サステナブル且つ安全・安心でスマートな社会インフラ（自動車・鉄道などモビリティ、半導体検査装置、医用機器、スマート工場など）を支える高信頼化および環境負荷低減など高付加価値な先端エレクトロニクス技術とその実装設計、および生成AIなどデジタル技術を活用したデータ処理技術の研究開発に取り組んでいます。
低ノイズ回路設計、電磁両立性(EMC)、高周波/高速伝送、ディペンダブル/ハードウェアセキュリティ、エッジ/AI診断、アナログ/デジタル回路、高電圧/高密度/パワエレ実装、スマート工場向けIoTセンシング、機械学習、環境配慮/自動設計
Building Relationships:
Applying deep learning to sensor data to support workers in manufacturing
https://www.hitachi.com/rd/sc/aiblog/202109_applying-deep-learning-to-sensor-data/index.html
Abstract: The demand for maximizing efficiency and reducing loss cost has become an even more pressing issue to ensure the availability of supply and maintain business continuity. To ensure the resilience of production lines and compliance with product quality, reliable execution of tasks is required. To address these issues, we developed an advanced “real-time work deviation detection” for human tasks utilizing deep learning technology. Compared to conventional approaches, we achieved a 15% reduction in product assembly time and a deviation detection leak of almost zero (more than 95% work identification accuracy).
Publishing Academic Papers:
Electro-Magnetic Compatibility: EMC
U. Paoletti, "Single-Channel Blind Source Separation for Periodic Electromagnetic Switching Noise," in IEEE Transactions on Electromagnetic Compatibility, vol. 65, no. 5, pp. 1300-1308, Oct. 2023, doi: 10.1109/TEMC.2023.3296634.
Abstract: In this article, a single-channel blind source separation method is proposed to decompose time-domain measurement results of electromagnetic noise into the underlying periodic switching noise source signals without requiring any information about the sources. This is realized by clustering the time-domain waveforms based on their period and similarity. At first, the start and end times of the waveforms need to be defined. Then, periods are determined and a waveform cluster is assigned to each period using a new probabilistic approach. Only in the final step, the waveform shape is considered, when the clusters are filtered by removing the waveform outliers that are too different from the remaining waveforms of each cluster. To this purpose, a distance definition based on the cross correlation among the waveforms is proposed. Using numerical and measurement examples, it is shown that it is possible to determine and rank the contribution to the spectrum of each source separately. This helps individuating the main noise sources more quickly and to analyze the contribution of single sources in a complex noisy environment.
K. Fukumasu, M. Nunokawa, U. Paoletti, K. Matsushima and T. Takami, "Analysis Method for Magnetic Field Strength on On-Board Antenna due to Inverter Common-Mode Noise at Whole Train Level," 2023 International Symposium on Electromagnetic Compatibility – EMC Europe, Krakow, Poland, 2023, pp. 1-6, doi: 10.1109/EMCEurope57790.2023.10274186.
Abstract: In order to reduce malfunctions of on-board equipment due to noise generated by inverters in rolling stock, a method for analyzing magnetic field noise received by on-board equipment is required. To achieve this, it was necessary to identify the main currents among the noise currents flowing near the onboard antenna and to construct a model that takes into account the phase of those currents. In the work reported here, we identified that the imbalance between the left and right rail currents contributes to the magnetic field noise and constructed a vehicle-level analysis model that includes these noise currents. The analysis confirmed that the model can represent the variation of noise fluctuation for each frame structure around the on-board equipment up to 2 MHz.
Electronic System Diagnostics
Hiroaki Itsuji; Takumi Uezono; Tadanobu Toba; Kojiro Ito; Masanori Hashimoto, Concurrent Detection of Failures in GPU Control Logic for Reliable Parallel Computing
https://ieeexplore.ieee.org/document/9325216
Abstract: The reliability of GPUs is becoming a major concern due to the increased probability of failures and the high vulnerability of GPUs compared to conventional CPUs in terms of tasks per failure. While there are extensive countermeasures against failures in GPU data units, there are fewer countermeasures for failures in GPU control logics. Currently, software-based techniques, such as inserting signature codes for detecting GPU control-logic failures by comparing the expected signature value with the current signature value, are being utilized. However, in the conventional software-based techniques, application calculations, signature calculations, and signature comparison calculations are executed in sequence, which degrades the application throughputs. We have developed a software-based technique that concurrently detects GPU control-logic failures in a running application while largely maintaining its throughput. Experimental results show that when our technique concurrently executed application calculations, signature calculations, and signature comparison calculations for a matrix multiplication application, the application throughput remains 78% of the original one, whereas 62% is reported in literature. We also developed fault injection simulators specialized for injecting GPU-specific control-logic faults into GPU intermediate codes and found that 100% of GPU-specific failures could be detected both during and after application execution. The proposed approach can be utilized for a wide variety of safety-and reliability-critical applications.
Analog circuit design
Wen Li, Masami Makuuchi and Norio Chujo, " Multi-Chips High-Speed and High-Voltage Amplifier," APCCAS2021
Abstract: A linear amplifying circuit with high voltage, high slew rate and wide bandwidth is presented in this paper. The circuit is composed of three chips with different substrate voltage. The maximum output voltage swing can achieve almost twice the withstand voltage. The circuit is verified with a 0.25-um SOI-LDMOS technology with 200V withstand voltage. The experimental result shows that the output voltage swing is 425 Vpp with the slew rate of 1120 V/μsec and bandwidth of 2.3 MHz. The multi-chips amplifier is expected to be used for many industrial applications.
High speed interconnect
Yutaka Uematsu; Hideyuki Sakamoto, High Bandwidth and Multi-Channel Power over Coaxial Filters for Automotive Low-Voltage Differential Signaling Interconnect. Proc. ECTC(2020)
https://ieeexplore.ieee.org/document/9159284
Abstract: We propose high bandwidth and low-cost multichannel power over coaxial (PoC) filter configurations for an automotive LVDS interconnect. To enhance the bandwidth of PoC filters toward a higher frequency range, we have designed a small filter pattern on the PoC filter electrodes and demonstrated a filter property improvement of about 5 dB at 10 GHz without degradation of the insertion loss of the signal line in a simulation. We have also designed a multi-channel PoC filter configuration with fewer components and a smaller mounting area and demonstrated sufficient filter performance in a simulation. These structures were fabricated on test boards and demonstrated by measurement.
Norio Chujo, Toru Yazaki, Toshiaki Takai, Takayasu Norimatsu, Yasunobu Matsuoka, and Takashi Takemoto, "Interconnect Technologies for High- Bandwidth ICT Systems," AVID2016
Abstract: The bandwidth of information and communication technologies (ICT) systems, such as servers and routers, doubles every two years. Interconnects thus require higher density, lower loss, and lower power consumption. To meet this requirement, high-speed optical and copper interconnects will be introduced. To realize high-speed interconnects for high-bandwidth ICT equipment, a transceiver for copper cable, an LD driver, and a trans-impedance amplifier (TIA) were developed. Moreover, a small-footprint low-power embedded optical module (EOM), with high-density optical-fiber wiring and an optical connector, was developed.
Smart factory
Yuicih Sakurai, et al. "Human Work Support Technology Utilizing Sensor Data", IEEE ICIEA(2020)
DOI: 10.1109/ICIEA49774.2020.9102053
Abstract: In response to problems associated with the shortage of factory workers, the demand for efficiency maximization by eliminating wasted work has recently become stronger. Moreover, to ensure compliance with product quality, the demand for reliable work execution is also increasing. Conventionally, productivity has fallen because workers must manually enter a system to start and finish work. To circumvent this, we have developed advanced human work techniques, “automatic switching of work instruction screen” and “real-time work deviation detection”, by utilizing deep learning technology. Compared to conventional approaches, we achieved a 15% reduction in product assembly time and a deviation detection leak of almost zero (more than 95% work identification accuracy).
2015年 第15回（平成27年度）山崎貞一賞 半導体及び半導体装置分野
https://www.mst.or.jp/portals/0/prize/japanese/winners/semiconductor/semiconductor2015.html
2021年度 第70回 電機工業技術功績者表彰
ものづくり部門 優秀賞(2021) 「パワー半導体製品の高信頼化を実現するはんだ接合技術」
2022年度(第71回) 電機工業技術功績者表彰
重電部門 最優秀賞(2022) 「800V駆動電気自動車用インバータのノーマルモードノイズ抑制技術」
https://www.jema-net.or.jp/Japanese/info/commendation/
第66回電気科学技術奨励賞 文部科学大臣賞(2018)
「最先端半導体微細パターンの高精度計測を実現する走査型電子顕微鏡の回路ノイズ相殺と帯電抑制技術の開発」
第68回電気科学技術奨励賞 電気科学技術奨励会会長賞(2020)
「世界初の 800V 駆動電気自動車を実現するインバータ低ノイズ化技術」
第71回電気科学技術奨励賞 (2023)
「高速道路での手放し運転を可能とする高度先進運転支援 ECU を片手サイズで実現するハードウェア設計技術」
12th IEEE CPMT Symposium Japan Young Researcher Award 2023
"Abnormal Position Identification Technique for Communication Channel using Adaptive DFE"
電磁ノイズの発生源を特定し、自動運転機器の誤作動を予防する小型センサーを開発
https://www.hitachi.co.jp/rd/news/press/2017/0316.html
2.45 GHz帯域の微弱な電磁波の到来方向を可視化する技術を開発
https://www.hitachi.co.jp/rd/news/press/2014/0514.html
通信装置のソフトエラー対策、ITU-T国際標準制定
https://www.hitachi.co.jp/New/cnews/month/2018/11/1122a.html
