Coupled Orbit-attitude Saturated Control for Solar Sail in Earth-Moon 3-body System

Liping Wu,Yu Guo,Zhihao Zhu 제어·로봇·시스템학회 2021 International Journal of Control, Automation, and Vol.19 No.11

This paper aims to investigate a coupled orbit-attitude control strategy for a kind of novel spacecraft, solar sail, to track the given orbit in Earth-Moon 3-Body dynamic environment in presence of the matched and mismatched disturbances, attitude control saturation, orbital modeling error and parametric uncertainties. A cascaded triple-loop control structure is proposed to deal with the strong couplings between the orbit and attitude systems. The inner loop focusing on the orbital effects on attitude dynamics, an adaptive saturation controller is proposed to achieve attitude angular tracking, where the uncertain inertia, unknown matched disturbance and saturated attitude control torque are compensated by combining the unknown knowledge. The middle loop is to handle the orbit effects on attitude kinematics facing the mismatched disturbance. In the outer loop, the effects of attitude systemon orbit dynamics are deal with, where an adaptive orbit controller is designed considering the uncertain optical parameter and orbital modeling error. The proposed control structure efficiently simplifies the coupled orbit-attitudecontrol design for solar sail. In contrast to traditional coupled controllers for solar sail, the proposed control laws do not require exact knowledge of parametric uncertainties, disturbances and orbit modeling errors. The combination of unknown information reduces the number of estimated parameters as well. The numerical simulation results demonstrate the effectiveness of the proposed control strategy.

Joint prediction of internal and external temperatures for cylindrical Li-ion batteries

Yu, Suoqing,Zhang, Liping,Wang, Aobing,Ni, Liyong The Korean Institute of Power Electronics 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.11

Online battery temperature prediction is beneficial when it comes to taking effective heating and cooling actions in advance to realize better thermal management. First, this paper derives a simple thermal managing equation, i.e., a lightweight temperature prediction approach based on basic electrical and thermal laws from an equivalent circuit model. Then, to improve adaptability to complex conditions, some previously neglected thermal processes like heat conduction hysteresis and heat radiation are taken into consideration to achieve more realistic effects. In particular, the considerable reversible heat during alternating charging and discharging due to the electrochemical reactions of solid-liquid phase transitions is also modeled as a dependent variable in terms of real-time ohmic heat. A series of experiments is conducted under various loads and ambient conditions. The obtained results show that the proposed temperature prediction method can follow real temperature trajectories with an accumulated error of only 2.1 ℃ after an hour running.

Research on the Dynamic Complex Spatial Network Relations in Spatial Database

Zhang Liping,Li Song,Liu Lei,Yu Jiaxi,Li Shuang,Fan Ruiguang 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.11

Representation and analysis of the complex spatial network relations are of great significance in fields such as Geographic Information System,spatial database, spatial data mining and intelligent inference. As the existing research achievements cannot be used to deal with the dynamic complex spatial network relations effectively in reality, in order to make up for the deficiency of existing methods, the dynamic complex spatial network relations is studied in detail. The predicate representation methods of the strict and extended complex spatial network relations are proposed respectively. The dynamic logical hierarchical relationship and dynamic migration relationship of the strict spatial network relation are given. Furthermore, this paper lay emphasis on the study of the dynamic conversion and adjacent relevance of the extended complex spatial network, and some instance analyses are provided. The research achievements in this paper is rather suitable for dealing with issues about the representation, error correction and forecast of the dynamic complex spatial network relations, therefore, the ability of spatial database to deal with spatial relations of complex spatial object has been enhanced.

Image Denoising Based on Adaptive Fractional Order Anisotropic Diffusion

( Jimin Yu ),( Lijian Tan ),( Shangbo Zhou ),( Liping Wang ),( Chaomei Wang ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.1

Recently, the method based on fractional order partial differential equation has been used in image processing. Usually, the optional order of fractional differentiation is determined by a lot of experiments. In this paper, a denoising model is proposed based on adaptive fractional order anisotropic diffusion. In the proposed model, the complexity of the local image texture is reflected by the local variance, and the order of the fractional differentiation is determined adaptively. In the process of the adaptive fractional order model, the discrete Fourier transform is applied to compute the fractional order difference as well as the dynamic evolution process. Experimental results show that the peak signal-to-noise ratio (PSNR) and structural similarity index measurement (SSIM) of the proposed image denoising algorithm is better than that of other some algorithms. The proposed algorithm not only can keep the detailed image information and edge information, but also obtain a good visual effect.

Correlation of H_2S and COS in the hot coal gas stream and its importance for high temperature desulfurization

Jianglong Yu,Liping Chang,Wei Xie,Dehai Wang 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.4

Thermodynamic analysis of the correlation of H_2S and COS has been carried out at the temperature range of 400-650 ℃ at which high temperature desulfurization of coal gas is usually performed. The correlation of the two sulfur species is mainly through the reaction H_2S+CO→COS+H_2. Simulated coal gas with the following composition CO 32.69%, H_2 39.58%, CO_2 18.27%, N2 8.92% and H_2S 0.47% was used in this study, and the equilibrium concentrations of the two species at different temperatures were calculated. The results of Fe-based sorbents during sulfidation were compared with calculations. It is concluded that the above reaction may reach equilibrium concentration in the presence of the Fe-based sorbents, which means the Fe-based sorbents may effectively catalyze the reaction between H_2S and CO. Because of the correlation of the two sulfur species, both can be effectively removed at high temperatures simultaneously, offering high temperature desulfurization some advantages over low temperature desulfurization processes.

Consensus of Multi-agent Systems with Dead-zone Nonlinearity

Haibo Jiang,Liping Zhang,Jianjiang Yu,Caigen Zhou 제어·로봇·시스템학회 2012 International Journal of Control, Automation, and Vol.10 No.4

In this paper, we investigate the consensus problem of multi-agent systems with dead-zone nonlinearity over undirected networks. Firstly, a control protocol is designed based on the local infor-mation of agents. Then by LaSalle’s invariance principle for non-smooth systems, we prove that if the undirected graph is connected then the consensus is achieved by the proposed control protocol. Sec-ondly, sufficient conditions are given to guarantee the consensus of multi-agent systems with dead-zone nonlinearity and switching topologies by Lyapunov method. Finally, numerical simulations show the effectiveness of our theoretical results.

The characteristics and application of grain-slag media in a biological aerated filter (BAF)

Yan Feng,Liping Qiu,Jianwei Zhang,Longlong Gao,Yanzhen Yu 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.3

Novel filter media-grain slag particles were prepared using waste material-grain slag, clay and poreforming material with a mass ratio of 3:2:1. Compared with haydite, grain-slag had higher total porosity,larger total surface area and lower bulk and apparent density. Tests of heavy metal elements in lixivium proved that grain-slag were safe for wastewater treatment. In order to ascertain the application of grainslag,grain-slag and haydite were applied as the media of biological aerated filters (BAF) to treat municipal wastewater in two lab scale upflow BAFs. The results showed that grain-slag reactor brought a relative superiority to haydite reactor in terms of chemical oxygen demand (CODcr) and ammonia nitrogen (NH3-N) removal at the conditions of water temperature ranging from 20 8C to 26 8C and DO 4.00 mg L1 when hydraulic retention time (HRT) ranging from 1 h to 5 h. In addition, the detection of the amount of hetero bacteria and nitrobacteria of two biological aerated filters in three HRTs also showed that grain-slag medium was more suitable to the attached growth of nitrobacteria, which is helpful to the improvement of nitrification performance in grain-slag BAF. Therefore, grain-slag application in BAF, as a novel process of treating wastes with wastes, provided a promising way in grain slag waste material utilization.

Experimental Study on Mechanical Performance and Microstructure of Polypropylene Fiber Recycled Concrete

Fangfang Wei,Liping Li,Yu Zhu,Youzheng Zhao 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.7

Recycled concrete reinforced by polypropylene fibers boosts an alternative sustainable solution to address the need of reusing waste concrete. This paper reports experimental and analytical studies of static and dynamic comprehensive behavior on recycled concrete specimens reinforced with different contents of polypropylene fiber (PPF). Electro-hydraulic pressure testing was used to obtain static compressive strength, whereas 74 mm diameter Split HopkinsonPressure Bar (SHPB) was applied for dynamic impact compression tests at four strain rates. In addition, the reinforcing mechanism of polypropylene fiber on recycled concrete was analyzed of the micro-structure through Scanning Electron Microscope (SEM). Finally, ANSYS/LS-DYNA was applied for the simulation of the SHPB test, which was validated by good agreements of the stress waveform and failure modes of the fiber-reinforced recycled concrete specimen during the impact test. It appears that polypropylene fiber can optimize the microscopic pore structure inside the concrete, thus effectively improving the mechanical properties of recycled concrete which were originally defected by recycled aggregate. Also, higher strain rates significantly increase dynamic compressive strength as well as impact toughness. This study shows that the optimal content of polypropylene fiber in recycled concrete is 0.1% − 0.2%. The numerical simulation by ANSYS/LS-DYNA further proved that the HOLMQUIST-JOHNSON-COOK (HJC) constitutive model can better reflect the dynamic performance of concrete.

Peptidomics analysis of enzymatic hydrolysis beef

Dan Qin,Liping Wang,Rui Fang,Ziteng Yu,Li Mo,Min Liu 한국식품과학회 2022 Food Science and Biotechnology Vol.31 No.10

In this study, we investigated the changes in the composition of peptides during the digestion of tenderized beef treated with commercial proteinase K, flavourzyme, and bromelain. The degree of hydrolysis (DH) values before and after simulating gastric digestion were highest with proteinase K treatment. In the proteinase K-treated sample, the highest number of missing peptides was identified after gastrointestinal digestion. Additionally, the maximum number of new peptides was identified during gastric digestion. The flavourzyme is the only exopeptidase among the three enzymes, and the sample treated with it could produce more unique peptides after gastrointestinal digestion. Enzymatic tenderization altered the peptide composition and bioactivity of beef proteins during gastrointestinal digestion. The number of peptides, as well as unique peptides in the protease-treated sample, were more than those in control through gastric digestion. In contrast, the opposite was observed post gastrointestinal digestion.

Impulsive Output Consensus of Networked Passive Systems

Haibo Jiang,Liping Zhang,Jianjiang Yu,Caigen Zhou 제어·로봇·시스템학회 2015 International Journal of Control, Automation, and Vol.13 No.6

In this paper, we study the problem of impulsive output consensus of multi-agent dynamical systems, where each agent is a passive system. Firstly, an impulsive control protocol is designed for networked passive systems based on the local information of agents. Secondly, sufficient conditions are derived to guarantee the output consensus of the multi-agent dynamical systems for the network with fixed and switching topologies, respectively. Finally numerical simulations are included to show the effectiveness of our theoretical results.