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Responsible Institution:  Ministry of Industry and Information Technology of the People's Republic of China

Sponsor: Northwestern Polytechnical University

Indexed Database:  Core Journal in Chinese Science Citation Database (CSCD) National Chinese Core Journals China Science and Technology Core Journals (Statistical Source Journals of Chinese Scientific and Technological Papers)

Contact: Tel: 029-88493054E-mail: mst@nwpu.edu.cn

Articles in press have been peer-reviewed and accepted, which are not yet assigned to volumes /issues, but are citable by Digital Object Identifier (DOI).
Display Method:
Study on Characteristrics of Nanopowder Continuous High Pressure Dispersing System
Yuan Fangyang, Cui Zhengwei
 doi: 10.13433/j.cnki.1003-8728.20190270
[Abstract](4778) [FullText HTML](152) PDF 1230KB(282)
Abstract:
A continuous dispersing device for deagglomerating ultrafine particles is established. The experimental results show that nanoparticles can be dispersed to the primary particle size range via a continuous jet dispersion system. In order to investigate the mechanism and high-pressure dispersion characteristics of high pressure dispersion, the secondary jet dispersion of dry-powder nanoparticles was modeled and numerical simulated. The results show that numerical results of dynamic pressure profile agree with experiments. The particle number density decreases along the flow direction, and the experimental data is lower than the simulation results. The high pressure dispersing nozzle should not be too long to avoid re-agglomeration of the particles when passing through the nozzle. The aspect ratio of nozzle near 2.5 can produce the maximum shear rate at the jet outlet to obtain the best particle dispersion effect.
Research on Vehicle Radar Data Processing with Improved Interactive Kalman Filter
Liu Quanzhou, Jia Pengfei, Li Zhanqi, Wang Qipei, Wang Shuyong
 doi: 10.13433/j.cnki.1003-8728.20200111
[Abstract](354) [FullText HTML](140) PDF 5156KB(192)
Abstract:
In order to reduce the influence of noise on millimeter wave radar data, an interactive Kalman filter algorithm is used to process the collected data and the optimal value of the data is obtained. The motion state equation of the target vehicle was constructed according to its motion trajectory, and the state matrix and observation matrix in different states were determined. Interactive multi-model filter was designed. The virtual traffic scene was built with dSPACE scene simulation software. The data acquisition of moving targets was realized with hardware-in-the-loop technology, and the radar data noise was analyzed and calculated. During the filtering process, the genetic algorithm was used to continuously optimize the process noise and measurement noise. The filtering performance of the algorithm was verified by the set target motion trajectory. The average error of the radar data obtained by the filtering algorithm was less than 0.1 m. The noise of the radar data was reduced, the positioning and tracking capabilities of the target vehicle were improved.
Analyzing Workspace of Sewing Robot
Wang Xiaohua, Wang Yuhe, Wang Wenjie, Wang Jin, Tao Qing
 doi: 10.13433/j.cnki.1003-8728.20190260
[Abstract](273) [FullText HTML](192) PDF 1176KB(48)
Abstract:
In order to determine the sewing robot′s workspace so as to meet its structural conditions and to improve the planning efficiency before its operation,its kinematics model is established with the screw theory.The correctness of the kinematic model is verified with the Adams software. The Monte Carlo method together with the control variable method is used to analyze the workspace that has regional restrictions and to determine the optimal range of rotation angles for each joint of the sewing robot in its actual working environment. The free and limited conditions of the cloud map of its workspace are simulated with the MATLAB. The simulation results show that the joint rotation angle range determined in this paper satisfies the actual workspace requirements of the sewing robot and provides a theoretical basis for the follow-up research of it.
Kinematics and Multi-objective Optimization of 4-URPU Multiple Locomotion Modes Mobile Parallel Mechanism
Zhang Chunyan, Xie Mingjuan, Lu Chenhui
 doi: 10.13433/j.cnki.1003-8728.20190255
[Abstract](316) [FullText HTML](124) PDF 1944KB(34)
Abstract:
To adapt to the multi-terrain environment, a 4-URPU multiple locomotion modes mobile parallel mechanism is proposed, which integrates three motion modes of quadruped walking, creeping and rolling. The kinematic feasibility of the mechanism in each mode is analyzed by the screw theory. The position solution and velocity Jacobian matrix of the mechanism in each mode are solved, and a multi-objective optimization model is established to obtain a set of relative optimal solutions. The results show that the maximum speed performance index in walking process is lower than that in rolling process, and there are different optimal solutions for different working environments. Finally, a prototype test is carried out to verify the theoretical correctness and kinematic feasibility of the mechanism. The proposed mechanism can be applied to geographic environments with multiple topographic features such as nuclear power accidents, field and natural disasters, and has a certain application prospect.
Adaptive Iterative Learning Control of SCARA Manipulator with Improved Wolf Pack Algorithm
Zhang Changsheng, Ma Ze′ nan, Li Kuan, Chen Biaofa, Li Wei, Yang Jun
 doi: 10.13433/j.cnki.1003-8728.20190227
[Abstract](355) [FullText HTML](354) PDF 1508KB(132)
Abstract:
Aiming at reducing the position and speed tracking error of robot repetitive motion, an adaptive iterative learning control strategy based on wolf group algorithm is presented in this paper. According to the SCARA (Selective compliance assembly robot arm) manipulator drive equation, the iterative learning control law of the dynamic system is designed. The wolf group algorithm with adaptive step size is introduced to enable the wolf to dynamically adjust the moving step size according to the prey odor concentration, which improves the convergence speed and accuracy. When the strategy optimizes the parameters of the arm controller KP and KD, the result is effect for control and achieves effective tracking of the desired trajectory. The experimental results show that the adaptive control systems has good flexibility, high tracking accuracy for the system's desired trajectory, and effectively reduces the position and velocity tracking error of the double joint manipulator, which has strong feasibility and effectiveness.
Design and Analysis of Rotors-modulate Magnetic Gear
Li Kaiyuan, Zhu Zina, Wu Peng, Wu Di
 doi: 10.13433/j.cnki.1003-8728.20190254
[Abstract](482) [FullText HTML](142) PDF 1496KB(41)
Abstract:
Aiming at the shortcoming that the permanent magnets would be broken in rotors when magnetic gear is working at high speed condition, a rotor-modulate magnetic gear without permanent magnet in rotors is proposed. According to the principle of magnetic field modulation, the relationship between input and output torque and air gap magnetic field is established. The torque transmission capacity is analyzed by 2D FEM. The parametric scanning is used to optimization analysis of different combinations of rotor size parameters to obtain the output torque, the reasons for the influence of rotor size parameters on the output torque are then explored. The simulation result shows that the output torque has a direct relationship with the size parameters of rotor. An optimal size will make the output torque reach the maximum value. After optimization, the output torque increases by 81.2%, and the low-speed rotor size has the greatest influence on the output torque. Finally, the harmonic analysis of the magnetic density in the air gap is carried out. The results show that the main harmonics change before and after the optimization are consistent with the torque variation, and the validity of the design and analysis of the rotor modulate magnetic gear is verified.
Display Method:
Crack Fault Characteristic Analysis of a Wind Turbine Gearbox with Flash Temperature Considered
ZHANG Xu, ZHONG Jiaxin, LI Wei
2024, 43(2): 187-196.   doi: 10.13433/j.cnki.1003-8728.20220212
Abstract(35) FullText HTML(10) PDF 5555KB(22)
Abstract:
In order to study the influence of the flash temperature on the crack fault characteristic of a wind turbine gearbox, the temperature and profile deformation of the tooth are calculated using the Blok flash temperature theory and thermal deformation formula, respectively, and the tooth stiffness considering the flash temperature is obtained using the Hertz contact theory. For the gearbox with crack fault occurred on the tooth root of the high-speed gear, the torsional dynamic model is established considering flash temperature, damping, meshing stiffness, transmission error and backlash. The variation laws of the vibration characteristics with flash temperature are investigated under different crack conditions through time domain, frequency spectrum, phase diagram and Poincaré section, and the numerical results in the time-frequency domain are compared with those of the test without considering the flash temperature. The results show that the flash temperature makes the impact amplitude from the crack in the time domain increase, the fault side frequency be more complex, the phase diagram expand and the number of discrete points in Poincaré section increase, and the changes are more obvious with increasing the crack length. The research provides the basis for diagnosing and monitoring the gear crack fault state.
Research on Lateral Tracking Control of Autonomous Vehicles
LI Boxiong, WANG Liyong, SUN Peng, JI Wenlong
2024, 43(2): 197-202.   doi: 10.13433/j.cnki.1003-8728.20220204
Abstract(34) FullText HTML(8) PDF 1463KB(18)
Abstract:
The traditional model predictive control method is used to track the vehicle trajectory, the road adhesion coefficient in the model is often fixed as the empirical value of the current road. When the vehicle is driving on unknown road, it is difficult to adjust the inboard constraint of predictive control model in real time, and it is difficult to correct the road adhesion coefficient in time, which leads to vehicle lateral instability. In this paper, a model predictive control algorithmconsidering real-time road adhesion coefficient is proposed to realize trajectory tracking. Under the condition of unknown road friction coefficient, the algorithm predicts the road adhesion coefficient through the vehicle's current transverse and longitudinal acceleration, yaw rate, front wheel angle and other state variables, and adjusts the yaw angle constraint in the control model in real time. Even under the unknown road surface, it can provide redundant protection for vehicle control and ensure the vehicle to follow the expected trajectory.
Torsional Vibration Analysis and Influencing Factors of Power Split Hybrid Transmission System
WANG Huan, GE Shuaishuai, JIANG Yanjun, ZHANG Zhigang, GUO Dong, LI Ming
2024, 43(2): 203-211.   doi: 10.13433/j.cnki.1003-8728.20220233
Abstract(17) FullText HTML(11) PDF 1522KB(9)
Abstract:
For a hybrid electric vehicle, considering the engine, motor, composite planetary gear mechanism, clutch, reducer, differential and half shaft, the dynamic model of power split transmission system is established with the centralized mass method. On this basis, the natural frequency and vibration mode of the transmission system under different operating conditions are analyzed, the relationship between the excitation frequency of motor, engine and the natural frequency of the transmission system is studied respectively, and the influence law of torsional damper stiffness on the natural frequency of the transmission system is simulated and analyzed. Finally, by changing the stiffness of the torsional shock absorber, the resonant speed of the transmission system is adjusted far away from the common working area of the engine.
Design on Pitching Control Strategy of Wheeled Crane Cab
WANG Quanwei, GAO Xiaohui, WEN Hao, HUANG Jin, ZHANG Guopeng
2024, 43(2): 212-217.   doi: 10.13433/j.cnki.1003-8728.20220306
Abstract(7) FullText HTML(3) PDF 4225KB(5)
Abstract:
When working at the lifting height in large service space, the cab of wheeled crane needs to adjust the up and down actions in time to adapt to the lifting changes. In order to obtain the stable spatial change of the cab, the physical topology decoupling is used to construct the mathematical model of the hydraulic system, and the whale algorithm is proposed to optimize the control strategy of the fractional order controller (WOA-FOPID), focusing on the analysis and comparison of the dynamic response and anti-interference before and after the optimization of the control strategy. The results show that WOA-FOPID control strategy can accurately, quickly and stably control the cab pitch, improve the comfort and amenity of the cab, and this study has certain guiding significance in engineering practice.
Effect of Musculoskeletal Parameters on Muscle Metabolism in Flat-ground Walking Mode
SHUAI Junfeng, WU Haohao, YIN Baolin, MA Changyou, YAN Bingbing
2024, 43(2): 218-224.   doi: 10.13433/j.cnki.1003-8728.20220234
Abstract(17) FullText HTML(7) PDF 1759KB(5)
Abstract:
More and more attention has been paid to daily walking assistance programs and exercise methods for the elderly. Aiming at different musculoskeletal parameters, this paper constructs a musculoskeletal model suitable for Chinese people's physique. OpenSim is used to obtain the changes of aging factors, height and weight on human lower limb muscle metabolism and joint torque under flat walking mode, and explore the influence law of musculoskeletal parameters on lower limb movement. And taking the lower limb movement metabolism as the evaluation index, the influence degree of related musculoskeletal parameters on the index is comprehensively evaluated by orthogonal test. The above research methods and results provide theoretical reference and data support for the scheme design of exoskeleton assisted walking device and the formulation of scientific exercise.
Multi-objective Optimal Design of Tooth Surface of High Speed and Heavy Load Spiral Bevel Gears
REN Hongfei, WANG Sanmin, CHEN Peng, ZHANG Xuyang, ZHANG Quanqing
2024, 43(2): 225-231.   doi: 10.13433/j.cnki.1003-8728.20220185
Abstract(17) FullText HTML(10) PDF 2937KB(7)
Abstract:
To improve the strength performance of spiral bevel gears and reduce vibration and noise, a multi-objective optimization design model for tooth surfaces of spiral bevel gears was established by using the tooth contact analysis (TCA), load tooth contact analysis (LTCA) and local synthesis method to increase the contact ratio and reduce the transmission error amplitude at the transition of meshing; the non-dominated sorting genetic algorithm with elite strategy NSGA-II was used to optimize three second-order the contact parameters of the tooth surfaces, and the optimized solution was selected from the Pareto optimal solution set according to the importance of the objective function. The results showed that, under the given conditions, the optimized second-order parameters increased the contact ratio of the spiral bevel gear pair by 16.69%, and reduced the transmission error amplitude at the meshing conversion by 87.33%; meanwhile, the average load transmission error, the average tooth surface contact stress and the average tooth root bending stress of the large and small gears were reduced by 11.82%, 0.25%, 12.32% and 13.61% respectively, which improved the strength performance and meshing performance of the gear pair, and achieved the effect of the vibration and noise reduction.
Experimental Study on Influence of Sway Radius and Cutting-tool Center Lifting on EDM Effect
LI Dianxin, LIU Jianyong, ZHANG Huijie, YANG Xiaoyu
2024, 43(2): 232-237.   doi: 10.13433/j.cnki.1003-8728.20220200
Abstract(10) FullText HTML(3) PDF 6131KB(5)
Abstract:
In order to improve the performance of electrical discharge machining (EDM) system, numerical control system of EDM was developed via PC platform. The cutting tool can be raised with high speed, and the axises can be sway machined under linkage control. In this paper, the cutting tool was set under center lifting mode, and the sway radiuses were set at 30 μm, 60 μm, and 90 μm, respectively. Then, the experimental results under different modes were compared. Setting the sway radius at 90 μm, the experimental results with and without cutting-tool center lifting mode were compared. The sway radiuses results show that, with the increasing of sway radius, the processing time extends and the machining etching rate decreases. Deviation of diameters and radius of bottom fillet decreases, although diameter and depth of the holes increased after machining. Despite the changes in sway radius, the surface roughness was basically the same and electrode loss rate decreased with the increasing of sway radius. Under the cutting-tool center lifting mode, efficiently, machining etching rate, electrode loss rate, diameters and deviation of diameters decrease. Radius of bottom fillet, machining depth and surface roughness was basically the same.
Application of 3D Vector Space and Best Worst Method in Decision-making Method of Green Product Design
PEI Huining, TAN Zhaoyun, YANG Dongmei, HUANG Xueqin, GUO Renzhe
2024, 43(2): 238-248.   doi: 10.13433/j.cnki.1003-8728.20220236
Abstract(10) FullText HTML(4) PDF 5271KB(1)
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In order to solve the problem of lack of consideration of basic product attributes and lack of visual comparison methods in current green product design schemes, a multiple attribute decision-making method for green product design based on 3D vector space and Best Worst Method (BWM) was proposed. Firstly, the model is constructed as a 3D vector space through the three dimensions of function, exterior and sustainability for the basic attributes of green product design, and the lower-level attributes of each dimension was expanded. Secondly, BWM that in-corporates the interval method was used to obtain the weight distribution of the three dimensions and the lower-level attributes of each dimension. Then, the overall evaluation score of each alternative was obtained through the 3D vector space to realize the objective and scientific multi-attribute decision-making of green product design. Finally, the feasibility and effectiveness of the proposed method was verified by taking the green product design scheme of electric vehicles as an example.
Effect of Heat Treatment Temperature on Microstructure and Mechanical Properties of 316L Stainless Steel Formed by SLM
YAO Yuquan
2024, 43(2): 249-257.   doi: 10.13433/j.cnki.1003-8728.20230390
Abstract(14) FullText HTML(5) PDF 24525KB(3)
Abstract:
The different 316L samples and residual stress parts were manufactured by the selective laser melting (SLM) technology. The effect of the different heat treatment conditions on the microstructure, micro-hardness, mechanical properties and residual stress of 316L stainless steel samples formed by using SLM were investigated via optical microscope, scanning electron microscopy (SEM, equipped with electron backscatter diffraction(EBSD) probe), micro-hardness tester. The optimum heat treatment condition is obtained. The result show that the structure of316L stainless steel parts formed by SLMare very dense. Under the best heat treatment condition, which is holding at 1000 ℃ for 2 h, the samples have stable mechanical properties, lower residual stress. This study provides a strong basis for optimizing the mechanical properties and microstructure adjustment of 316L stainless steel formed by using SLM.
Design and Experimental Study of Piezoelectric Ultrasonic Atomizing Dust Removal System
CAO Shuai, HAN Guangchao, XU Linhong, JIANG Jinguo, LU Luhua, PENG Qingwei
2024, 43(2): 258-264.   doi: 10.13433/j.cnki.1003-8728.20220229
Abstract(7) FullText HTML(3) PDF 3672KB(3)
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Conveying materials through a conveyor belt is the main way of bulk material industrial transportation, and the dust control in the transportation process in the bulk material transportation urgently needs to be solved.Currently, more methods for atomized dust removalare applied. In order to enhance the atomization and dust removal effects, this paper designs a 30 kHz horn piezoelectric ultrasonic atomization device and its supporting atomized dust removal system and then uses the single factor test to study the effects of process parameters such as inlet water flow, wind speed, dust type, particle diameter and nozzle installation angle on atomization and dust removal efficiency. The results show that when the inlet water flow is 30 L/h, the coal dust removal efficiency is 75.9% and thatwhen the wind speed is 2.1 m/s, the removal efficiency is 61.1%. Compared with pulverized coal and sand, loess has higher dust removal efficiency. The pulverized coal dust removal efficiency of the nozzle increases to 73.9%, ranging between 107 ~ 180 μm. When the nozzle installation angle is 0, the coal dust removal efficiency is the highest, being 81%.
SE-KSD Optimized FRFT-VMD Bearing Fault Diagnosis Method
WEI Minghui, JIANG Lixia, TU Fengmiao, JIANG Pengbo
2024, 43(2): 265-273.   doi: 10.13433/j.cnki.1003-8728.20220202
Abstract(15) FullText HTML(3) PDF 6652KB(6)
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A fault feature extraction method based on sample entropy (SE) and kurtosis standard deviation (KSD) optimization of fractional variational modal decomposition (FRFT-VMD) is proposed, and a random forest (RF) classifier is combined to perform fault detection. Automatic recognition of classification. Aiming at the problem that the choice of order in the fractional Fourier transform has a greater impact on the separability of data, it is proposed to search for the minimum entropy of the sample to obtain the optimal order of the fractional order. Makes the overlapped part of the data better separated in the score domain. At the same time, the kurtosis standard deviation criterion is used to find the optimal parameters of the variational modal decomposition to make the effect of the variational modal decomposition better. The research results based on database data and measured data show that the signals extracted by this method contain more and more obvious fault characteristic frequencies, which greatly improves the fault diagnosis accuracy of rolling bearings in different states.
Depth Diagnosis of Spring Mechanical Faults of High Voltage Circuit Breakers Considering Wavelet Packet-Gray Level Co-occurrence Matrix Method
ZHANG Yanfei, SHAO Yang, GONG Weiwei, ZHANG Zhaowei, WU Jianwen
2024, 43(2): 274-281.   doi: 10.13433/j.cnki.1003-8728.20220199
Abstract(8) FullText HTML(3) PDF 3757KB(2)
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As an energy storage unit for the opening and closing operations of high-voltage circuit breakers (HVCBs), the reliability of the spring operating mechanism is of great significance to the safe operation of the power system. In this paper, the spring operating mechanism of the SF6 HVCB is the research object, the action mechanism of the opening and closing spring is analyzed, and the mechanical failure of the spring is simulated. The vibration and sound sensor equipment and acquisition parameters are introduced. Aiming at the shortcomings of wavelet packet time-frequency analysis, a feature extraction method based on wavelet packet-gray level co-occurrence matrix (GLCM) is proposed. Then, the four diagnostic models of support vector machine (SVM), decision tree (DT), naive Bayes, and K nearest neighbors (KNN) were compared in terms of diagnosis speed and diagnosis accuracy. The experimental results demonstrate that in the simulation actual application scenario, the KNN algorithm is selected to perform an in-depth diagnosis of the opening and closing spring faults, which can accurately determine the type and degree of the fault, and has practical application value for the safe and reliable operation of high-voltage circuit breakers.
CNN Based Fault Diagnosis of R oll ing Bearings Using MCU
ZHANG Mintao, LIAO Wenhao, QING Chaojin
2024, 43(2): 282-290.   doi: 10.13433/j.cnki.1003-8728.20220228
Abstract(14) FullText HTML(6) PDF 12590KB(4)
Abstract:
The deep neural network is applied to intelligent fault diagnosis (IFD) of rolling bearings, and artificial intelligence is realized in low cost miniaturized platform in this paper. The author optimized and improved a neural network architecture of two-dimensional convolutional neural network (CNN2D), and deployed it to STM32H743VI MCU to realize the identification and classification of bearing fault vibration signals. The training and validation of the network uses the Case Western Reserve University (CWRU) bearing fault data set and obtains data containing 10 fault types. The neural network of CNN2D is trained by Keras tool based on Tensorflow deep learning framework. Verification shows that the accuracy of fault identification can reach 98.90%. Then CubeAI tool is used to deploy the network to the microcontroller. The random bearing data is obtained through communication between serial port and computer, and the measured running time of each diagnosis is about 19 ms.
Two Sound Source Separation and Power Calculation Methods Combined with Three-dimensional Sound Intensity and Vibration Velocity Beamforming
FANG Fumin, LIU Xiaoqin, WU Xing, GUO Xiang
2024, 43(2): 291-296.   doi: 10.13433/j.cnki.1003-8728.20220305
Abstract(9) FullText HTML(5) PDF 9802KB(2)
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Aiming at the problem of separation of two sound sources with the same frequency and calculation of sound power, a sound source recognition method combining three-dimensional sound intensity vector with conventional beamforming technology of particle vibration velocity is proposed, which is used for sound source localization and sound power separation. The particle vibration velocity and the sound intensity value are solved by the sound intensity characteristics; the particle vibration velocity is introduced into the conventional beamforming to locate the sound source; the positioning result is substituted into the nonlinear equation system of sound intensity and sound power to solve the sound power value of each sound source. Experiments in a semi-anechoic chamber show that the sound source positioning method of particle vibration velocity beamforming is feasible, and the error of solving the sound power value is within 5%.
An Assembly Operation Perception Model in Augmented Reality Environment
LIANG Jianbin, HE Hanwu, WU Yueming, HU Zhaoyong, XU Ziqi
2024, 43(2): 297-304.   doi: 10.13433/j.cnki.1003-8728.20220217
Abstract(8) FullText HTML(4) PDF 14807KB(1)
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The existing virtual assembly system’s natural assembly operation and interaction models have defects for expressing the workload of two-handed cooperative operation and single-step operation. To solve this problem, an assembly operation perception model in its augmented reality environment is proposed. The model can parametrically express the mechanical assembly operation. A virtual object pose calculation method based on assembly motion characteristics is proposed. The method is based on the motion correlation between the elements of the model, namely the real hand and the manipulated virtual object. The calculation methods of the model's key states based on its elements are proposed to meet the requirements of the model's operation. An application case is developed. The experimental results show that the assembly operation perception model can express five common assembly operations and satisfy the requirements for assembly training.
Modeling and Simulation of Wing Bending Simulation System
ZHAO Mengwen, FAN Zeming
2024, 43(2): 305-311.   doi: 10.13433/j.cnki.1003-8728.20230337
Abstract(14) FullText HTML(5) PDF 4522KB(5)
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In the flight of a certain aircraft, the maximum deformation of the wing will be up to 3 meters, which will seriously affect the handling performance of the steel cable transmission device installed on the aircraft wing. Considering the cost, difficulty and risk of handling performance in the real flight, a ground wing bending simulation system is constructed. Firstly, a semi-physical simulation model for the whole wing is constructed, which consists of 16 sets of mechanisms. Each mechanism is equipped with a set of displacement servo control system and an angle servo control system. Then, the angle control and displacement control of the wing bending simulation system are modeled and simulated, and an effective control strategy by combining feedforward and fuzzy control is put forward. Finally, an experimental verification system is built to verify the rationality of the simulation system. The results show that this system is reasonable in design and strong in practicability, and can meet the test of steel cable handling performance under wing bending deformation.
Optimization Design of Cab Structure in Power Concentrated EMU
LIU Zhanyu, YU Dezhuang, YANG Fan, LI Dongyuan, ZHANG Wei, ZHANG Zhao
2024, 43(2): 312-317.   doi: 10.13433/j.cnki.1003-8728.20220195
Abstract(11) FullText HTML(4) PDF 23617KB(3)
Abstract:
The cab structure takes the key role for the safety of driver inthe powder concentrated EMU. The structural strengthening by the design of reasonable load paths can be used for the structural weight reduction of the corner and collision pillars in the load case of collision under the condition of structural safety. This can be meaningful for designing the power concentrated EMU with heavy load and high speed. The topological optimization was used for the topology design of the cab structure in the power concentrated EMU, in which the distributions of the corner and collision pillars can be obtained. Based on the obtained re-generated structures, the geometrical size optimization is further used. Results indicate that the weight of the cab structure can be obviously reduced by integratingthe topological and geometrical optimizations under the condition of structural safety. In comparison with the initial design, the weight of the cab structure can be obviously reduced. All the weight of the new corner pillar andcollision pillar can be reduced by up to 67.5%. The weight of cab can be obviously reduced by the present integrating topological and geometrical optimization method.
Data-driven Energy Consumption Prediction of New Energy Buses
HU Jie, YANG Guangyu, HE Chen, ZHU Xueling
2024, 43(2): 318-324.   doi: 10.13433/j.cnki.1003-8728.20220303
Abstract(13) FullText HTML(4) PDF 1135KB(4)
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In view of the most of the existing energy consumption prediction of electric vehicles based on the laboratory conditions, the results are too ideal and the actual deviation is large or the accuracy is insufficient. According to the actual running data of Beijing No. 51 bus, the influencing factors of energy consumption is analyzed, the time information through clock cycle coding is optimized, and a driving behavior evaluation system is established based on the entropy weight method for auxiliary analysis of driving behavior and operating conditions by using the boxplots to set thresholds to construct driving conditions. Finally, the LSTM energy consumption prediction model by introducing the attention mechanism is established for the four types of typical working condition segments after clustering, and it is compared and analyzed with the various prediction models such as traditional LSTM and LGBM, the validation results show that the performance of the LSTM prediction model by incorporating the attention mechanism is significantly higher than the other models.
Research on Adaptive Cruise Control Strategy of Distributed Driving Electric Vehicles
HU Shengli, ZHANG Huanhuan, JIANG Zhongshun, CHANG Xiaoyu
2024, 43(2): 325-335.   doi: 10.13433/j.cnki.1003-8728.20220211
Abstract(19) FullText HTML(5) PDF 1420KB(5)
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Taking distributed driven vehicle as research object, aiming at the adaptive cruise problem of multi-objective coordination, the nonlinear variable time headway model was applied to design the spacing compensation strategy for the rampway and curve road conditions, which improved the accuracy of the distance signal of the actual workspace. The adaptive cruise control (ACC) system based on model predictive control (MPC) algorithm and layered control was designed considering vehicle safety, comfort and energy saving. The variable step size discretization method is used to improve ACC system multi-objective cooperative upper controller, enhancing the accuracy and real-time performance of system. In the lower controller, the inverse drive system model, the inverse brake system model, and the brake switch/drive logic were established, and the expected torque distribution strategy was designed to optimize the overall driving efficiency of the vehicle. The simulation environment was built in CarSim/Simulink to verify the effectiveness of the designed strategy.
Energy Management Strategy Design for Double Fuzzy Control of Hybrid Storage Electric Vehicle
YANG Lei, BAI Zhifeng, WANG Juan, HUANG Lin
2024, 43(2): 336-343.   doi: 10.13433/j.cnki.1003-8728.20220238
Abstract(14) FullText HTML(5) PDF 13080KB(2)
Abstract:
In order to enhance the suppression effect on the peak current of lithium battery in hybrid storage electric vehicles and strengthen the protection of the lithium battery, a double fuzzy control energy management strategy is proposed in this paper. Based on the AVL CRUISE software platform, the vehicle model was built, and the energy management control strategy model was established in MATLAB/Simulink, and the effectiveness of the control strategy was verified by co-simulation. Compared with the rule-based and single fuzzy control-based energy management strategies, the control strategy proposed in this paper can effectively reduce the peak current of lithium batteries. At the same time, the lithium battery current fluctuation suppression targets in the high and low power range are taken into account, which makes the discharge power of the supercapacitor more reasonable in the required power range of the car, and the lithium battery is better protected.
Study on Recognition of Wheel Flat Scars Using Acceleration Signal of Wheel-rail Vibration
YANG Lirong, HE Zhenxing, WANG Kaiyun, LIU Xuqi, CAO Ziyong
2024, 43(2): 344-350.   doi: 10.13433/j.cnki.1003-8728.20220206
Abstract(5) FullText HTML(4) PDF 3393KB(1)
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Early detecting of wheel flat and tracking development process are important contents for the rail transit fault intelligent identification system. Current work emphasizes the impact of wheel flat excitation on vehicle and track system components, and how to determine the safety limit of the scar to ensure driving safety, lack of research on the recognition mechanism of wheel flat. Therefore, in terms of the vehicle-track coupled dynamics theory, the dynamic response of vehicle system and track system under wheel flat excitation is obtained by using the dynamic simulation. Using wavelet packet decomposition, the energy values of vertical vibration acceleration of different components are extracted as the evaluation indexes, and the evaluation method of wheel flat impact response is studied from the perspective of energy characteristics. The acceleration time domain the signal eigenvalue and energy eigenvalue of the vehicle body, frame, axle box, wheelset and rail are compared and analyzed by considering three excitation states of wheel-rail irregularity, random irregularity and superimposed roughness. It is found that there is a linear increasing relationship between the wavelet packet energy of the rail and the flat depth, the wheel flat only affects the wavelet packet energy of identical side rail. Therefore, the wavelet packet energy of the rail vibration response can be used to detect the wheel flat.
Model for Thermoelectric-generator Based on Engine Exhaust Gas and Influencing Law Analysis
MA Zongzheng
2024, 43(2): 351-357.   doi: 10.13433/j.cnki.1003-8728.20220224
Abstract(11) FullText HTML(5) PDF 2366KB(3)
Abstract:
In order to recover and utilize the energy of engine exhaust gas with high temperature based on thermoelectric generation technology, the influencing factors of the thermoelectric generator system and the influencing laws of output power were studied based on the validation of equation with the compassion of experimental and simulation results. The simulation results show that the output power increases firstly and decreases with the increasing of external load. The influencing law of See-beck coefficient is basically the same as the external load which shows a trend of increasing first and then decreasing. The relation between the internal resistance and the output power is quasi-quadratic, and the output power decreases with the increasing of internal resistance. The change in thermal conductivity of the thermoelectric generation module has a great effect on the output power. When the thermal conductivity becomes larger, the output power decreases and when the thermal conductivity increases from 0.01 to 0.9, the output power decreases by 80%. The effect of the heat dissipation coefficient of the hot and cold ends on the output power is basically the same which is that the output power increases with the increasing of heat dissipation coefficient.
Intelligent Optimization Method and Rapid Design of Cross-scale Structure
HUO Shulin, JIANG Hexin, SONG Xianhai, ZHOU Enlin, HE Zhicheng
2024, 43(2): 358-365.   doi: 10.13433/j.cnki.1003-8728.20220237
Abstract(18) FullText HTML(3) PDF 2192KB(5)
Abstract:
The multiscale topology optimization design has greatly stimulated the lightweight potential of the structure and play an important role in the development of advanced equipment. However, the structural topology optimization algorithm based on traditional finite element is difficult to meet the needs of rapid product iteration. To this end, this paper proposes a coupled deep learning-based cross-scale topology optimization method to establish a deep learning model for fast generation of dual-scale topologies by integrating residual neural networks (Resnet), U-net architecture and attention mechanism in SEnet. The training data are generated using a bidirectional evolutionary structure optimization algorithm, and the model is tested with a completely new set of data. Numerical examples show that the proposed deep learning model can efficiently and accurately generate macroscopic material distribution and microscopic topology based on various boundaries.
Study on Group Technologyof T-section Aluminum Alloy Profile Parts and Application
CHEN Dongdong, DENG Tao, MEN Xiangnan, TONG Pengyan, WANG Yongjun, ZHANG Jian
2024, 43(2): 366-372.   doi: 10.13433/j.cnki.1003-8728.20220189
Abstract(14) FullText HTML(5) PDF 2875KB(5)
Abstract:
A group processing method was proposed for the problem of low forming efficiency and poor forming accuracy in single-piece stretch bending forming with T-section in this paper.Based on the section size and radius of curvature of guide line, the analysis algorithm of group technology was established. T-section profile was grouped, and the long profile was formed and cut into sections to obtain T-section parts that meet the requirements of precise shape. Through the calculation, simulation analysis, and stretch bending tests, the feasibility of the group technology of forming T-section profile by stretch bending was verified. This method can improve the manufacturing efficiency and forming accuracy of parts, and greatly reduced the workload and processing cost of manual correction.