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Table of Content

    20 July 2019, Volume 26 Issue 7

    Blade Tip Clearance and Blade Tip Timing Measurement Based on Microwave Sensors

    ZHANG Ji-long, DUAN Fa-jie, NIU Guang-yue
    2019, 26(7):  1233-1238. 
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    Blade tip clearance and blade vibration are important parameters which affect the efficiency, operation safety and life span of turbomachinery. To meet the requirements of blade tip clearance and tip timing measurement under harsh working environments such as aircraft engine, a tip parameter measurement system based on microwave method is proposed, and the system can achieve the measurement of tip clearance and tip timing simultaneously. The system structure and measuring principle is analyzed. Microwave sensors of 24GHz based on microstrip antenna and PIFA are designed, the diameter of the sensor is less than 8mm. The sensors and measurement system prototype are tested in experiment and compared with the fiber optic tip timing system, the result indicates that the microwave measurement system can realize the dynamic measurement of blade tip clearance and tip timing, the measurement accuracy of tip clearance is ±35μm.
    Sparse Fault Degradation Oriented Fisher Discriminant Analysis Based Fault Trace
    FAN Hai-dong, WANG Yue, LI Qing-yi, ZHAO Chun-hui
    2019, 26(7):  1239-1244. 
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    The thermal power processes contain many variables, while only a part of variables will be influenced when the fault occurs. It is meaningful to analyze the fault causalities, which may help track root fault reasons and locate abnormal components. Therefore, for the fault processes, this paper isolates the faulty variables on basis of sparse fault degradation oriented fisher discriminant analysis (FDFDA) and then analyzes the causalities between different variables by Granger Causality analysis for identifying root faulty reasons.
    Multi-variable Fault Detection Method Based on Reconstruction Contribution Analysis
    ZHANG Ze-yu, LV Feng, DU Wen-xia, ZHAI kun, HUANG Zhan-ping
    2019, 26(7):  1245-1249. 
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    A multi-variable fault detection method based on reconstruction contribution analysis is proposed in view of the characteristics of multiple variables, large amount of collected data and varied data during the operation of complex systems. The improved reconstruction method can eliminate the shortcomings of the traditional SPE contribution graph method, such as insensitivity to fault data and insufficient diagnostic ability, and can conduct fault location when multi-variable faults occur simultaneously after the establishment of PCA model. The experimental simulation of the wind turbine system shows that this method can achieve accurate diagnosis when the faults of multiple variables occur simultaneously, no matter whether there are minor faults with gradual changes or abrupt changes.

    Bearing Fault Diagnosis Based on EEMD-Hilbert and Optimized Cyclic Spectrum

    WANG Xiao-hui, SUI Guang-zhou, GONG Man-feng
    2019, 26(7):  1250-1255. 
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    Against the weakening of mixed-fault signal characteristics because of severe operating conditions, a bearing fault diagnosis method based on EEMD-Hilbert signal reconstruction and improved cyclic spectrum correlation algorithm is proposed. First, the cyclic spectrum function at the modulation frequency of the system is derived from the traditional second-order cyclostationary theory, this function can eliminate interference by its appropriate mediation information. Second, the EEMD-Hilbert algorithm is designed, and then is applied to the cyclostationary signal to eliminate the interference from gaussian noise and colored noise. At the last, a simulation experiment of bearing fault diagnosis conditions is designed, and the experimental results show that this method can effectively enhance the characteristics of the weak cycled stationary signal and avoid missed sentences.
    Research on Model Reference and Sliding Mode Control Strategy of Six Rotorcraft
    LI Wei-jie, WANG Si-ming, LIANG Xu-dong
    2019, 26(7):  1256-1261. 
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    To deal with the controlling complexity and strong state coupling for six rotorcraft, a attitude and trajectory control strategy based on model reference and sliding mode is proposed. First, on the basis of establishing a simplified kinetic and kinematic model of the six rotorcraft, a reference model with good performance is constructed by linear quadratic regulator(LQR) method, and the integral sliding mode is designed according to the pseudo inverse theory and the state error. Then, the attitude controller and trajectory tracking controller are designed in the presence of interference, and the Lyapunov stability theory is used to analyze and guarantee the stability of the closed-loop system. The simulation results show that the designed control system is superior to the general PID controller, which can achieve the attitude and trajectory control with a satisfied control performance.
    Balance Control for a Two-bared and Two-wheeled Vehicle Robot under Synchronously Bars Turning
    HUANG Yong-hua, WANG Chang-sheng, HE Shu-tong, ZHUANG Wei, ZHANG Jie
    2019, 26(7):  1262-1269. 
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    This paper presents the strategy to balance a two-bared and two-wheeled vehicle robot under synchronously turning its two bars. Dynamics model of the vehicle robot was established by Chaplygin Formulation. As for the balance controller, the running angle of the robot's wheel was linearized by partial feedback linearization method, and the running angle of the two wheels was taken as input. Moreover, considering the undesirable influence of the drifting controller parameters, a fuzzy algorithm was adopted to tuning these parameters online. On the condition that the handlebars being turn between ±45°, the mode switching numerical simulations of the track-stand motion and the forward movement were performed. The results show that, the pitch angle of the frame can rapidly turn back to a balanced state, and the controller with the fuzzy algorithm has shorter adjustment time and smaller overshoot. Physical prototype experiments further testify the effectiveness of the controlling strategy.
    The Fluctuation Suppression Strategy of Photovoltaic and Energy Storage Integration Based on Vanadium Redox Flow Battery
    LI Xin, NI Xiao, QIU Ya, Zhang Hong
    2019, 26(7):  1270-1275. 
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    The abandonment of wind and light is the core issue of renewable energy development, and suppressing fluctuation with the combined power generation system of photovolatic and energy storage is a research hotspot. The combined power generation system of photovolatic and energy storage is the research object of this paper, which is used to study the interaction between PV output and energy storage. Stabilizing the photovoltaic fluctuation with vanadium redox flow battery can make the output power of the combined system smooth, which is based on the first-order low-pass filter and the moving average principle. The mathematical model of vanadium redox flow battery is established to verify that vanadium battery can stabilize fluctuations in different time scales. We did a simulation of 5kW/6h vanadium redox flow battery on Matlab/Simulink, and the simulation results show that the power output of the system of photovolatic and energy storage is smooth and the maximum power output is reduced under different filter time constants. This paper calculates the maximum power and the maximum energy requirement, which can provide the basis for the capacity configuration of each component of the combined power generation system of photovolatic and energy storage; And considering the battery characteristics, vanadium redox flow battery can also meet the requirements of the depth charge and discharge times.
    The Aggregation Based Model Predictive Control Approach for Inverter
    GAN Zhong-xue, CHEN Wen-bo, XU Yu-li, LI De-wei
    2019, 26(7):  1276-1283. 
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    Inverters are the important devices for the modern power systems. The control performance of the inverters has influence on the efficiency and quality of the power systems. In this paper, an aggregation based model predictive control method (AMPC) is presented in three-phase three-wire voltage source inverter control. The AMPC can decrease computational complexity significantly, which makes the online computation fast and feasible. The cumulate incremental state space model (CISS-Model) is set on the d-q rotation coordinate, which is able to transfer the control as a constant reference tracking problem, eliminate the steady state error and improve the control accuracy. Simulation results demonstrate that the proposed strategy can eliminate the steady state error and has good dynamic characteristics. The calculation amount is as much as PID control.
    Traffic Signal Optimization Control in Five-road Intersection Based on Artificial Fish Swarm Algorithm
    TANG Min-an, DONG Hai-long, CHENG Hai-peng
    2019, 26(7):  1284-1290. 
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    : The traffic signal control system plays a key role in the road network, and its control performance directly affects the traffic safety and delay time in the intersection. Traditional control in five-road intersection does not have the ability to adjust itself, which wastes green time. This paper adopts a method that use artificial fish swarm algorithm (AFSA) to optimize dynamic-fuzzy neural network (D-FNN) to achieve multi-phase and variable phase sequence intelligent control in five-road intersection. Taking the reciprocal of average vehicle delay as the food concentration of AFSA, and the weights and thresholds of the dynamic-fuzzy neural network which need to be modified are used as the individual state of artificial fish. A set of optimal dynamic-fuzzy neural network parameters are obtained through iterating and updating. After doing simulation analyses in the case of different rates of vehicles arrival, the result shows that this method is better than the traditional control in automatically adjusting the signal cycle, and it reduces the average delay of vehicles for about 11%.
    Research on Optimal Scheduling Strategy of Generalized Power Sources in Active Distribution Network
    LI Ying, ZHAO Feng, WU Meng-di, WEI Li-bing
    2019, 26(7):  1291-1297. 
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    System power loss and voltage deviation of the active distribution network have important influence on the system operation safety. Firstly the influence of generalized power sources output on active distribution network is considered in this paper, the outputs of generalized power sources are taken as control variables to obtain the multi-objective optimization model with both minimum of the system power loss and node voltage deviation in active distribution network as the objective function. Secondly the model of multi-objective function is transformed into a single objective function by using the fusion of AHP and the entropy method, and then the active power output values of generalized power source are optimized with the chaotic particle swarm optimization algorithm. Finally the feasibility and superiority of the proposed model and algorithm are verified with both the improved IEEE-33 nodes system and a practical active distribution network system respectively as examples.
    Research on Optimal Vehicle Scheduling in Open Mine Under Uncertainty 
    ZHOU Tian-pei , YANG Li-juan , SUN Wei
    2019, 26(7):  1298. 
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    In view of the present situation that research on optimal vehicle scheduling in open mine under uncertainty is less, the optimization objective function and constrains of vehicle scheduling are discussed firstly, and then the stochastic expected value goal programming model is established. In the process of solving the model, the chaotic theory is applied because of local convergence of PSO algorithm, and adaptive chaotic PSO algorithm is proposed. The proposed algorithm is applied to the vehicle scheduling in an open mine, which can enhances the global convergence effectively compared with the traditional PSO algorithm.
    Research of Sine Signal Amplitude and Phase Property's Measurement Based on Interactive Learning
    Sine signal, iterative learning, amplitude and phase property
    2019, 26(7):  1304-1307. 
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     In actual industrial applications, many measurement problems are essentially the corresponding sine signal amplitude and phase characteristics' measurement. For the sine signal with DC offset, measurement noise and frequency change, an amplitude and phase's measurement method based on iterative learning is proposed. Firstly, the parameters which need to be measured should be estimated one step. The iterative learning law should be set as the derivatives of the difference's square of measurement output value and estimation output value, and the parameters. The estimation algorithm is established when the derivatives are weighted properly. Simulation results show that when the measurement error's variance is at the level of the tenth of the maximum measured value, each measured parameter's estimated error can be up to one percent or smaller. Moreover, with a decrease of noise level, each parameter's estimated accuracy increase rapidly. This method can achieve high-precision measurement of sine signal's amplitude, phase, frequency and DC offset, and it also has great prospect for interferometer's electronic subdivision and motor's displacement measurement based on magnetic field information.

    Performance Evaluation of Bulk Cargo Port Based on GHS Functional Neural Network

    RAO Yi-fei, CHEN Dong-xu
    2019, 26(7):  1308-1314. 
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    In order to improve the effectiveness of the bulk cargo port productivity evaluation,a method based on Gauss harmony algorithm(GHS)and the improved functional link neural fuzzy network are combined to evluate bulk cargo port productivity. Firstly, according to the evaluation index of the operating properties, the comprehensive coverage of the model parameters is designed, and the selection of evaluation indicators of productivity bulk cargo port is realized by combining the actual property of data acquisition and process analysis; Secondly, the bulk port productivity evaluation model using the functional link neural network is designed, and the construction of bulk cargo port productivity evaluation model is realized by taking the network as the output of the network for model design of fuzzy rules; Finally, through simulation experiments, the fitting degree between the actual and expected outputs of the model is very close, which can achieve more than 95% sample data recognition efficiency, and can meet the accuracy requirement of bulk cargo port productivity evaluation in real bulk cargo port.
    Robust Fault Detection for Asynchronous Traction Motor of CRH5 Electric Multiple Unit
    Traction motor, unknown input observer, load disturbance, parameter uncertainty, robust fault detection
    2019, 26(7):  1315-1320. 
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    Reliability requirement of CRH5 electric multiple unit is more and more high with its wide application, and fault detection for induction motor is critical as the motor is important part of traction system. Firstly, taking the operating condition of induction motor into consideration, an unknown input observer design method is proposed, which has good robustness for the load disturbance. Meanwhile, the resistance of rotor is varied because of special environment so the system matrix is uncertain, the designed observer must be sensitive to faults and robust to the load disturbance as well as the uncertainty so that it can decrease the missing false rate and the false alarm rate; Finally, the designed unknown input observer is applied to the actuator fault detection of the traction motor, and the effectiveness of the proposed method is proved.
    Optimization of Evacuation Routes Under Unexpected Events Based on Petri Net
    MU Hai-bo, SONG Yu-bo
    2019, 26(7):  1321-1327. 
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    When emergency vehicles are used for evacuation and rescue under unexpected events, the superior evacuation routes should be determined according to the time delay. The travel time of an emergency vehicle on a road section is depended on the traffic flow on this road, and emergency vehicle starting at different time will face different phases when arriving at an intersection, which in turn results in different intersection delays. A generalized timed Petri net model of urban traffic network is established. Considering the uncertainty of signal at intersections and the time dependence of road travel time, a labeling algorithm based on the parameters of Petri net is designed to find the optimal evacuation route for emergency vehicles. Finally, the effectiveness of the method is indicated by a numerical example. For the purpose of comparison, evacuation routes corresponding to different starting time- same marking and same starting time- different marking are listed, which indicates that this method can better reflect the influence of evacuation starting time and traffic flow on evacuation routes.

    Research on Obstacle Avoidance Algorithm for Mobile Robot Based on Hybrid Strategy

    ZHANG Qian-qian, YU Dao-yang, LI Min-qiang
    2019, 26(7):  1328-1334. 
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    A new hybrid real-time obstacle avoidance strategy based on VFH (Vector Field Histogram) and neural network algorithm is proposed according to traditional obstacle avoidance algorithm. In this strategy the vector field histogram method is used to achieve obstacle avoidance firstly, while obtaining a large number of data sets. And a neural network predictor can be obtained by training the data sets. Thereby by this algorithm it can achieve the effect of simultaneously predicting and controlling the motion vector. In order to verify the effectiveness of the strategy, simulation is carried out for different obstacles, and comparing with the single obstacle avoidance. The simulation experiment verifies the feasibility and superiority of this real-time obstacle avoidance strategy.
    Improved Low Frequency Oscillation Analysis Based on Multi-signal Power System
    WANG Yu-hong, DONG Rui
    2019, 26(7):  1335-1340. 
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    Using EMD method to denoise the low frequency oscillation signal of the power system with low signal-to-noise ratio, there will be a large error, affecting the identification accuracy of low-frequency oscillation signal. In order to solve these problems, an improved EMD denoising method is proposed in this paper. The   IMF modal components are obtained by EMD decomposition of the low frequency oscillation signal of the power system, the normalized autocorrelation functions are obtained and the demarcation point   between noise dominant mode and signal dominant mode is determined. Then, the noise dominant mode is denoised, and the denoised components are reconstructed with the signal dominant mode to obtain the power system low frequency oscillation signal. Finally, multi-signal Prony analysis of reconstructed signals is carried out to extract the characteristics of low-frequency oscillation in power system. The experimental results show that the improved EMD method is more effective for low frequency signal denoising with low signal-to-noise ratio (SNR), the improved EMD method and the multi-signal Prony algorithm are applied to improve the performance of the EMD multi-signal Prony algorithm. The characteristics of low-frequency oscillation signal in power system have the advantages of fast speed, high resolution and good fitting effect.
    Data Access Point Planning of Power Distribution Communication Network with LTE-PON Hybrid Deployment
    CHANG Hai-jiao, LI Xin, XING Ning-zhe, LI Cai-yun
    2019, 26(7):  1341-1347. 
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    For purpose of promoting the coverage rate of Access Point (AP) in power distribution communication network, an AP planning model and the corresponding solving algorithm in the network composed of PON and wireless LTE private network are proposed. Firstly, the reliability of APs are analyzed according to their importance so that the covering mode can be determined. Secondly, considering the constraints of reliability and budget deployment cost, an AP planning problem model in PON-LTE mixed network is established with the aim of maximizing AP coverage rate. Then, the solution based on a hybrid of multiple intelligent optimization algorithms is proposed for this NP-hard problem. Finally, the proposed method is simulated to show the numerical network performance and the planning effect. The simulation results show that the proposed method owns better performance on coverage rate of AP in the LTE-PON mixed network than the strategies of separately deploying LTE or PON network.

    Application of RBF-ARX Model in the Ship Course-keeping System

    LUO Zhu
    2019, 26(7):  1348-1352. 
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    Based on the nonlinear characteristic of the ship, it is difficult to obtain accurate physical parameters of the ship physical model. Therefore, the statistical modeling method and RBF-ARX model is used to model the ship course-keeping control process. In this paper, the RBF-ARX model, the ARX model and the long-term predictive output of the physical model are compared, and the effectiveness and superiority of the RBF-ARX model in the ship course-keeping control system modeling are verified.

    Detection of Navel Orange Diseases Based on Watershed Edge Segmentation FSONN
    GU Si-si, LI Wen, HUANG Li-shao, CHEN Wei
    2019, 26(7):  1353-1359. 
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     In order to further improve the performance of detection and recognition algorithm for navel orange disease, a kind of fuzzy detection method based on the watershed segmented edge self-organizing neural network(FSONN) is proposed. Firstly, the watershed segmentation algorithm was used to realize the effective extraction of the boundary of navel orange, and used the expression of red, green components in the disease region to characterize the disease of navel orange, used the fractal dimension of the navel orange disease to be the shape expression, and used the above features as the input of neural network algorithm to construct an automatic detection model of navel orange disease. Secondly, the fuzzy self-organizing neural network algorithm was proposed to realize the automatic model parameters and structure identification based on the self-organizing clustering method; Finally, through the experiment on the MackeyGLass approximation of nonlinear sequences in the proposed algorithm, the performance advantages can be verified, and applies it in navel orange disease detection, the experimental results show that the correct rate of 4 kinds of navel orange disease detection by proposed algorithm can reach more than 90%, which can meet the needs of practical applications.
    Sampled-data Model of Nonlinear Mass-spring-damper Mechanical Vibration Systems with Relative Degrees Two
    XU Ming-can, ZENG Cheng
    2019, 26(7):  1360-1364. 
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    The approximate sampled-data models and discretization properties are derived for nonlinear multivariable mass-spring-damper mechanical vibration systems when the corresponding relative degrees of continuous plant are both two. The proposed sampled-data models use a more sophisticated derivative approximation than the simple Euler approach, and the local truncation error and global truncation error are also represented, respectively. An insightful interpretation of the given sampled-data models can be made in terms of an explicit characterization of nonlinear sampling zero dynamics which have no continuous-time counterpart. More importantly, nonlinear discrete-time controller design is also represented based on the above sampled-data model and zero dynamics. The ideas presented here generalize well-known results from the linear case to nonlinear plants. Finally, we also explore the implications of these results in nonlinear system identification.
    Optimization Technology of Capacity Control Method for Reciprocating Compressor
    LIU Wen-hua, JIANG Zhi-nong, ZHANG Tian-yu, WANG Yao, ZHANG Jin-jie
    2019, 26(7):  1365-1371. 
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    In order to meet the demand for capacity control of reciprocating compressors, the mechanism modeling of the relationship between discharge pressure and flow is established. Then the variable pairs with smaller coupling correlation degree are selected by calculating the steady-state relative gain of the model. The distributed PI control strategy is used to verify the matching relationship between the mechanism model and the actual system. Meanwhile, the model identification method is used to translate the mechanism model into transfer function matrix. And for the first time, the transfer function matrix is used to design the internal model controller of the paired main loop to replace the traditional PI controller, which reduces the difficulty of parameter tuning. Simulation and experimental results show that the proposed method achieves good target tracking performance and robustness, and optimizes the control effect of the system.
    Energy Efficiency Optimization of Power Plant Coal Conveyor System Based on Model Predictive Control
    REN Zhi-ling, ZHAO Xing, LIN Dong, ZHANG Guang-quan, ZHANG Zhong-bao
    2019, 26(7):  1372-1377. 
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    In order to improve the operation efficiency of belt conveyor for coal-fired power plant, an optimization approach is proposed. The mathematical model of the belt conveyor is built firstly, its optimal parameters are obtained by using the dynamic parameter analysis method based on the finite element model. Then the load shifting strategy is carried out with open loop optimal control. Finally, the model predictive control is used with feedback correction and rolling optimization because of the control error due to interference. The results show that the model predictive control strategy can save energy remarkably, reduce production cost greatly, increase production efficiency of power plant, and have good practical application value.
    Anti-swing Control of Bridge Crane Based on Model Predictive Algorithm
    HU Fu-yuan, SHAO Xue-juan, ZHANG Jing-gang
    2019, 26(7):  1378-1383. 
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    The main control objective of bridge crane systems is to transport cargos to the desired location rapidly and accurately, with cargos swing being as small as possible in the transportation process. In order to tackle this problem, a differential flatness theory based model predictive control approach is presented in this paper to guarantee playload to reach desired location rapidly and accurately while simultaneously limiting swing of playload within a safe range. According to the differential flatness property of bridge crane systems, a predictive model in form of differential flat outputs with a simple structure is established, and dynamic characteristics of the model are used to achieve system optimum online. Simulation results illustrate the proposed method can achieve bridge crane’s trolley positioning rapidly while simultaneously limiting playload's swing angle within a permitted range.
    Modeling and Sliding-mode Control for the Automotive Electronic Throttle
    BAI Rui, WANG Sheng-xian, WANG He-bin
    2019, 26(7):  1384-1390. 
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    The main function of electronic throttle is to regulate the air inflow into the engine system of the vehicle by changing the opening angle of the valve plate. The nonlinear mathematic model of the electronic throttle is proposed based on the mechanism and work principle. In the proposed model, the nonlinear factors spring and friction and the external disturbance caused by the gas flowrate are considered. Therefore, the proposed model can describe the nonlinear characteristics of the electronic throttle. Based on the proposed model, the sliding-mode control is designed for the electronic throttle, which can handle the strong nonlinearity and external disturbance of the electronic throttle. The closed-loop stability is proved. The control experiment platform of the electronic throttle is developed. Computer simulation and experiments are implemented. The research results of the simulation and experiment show that the proposed controller can make the actual angle of the electronic throttle track its set point with the satisfactory performance, and the external disturbance can be effectively suppressed.
    Synchronization Method between Control and Communication in the System based on EPA Real-time Ethernet
    LIU Ning, LV Kun, XUE Tong-long
    2019, 26(7):  1391-1396. 
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    In order to improve the real-time performance of EPA (Ethernet for Plant Automation) system, EPA-CCS (EPA Control and Communication Synchronization) method that accomplishes the synchronization between control and communication in EPA system is proposed. On the base of EPA deterministic scheduling mechanism, EPA-CCS method divides EPA macro cycle into two parts: communication time slice and control time slice. EPA device acquires the current time during its each round scan and determines whether to implement its communication task or to implement its control task according to whether the current time is in the communication time slice or in the control time slice. When the control task is implemented, EPA device ensures the function blocks can be implemented only once in a macro cycle through setting and scanning state signs. An experiment proves that this method can effectively avoid the invalid executions of function blocks and the invalid transmission of data, so that the operation efficiency and the real-time performance of EPA system are improved.
    Fractional Order PID Sliding Mode Variable Structure Control based Inverter Circuits
    GUO Wei, WEI Miao, LI Tao, ZHOU Cheng-jie, WANG Xin
    2019, 26(7):  1397-1404. 
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    Voltage source inverter (VSI)-based higher-order circuits are widely applied in various industrial fields for their fast response and accurate control. The key to the successful application of the inverter is the steady-state performance, and the research focus is the control strategy. First, for one-to-four-order inverter circuit systems, the state space model is established in this paper, and then a novel sliding mode variable structure control strategy, fractional order PID sliding mode variable structure control algorithm, is introduced. And the simulation experiments show that the proposed fractional order PID sliding mode variable structure control has good control performance, such as, fast convergence rate, little tracking error and strong robust performance, so it has positive instruction significance for engineering practice.
    Design of a kind of Fault Diagnosis Observer in Nonlinear System
    WEN Xiu-ping, CHEN Wei, FU Xiao-yan, ZHANG Jun
    2019, 26(7):  1405-1412. 
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    To study the design of a kind of fault diagnosis observer in nonlinear system, the fault diagnosis observer is designed according to the faults of actuator and sensor in the same nonlinear system. The stable and sufficient conditions of fault closed-loop system that is able to meet certain performance indicators are made using linear matrix inequality approach. Finally, a numerical example is used to verify the effectiveness of the proposed fault diagnosis observer, and the simulation results show that the fault diagnosis observer can diagnose the system faults well.
    Inverse Control of Permanent Magnet Synchronous Motor Based on ESO Self Anti-Perturbation
    BIAN Jiang, NIU Cong , YAO Jia-chen
    2019, 26(7):  1413-1418. 
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     In order to effectively solve the influence of the internal and external disturbance of the permanent magnet synchronous motor on the control system, and improve the self anti-perturbation ability of the control system. An adaptive inverse system synthesis control algorithm based on extended state observer (ESO) compensation is proposed. The second-order extended state observer (ESO1) of d axis current system and the third-order extended state observer (ESO2) of the speed control system are designed for real-time estimation of the uncertain disturbance and unknown state of the speed control system, and use it to do feedforward compensation. The stator resistance and inductance parameters of the motor are identified by model reference adaptation. The experimental results show that the proposed algorithm has strong robustness to the internal parameters perturbation and external load disturbance of the motor.
    Control Algorithm with Neutral Point Potential of Three-level APF
    LIAN Han
    2019, 26(7):  1419-1424. 
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     An improved algorithm is proposed that mainly focused on neutral point potential balance control of the diode clamped three-level active power filter in this paper. Firstly, this paper describes the cause of neutral point potential fluctuation in DC-side of three-level active power filter, and analyzes the control principles. In actual work, the main circuit state of active power filter is often required to switch between the rectifier and inverter, so it is difficult to determine the appropriate balance factor. This paper conducts a thorough study, and takes the fuzzy control method to solve this problem. The study found that the problem was solved by introducing fuzzy control into the balance control of the midpoint potential. Finally, the effectiveness of this method is verified by simulation and experimental results.
    Sensor Fault Diagnosis and Identification Method Using Adaptive Particle Filter
    LIU Hong-yan, MAI Yan-hong, KONG Fan-nie, MU San-min
    2019, 26(7):  1425-1430. 
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    In the general stochastic nonlinear and non-Gaussian systems, the sensor faults including biased and scaled readings caused by sudden calibration errors have adverse effect on the precise monitor and stable control of the system. To deal with this problem, a novel diagnosis and identification method is proposed. An adaptive particle filter is developed to calculate the difference between the measurements and the particle filter estimates, then the type and magnitude of sensor faults are determined through with maximum likelihood estimation, thus the fast and precise detection of sensor fault is realized, and the adverse effect caused by the faults can be compensated. Some simulations are carried out on a boiler model, and the results validate the effectiveness of the proposed method.

    Small Sample Expansion Method and Application Based on Data Distribution
    BI Lve, XIONG Wei-li
    2019, 26(7):  1431-1436. 
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    In the data-driven based soft sensor modeling procedure, the number of data samples has an apparent affect on the model accuracy. In the case of a small number of training samples, a method of data expansion combining Euclidean distance and angle principle is proposed. This method can determine the range of the sample expansion by analyzing the distribution characteristics of data, and the process information of modeling plant in each stage is improved by the extended data-set. By reconstructing the modeling data sets, the prediction performance of the model is improved. The simulation results of different industrial processes have indicated that the proposed method has good prediction accuracy and generalization performance in the case of less number of samples.