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Gain-enhanced reconfigurable radiation array with mechanically driven system and directive elements

《机械工程前沿（英文）》 2022年第17卷第4期 doi: 10.1007/s11465-022-0716-0

摘要： In the artificial intelligence-driven modern wireless communication system, antennas are required to be reconfigurable in terms of size according to changing application scenarios. However, conventional antennas with constant phase distributions cannot achieve enhanced gains in different reconfigurable sizes. In this paper, we propose a mechanically reconfigurable radiation array (RRA) based on miniaturized elements and a mechanically reconfigurable system to obtain gain-enhanced antennas in compact and deployed states. A five-element RRA with a phase-reconfigurable center element is designed and analyzed theoretically. The experimental sample has been fabricated, driven by a deployable frame with only one degree of freedom to realize the size and phase distribution reconfiguration simultaneously to validate the enhanced gains of RRA. The proposed RRA can be tessellated into larger arrays to achieve higher gains in other frequency regimes, such as terahertz or photonics applications with nanometer fabrication technology.

关键词： mechanism reconfigurable radiation array (RRA) compact state deployed state enhanced gain

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基于信息超表面设计理念的一种平面4比特可重构天线阵列 Article

汪正兴, 杨汉卿, 邵睿文, 武军伟, 刘国标, 翟峰, 程强, 崔铁军

《工程（英文）》 2022年第17卷第10期页码 64-74 doi: 10.1016/j.eng.2022.03.019

摘要：

受信息超表面设计理念即数字编码概念的启发，一种具有0.15λ₀（λ₀为波长）低剖面的平面4比特可重构天线阵列被提出。这个阵列是基于由1比特磁电偶极子和小型化反射式移相器组成的数字编码辐射单元组成。通过对两个对称馈电端口单独馈电，所提出的1比特磁电偶极子能够在宽带范围内提供“0”和“1”两种数字状态。所涉及的反射式移相器可以提供173°的相对相移。通过在157.5°的相位范围内进行数字量化，可以进一步得到相移间隔22.5°的8种数字状态。为了实现低副瓣水平，一个基于泰勒线源方法的1:16功分器被用来给阵列馈电。我们加工并测试了所提出的4比特天线阵列样机，实验结果与仿真结果吻合很好。阵列能够实现±45°的扫角，12 GHz的最大增益为13.4 dBi，副瓣和交叉极化水平分别低于–14.3 dB和–23 dB。另外，波束指向误差在0.8°，法向波束的3–dB增益带宽为25%。由于阵列卓越的性能，它在雷达和通信系统中将有重要的应用前景。

关键词： 4比特可重构天线阵列信息超表面数字编码方法低副瓣低剖面

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使用猫群算法优化线性天线阵列的最佳阵因子辐射方向图：电磁仿真验证 Article

Gopi RAM, Durbadal MANDAL, Sakti Prasad GHOSHAL, Rajib KAR

《信息与电子工程前沿（英文）》 2017年第18卷第4期页码 570-577 doi: 10.1631/FITEE.1500371

摘要：本研究进行了微带贴片天线线性阵列的优化设计。通过猫群算法（Cat swarm optimization, CSO）优化天线阵列辐射方向图的各控制参数。通过优化每个单元的激励电流权重和阵元间隙获得各向同性天线单元阵列的最佳辐射方向图。以12、16和20单元的天线阵列为例，运用MATLAB进行阵列优化设计，采用CST-MWS对设计结果进行仿真验证。由仿真结果可见，CSO能给出微带贴片天线线性阵列的最优设计。

关键词：贴片天线；线性天线阵列；猫群优化（CSO）；旁瓣水平（SLL）

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用于5.8 GHz WBAN应用的方向图可重构天线阵列

杨凌升,王斌,李雅洁

《信息与电子工程前沿（英文）》 2023年第24卷第9期页码 1357-1365 doi: 10.1631/FITEE.2200542

摘要：本文提出一种适用于5.8 GHz WBAN应用的方向图可重构天线阵列。天线阵列由辐射组件和控制网络组件组成。辐射组件包括4个平面F型天线，它们位于上层的4个角上，彼此逆时针旋转90°。控制网络组件位于底层，包括一个4端口可控网络。通过控制集成在可控网络中的PIN二极管，可以获得与人体表面相切的全向辐射图和与人体表面垂直的定向辐射图。我们测量了阵列安装在人体或前臂假体上时的阻抗带宽、辐射模式和增益，实验结果与仿真结果一致。同时仿真了两种辐射模式下的电磁波吸收比值（SAR）和波束切换能力，以确保该阵列的实用性。

关键词：无线体域网方向图可重构 PIN二极管控制网络比吸收率

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A zone-layered trimming method for ceramic core of aero-engine blade based on an advanced reconfigurable

《机械工程前沿（英文）》 2022年第17卷第2期 doi: 10.1007/s11465-022-0675-5

摘要： Ceramic structural parts are one of the most widely utilized structural parts in the industry. However, they usually contain defects following the pressing process, such as burrs. Therefore, additional trimming is usually required, despite the deformation challenges and difficulty in positioning. This paper proposes an ultrafast laser processing system for trimming complex ceramic structural parts. Opto-electromechanical cooperative control software is developed to control the laser processing system. The trimming problem of the ceramic cores used in aero engines is studied. The regional registration method is introduced based on the iterative closest point algorithm to register the path extracted from the computer-aided design model with the deformed ceramic core. A zonal and layering processing method for three-dimensional contours on complex surfaces is proposed to generate the working data of high-speed scanning galvanometer and the computer numerical control machine tool, respectively. The results show that the laser system and the method proposed in this paper are suitable for trimming complex non-datum parts such as ceramic cores. Compared with the results of manual trimming, the method proposed in this paper has higher accuracy, efficiency, and yield. The method mentioned above has been used in practical application with satisfactory results.

关键词： ceramic parts trimming computer-aided laser manufacturing 3D vision reconfigurable laser processing system

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Recent development on innovation design of reconfigurable mechanisms in China

Wuxiang ZHANG, Shengnan LU, Xilun DING

《机械工程前沿（英文）》 2019年第14卷第1期页码 15-20 doi: 10.1007/s11465-018-0517-7

摘要： Reconfigurable mechanisms can deliberately reconfigure themselves by rearranging the connectivity of components to meet the different requirements of tasks. Metamorphic and origami-derived mechanisms are two kinds of typical reconfigurable mechanisms, which have attracted increasing attention in the field of mechanisms since they were proposed. Improving the independent design level, innovation, and international competitive powers of reconfigurable mechanical products is important. Summarizing related significant innovation research and application achievements periodically will shed light on research directions and promote academic exchanges. This paper presents an overview of recent developments in innovation design of reconfigurable mechanisms in China, including metamorphic and origami mechanisms and their typical applications. The future development trends are analyzed and forecasted.

关键词： innovation design reconfigurable mechanisms metamorphic mechanisms origami-derived mechanisms development trends

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Distributed flexible reconfigurable condition monitoring and diagnosis technology

HU You-min, YANG Shu-zi, DU Run-sheng

《机械工程前沿（英文）》 2006年第1卷第3期页码 276-281 doi: 10.1007/s11465-006-0025-z

摘要： As manufacturing becomes increasingly decentralized, flexible and reconfigurable, more research needs to be done on monitoring and diagnosis technology that accommodate these new trends. The distributed condition monitoring and diagnosis technology based on the flexible and reconfigurable concept is studied here. A condition monitoring diagnosis model based on the distributed flexible and reconfigurable idea is proposed in this paper. The component makeup and functions of this model are discussed in detail. The model can fulfill in most instances the manufacturing system requirements for changing the configuration of the monitoring diagnosis system according to different manufacturing system configurations. This model also realizes the flexibility and reconfigurability of the monitoring diagnosis system in some degree. The model has already spawned a successful prototype for monitoring a chemical plant in accomplishing monitoring and control of the production process and equipment. Finally, some future research work is pointed out.

关键词： chemical diagnosis system configuration monitoring equipment

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Modular structure of a self-reconfigurable robot

FEI Yanqiong, DONG Qinglei, ZHAO Xifang

《机械工程前沿（英文）》 2007年第2卷第1期页码 116-119 doi: 10.1007/s11465-007-0020-z

摘要： This paper proposes a novel, hermaphroditic, and lattice self-reconfigurable modular robot. Each module is composed of a center body a cubic part and six sides that can rotate independently. There are two holes and two extensible pegs on each side. The rotary motion of each side and the extensible motion of the pegs are generated by a motor connected to a reducer, using a cone-shaped gear, belt, clutch, etc. The structure of the module is compact, and has space to extend further.

关键词： compact self-reconfigurable modular hermaphroditic cone-shaped clutch

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Module-based method for design and analysis of reconfigurable parallel robots

Fengfeng XI, Yuwen LI, Hongbo WANG

《机械工程前沿（英文）》 2011年第6卷第2期页码 151-159 doi: 10.1007/s11465-011-0121-6

摘要：

This paper presents a method for the design and analysis of reconfigurable parallel robots. The inherent modularity in a parallel robot lends itself as a natural candidate for reconfiguration. By taking the branches as building blocks, many modular parallel robots can be constructed, from which a reconfigurable parallel robot can be realized. Among three types of reconfigurations, namely, geometry morphing, topology morphing, and group morphing, the method presented here is for the last two reconfigurations, thereby advancing the current research that is mainly limited to geometry morphing. It is shown that the module-based method not only provides a systematic way of designing a reconfigurable parallel robot, but also offers a unified modeling for robot analysis. Two examples are provided, one showing the topology morphing and the other showing the group morphing.

关键词： reconfigurable parallel robot topology morphing group morphing

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Generation of closed-form inverse kinematics for reconfigurable robots

ZHAO Jie, WANG Weizhong, GAO Yongsheng, CAI Hegao

《机械工程前沿（英文）》 2008年第3卷第1期页码 91-96 doi: 10.1007/s11465-008-0013-6

摘要： For reconfigurable robots, the automatic generation of inverse kinematics is a key problem, because such robots may assume various configurations. In this paper, the screw and product-of-exponentials (POE) formula are used to model the kinematics of reconfigurable robots. The POE formula can be converted to canonical subproblems through decomposition and adjoint transformation. Three classes and 28 types of subproblems containing geometric or algebraic solutions are identified and solved, which can be reused in different configurations. A generalized, decomposable, and reusable approach for close-form inverse kinematics of reconfigurable robots is developed based on POE and subproblems. The effectiveness of this method is shown in an example.

关键词： different effectiveness generation reconfigurable algebraic

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Particle therapy for cancers: a new weapon in radiation therapy

null

《医学前沿（英文）》 2012年第6卷第2期页码 165-172 doi: 10.1007/s11684-012-0196-4

摘要：

Particle irradiation started to draw attention in the past decade and has now become a hotspot in the radiation oncology community. This article reviews the most advanced developments in particle irradiation, focusing on the characteristics of proton and carbon ions in radiation physics and radiobiology. The Bragg peak of physical dose distribution causes proton and carbon beams to optimally meet the requirement for cancer irradiation because the Bragg peak permits the accurate concentration of the dose on the tumor, thus sparing the adjacent normal tissues. Moreover, carbon ion has more radiobiological benefits than photon and proton beams. These benefits include stronger sterilization effects on intrinsic radio-resistant tumors and more effective killing of hypoxic, G₀, and S phase cells. Compared with the most advanced radiation techniques using photon, such as three-dimensional conformal radiation therapy and intensity-modulated radiation therapy, proton therapy has yielded more promising outcomes in local control and survival for head and neck cancers, prostate carcinoma, and pediatric cancers. Carbon therapy in Japan showed even more promising results than proton therapy. The local controls and overall survivals were as good as that treated by surgery in early stages of non-small cell lung cancer, hepatocellular carcinoma, prostate carcinoma, and head and neck cancers, especially for such highly resistant tumors as melanoma. The non-invasive nature of particle therapy affords more patients with chances to receive and benefit from treatment. Particle therapy is gradually getting attention from the oncology community. However, the cost of particle therapy facilities has limited the worldwide use of this technology.

关键词： radiation therapy particle therapy proton carbon cancer

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Reconfigurable manufacturing systems: Principles, design, and future trends

Yoram KOREN, Xi GU, Weihong GUO

《机械工程前沿（英文）》 2018年第13卷第2期页码 121-136 doi: 10.1007/s11465-018-0483-0

摘要：

Reconfigurable manufacturing systems (RMSs), which possess the advantages of both dedicated serial lines and flexible manufacturing systems, were introduced in the mid-1990s to address the challenges initiated by globalization. The principal goal of an RMS is to enhance the responsiveness of manufacturing systems to unforeseen changes in product demand. RMSs are cost-effective because they boost productivity, and increase the lifetime of the manufacturing system. Because of the many streams in which a product may be produced on an RMS, maintaining product precision in an RMS is a challenge. But the experience with RMS in the last 20 years indicates that product quality can be definitely maintained by inserting in-line inspection stations. In this paper, we formulate the design and operational principles for RMSs, and provide a state-of-the-art review of the design and operations methodologies of RMSs according to these principles. Finally, we propose future research directions, and deliberate on how recent intelligent manufacturing technologies may advance the design and operations of RMSs.

关键词： reconfigurable manufacturing systems responsiveness intelligent manufacturing

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Dimensional synthesis of a novel 5-DOF reconfigurable hybrid perfusion manipulator for large-scale spherical

Hui YANG, Hairong FANG, Yuefa FANG, Xiangyun LI

《机械工程前沿（英文）》 2021年第16卷第1期页码 46-60 doi: 10.1007/s11465-020-0606-2

摘要： A novel hybrid perfusion manipulator (HPM) with five degrees of freedom (DOFs) is introduced by combining the 5PUS-PRPU (P, R, U and S represent prismatic, revolute, universal and spherical joint, respectively) parallel mechanism with the 5PRR reconfigurable base to enhance the perfusion efficiency of the large-scale spherical honeycomb thermal protection layer. This study mainly presents the dimensional synthesis of the proposed HPM. First, the inverse kinematics, including the analytic expression of the rotation angles of the U joint in the PUS limb, is obtained, and mobility analysis is conducted based on screw theory. The Jacobian matrix of 5PUS-PRPU is also determined with screw theory and used for the establishment of the objective function. Second, a global and comprehensive objective function (GCOF) is proposed to represent the Jacobian matrix’s condition number. With the genetic algorithm, dimensional synthesis is conducted by minimizing GCOF subject to the given variable constraints. The values of the designed variables corresponding to different configurations of the reconfigurable base are then obtained. Lastly, the optimal structure parameters of the proposed 5-DOF HPM are determined. Results show that the HPM with the optimized parameters has an enlarged orientation workspace, and the maximum angle of the reconfigurable base is decreased, which is conducive to improving the overall stiffness of HPM.

关键词： 5-DOF hybrid manipulator reconfigurable base large workspace dimensional synthesis optimal design

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Analysis of radiation heat transfer and temperature distributions of solar thermochemical reactor for

Bachirou GUENE LOUGOU, Yong SHUAI, Xiang CHEN, Yuan YUAN, Heping TAN, Huang XING

《能源前沿（英文）》 2017年第11卷第4期页码 480-492 doi: 10.1007/s11708-017-0506-2

摘要： This paper investigated radiation heat transfer and temperature distributions of solar thermochemical reactor for syngas production using the finite volume discrete ordinate method (fvDOM) and P1 approximation for radiation heat transfer. Different parameters including absorptivity, emissivity, reflection based radiation scattering, and carrier gas flow inlet velocity that would greatly affect the reactor thermal performance were sufficiently investigated. The fvDOM approximation was used to obtain the radiation intensity distribution along the reactor. The drop in the temperature resulted from the radiation scattering was further investigated using the P1 approximation. The results indicated that the reactor temperature difference between the P1 approximation and the fvDOM radiation model was very close under different operating conditions. However, a big temperature difference which increased with an increase in the radiation emissivity due to the thermal non-equilibrium was observed in the radiation inlet region. It was found that the incident radiation flux distribution had a strong impact on the temperature distribution throughout the reactor. This paper revealed that the temperature drop caused by the boundary radiation heat loss should not be neglected for the thermal performance analysis of solar thermochemical reactor.

关键词： solar thermochemical reactor incident radiation flux temperature distribution radiation absorptivity radiation emissivity thermal performance analysis

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Security of solar radiation management geoengineering

Andrew LOCKLEY

《工程管理前沿（英文）》 2019年第6卷第1期页码 102-116 doi: 10.1007/s42524-019-0008-5

摘要：

Solar Radiation Management (SRM) geoengineering is a proposed response to anthropogenic global warming (AGW) (National Academy of Sciences, 2015). There may be profound – even violent – disagreement on preferred temperature. SRM disruption risks dangerous temperature rise (termination shock). Concentrating on aircraft-delivered Stratospheric Aerosol Injection (SAI), we appraise threats to SRM and defense methodologies. Civil protest and minor cyberattacks are almost inevitable but are manageable (unless state-sponsored). Overt military attacks are more disruptive, but unlikely – although superpowers’ symbolic overt attacks may deter SRM. Unattributable attacks are likely, and mandate use of widely-available weapons. Risks from unsophisticated weapons are therefore higher. An extended supply chain is more vulnerable than a secure airbase – necessitating supply-chain hardening. Recommendations to improve SRM resilience include heterogeneous operations from diverse, secure, well-stocked bases (possibly ocean islands or aircraft carriers); and avoidance of single-point-of-failure risks (e.g. balloons). A distributed, civilian-operated system offers an alternative strategy. A multilateral, consensual SRM approach reduces likely attack triggers.

关键词： security geoengineering solar radiation ma-nagement SRM