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A novel motion coordination method for variable-sized multi-mobile robots

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Frontiers of Information Technology & Electronic Engineering 2023年第4期24卷 521-535页

作者： Zichao XING xingkai wang Shuo wang Weimin WU Ruifen HU State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and ControlZhejiang UniversityHangzhou 310027China

Multi-mobile robot systems(MMRSs)are widely used for transportation in industrial scenes such as manufacturing and warehousing.In an MMRS,motion coordination is important as collisions and deadlocks may lead to losses or system stagnation.However,in some scenarios,robot sizes are different when loaded and unloaded,which means that the robots are variable-sized,making motion coordination more difficult.The methods based on zone control need to first divide the environment into disjoint zones,and then allocate the zones statically or dynamically for motion coordination.The zone-control-based methods are not accurate enough for variable-sized multi-mobile robots and reduce the efficiency of the system.This paper describes a motion coordination method based on glued nodes,which can dynamically avoid collisions and deadlocks according to the roadmap structure and the real-time paths of robots.Dynamic features make this method directly applicable to various scenarios,instead of dividing a roadmap into disjoint zones.The proposed method has been applied to many industrial projects,and this study is based on some manufacturing projects for experiments.Theoretical analysis and experimental results show that the proposed algorithm is effective and efficient.

关键词： Multi-mobile robot system Collision avoidance Deadlock avoidance Glued nodes Motion coordination

Collision and Deadlock Avoidance in Multi-Robot Systems Based on Glued Nodes

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IEEE/CAA Journal of Automatica Sinica 2022年第7期9卷 1327-1330页

作者： Zichao Xing Xinyu Chen xingkai wang Weimin Wu Ruifen Hu The authors are with the State Key Laboratory of Industrial Control Technology Institute of Cyber-Systems and ControlZhejiang UniversityHangzhou 310027China IEEE

Dear editor,In this letter,we would like to discuss a method to avoid collisions and deadlocks in multi-robot systems based on a new concept of glued nodes.In terms of collision and deadlock avoidance,many methods are based on zone control which has two disadvantages.First,unless all nodes are collision-free,the roadmap must be divided into disjoint zones,which increases the difficulty of applying the methods.Moreover,each zone should be able to accommodate a robot,which leads to imprecision and waste of space.This letter proposes the concept of glued nodes,which can dynamically determine the mutual influence between nodes based on the real-time sizes and paths of the robots.Based on the glued nodes,this letter proposes a collision and deadlock avoidance algorithm,which can be applied to multi-robot systems with variable-sized robots and roadmaps with any structure.The experimental results indicate that the method proposed in this letter is effective and efficient.

关键词： lock collision letter

Thermal effects on fracture toughness of cracked straight-through Brazilian disk green sandstone and granite

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1447-1460页

作者： Lei Zhou Weiting Gao Liyuan Yu Zheming Zhu Jianxing Chen xingkai wang Key Laboratory of Deep Earth Science and Engineering Ministry of EducationSichuan UniversityChengdu610065China State Key Laboratory for Geomechanics and Deep Underground Engineering China University of Mining and TechnologyXuzhou221116China Failure Mechanics and Engineering Disaster Prevention and Mitigation Key Laboratory of Sichuan ProvinceSichuan UniversityChengdu610065China Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province Shaoxing UniversityShaoxing312000China

Cracked straight-through Brazilian disc(CSTBD) samples prepared using two rock materials were used for thermal treatment from room temperature to 700℃. Uniaxial splitting experiments were performed using an automatic electro-hydraulic servo press to study the evolution laws of physical and fracture properties of different deep rock materials under high-temperature geological conditions. The fracture characteristics were measured using an industrial camera and digital image correlation technology to analyze the effect of high temperature on fracture properties and failure modes of the CSTBD samples after different thermal treatments. The micro-damage properties of green sandstone and granite materials were obtained using a scanning electron microscope(SEM). The following conclusions were drawn from the test results:(1) With the increasing temperature, the fracture characteristics of green sandstone and granite change from brittle fracture to plasticity fracture, the longitudinal wave velocity of granite decreases sharply at 600℃, and the damage factor reaches 0.8748 at 700℃.(2) The fracture toughness of green sandstone and granite decreases with increasing temperature;however, the decreasing range of granite is larger than that of green sandstone.(3) As the temperature increases, the fracture morphologies of green sandstone and granite materials become rougher, whereas thermal damage cracks of granite and intergranular fractures inside sandstone as well as pores of sandstone increase.(4) The crack tip opening displacement and peak strain corresponding to peak load increase with the temperature.

关键词： High temperature Cracked straight-through Brazilian disc(CSTBD)sample Fracture toughnessm Scanning electron microscope(SEM)

Multifunctional dual-anion compensation of amphoteric glycine hydrochloride enabled highly stable perovskite solar cells with prolonged carrier lifetime

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Nano Research 2024年第6期17卷 5131-5137页

作者： Lina Qin Mengfei Zhu Yuren Xia xingkai Ma Daocheng Hong Yuxi Tian Zuoxiu Tie Zhong Jin State Key Laboratory of Coordination Chemistry MOE Key Laboratory of Mesoscopic ChemistryMOE Key Laboratory of High Performance Polymer Materials and TechnologyJiangsu Key Laboratory of Advanced Organic MaterialsSchool of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China Nanjing Tieming Energy Technology Co.Ltd. Nanjing 210093China Suzhou Tierui New Energy Technology Co.Ltd. Suzhou 215228China

Throughout years,the two-step spin-coating process is the most common method to prepare organic lead halide perovskite materials.However,the short reaction time of dropping the solution at the second step means that PbI2 cannot be completely transformed into perovskite phase.To solve this problem,we report the introduction of glycine hydrochloride(GlyHCl)into the second step of the two-step spin-coating process to prepare a FA_(0.9)MA_(0.1)PbI_(3-x)%-GlyHCl perovskite material(namely FAMA-x%-GlyHCl,where FA=formamidinium,MA=methylammonium,and x%stands for the molar ratio of GlyHCl added in FA iodide/MA iodide(FAI/MAI)precursor solution).The Cl−ion in GlyHCl assists the formation ofα-phase perovskite,and the-COO−group coordinates with Pb2+cation in a bridging way,making up for the anion vacancy in perovskite lattice and resulting in high absorption intensity.The perovskite solar cells(PSCs)based on FAMA-9%-GlyHCl achieve a long carrier lifetime(527.0 ns),a photoelectric conversion efficiency(PCE)of 19.40%and good thermal stability,maintaining 85.8%of the initial PCE after being continuously heated at 60℃for 500 h.This study helps to solve the problem of incomplete reaction in the two-step spin-coating process and puts forward a new solution for preparing high coverage perovskite films with large grain size.

关键词： dual-anion compensation glycine hydrochloride perovskite solar cells carrier lifetime thermal and moisture stability

A dual adaptive unscented Kalman filter algorithm for SINS-based integrated navigation system

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Journal of Systems Engineering and Electronics 2024年第3期35卷 732-740页

作者： LYU Xu MENG Ziyang LI Chunyu CAI Zhenyu HUANG Yi LI Xiaoyong YU xingkai Department of Precision Instrument Tsinghua UniversityBeijing 100084China College of Mechanical and Power Engineering Three Gorges UniversityYichang 443002China Unit 91001 of the PLA Beijing 100161China School of Control and Computer Engineering North China Electric Power UniversityBeijing 100096China

In this study, the problem of measuring noise pollution distribution by the intertial-based integrated navigation system is effectively suppressed. Based on nonlinear inertial navigation error modeling, a nested dual Kalman filter framework structure is developed. It consists of unscented Kalman filter (UKF)master filter and Kalman filter slave filter. This method uses nonlinear UKF for integrated navigation state estimation. At the same time, the exact noise measurement covariance is estimated by the Kalman filter dependency filter. The algorithm based on dual adaptive UKF (Dual-AUKF) has high accuracy and robustness, especially in the case of measurement information interference. Finally, vehicle-mounted and ship-mounted integrated navigation tests are conducted. Compared with traditional UKF and the Sage-Husa adaptive UKF (SH-AUKF), this method has comparable filtering accuracy and better filtering stability. The effectiveness of the proposed algorithm is verified.

关键词： Kalman filter dual-adaptive integrated navigation unscented Kalman filter(UKF) robust

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税收征管与企业金融化

经济学报 2024年第2期11卷 105-125页

作者：王宜峰魏兴凯广西师范大学经济管理学院

税收征管不仅发挥了保证国家收入、稳定社会发展的重要作用,还会对企业运营产生重要影响。在当前经济“脱实向虚”问题愈演愈烈的情况下,从政策角度出发研究税收征管对企业金融化的影响具有重要的理论意义和现实意义。本文以2012—2020... 详细信息

税收征管不仅发挥了保证国家收入、稳定社会发展的重要作用,还会对企业运营产生重要影响。在当前经济“脱实向虚”问题愈演愈烈的情况下,从政策角度出发研究税收征管对企业金融化的影响具有重要的理论意义和现实意义。本文以2012—2020年A股上市公司为样本,利用金税三期这一准自然实验,应用多期双重差分模型(DID)研究税收征管对企业金融化的影响。研究发现,金税三期显著促进企业金融化。机制分析表明,金税三期给企业运营带来冲击,通过现金流机制和成本机制激发了企业储蓄动机进而促进企业金融化,现金流冲击大和实体盈利能力差的企业受到的促进作用更强。进一步研究发现,金税三期增加了短期金融投资、抑制了企业金融投机动机、提高了企业的实体投资效率。本文丰富了税收征管经济后果和企业金融化影响因素的研究,也为增强金融业对实体经济服务能力提供重要的思路。

关键词：税收征管企业金融化储蓄动机

A Novel Method for Determining the Void Fraction in Gas-Liquid Multi-Phase Systems Using a Dynamic Conductivity Probe

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Fluid Dynamics & Materials Processing 2024年第6期20卷 1233-1249页

作者： Xiaochu Luo Xiaobing Qi Zhao Luo Zhonghao Li Ruiquan Liao xingkai Zhang Hubei Key Laboratory of Oil and Gas Drilling and Production Engineering Yangtze UniversityWuhan434000China Oil and Gas Engineering Research Institute PetroChina Tarim Oilfield CompanyKorla84100China Xinjiang Kunlun Engineering Consulting Co. Ltd.Karamay834000China Petrochina Dagang Oilfield Company Production Technology Research Institute Tianjin300000China

Conventional conductivity methods for measuring the void fraction in gas-liquid multiphase systems are typically affected by accuracy problems due to the presence of fluid flow and salinity.This study presents a novel approach for determining the void fraction based on a reciprocating dynamic conductivity probe used to measure the liquid film thickness under forced annular-flow conditions.The measurement system comprises a cyclone,a conductivity probe,a probe reciprocating device,and a data acquisition and processing system.This method ensures that the flow pattern is adjusted to a forced annular flow,thereby minimizing the influence of complex and variable gas-liquid flow patterns on the measurement results;Moreover,it determines the liquid film thickness solely according to circuit connectivity rather than specific conductivity values,thereby mitigating the impact of salinity.The reliability of the measurement system is demonstrated through laboratory experiments.The experimental results indicate that,in a range of gas phase superficial velocities 5–20 m/s and liquid phase superficial velocities 0.079–0.48 m/s,the maximum measurement deviation for the void fraction is 4.23%.

关键词： Forced annular flow dynamic conductivity probe void fraction gas-liquid flow liquid film thickness

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煤储层破裂压力对压裂改造的影响与工程应用

煤矿安全 2024年第3期55卷 84-90页

作者：冯兴凯山东省煤田地质局第二勘探队山东济宁272000

我国煤储层渗透率普遍较低,低渗储层直接进行地面煤层气开发的效益较低,而水力压裂是增加煤储层渗透率和导流能力的有效手段。通过对沁水盆地PN-1井、PN-2井的测井参数进行分析,掌握煤储层的岩石力学特征,为煤储层水力压裂参数优化提供... 详细信息

我国煤储层渗透率普遍较低,低渗储层直接进行地面煤层气开发的效益较低,而水力压裂是增加煤储层渗透率和导流能力的有效手段。通过对沁水盆地PN-1井、PN-2井的测井参数进行分析,掌握煤储层的岩石力学特征,为煤储层水力压裂参数优化提供指导。结果表明:2口井的测井数据反演的煤层具有低泊松比、低杨氏模量、低强度、低破裂压力的特点;通过在前置液阶段控制施工排量及施工压力、提高阶段液量,可以有效避免压裂裂缝沿煤层顶底板之间的层间界面延伸及扩展至煤层顶底板;测井数据反演的PN-1井煤层破裂压力与实际压裂施工的破裂压力较接近,误差仅为3.01%,对压裂施工参数优化的指导意义较高;PN-2井煤层破裂压力略低于顶底板岩层的破裂压力,压裂初期的施工排量偏高,导致施工压力达到顶底板的破裂压力,压裂裂缝在顶底板之间延伸形成单一裂缝,改造效果及产气效果均较差。

关键词：瓦斯抽采煤储层破裂压力水力压裂可压性改造效果

被审计单位人工智能应用对审计投入和审计费用的影响

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审计研究 2024年第3期 102-112页

作者：王稳华裴璇聂兴凯对外经济贸易大学国际商学院云南财经大学会计学院中国农业大学经济管理学院北京国家会计学院

基于2011-2021年我国沪深A股上市公司样本，本文从外部审计师的投入和定价决策视角，实证检验人工智能和微观企业融合的经济后果。研究发现，被审计单位应用人工智能会增加审计师的审计投入和审计费用。机制检验发现，人工智能应用会显... 详细信息

基于2011-2021年我国沪深A股上市公司样本，本文从外部审计师的投入和定价决策视角，实证检验人工智能和微观企业融合的经济后果。研究发现，被审计单位应用人工智能会增加审计师的审计投入和审计费用。机制检验发现，人工智能应用会显著增加被审计单位经营风险，使得审计师面临的业务风险提高，进而导致审计师的上述决策行为。横截面检验发现，审计师主要针对应用人工智能的非高科技公司采取增加审计投入和审计费用的决策行为。此外，较高的行业专长能够降低人工智能应用引起的审计师高投入和高收费决策行为。研究结论丰富了微观层面人工智能和审计师投入和定价决策行为的相关研究，对更好地理解人工智能和实体企业融合具有重要的启示意义。

关键词：人工智能审计费用审计投入审计师决策行为