Midair Flow Control with High Spatiotemporal Resolution based on Ultrasound-Driven Streaming

• Project/Area Number: 18H01458
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 21040:Control and system engineering-related
• Research Institution: The University of Tokyo
• Principal Investigator: Hasegawa Keisuke 東京大学, 大学院情報理工学系研究科, 講師 (20733108)
• Project Period (FY): 2018-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥15,990,000 (Direct Cost: ¥12,300,000、Indirect Cost: ¥3,690,000); Fiscal Year 2021: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2020: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2019: ¥3,900,000 (Direct Cost: ¥3,000,000、Indirect Cost: ¥900,000); Fiscal Year 2018: ¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
• Keywords: 非線形音響現象 / 収束超音波 / 音響流 / 気流制御 / 非線形音響 / 流体力学 / フェーズドアレー / 最適化 / 流れ場設計 / 逆問題 / 音響ホログラフィ / 流体制御 / 音場制御 / 波面合成 / 温度制御 / 制御

Outline of Final Research Achievements

The main results of this research are summarized into the three following topics. (1) A construction method of acoustic intensity field that corresponds to acoustic streaming field to generate is established by means of continuous optimization of amplitude distribution with a proper regularization. (2) An arc-shaped intense ultrasound beam is generated by creating series of congregative ultrasound foci that forms the beam. It is verified that the acceleration of air is done in direction of the beam tangent at each line segment of the beam. (3) Binary M-sequence pattern of ultrasound amplitude is generated in the workspace to enable a single monoaural microphone to estimate its self-position. In this framework, the amplitude pattern is spatially scanned so that the microphone position can be retrieved using amplitude signal received by the microphone as a position-dependent positional clue.

Academic Significance and Societal Importance of the Research Achievements

従来のファンやジェットで実現するものよりも時空間的な自由度の高い流れを設計し、音響流を用いることで初めて生成可能な性質の気流の実現および新たな応用提案をおこなうことにより、ヒトの生活空間における空気制御の有力な手法としての音響流の利用をこれまでよりも説得力のある形で示すことができた。同時に、「目的に応じた時空間分布を持つ超音波音場（構造化超音波音場）」の新しい用途としてモノラルマイクロホンの非同期自己定位などの可能性を示し、生活空間における超音波の利用についても併せて新しい応用シナリオを提示できた。

Research Products

• [Journal Article] Sequential structured volumetric ultrasound holography for self-positioning using monaural recording (2021)
  • Author(s): Mukai Honoka、Hasegawa Keisuke、Nara Takaaki
  • Journal Title: The Journal of the Acoustical Society of America Volume: 150 Issue: 6 Pages: 4178-4190
  • DOI: 10.1121/10.0007464
  • Peer Reviewed / Open Access
• [Journal Article] Volumetric acoustic holography and its application to self-positioning by single channel measurement (2020)
  • Author(s): Hasegawa Keisuke、Shinoda Hiroyuki、Nara Takaaki
  • Journal Title: Journal of Applied Physics Volume: 127 Issue: 24 Pages: 244904-244904
  • DOI: 10.1063/5.0007706
  • Peer Reviewed / Open Access
• [Journal Article] Curved acceleration path of ultrasound-driven air flow (2019)
  • Author(s): Hasegawa Keisuke、Yuki Hiroki、Shinoda Hiroyuki
  • Journal Title: Journal of Applied Physics Volume: 125 Issue: 5 Pages: 054902-054902
  • DOI: 10.1063/1.5052423
  • Peer Reviewed / Open Access
• [Presentation] Single microphone positioning based on Angular scanning of acoustic Bessel beam from symmetric ultrasound emission (2021)
  • Author(s): Keisuke Hasegawa
  • Organizer: IMEKO 2021
  • Int'l Joint Research
• [Presentation] 空中収束超音波の走査による結合波を用いた遠隔音場計測 (2021)
  • Author(s): 小塚詩穂里, 長谷川圭介, 奈良高明
  • Organizer: 第38回センシングフォーラム
• [Presentation] Indoor Self Localization of a Single Microphone based on Asynchronous Scanning of Modulated Bessel Beams (2019)
  • Author(s): Keisuke Hasegawa
  • Organizer: SICE Annual Conference 2019
  • Int'l Joint Research
• [Presentation] Self-Localization of Single Microphone from Ultrasound Field Generated by Sources with Subwavelength Displacement (2019)
  • Author(s): Keisuke Hasegawa, Takaaki Nara
  • Organizer: IEEE IUS 2019
  • Int'l Joint Research