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Improving performance of micro-hole EDM based on frequency detection method

INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY 2022年第5-6期121卷 3259-3270页

作者： Hou, Shaojie Bai, Jicheng Liu, Huan Tian, Boyu Zhou, Zimu Harbin Inst Technol Sch Mechatron Engn 92 West Dazhi St Harbin 150001 Heilongjiang Peoples R China

Electrical discharge machining (EDM) mainly uses the spark discharge generated between the workpiece and the tool electrode for material erosion;however, abnormal discharge status such as arcing and short circuit often occurs in the process of EDM, and normal discharge will also change into abnormal under certain conditions, which increases the difficulty of discharge state detection. To improve the detection accuracy of discharge states, the amplitude frequency characteristics of discharge voltage signal were studied and a discharge state detection system based on frequency detection was developed. The results showed that the amplitude of voltage signal of spark in the high-frequency range (> 30 MHz) is greater than that of the arcing. Spark and arcing can be effectively distinguished by detecting the amplitude of high-frequency component of the voltage signal. Combined with high-frequency component amplitude detection, voltage detection, and current detection, a discharge state detection system is developed, which can accurately distinguish open circuit, spark, arcing, and short circuit. The discharge state coefficients are calculated and used as the feedback signals of the adaptive control system for micro-EDM drilling process. Compared with the general control based on the average voltage method, using adaptive control can increase the average machining efficiency by 22.4%, reduce the average burned area of the inner surface of micro-holes by 38.2%, and reduce the number and size of micro-cracks in the recast layer.

关键词： Discharge state Micro-EDM frequency detection Adaptive control Machining quality

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Attitude estimation for artillery shells using magnetometers and frequency detection of accelerometers

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CONTROL ENGINEERING PRACTICE 2022年第0期122卷 105080-105080页

作者： Fiot, Aurelien Changey, Sebastien Petit, Nicolas French German Res Inst St Louis Guidance Nav & Control Dept ISL 5 Rue Gen Cassagnou F-68300 St Louis France PSL Univ CAS Ctr Automat & Syst MINES Paris 60 bd St Michel F-75272 Paris France

The article proposes a method to estimate the attitude of an artillery shell in free flight. It uses strapdownaccelerometers and magnetometers, and circumvents the intrinsic inability of accelerometers to providedirection information during free flight by employing them not to measure the gravity but to estimate thevelocity w.r.t. the air. This is achieved in an innovative way, through frequency detection applied to thepitch and yaw rotational dynamics generated by aerodynamic moments, directly visible on the accelerometers'signals. The determination of the shell's velocity without any ground-based position radar is a first *** velocity variation gives information regarding the shell's orientation that complements the direction givenby the 3-axis magnetometer. The two sources of information are combined into an attitude estimate by aspecific nonlinear observer. Experimental results obtained with a gyrostabilized supersonic155mm shell arepresented

关键词： Exterior ballistics Flight dynamics frequency detection Attitude estimation Inertial sensors Embedded sensors

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Analysis of aroma-active compounds in four Chinese dry-cured hams based on GC-O combined with AEDA and frequency detection methods

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LWT-FOOD SCIENCE AND TECHNOLOGY 2022年 153卷

作者： Jiang, Shui Xia, Dong Wang, Xiaoming Zhu, Yaozhou Chen, Gaole Liu, Yuan Tianjin Univ Sci & Technol State Key Lab Food Nutr & Safety Tianjin 300457 Peoples R China Shanghai Jiao Tong Univ Sch Agr & Biol Dept Food Sci & Technol Shanghai 200240 Peoples R China Shanghai Ocean Univ Coll Food Sci & Technol Shanghai 201306 Peoples R China Shanghai Engn Res Ctr Food Safety Dongchuan Rd 800 Shanghai 200240 Peoples R China Guangdong Wens Jia Wei Foodstuff Co Ltd Yunfu 510507 Guangdong Peoples R China Gruma Corp Irving TX 75038 USA

Chinese dry-cured hams have become increasingly appreciated by consumers because of their unique flavor characteristics. In this study, the volatile compounds of four Yunnan dry-cured hams (Xuanwei, Nuodeng, Sanchuan, and Saba) were characterized by monolithic material sorptive extraction (MMSE) and GC-MS. A total of 66 volatile compounds were identified, of which aldehydes and alkanes were the most abundant (>76.43%) in all four hams. The PCA result with 71.04% of the variability demonstrated the potential dominant compounds for the different dry-cured hams. The similarities and differences of aroma-active compounds among the different Yunnan dry-cured hams were studied by using gas chromatography-olfactometry (GC-O) combined with aroma extract dilution analysis (AEDA) and frequency detection (FD) methods. The results demonstrated that 3-methylbutanal, hexanal, 2,6-dimethylpyrazine, 1-octen-3-ol, dimethyl trisulfide, and nonanal were the most important aroma-active compounds in the Yunnan dry-cured hams. This study contributes to a better understanding of odor quality in Chinese dry-cured hams.

关键词： Dry-cured ham Aroma extract dilution analysis frequency detection Aroma-active compounds Gas chromatography-olfactometry

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Weak Signal frequency detection Using Chaos Theory: A Comprehensive Analysis

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IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 2021年第9期70卷 8950-8963页

作者： Chen, Dawei Shi, Shuo Gu, Xuemai Shim, Byonghyo Harbin Inst Technol HIT Dept Elect & Informat Engn Harbin 150001 Peoples R China HIT Huizhou Int Innovat Inst Huizhou 516000 Peoples R China Seoul Natl Univ Dept Elect & Comp Engn Seoul 151742 South Korea Seoul Natl Univ Inst New Media & Commun Seoul 151742 South Korea

As a potential technology in weak signal detection (WSD), the chaos theory benefits from its characteristics of the sensitivity to the initial condition and the immunity to the Additive White Gaussian Noise (AWGN). Traditional methods based on chaos theory perform well on single non-variable-frequency signal detection (SNVFSD), which is a common situation in texture flaw detection while it is a rare scenario in the communication field. In this paper, we give a comprehensive analysis of the chaos-based approach for weak signal frequency detection. To better understand the advantages and limitations of the chaos theory, we present the research results for several typical communication scenarios. Specifically, we proposed several chaos-based approaches to get a satisfying performance in the following situations: single variable-frequency signal detection (SVFSD), multiple non-variable-frequency signals detection (MNVFSD), multiple variable-frequency signals detection (MVFSD). To enhance the generalization performance to real application, the critical state's characteristics, Lyapunov Exponents (LE) and Melnikov method are analyzed to employed in these proposed chaos-based approaches. By theoretical analysis and numerical simulations, we study the performance of chaos-based detection systems in terms of SVFSD, MNVFSD, MVFSD. Our results show that these proposed schemes can obtain a satisfying performance in terms of accuracy and robustness, and the extensive simulations demonstrate their effectiveness.

关键词： Weak signal detection frequency detection chaos theory variable-frequency signal non-variable-frequency signal

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High Accuracy frequency detection Method Using 1 to mth Harmonics 48

High Accuracy Frequency Detection Method Using 1 to mth Harm...

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48th European Microwave Conference (EuMC)

作者： Shimokawatoko, Jun Mizutani, Hiroyuki Tajima, Ken'ichi Kazutomi, Mori Mitsubishi Electr Corp Informat Technol R&D Ctr Tokyo Japan

ISBN: (纸本)9782874870514

This paper proposes the high Accuracy frequency detection method by using 1 to mth harmonics. In the proposed method, frequencies of harmonics are detected, and the sum of them is divided by the sum of these orders. The proposed method improves the frequency detection accuracy by (m + 1)/(2 root m) as compared with the conventional method using only the mth harmonic. The improvement of the frequency detection accuracy is derived from formulation and is confirmed by simulation and measurement results.

关键词： frequency detection Harmonics Digital Signal Processing

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High-Resolution frequency detection with Multiple AWGs and Post-Processing for Multi-Channel Fiber Sensors

High-Resolution Frequency Detection with Multiple AWGs and P...

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Conference on Lasers and Electro-Optics Pacific Rim (CLEO-PR)

作者： Takahashi, Kazuto Kishikawa, Hiroki Goto, Nobuo Yu, Yi-Lin Liaw, Shien-Kuei Univ Tokushima Dept Opt Sci & Technol 2-1 Minamijosanjima Cho Tokushima 7708506 Japan Natl Taiwan Univ Sci & Technol Taipei 10617 Taiwan

We propose two kinds of simple frequency detection methods. One consists of cascaded AWGs with different frequency intervals. The other consists of frequency-shifted two kinds of AWGs and a post processing circuit.

ISBN: (纸本)9781509062904

关键词： Fiber sensor frequency detection AWG high-resolution

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frequency detection for SSVEP-Based BCI using Deep Canonical Correlation Analysis

Frequency Detection for SSVEP-Based BCI using Deep Canonical...

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IEEE International Conference on Systems, Man, and Cybernetics (SMC)

作者： Vu, Hanh Koo, Bonkon Choi, Seungjin Pohang Univ Sci & Technol Sch Interdisciplinary Biosci & Bioengn 77 Cheongam Ro Pohang 37673 South Korea Pohang Univ Sci & Technol Dept Comp Sci & Engn 77 Cheongam Ro Pohang 37673 South Korea

ISBN: (纸本)9781509018970

Canonical correlation analysis (CCA) has been successfully used for extracting frequency components of steady-state visual evoked potential (SSVEP) in electroencephalography (EEG). Recently, a few efforts on CCA-based SSVEP methods have been made to demonstrate the benefits for brain computer interface (BCI). Most of these methods are limited to linear CCA. In this paper consider a deep extension of CCA where input data are processed through multiple layers before their correlations are computed. To our best knowledge, it is the first time to apply deep CCA (DCCA) to the task of frequency component extraction in SSVEP. Our empirical study demonstrates that DCCA extracts more robust feature, which has significantly higher signal to noise ratio (SNR) compared to those of CCA, and it results in better performance in classification with the averaged accuracy of 92%.

关键词： Brain computer interface canonical correlation analysis (CCA) deep CCA frequency detection SSVEP

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A 400 Mb/s∼2.5 Gb/s Referenceless CDR IC Using Intrinsic frequency detection Capability of Half-Rate Linear Phase Detector

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IEEE TRANSACTIONS ON CIRCUITS AND SYSTEMS I-REGULAR PAPERS 2016年第10期63卷 1592-1604页

作者： Byun, Sangjin Dongguk Univ Seoul Div Elect & Elect Engn Seoul 100715 South Korea

A 400 Mb/s similar to 2.5 Gb/s referenceless clock and data recovery (CDR) IC is presented. This paper shows that the half-rate linear phase detector (PD) has not only phase detection capability but also single-sided frequency detection capability in itself. By using this intrinsic frequency detection capability of the half-rate linear PD, a CDR can be implemented in the single loop architecture without both an external reference clock and a separate frequency detector. For verification, a prototype CDR IC was fabricated in a 0.13 mu m CMOS process. With 2.5 Gb/s, 2(31) - 1 pseudorandom binary sequence (PRBS), the measurement results show that the frequency acquisition time is 17 mu s, the bit error rate (BER) is better than 10(-12), the jitter of the recovered clock is 8.6 ps(rms) and the out-of-band jitter tolerance is 0.32 UIpp.

关键词： Clock and data recovery CMOS integrated circuits frequency detection linear phase detector

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Development of a mathematical model of the frequency detection signal passing through a nonlinear device

Development of a mathematical model of the frequency detecti...

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10th IEEE International Scientific and Technical Conference on Dynamics of Systems, Mechanisms and Machines (Dynamics)

作者： Zhiganova, E. A. Vladimir State Univ Vladimir Russia

ISBN: (纸本)9781509040490

A mathematical model of the frequency detection signals of nonlinear devices and mathematical modeling of the quadrature power amplifier frequency-modulated signal under the influence of harmonic interference on the non-linear reinforcing elements of the device are presented. Assess the degree of reduction of intermodulation oscillations in a narrow frequency band of the output signal of the quadrature amplifier power than a single amplifier. Defined as the non-linearity characteristics of the power amplifiers included in quadrature amplifier affects the frequency of the modulating signal changes.

关键词： frequency detection mathematical model non-linear device quadrature power amplifier intermodulation compensation fluctuations

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frequency detection of self-adaption control based on chaotic theory

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Chinese Physics B 2015年第3期24卷 202-206页

作者：徐艳春瞿晓东李振兴 College of Electrical Engineering and New Energy China Three Gorges University

Low-order Duffing and high-order Rossler chaotic oscillator are connected together and new self-adaption frequency detection method is presented. The frequency difference control between unknown signal and the periodic driving force is realized in this paper and the self-adaption is obtained. Thus, the detection precision and speed are promoted. The limitation that there are too many chaotic oscillators in Duffing system is broken. Meanwhile the disadvantage that the detection speed is lower in R ssler chaotic control is overcome. The self-adaption choice of frequency difference control is realized using the Duffing and Rssler different chaotic oscillators to obtain unknown signal frequency. The simulation results show that the presented method is feasible and effective.

关键词： frequency detection self-adaption control chaotic theory

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