure sensor reflective spectrum envelope signal, using three parameters of sine fitting method to find the peak position of the adjacent two peak, at the same time, optimization of sinusoidal frequency estimation method reduce the computational burden of the three parameters of sine fitting, through the relationship between the cavity length and signal cycle can eventually get the exact cavity length value.In this paper, a detailed theoretical analysis and numerical simulation of the demodulation algorithm is carried out, and the experiment verifies that the peak value detection method in the spectral method can accurately demodulate the static cavity length of the 80 millimeter-air cavity with a relative error of 0.13% for the composite optical fiber fabry-perot pressure sensor.

Abstract:Plug-in hybrid electric vehicles are often in start-up and stop state under complex driving conditions. High current pulse has a great impact on the high-voltage bus of automotive electric drive system, resulting in the rising peak voltage of high-voltage bus, which is very easy to cause vehicle safety accidents. Aiming at the problem of high voltage bus overvoltage in plug-in hybrid electric vehicle electric drive system, a Bang-Bang control strategy is proposed to suppress the peak voltage on the high voltage bus. The accuracy of the control strategy is verified in the experimental environment of the overvoltage protection device of the electric drive system. The experimental results show that the Bang-Bang control strategy is adopted. It can effectively suppress high voltage bus overvoltage and ensure the safety of hybrid electric vehicles.

Abstract:In order to improve the precision of attitude calculation of strapdown inertial navigation system based on MEMS inertial sensor, an adaptive cubature Kalman filter (CKF) data fusion algorithm is proposed. The data fusion algorithm takes the attitude quaternion as the system state, uses the accelerometer information and the magnetometer information as the system observation, and performs real-time adaptive estimation on the system process noise matrix and the observed noise matrix to solve the problem of rapid descent of attitude calculation accuracy caused by the sudden change of system noise. The experimental results show that the adaptive CKF data fusion algorithm is significantly better on calculation accuracy than the gyroscope-based strapdown attitude calculation. The roll and pitch angle errors measured in the carrier dynamics are within 1° and the heading angle error is within 2°.

Abstract:The eye is the most important part of the facial features. Studying the feature point location and shape classification of the eye plays an important role in face recognition. This paper proposes a human eye classification method based on cascaded convolutional neural network and semantic features. Three levels of cascaded convolutional neural networks were used to detect and locate 106 feature points from rough to meticulous, among which 20 feature points can accurately locate the eyes. Based on these 20 feature points, the shape of the eye is modeled and three shape parameters defining the eye shape are defined. These three parameters are segmented to achieve the purpose of eye classification according to different semantic descriptions of each interval. Experimental results show that this method is accurate and can achieve good eye classification effect.

Abstract:In view of the complex background environment (light changes, micro-animals, etc.) in real video images, moving target detection is not easy to extract complete moving targets, and an adaptive three-frame difference algorithm based on improved mean modeling is proposed. The algorithm uses the mean background model established by the previous k-frame as the intermediate frame of the three-frame difference method, and then uses the three-frame difference method, and selects the adaptive threshold to binarize the difference result. An AND operation is performed on the two detected targets, followed by morphological processing, filtering, etc., and then the true position of the moving target is obtained. Finally, the experimental results show that the proposed algorithm can adapt to the more complex background environment, is not susceptible to illumination changes or other minor changes, and can effectively overcome the phenomenon of void and edge loss, and has higher detection accuracy, suitable for unattended monitoring. surroundings.

Abstract:Taking the voltage, current, temperature and internal resistance of the power battery as input and the state of charge as output, a neural network simulation model with four inputs and one output was established to predict the state of charge of the battery. Then, based on the state of charge, the health state of the battery is estimated by the improved capacity method, the improved internal resistance method and the voltage method, respectively. The health state of the battery is estimated by the genetic neural network algorithm. By Simulink simulation and experimental study were carried out on four 12 V series lithium ion battery packs. The charge state and healthy state of the battery were tested by collecting voltage, current, temperature, internal resistance and discharge quantity data during charging and discharging. The experimental results show that the prediction accuracy of the battery state is 1.6%. The results of simulation and experiment show that the maximum error of the combined method is 1.5%, which is higher than the other three methods. In this paper, the health state prediction method is proposed, which omits the complex steps of finding health factors by traditional neural network algorithm, and avoids the limitation of single parameter judgment method for battery health state estimation.

Abstract:Aperture coupling is the most important way of electronic interference. In the existing literatures, the method of calculating the average electrical susceptibilities of arbitrary shaped apertures is based on hypergeometric theory. Although this method can accurately calculate the average electric polarization density of small holes in any shape, the hypergeometric function is too complex for the engineers of non-mathematics. Therefore, the method of calculating the average electric polarization density of small holes is seldom used in the field of electromagnetic field engineering. In order to solve this problem, a new analytical formula is proposed in this paper, which greatly simplifies the calculation without loss of precision, and can greatly improve the efficiency of the solution of the small hole coupling problem. The core idea of this method is to convert the calculation of the average electric polarization density of a small hole to the arithmetic average of the average electrical polarization rate density of numerous small circular holes, and then deduce an analytic formula of the line integral along the edge of a small hole. The average electrical polarization rate density.

Abstract:In view of the problems that the online judge is widely used and the existing paper-generating algorithm is low in efficiency, process complexity, and the quality of the paper-generating is not high. Study the artificial paper-generating, random function selection method, backtracking search method and genetic algorithm, and proposes a Hierarchical Solving paper-generating algorithm based on backtracking search. First, establish an algorithm model according to the idea of hierarchical solving pruning, and then the algorithm analysis model is set up with the goal is to improve efficiency and quality of the paper-generating, according to the type of questions, chapters and other indicators, the question bank is hierarchical solved to improve the efficiency of the paper-generating and the quality of the paper-generating. The experimental results show that with the increase of the amount of data, the hierarchical solving paper-generating algorithm based on backtracking search has obviously improved in the efficiency of paper-generating(repetition rate, coverage rate), the quality of paper-generating and the quality of paper(discrimination, reliability).

Abstract:Neutral-point-clamped three-level inverter has many advantages compared with the traditional two-level inverter, which have make it widely used in high-voltage and high-power applications. But the special topology also has inherent problem about neutral-point voltage imbalance. On the basis of space vector pulse width modulation (SVPWM), a neutral-point charge prediction control strategy based on the combination of balance-factor and vectors-selection is proposed. during the modulation, neutral point charge can be eliminated according to the balance-factor. but when the balance-factor exceeds it’s limit, the fluctuation of neutral voltage can be further restrained by vectors-selection. Finally the MATLAB simulation model was established and studied, the simulation results of which proved it’s effectiveness.

Abstract:In order to improve the anti-disturbance ability of the unmanned aerial vehicle Line of sight stabilization platform, a method of visual axis stabilization for the quantitative feedback theory (QFT) and PID composite parallel control is proposed. First, the QFT stabilization controller is designed by loop shaping method, then the QFT is used as main controller and PID is applied to realize the dynamic compensation of QFT. Finally, the simulation experiment is carried out. The results show that the QFT and PID parallel control system reduces the step response stabilization time by 58% and the platform disturbance isolation by 75% compared with the independent QFT control system. The experimental results verify that the method can meet the requirements of the unmanned aerial vehicle for the stability of the visual axis and is superior to the QFT control method.

Abstract:In order to better apply the original English topic vector model to the training of Chinese topic model vector, and solve the shortcomings of setting the topic number. This paper changes the linear addition of the document vector and the word vector in the original topic vector model to the inner product. and combines with the document vector, character vector and word vector to train the topic vector. When the topic vector is obtained, the similar topics are gathered together by the clustering method. Meanwhile, it can determine the number of topics. Experiments show that the relevance of the topic words trained by this method is improved compared with original and traditional model, and the number of themes can be obtained reasonably. At the same time, word vector, topic vector and document representation can be obtained.

Abstract:Due to the inappropriate value of inertia weight and the diversity of particle population decreases in late iteration, traditional particle algorithm in the process of mobile robot path planning easy falls into the local optimal solution problem. Aiming at this problem, a path planning method of mobile robot with improved particle swarm optimization is proposed. Firstly, a grid map model of robot path planning is established. On this basis, the traditional particle swarm optimization algorithm is improved. The weight dynamic adjustment method based on the concept of similarity is introduced to update the particle update rate with the various stages of the optimization process, by introducing the immune information regulation mechanism in the immune algorithm to increase the diversity of particles to enhance its ability to get rid of the local optimum. The simulation results show that the proposed method can obviously improve the searching ability of the best path and its comprehensive performance is better than the traditional particle swarm optimization.

Abstract:In order to solve the problem of the shortage of effective monitoring ways of battery residual capacity in regional weather station maintenance service, relevant research work has been carried out. Firstly, through the voltage measurement to obtain the voltage change curve of regional station battery, and the prediction algorithm of its residual capacity was adopted by partial quadratic polynomial cooperation. Secondly, MATLAB script code was used to calculate the fitting optimal parameters based on experimental samples. Finally, according to the set calculation model and relevant parameters, the residual capacity monitoring software of the battery is developed. After testing, the prediction error value is less than 10%. This software can provide the maintenance staff with the effective monitoring information and prediction information of the battery in time.

Abstract:A new type of end-fire antenna element is designed. The unique series-fed monopole has good bandwidth performance. The LCD material is used in the substrate to make the dielectric constant of the substrate controllable. By changing the operating frequency of the element and the dielectric constant of the substrate, the antenna element has the ability of horizontal phase sweep. The symmetrical structure of the upper and lower layers is used to restrain the beam warping caused by the floor. The feasibility of the end-fire antenna element is verified by modeling and simulation. In this way, the series-fed antenna is easy to realize the miniaturization and thinning of the antenna. It has good conformal ability and is suitable for airborne platforms with high-speed motion.

Abstract:The testing method of RTCA/DO-160G section 20 has been widely utilized in civil aviation sector to verify the susceptibility of electronic equipments both at the system and at the unit level. Based on the procedure of section 20 originated from RTCA/DO-160G, a theoretical model of calibration phase was proposed by means of scattering parameter and validated its effectiveness through measurements, besides, the performance of injection probe also play a major role in conducted susceptibility test, Secondly, the corresponding susceptibility evaluation model was proposed based on the test signal test method, the obtained minimum susceptibility thresholds are 26 and 26.1 dBm, which indicates good agreement with theory, Finally, a measurement uncertainty evaluation based on monte carlo method is conducted. The expanded uncertainty is 2.60 dB lower than the value specified by CISPR, which indicates it can be a evaluation criteria for the susceptibility phenomenon occurring during the conductive susceptibility test. This paper is aimed to provided theoretical reference and practical foundations for conductive susceptibility of Beidou airborne receiver.

Abstract:The virtual binocular vision test is based on a high-speed camera and two planar mirrors to realize the 3D reconstruction of objects, and it solves the problems of synchronization and high cost in traditional binocular vision test. The internal and external parameters of camera calibration are an important guarantee of test precision. In order to solve the issue of human intervention and the complicated process during the calibration, a kind of automatic calibration system of high-speed camera parameter is designed based on the virtual binocular vision and Zhang’s calibration method. The external trigger circuit is designed to control the automatic rotation of the calibration board mounted on the platform bracket so as to realize automatic image shooting of different angle calibration board. The internal and external parameters of the high speed camera are obtained through the automatic processing of images by the open source computer vision library. Finally, the accuracy and practicability of the automatic calibration system of high speed camera are verified, It could provide the basis for subsequent 3D reconstruction and dynamic 3D testing.

Abstract:Generally, formation flying should be taken into consideration during satellite development. Aiming at the demand of precise formation control, a distributed dynamics simulation and test system for formation flying satellites based on EtherCAT is proposed in this article, compared with traditional single satellite dynamics simulation systems. Taking the advantages of EtherCAT’s real-time character, flexible topology and extensibility, the system is capable of integrated dispatching and data management, including the real-time simulation function of satellite data, formation topology and dynamic characteristics. In this paper, the validity has been demonstrated by constructing the EtherCAT based distributed system and designing the integrated dispatching software. Finally, the real-time performance of the proposed system has been tested and verified better than 1 ms, which meets the requirement of satellite formation dynamics simulation and test.

Abstract:With the data rate of digital ports is improved, the electrical specifications of the high-speed device under test (DUT）as AISC、SOC、ADC and DAC are severely affected by the test system’s signal integrity problem in the test. The test system’s Signal Integrity problem can leads to the difference between measurement results and actual electrical specifications. This paper proposed a method to avoid the signal integrity problem of test system by simulation and combined with good PCB design, analyzed and solved the problem of imperfect model. Through the signal integrity designing of a DUT test system and testing, verified the design method and modeling is validated.

Abstract:Due to the traditional feeding vibrator of color sorter could not effectively solve the problem of non-linear variation of vibration and cannot synchronizing command signal and control signal caused by voltage fluctuation of power grid, a method for vibration control of feeding vibrator of color sorter based on FPGA is proposed. This method is based on Verilog HDL language and multiple submodules. The PWM parameter is configured to realize the thyristor turn-on delay design and realize synchronous adjustment of vibration volume. Simulation and waveform detection show that this method can effectively synchronize the control signal with the sending instruction; through the filed vibration tests shows that this method can realize linear vibration acceleration with the vibration magnitude of the input value change, under no-load condition, the linear fitting degree reaches to 0.95, under the feeding condition and large vibration input, the linear fitting degree can reach to 0.99.

Abstract:The complexity of software is enlarged greatly in power electronic field because of complicated control algorithm applied, and the development of hardware drive codes become tedious with advanced DSP used. As a result, the traditional methods of programming and test by manual can’t develop the embedded software of control system efficiently. Aiming at this problem, a kind of embedded software developing method, model based design (MBD), is studied in this paper, by which the embedded codes can be generated automatically and early test can be executed on Simulink platform. Firstly, the basic conception and workflow of MBD are introduced. Secondly, aiming at the software development of SVPWM algorithm, the build process of algorithm model, model early test and means of fixed-point are explained in detail, and after that, software-in-the-loop test and integration of algorithm model and bottom drive are demonstrated clearly. Finally, the C codes are generated automatically by one-click and embed the code on the DSP-controlled motor control system for testing. The study results show that the embedded software of complicated algorithm can be developed efficiently through the standardized processes of MBD.

Abstract:In order to remotely monitor and record the acceleration and location of the equipment during transportation, a distributed overload detection system based on ARM is designed. The hardware consists of multi-sensors such as gyroscopes, acceleration chips, GPS chips, etc. In terms of software, the signal monitoring uses WEB technology to transmit data to the web page for real-time monitoring via GPRS. In the experiment part, the designed overload detection system is loaded on the bicycle and the data acquisition test is carried out several times on the same section. The experimental results show that the system can monitor the various motion trajectories, road conditions and states of the measured object in real time, and has reliability and stability for data acquisition, processing and transmission.

Abstract:As the existing fingerprint locks and face locks on the market, there is still a lack of a mature voice lock, and a smart voice lock system that uses the difference between different speaker voices to identify the unlocked person is designed and implemented. The system uses the smart phone as the client platform, collects the user’s voice, uploads it to the cloud server, and uses the voiceprint recognition technology to identify the user identity. When the user passes the identity authentication, the system sends the unlock signal to the NodeMCU which is the door lock end of the hardware platform through wireless network communication, thereby realizing the unlocking operation. In addition, the system uses the web page to display the server background, which enables the administrator to remotely manage and monitor the system. The experimental results show that the door lock system has a recognition accuracy of about 90%, and the error acceptance rate is very low, which fully proves the safety and stability of the system.

Abstract:In view of the single function of the traditional desk lamp and low security, this paper proposes a scheme to realize the LED lamp which combines the wireless power supply, the electromagnetic suspension technology and the pulse width modulation (PWM) technology. The principle of resonant electromagnetic coupling electric energy transmission is used to realize the wireless power supply. The lamp head and the base are separated by the electromagnetic suspension technology, and the control of the light is realized by using the STC12 MCU and the PWM technology. Finally, the mobile phone APP program is designed, and the HC-05 and Bluetooth technology is used to control the LED lamp’s lighting and color. Based on these technologies, a new type of magnetic levitation LED lamp has been successfully developed, and the lamp holder is suspended and rotated on the base. Lighting has the characteristics of safety and convenience, multi-level dimming and so on, and has good market prospects.

Abstract:Aiming at the problem that the existing domestic formaldehyde measurement methods are single and cannot be remotely monitored, a remote real-time monitoring system for indoor formaldehyde concentration based on wireless sensor network ZigBee was designed. The overall system construction scheme was given and the wireless sensor network for formaldehyde concentration detection was constructed. The wireless sensor network for concentration detection realizes real-time measurement of multiple measurement points in the home space through the ZigBee network. After remote transmission through the network, the remote real-time display of data was realized through the LabVIEW monitoring program. After testing, the remote real-time monitoring of indoor formaldehyde concentration at multiple measuring points in the home environment was completed, which verified the feasibility and reliability of the system.

Abstract:As for the problems of inefficient monitoring for agricultural products storage or transport, an agricultural products monitoring system based on STM32F103VET6 MCU is designed. The temperature and humidity sensor DHT11 is used in this system to measure temperature and humidity value. The measured data can be displayed directly on the screen and the data can be sent to mobile phone APP, which is convenient for observers to check. In addition, the required temperature and humidity threshold value can be set for different storage environment through the buttons or the mobile phone APP communication. The beep will be triggered immediately when the real-time temperature and humidity exceeds the threshold value, After the system test, the results show that monitor can work in different conditions, which also can send every value accurately to users. the expected effect can be achieved completely, the system is able to as an accuracy, convenient and real-time monitor for storage environment of agricultural products, which is low cost and can be used widely.

Abstract:To measure the lamp installation clearance, this paper proposes a method for measuring the installation gap of the headlights based on the combination of laser scanning technology and industrial robot technology. The method simulates a vehicle body with a gage and establishes a measurement system for a lamp installation gap. First, the laser scan data is preprocessed to remove the invalid data points of the overrange, and then the bilateral filter is used to smooth the data denoising. Through the selection of the height difference threshold in the determination algorithm of the boundary point of the vehicle lamp and the inspection tool, the boundary point between the vehicle lamp and the inspection tool is found, and the gap size is determined by the lamp installation clearance calculation model. The experimental results show that the measurement method has high accuracy, high efficiency, and repeatability also meets the requirements.

Abstract:Time synchronization technology is critical to the normal work and operational efficiency of wireless sensor networks. It’s an indispensable part. The traditional time synchronization algorithm is mainly used for time delay during node packet transmission and offset and drift of the node clock. But due to the influence of many complicated factors, the synchronization accuracy is not very high. So this paper uses time division multiple access (TDMA) technology for time synchronization of wireless sensor networks. The gateway node sends a beacon to notify each node of the time slot allocation. Simultaneously, those nodes that are not within the communication radius of the gateway use node listening to obtain the time slot situation. Each node sends a message in its assigned slot. Finally, the TDMA protocol of the media access control （MAC) sublayer is combined with tree cluster tree protocol (CTP) to analyze the effect of the proposed method by calculating the packet loss rate. The experimental results show that the packet loss rate decreases significantly after TDMA is applied, indicating that TDMA has a good effect on time synchronization.

Abstract:After many years of development, motion capture technology has been widely used in many fields. Studying how to apply motion capture technology to the field of sports is of great significance to scientific physical exercise and standardized physical education.This paper classifies the working principle and products of the existing motion capture technology, and collects the research use of motion capture in the domestic and international sports fields in the existing literature, focusing on the analysis of the application of motion capture technology in physical education and index testing. Research status and discuss their respective strengths and limitations. On the basis of summarizing the existing research, the technology is applied to some new sports projects, and the future development is discussed.