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Detecting Cyber-Attacks Against Cyber-Physical Manufacturing System: A Machining Process Invariant Approach

IEEE INTERNET OF THINGS JOURNAL 2024年第10期11卷 17602-17614页

作者： Li, Zedong Chen, Xin Chen, Yuqi Li, Shijie Wang, Hangyu Lv, Shichao Sun, Limin Chinese Acad Sci Inst Informat Engn Beijing Key Lab IOT Informat Secur Technol Beijing 100085 Peoples R China Univ Chinese Acad Sci Sch Cyber Secur Beijing 101408 Peoples R China ShanghaiTech Univ Sch Informat Sci & Technol Shanghai 201210 Peoples R China

The era of the Industrial Internet of Things has led to an escalating menace of cyber-physical manufacturing systems (CPMSs) to cyber-attacks. Presently, the field of intrusion detection for CPMS has significant advancements. However, current methodologies require significant costs for collecting historical data to train detection models, which are tailored to specific machining scenarios. Evolving machining scenarios in the real world challenge the adaptability of these methods. In this article, We found that the machining code of the CPMS contains a complete machining process, which is an excellent detection basis. Therefore, we propose MPI-CNC, an intrusion detection approach based on Machining Process Invariant in the machining code. Specifically, MPI-CNC automates the analysis of the machining codes to extract machining process rules and key parameter rules, which serve as essential detection rules. Then, MPI-CNC actively acquires runtime status from the CPMS and matches the detection rules to identify cyber-attacks behavior. MPI-CNC was evaluated using two FANUC computer numerical control (CNC) machine tools across ten real machining scenarios. The experiment demonstrated the exceptional adaptability capability of MPI-CNC. Furthermore, MPI-CNC showed superior accuracy in detecting cyber-attacks against CPMS compared to existing state-of-the-art detection methods while ensuring normal machining operations.

关键词： Machining Codes Servers Cyberattack computer numerical control Intrusion detection Process control computer numerical control (CNC) cyber attack cyber-physical manufacturing systems (CPMSs) Industrial Internet of Things intrusion detection

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Quadruple Folded Groove-Guide Slow Wave Structure With Power Synthesis Circuit for Terahertz TWT

IEEE ELECTRON DEVICE LETTERS

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IEEE ELECTRON DEVICE LETTERS 2025年第2期46卷 302-305页

作者： Duan, Jingrui Lu, Zhigang Gao, Peng Wang, Zechuan Guo, Jingyu Dong, Yang Zheng, Yuan Wang, Zhanliang Wang, Shaomeng Gong, Huarong Gong, Yubin Univ Elect Sci & Technol China Sch Elect Sci & Engn Natl Key Lab Sci & Technol Vacuum Elect Chengdu 611731 Peoples R China Univ Elect Sci & Technol China Yangtze Delta Reg Inst Huzhou Huzhou 313001 Zhejiang Peoples R China Univ Elect Sci & Technol China Sch Resources & Environm Chengdu 610054 Peoples R China

In this letter, a novel power synthesis scheme is proposed for high-power terahertz (THz) traveling-wave tube (TWT), which features a quadruple folded groove-guide (Q-FGG) slow wave structure (SWS) and a power synthesis circuit. numerical simulations validate the high-frequency characteristics of Q-FGG-SWS. Particle-In-Cell (PIC) simulations predict that, driven by four 125mA electron beams at 28.4kV, the Q-FGG-TWT is expected to achieve possibility of output power of approximately 177.3W at 316GHz. The Q-FGG-SWSs were fabricated using high-precision computer numerical control (CNC) milling technology. The dispersion characteristics of Q-FGG-SWS and transmission characteristics of the Q-FGG-SWSs based on the compact multi-stage groove-T coupler were experimentally verified. Therefore, the Q-FGG-SWS with a compact power synthesis circuit offers a promising approach for enhancing the power output of THz-TWTs.

关键词： Electrons Power generation Power amplifiers Dispersion Integrated circuit modeling Terahertz radiation Impedance Electron beams Electric fields computer numerical control Terahertz (THz) traveling-wave tube (TWT) slow wave structure (SWS) power synthesis multiple-beams

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Sawtooth scanning strategy for additive manufacturing

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RAPID PROTOTYPING JOURNAL 2024年第8期30卷 1502-1516页

作者： Patil, Yogesh Patel, Ashik Kumar Gote, Gopal Dnyanba Mittal, Yash G. Mehta, Avinash Kumar Singh, Sahil Devendra Karunakaran, K. P. Akarte, Milind Indian Inst Management Mumbai Dept Operat & Supply Chain Management Mumbai India Indian Inst Technol Dept Mech Engn Mumbai India Indian Inst Technol Mumbai India

PurposeThis study aims to improve the acceleration in the additive manufacturing (AM) process. AM tools, such as extrusion heads, jets, electric arcs, lasers and electron beams (EB), experience negligible forces. However, their speeds are limited by the positioning systems. In addition, a thin tool must travel several kilometers in tiny motions with several turns while realizing the AM part. Hence, acceleration is a more significant limiting factor than the velocity or precision for all except ***/methodology/approachThe sawtooth (ST) scanning strategy presented in this paper minimizes the time by combining three motion features: zigzag scan, 45 degrees or 135 degrees rotation for successive layers in G00 to avoid the CNC interpolation, and modifying these movements along 45 degrees or 135 degrees into sawtooth to halve the *** effectiveness is tested using an in-house developed Sand AM (SaAM) apparatus based on the laser-powder bed fusion AM technique. For a simple rectangle layer, the sawtooth achieved a path length reduction of 0.19%-1.49% and reduced the overall time by 3.508-4.889 times, proving that sawtooth uses increased acceleration more effectively than the other three scans. The complex layer study reduced calculated time by 69.80%-139.96% and manufacturing time by 47.35%-86.85%. Sawtooth samples also exhibited less dimensional variation (0.88%) than zigzag 45 degrees (12.94%) along the build *** limitations/implicationsSawtooth is limited to flying optics AM ***/valueDevelopment of scanning strategy for flying optics AM process to reduce the warpage by improving the acceleration.

关键词： Additive manufacturing computer numerical control Interpolation Path planning Scanning technique

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CNC-Machined and 3-D-Printed Metal G-Band Diplexers for Earth Observation Applications

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IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY 2024年第6期14卷 1071-1078页

作者： Skaik, Talal Hunyor, Peter Beardsley, Mat Wang, Hui Huggard, Peter G. Wang, Yi Univ Birmingham Sch Elect Elect & Syst Engn Birmingham B15 2TT England RAL Space STFC Rutherford Appleton Lab Didcot OX11 0QX England

This work presents two manufacturing approaches for waveguide diplexers applicable to separating two of the G-band, 140-220 GHz, channels used in space borne radiometry of the Earth's atmosphere. Waveguide diplexing is a lower volume alternative to a quasi-optical, i.e., frequency selective surface-based, system. The two channels considered are 164-167 and 175-191 GHz. The diplexer comprises a Y-junction with two waveguide-cavity filters. Two high-precision fabrication technologies have been utilized: computer numerical control (CNC) machining and 3-D printing. Two units were CNC machined as brass split blocks and a third was 3-D printed monolithically in stainless steel by a microlaser sintering (MLS) process. The latter is an innovative structure that incorporates the diplexer with the waveguide flanges. All devices were gold coated to reduce loss. Measured insertion losses (ILs) in the two channels were 0.6 and 0.34 dB for the CNC-machined diplexers and 1.8 and 0.8 dB for the 3-D printed diplexer. The maximum frequency shifts from design were 0.695 GHz in the CNC diplexers and 1.55 GHz in the 3-D printed diplexer.

关键词： Filters Waveguide lasers Three-dimensional displays Flanges computer numerical control Loss measurement Gold 3-D printing computer numerical control (CNC) machining diplexer G-band microlaser sintering (MLS) microwave sounder (MWS) waveguide filter

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Time-Bound Optimal Planning in CNC Machine Considering Machining Safety

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IEEE TRANSACTIONS ON AUTOMATION SCIENCE AND ENGINEERING 2024年第4期21卷 6358-6370页

作者： Guo, Jianxin Zhao, Mingyong Zhang, Lixian Chinese Acad Sci Inst Sci & Dev Beijing 100190 Peoples R China Tsinghua Univ Dept Mech Engn BKLPUMEC Beijing 100084 Peoples R China Chinese Acad Sci Acad Math & Syst Sci Beijing 100190 Peoples R China

In this paper, we propose a time-bound optimal planning model to reconcile the dilemma between the cutting efficiency and the cutting security. Unlike the traditional planning method, we consider the bound of the kinematic constraints to be flexible in the form of a fuzzy set. It is reasonable to use such an expression considering that the safety of the computer numerical control (CNC) machine is susceptible to the potential disturbance in the cutting process. A fuzzy optimization method is used to obtain a compromise bound aiming to balance the cutting efficiency and the cutting security. The original problem can be reduced into a convex problem in some weak conditions, for which some interesting results are proved and the numerical method is also used to solve it. The proposed algorithm is experimented on our self-designed CNC machine. We verify the effectiveness of our proposed method through air-cutting and milling process with two respect experiment, and verify the efficiency of our algorithm by comparing traditional open-loop strategies.

关键词： Planning Machining Kinematics Safety computer numerical control Manufacturing Machine tools Velocity planning flexible kinematic bound open-loop strategy milling operation

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A Physics-Guided Data-Driven Feedforward Tracking controller for Systems With Unmodeled Dynamics-Applied to 3D Printing

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IEEE ACCESS 2023年 11卷 14563-14574页

作者： Chou, Cheng-Hao Duan, Molong Okwudire, Chinedum E. Univ Michigan Dept Mech Engn Ann Arbor MI 48109 USA Hong Kong Univ Sci & Technol Dept Mech & Aerosp Engn Hong Kong Peoples R China HKUST Shenzhen Hong Kong Collaborat Innovat Res In Shenzhen Peoples R China

A hybrid (i.e., physics-guided data-driven) feedforward tracking controller is proposed for systems with unmodeled linear or nonlinear dynamics. The proposed controller is based on the filtered basis functions (FBF) approach, and hence called a hybrid FBF controller. It formulates the feedforward control input to a system as a linear combination of a set of basis functions whose coefficients are selected to minimize tracking errors. To predict the system response and thereby the tracking errors, the basis functions are filtered using a combination of two linear models. The first model is physics-based and remains unaltered during the execution of the controller, while the second is data-driven and is continuously updated during the execution of the controller. To ensure its practicality and safe learning, the proposed hybrid FBF controller is equipped with the abilities to handle delays in data acquisition and to detect impending instability due to its inherent data-driven feedback loop. The effectiveness of the hybrid FBF controller is demonstrated via application to vibration compensation of a 3D printer with unmodeled linear and nonlinear dynamics. Thanks to the proposed hybrid FBF controller, the tracking accuracy of the 3D printer and the print quality are both significantly improved in experiments involving high-speed printing, compared to standard FBF controller that does not incorporate a data-driven model. Furthermore, the ability of the hybrid FBF controller to detect, and hence to potentially avoid, impending instability is demonstrated offline using data collected online from experiments.

关键词： computer numerical control data-driven modeling motion control nonlinear dynamical systems predictive control smart manufacturing three-dimensional printing trajectory tracking vibration control

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A framework for practically effective creation of postprocessors for 5-axis CNC machines with all possible configurations and working mechanisms

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART B-JOURNAL OF ENGINEERING MANUFACTURE 2024年第5期238卷 682-694页

作者： Chu, Anh My Le, Minh Thai Hoang, Ngoc Ha Le, Chi Hieu Egbe, Uyi-Osa Gao, James Zlatov, Nikolay Packianather, Michael S. Le Quy Don Tech Univ Inst Simulat Technol Hanoi Vietnam Le Quy Don Tech Univ Fac Special Equipments Hanoi Vietnam Hanoi Univ Civil Engn Hanoi Vietnam Univ Greenwich Fac Engn & Sci Gillingham Kent England Bulgarian Acad Sci Inst Mech Sofia Bulgaria Cardiff Univ Sch Engn Cardiff Wales Le Quy Don Tech Univ Inst Simulat Technol 236 Hoang Quoc Viet Hanoi 100000 Vietnam Quy Don Tech Univ Fac Special Equipments 236 Hoang Quoc Viet Hanoi 100000 Vietnam

The 5-axis CNC (computer numerical control) machining plays an important role in manufacturing, especially in making parts of complex shapes such as turbine or propeller blades. However, there are always challenges of generating 5-axis CNC machining programs when working with different 5-axis CNC machines of various structures;and 5-axis CNC programs must be automatically generated by CNC postprocessors which calculate the inverse kinematics and convert the Cutter Location data to the CNC programs that are used for operating 5-axis CNC machines. Since the family of 5-axis CNC machines has a wide spectrum of machine configurations, with hundreds of mechanisms of 5 degrees of freedom, it is therefore practically challenging for engineers and CNC machine operators to create CNC postprocessors for specific 5-axis CNC machines. It is more challenging to create CNC postprocessors if engineers or CNC operators do not have strong backgrounds and professional skills in mathematical modeling and kinematics of machines. This paper presents a universal and intuitive framework and practical guidance to create CNC postprocessors for all 5-axis CNC machines, with the focus on a novel mathematical formulation of inverse kinematics of three main groups of 5-axis CNC machines. The case studies of creating CNC postprocessors with the commercially available 5-axis CNC machines were successfully demonstrated, in which the simulation scenarios and experiments were implemented to verify the created CNC postprocessors. The proposed frameworks and guides for generating CNC postprocessors can be conveniently and effectively applied in industrial practices, without the required strong backgrounds and skills for engineers or CNC operators in mathematical modeling and kinematics of machines, especially mathematical modeling of multibody systems.

关键词： computer numerical control CNC postprocessor 5-axis CNC machining 5-axis mechanism kinematics modeling framework guidance

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Terahertz Circular Dichroism Spectroscopy of 3D Chiral Metallic Microstructures Fabricated Using High Precision CNC Machining

IEEE JOURNAL OF MICROWAVES

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IEEE JOURNAL OF MICROWAVES 2025年第1期5卷 108-115页

作者： Ouchi, Atsushi Tripathi, Saroj R. Shizuoka Univ Dept Mech Engn Hamamatsu 4328561 Japan Shizuoka Univ Grad Sch Sci & Technol Hamamatsu 4328561 Japan

Recent advancements in terahertz wave applications for sensing, imaging, and high-speed communication have spurred a substantial demand for low-cost, easily accessible optical components capable of manipulating terahertz wave polarization. In this study, terahertz circular dichroism spectroscopic measurements of micrometer-sized metallic chiral helix arrays, fabricated using computer numerical control (CNC) machining, are presented. Experimental results demonstrate a giant circular dichroism of +/- 0.6 in an axial mode of operation for left- and right-handed arrays within a sub-terahertz frequency range. The helix array converts linearly polarized light into circularly polarized light from 120 GHz to 200 GHz, with a 3 dB axial ratio relative bandwidth approaching 50%. The polarization extinction ratio is in excess of 20 dB. These outstanding features, combined with their low cost, high accessibility, as well as their potential for mass production, pave the way for development of diverse range of optical components such as polarizers, filters, absorbers, and isolators operating in the terahertz frequency region.

关键词： Spectroscopy Three-dimensional printing computer numerical control Wire Metamaterials Microstructure Optical devices Time-domain analysis Helical antennas Terahertz wave imaging Chiral metamaterials circular polarizer dichroism optical components spectroscopy sub-terahertz terahertz

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An Efficient Algorithm for Approximate Polyline-Sourced Offset Computation on Triangulated Surfaces

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TSINGHUA SCIENCE AND TECHNOLOGY 2025年第4期30卷 1744-1761页

作者： Meng, Wenlong Yu, Hang Geng, Yixuan Bo, Pengbo Harbin Inst Technol Sch Comp Sci & Technol Weihai 264209 Peoples R China

The computation of polyline-sourced geodesic offset holds significant importance in a variety of applications, including but not limited to solid modeling, tool path generation for computer numerical control (CNC) machining, and parametrization. The traditional approaches for geodesic offsets have typically relied on the availability of an exact geodesic metric. Nevertheless, the computation of exact geodesics is characterized by its time-consuming nature and substantial memory usage. To tackle the limitation, our study puts forward a novel approach that seeks to circumvent the reliance on exact geodesic metrics. The proposed method entails a reformulated graph method that incorporates Steiner point insertion, serving as an effective solution for obtaining geodesic distances. By leveraging the aforementioned strategies, we present an efficient and robust algorithm designed for the computation of polyline-sourced geodesic offsets. The experimental evaluation, conducted on a diverse set of three-dimensional models, demonstrates significant improvements in computational speed and memory requirements compared to established state-of-the-art methods.

关键词： Measurement Steiner trees Solid modeling Memory management Machining Approximation algorithms Path planning Computational efficiency numerical models computer numerical control geodesic offsets graph-based algorithm computer numerical control (CNC) milling tool path planning

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Single-Conductor Endfire Antenna With Easy Assembly and High Gain for 5G Millimeter Wave Application

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IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS 2024年第12期23卷 4917-4921页

作者： Wang, Shixuan Hou, Yuefeng Teng, Xihui Yang, Liqi Liu, Meicheng Jin, Peiqi You, Can Luo, Yu Ma, Kaixue Tianjin Univ Sch Microelect Tianjin 300072 Peoples R China Tianjin Key Lab Imaging & Sensing Microelect Techn Tianjin 300072 Peoples R China

This letter presents an air-substrate single-conductor millimeter-wave endfire antenna characterized by stable endfire radiation, high gain, high gain-to-length ratio, and ease of assembly. The proposed antenna is fed by air-substrate double-sided parallel strip lines (DSPSLs) in the TEM mode, ensuring a stable endfire radiation pattern. As an evolution of the periodic leaky-wave antenna, the proposed design also exhibits high gain. Furthermore, the gain-to-length ratio is enhanced through a uniform radiation aperture distribution, which is achieved by adjusting the coupling energy from two paths, including DSPSLs and spatial coupling of elements. In particular, performance degradation caused by assembly errors in the millimeter-wave frequency band is reduced through the implementation of a terminal short-circuited single-conductor antenna structure, which maintains stable endfire radiation, high gain, and high gain-to-length ratio. Finally, the antenna is fabricated using computer numerical control technology and measured. With a total length of 4.72 lambda(0), the antenna achieves a high gain of 15.64 dBi and a high gain-to-length ratio of 7.76, exhibiting a wide 3 dB gain bandwidth of 22.70 GHz to 29.70 GHz (26.92%). Given these characteristics, the antenna holds promising applications in 5G millimeter-wave wireless communication systems.

关键词： Dipole antennas Antennas Assembly Gain Antenna radiation patterns Millimeter wave technology Millimeter wave communication Conductors Couplings computer numerical control Air-substrate endfire high-gain millimeter-wave single-conductor

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