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Acta Mechanica Solida Sinica 2019年第3期32卷 298-309页

作者： Ye-Wei Zhang Zhi-Wei Fang Shi-Lei Wang Zhi-Yu Ni Jian Zang Bo Fang College of Aerospace Engineering Shenyang Aerospace University Shenyang 110136 China Shanghai Prime Machinery Company Limited Shanghai 200072 China

This paper presents a new device integrating a nonlinear vibration absorber with a levitation magnetoelectric energy harvester for whole-spacecraft systems. This device effectively reduces vibration and has a stronger energy harvesting capability than the existing systems. It harvests energy from a wide frequency range and has a high output voltage. The harvested energy is determined by magnetic field strength, excitation frequency, and resistive load. The change in the magnetic field strength has the least impact on the output voltage. The vibration reduction effects and harvested energy of the system are analyzed with an approximate analytical method that combines the harmonic balance approach and the pseudo-arclength continuation algorithm. The results of the Runge-Kutta method are nearly consistent with those of the approximate analytical method. Moreover, the effects of the excitation frequency, resistive load, and parameters of the nonlinear energy sink on the system vibration response and energy harvesting are analyzed.

关键词： Levitation magnetoelectric energy harvester Whole spacecraft Nonlinear energy sink Vibration reduction

Nonlinear vibration analysis of a circular composite plate harvester via harmonic balance

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Acta Mechanica Sinica 2019年第4期35卷 912-925页

作者： Tian-Chen Yuan Jian Yang Li-Qun Chen Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China School of Urban Railway Transportation Shanghai University of Engineering Science Shanghai 201620 China Department of Mechanics Shanghai University Shanghai 200444 China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University Shanghai 200072 China

Alumped parameter transversevibration model of a composite plate harvester is analyzed via harmonic balance approaches. The harvester is mainly composed of a piezoelectriccircular composite clamped by two steel rings and a proof mass on the *** lumped parameter model is a 1.5 degree-of-freedom strongly nonlinear system with a higher order polynomial stiffness. Aharmonic balance approach is developed to analyze the system, and the resulting algebraic equations are numerically solved by adopting an arc-length continuation technique. Anincremental harmonic balance approach is also developedfor the lumped parameter model. The two approaches yieldthe same *** amplitude-frequency responses produced by the harmonic balance approach are validated by the numericalintegrations and the experimental data. The investigation reveals that there coexist hardening and softening characteristics in the amplitude-frequency response curves under sufficiently large excitations. The harvester with thecoexistenceof hardening and softening nonlinearitiescan outperform not only linear energy harvesters but also typical hardening nonlinear energy harvesters.

关键词： Piezoelectricenergy harvester Circular composite plate Transverse nonlinear vibration Harmonic balance Arc-length continuation

Electroaeroelastic Modeling and Analysis for Flow Energy Piezoelectric harvester

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Transactions of Nanjing University of Aeronautics and Astronautics 2017年第1期34卷 9-14页

作者： Zhang Jiantao Wu Song Shu Chang Li Chaodong School of Mechatronic Engineering and Automation Shanghai UniversityShanghai 200072P.R.China

An electroaeroelastic model for wind energy harvesting using piezoelectric generators is *** flow field is mapped in *** force which the fluid flow exerts on the generator is *** output voltage levels generated from the mechanical strain within the piezoelectric elements are *** analytical model is developed with consideration of the interactions between the fluid,solid and *** analytical results are obtained,such as flow velocity contour and pressure contour for the flow,moving trajectories,stress contour and output voltage of the harvester.A prototype is fabricated and *** simulation result is close to the experimental *** model developed in this paper can predict the performance and behavior of different energy *** it also can be used as a design tool for optimizing the performance of the harvester.

关键词： wind energy harvester piezoelectric aeroelasticity electromechanics

The effect of the beam shapes on the doubly-clamped piezoelectric energy harvester

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Applied Mathematics and Mechanics(English Edition) 2019年第9期40卷 1361-1374页

作者： Lei JIN Shiqiao GAO Xiyang ZHANG School of Mechatronic Engineering Beijing Institute of Technology

For a piezoelectric energy harvester composed of a doubly-clamped beam with arbitrary width shapes and a proof mass, the influence of beam shapes and electrode arrangements on different electric outputs is analyzed. The output performances of piezoelectric energy harvesters with rectangular shape, concave trapezoidal shape, and concave parabolic shape are compared, and an optimization way is given. The experimental results validate the effectiveness of the methods.

关键词： doubly-clamped width shape piezoelectric energy harvester electrode connection

An improved piezoelectric harvester available in scavenging-energy from the operating environment with either weaker or stronger vibration levels

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Science China(Physics,Mechanics & Astronomy) 2009年第2期52卷 218-225页

作者： XUE Huan HU HongPing HU YuanTai CHEN XueDong Department of Mechanics Huazhong University of Science and TechnologyWuhan 430074China

An improved harvester available in scavenging energy from the operating environment with either weaker or stronger vibration levels is studied. To ensure the optimal harvester performance, a Cuk dc-dc converter is employed into the modulating circuit. This paper reports how this harvester scav- enges maximal energy from varying-level vibrations and store energy into an electrochemical battery. Dependence of the duty cycle upon the external vibration level is calculated, and it is found that: 1) for weaker vibrations, the charging current into the battery is smaller than the allowable current, and thus all the optimal output power of the harvesting structure can be absorbed by the battery. In this case, the duty cycle should be fixed at 1.86%; 2) for stronger external forcing, the allowable charging current of the battery is smaller than the optimal harvested current. This indicates that just a portion of the sca- venged energy can be accepted by the battery. Thus, the duty cycle should be decreased gradually with the increase of the vibration level. Finally the energy transmission process and the roles of each elec- tronic element are analyzed. It is shown that a Cuk converter can greatly raise the efficiency of such a harvester, particularly when subjected to a weaker ambient vibration.

关键词： piezoelectric harvester scavenging energy Cuk converter duty cycle

Design and experiment of a Chinese chive harvester

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International Journal of Agricultural and Biological Engineering 2023年第2期16卷 125-131页

作者： Yulong Feng Xuchao Yin Hairong Jin Wenyu Tong Xiaofeng Ning College of Engineering Shenyang Agricultural UniversityShenyang 110866China Key Laboratory of Modern Horticultural Equipment Ministry of Agriculture and Rural AffairsShenyang 110866China

Recognizing the labor intensity of current domestic Chinese chive harvesting and the need for its mechanized harvesting,a self-propelled electric Chinese chive harvester is *** machine is composed of a control system,supporting mechanism,cutting parts,conveying and clamping mechanisms,frame,and collection *** can complete Chinese chive feeding,cutting,transmission,and binning operations at one *** has a cutting width of 0.25 m and wheelbases of 260 mm and 460 *** 12 V,42 Ah lead-acid batteries were used in series as the power *** mechanical properties of Chinese chive were analyzed,and shear and compression tests were carried out to determine that the average value of the maximum shear force on the chives is 129 *** to a compressive force of 225 N,Chinese chives are not *** to the physical characteristics of Chinese chives and the requirements of the harvesting operations,design and calculation of the key components of the harvester’s transmission mechanism and the strength of the whole machine frame were *** embedded control system and Cortex-M3 microprocessor were used to control the harvester and realize its functions of rolling and harvesting while regulating its speed and protecting its *** the Box-Behnken test design method,the machine’s operating speed,cutter speed,and cutter height were selected as influencing factors,and the lodging rate and loss rate were evaluated as a test.A mathematical regression model of influencing factors and evaluation indexes was established to analyze the influence of these factors and indexes and optimize test *** optimal parameter combination is determined to be:operating speed,1.1 km/h;cutter speed,220 r/min;cutter height 2.0 *** parameters were verified from field tests and the results showed that under the optimized parameter combination,the average lodging rate was 3.96% and the average loss rate was 3.23%,indicating that the Chinese chive harvester

关键词： harvester clamping mechanism test design lodging rate Chinese chive

Design and optimization of the parameters of the key components for reed harvester

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International Journal of Agricultural and Biological Engineering 2022年第6期15卷 96-103页

作者： Jicheng Huang Bin Zhang Kunpeng Tian Haolu Liu Cheng Shen Nanjing Institute of Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014China College of Mechanical and Electrical Engineering Hohai UniversityChangzhou 213022JiangsuChina School of Mechanical Engineering Southeast UniversityNanjing 211189China

In the present,most of domestic reed harvesters are still in the research and prototype stage,and there is not yet a model with mature technology,strong versatility and mass *** modified reed harvesters used in some places can partially solve the reed harvesting problem,but there are problems such as small cutting width,unstable harvesting quality and low operational efficiency that need further *** the study,a reed harvester was designed to integrate with the cutting and *** key components of reed harvester were analyzed to determine the working parameters of the upper stalk-guiding device,the reciprocating double-acting cutter and the three-layer chain ***,a quadratic orthogonal rotation combination test was designed to process the data by Design-Expert,where the failure rate,cutting efficiency and conveying rate were taken as the response *** analysis was also made to explore the effects of forward speed,cutting speed,and chain conveying speed on the response index of the reed harvester.A regression mathematical model was established for the response *** response surface method was then selected to implement the multi-objective optimization of the regression *** results demonstrated that an optimal combination of operation parameters was achieved as follows:the forward speed was 0.85 m/s,the cutting speed was 1.40 m/s,and the chain conveying speed was 1.33 m/s,where the failure rate was 4.17%,the cutting efficiency was 44.21 plants/s,and the conveying rate was 93.60%.The optimized parameters were verified in the field on the reed *** the field test,failure rate,cutting efficiency,and conveying rate were 4.38%,43.82 plants/s,and 92.55%,*** relative errors with the optimized values were 9.8%,5.0%,and 1.1%,*** results of the study provide a theoretical basis for the control of operating parameters and improved design of reed harvesting implements.

关键词： reed harvester operation parameters multi-objective optimization response surface

Design and experiment analysis of the small maize harvester with attitude adjustment in the hilly and mountainous areas of China

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International Journal of Agricultural and Biological Engineering 2024年第1期17卷 118-127页

作者： Meizhou Chen Guangfei Xu Yuanzhen Wei Yinping Zhang Peisong Diao Huanxiao Pang College of Agricultural Engineering and Food Science Shandong University of TechnologyZibo255000ShandongChina School of Mechanical and Automotive Engineering Liaocheng UniversityLiaocheng252000ShandongChina Shandong Academy of Agricultural Machinery Sciences Jinan 250000China

To solve the problem of small planting plots and large sloping land for mechanized maize harvesting in China hilly and mountainous areas,a small maize harvester with attitude adjustment was designed to realize maize snapping,peeling,straw crushing and attitude adjusting at on time in this *** basic structure and working principle of the small maize harvester were described,and the key components were designed as *** maize snapping device adopted the combination form of maize snapping plates and straw pulling rollers,and the gap of the straw pulling rollers can be adjusted to adapt to different maize *** pairs of peeling rollers formed a groove arrangement to improve peeling rate and reduced ear grain *** pressure feeding device mainly comprised drive chain and three grade pressure feeding rollers to increase the friction between ears and the peeling rollers,and help ears *** attitude adjustment advice was designed according to the high point stationary pursuit leveling *** the attitude angle of the rack approached 0,the small maize harvester reached the level *** actual range of attitude adjustment was obtained and the accuracy of static attitude adjustment was verified through attitude adjustment *** influencing factors of ear loss rate and bract peeling rate were determined by orthogonal test,including the rotational speed of straw pulling rollers,peeling rollers and pressure feeding *** mathematical regression model between the experimental factors and indicators was established by using Design Expert,and through the analysis variance to verify the significance of the evaluation indicators,the best combination of operation parameters was determined that the rotational speed of straw pulling rollers,peeling rollers and pressure feeding rollers were 1440 r/min,1535 r/min and 406 r/*** the optimal combination of the operation parameters,the ear loss rate and bract peeling rate were 1.33%and 93.98%.T

关键词： maize harvester hilly and mountains areas attitude adjustment anti rollover structure

Design and test of 4ZZ-4A2 full-hydraulic self-propelled jujube harvester

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International Journal of Agricultural and Biological Engineering 2018年第4期11卷 104-110页

作者： Wei Fu Zhiyuan Zhang Kai Ding Weibin Cao Za Kan Junbing Pan Yudong Liu College of Mechanical and Electrical Engineering Shihezi UniversityShihezi 832003XinjiangChina Agricultural Machinery Key Laboratory of Xinjiang Production and Construction Corps Shihezi 832003XinjiangChina

The cultivated area of jujube in Xinjiang has increased rapidly in recent *** the jujube harvest by hand has the shortage of high labor intensity,low efficiency and high labor cost,in addition,the harvesting machinery applying to dwarf and dense planting mode of jujubes is unavailable in *** 4ZZ-4A2 based on the full-hydraulic self-propelled jujube harvester was designed to solve the above *** harvester was mainly composed of a frame,a vibrating device,a jujube collecting and conveying device,an air separation device,a steering system,a hydraulic system and a jujube suction device and was capable of completing vibration,collection,conveying,cleaning and sundries removal work of jujubes through one *** jujubes dropped on the ground were picked up at the same *** AMESim simulation software was adopted to perform simulation analysis on the overall hydraulic *** results showed that the speed of the vibrating motor was stable at about 650 r/min(the corresponding vibration frequency is 10.83 Hz)with the torque of 80 N·m,the speed of the conveyor motor was stable at 77 r/min with the torque of 77 N·m;the speed of the fan motor was stable at 54 r/min with the torque of 53.6 N·m;the speed of the walking motor fluctuated around 100 r/min with the torque of about 1000 N·m;the hydraulic steering system responded rapidly and could satisfy the actual working requirements of the jujube *** jujube garden test results showed that the harvester could reach to the optimum harvesting effect when running at the speed of 0.5 m/*** such speed,the ground jujube picking rate was 45.1%,the tree jujube harvesting rate was 93.2%,the loss rate was 2.9%,and the damage rate was 0.9%.This study can provide theoretical basis and technical support for the jujube harvester.

关键词： harvester jujube hydraulic simulation dwarf and close planting design

Design and test of two-wheeled walking hemp harvester

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International Journal of Agricultural and Biological Engineering 2020年第1期13卷 127-137页

作者： Jicheng Huang Cheng Shen Aimin Ji Kunpeng Tian Bin Zhang Xianwang Li Qiaomin Chen College of Mechanical and Electrical Engineering Hohai UniversityChangzhou 213022China Nanjing Institute of Agricultural Mechanization Ministry of Agriculture and Rural AffairsNanjing 210014China School of Mechanical Engineering Southeast UniversityNanjing 211189China

Aiming at the planting characteristics of hemp in southern hilly regions,a two-wheeled walking hemp harvester suitable for harvesting hemp in southern hilly regions is studied and *** harvester mainly consists of a header frame,single-moving cutter,cutter mechanical transmission,stalk lifter and reel,stalk divider,stalk horizontal conveyor,wheeled chassis,motor,gearbox,*** improve the cutting performance of the two-wheeled walking hemp harvester,response surface tests of three levels are conducted for three factors influencing the operation quality,including the cutting speed,blade length,and forward speed,on the constructed hemp cutting test ***,test results are analyzed with the response surface method,and multi-objective optimization is carried out for the regression mathematical model with Design-Expert *** show that when the cutting speed is 1.2 m/s,the blade length is 120 mm,forward speed is 0.6 m/s,the cutting efficiency is 38.92 stalks/s,the cutting power is 776.37 W and the failure rate is 6.24%.Trial production of sample machine and field trial are finished according to the optimized parameters and structural design scheme,and the test results reveal that the cutting rate can reach 92.5%,the rate of transmission can reach 86.7%,the productivity is 0.18 hm2/h,and all performance indexes can meet the design *** research can provide references for resolving the mechanical harvesting of hemp.

关键词： hemp harvester structural design parameter optimization productivity