Understanding of interlocking mechansim in forearm of mammals for design of versatile quadrupedal robot

2023 Fiscal Year Final Research Report

• Project/Area Number: 21H01269
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 20010:Mechanics and mechatronics-related
• Research Institution: Tohoku University
• Principal Investigator: Fukuhara Akira 東北大学, 電気通信研究所, 助教 (10827611)
• Co-Investigator(Kenkyū-buntansha): 増田 容一 大阪大学, 大学院工学研究科, 助教 (70849760) ; 郡司 芽久 東洋大学, 生命科学部, 助教 (80833839)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 前腕不動化現象 / 旋回歩行の運動計測 / 旋回歩行の運動制御 / 反射バランス制御

Outline of Final Research Achievements

This study found locking phenomenon in the forearms of carnivorous mammals depending on body supporting weight. To understand the forelimb locking mechanism and to clarify the effects of the forearm' locking phenomenon on the turning gait motion, this study conducted animal dissection, locomotion measurement, and robot experiments. The results of anatomical measurements revealed that the immobilization phenomenon of the forearm is caused by the linkage through flexor muscles such as palmaris longus and carpometacarpal flexor muscles. In addition, the gait analysis of a red panda’ walking turn revealed that the duty factor of the hind-inside limb increased during the turning gait. In addition, a sensor feedback law based on leg load and trunk movement speed was successfully used to generate a turning gait of the robot according to the timing of turning and the robot's morphology.

Free Research Field

ロボティクス

Academic Significance and Societal Importance of the Research Achievements

四肢の筋骨格ネットワークを介することで矢状面上の関節が連動し，体重指示などの機能を発現することは，ウマなどの走行性哺乳類や，ワニなどの爬虫類，走行性の鳥類の事例が報告されていた．本研究で明らかになった前腕不動化機構では，肘や手首，指関節といった矢状面上の関節の連動だけでなく，手首のねじりを生み出す橈尺関節にまで連動が及び，体重指示に伴う屈筋群の張力の増加が前腕の回外運動を阻害するものである．こうした負荷状況に応じた３次元的な連動メカニズムは，マニピュレーションなどに活用可能な前脚抹消を多自由度にしつつ，運動制御を簡易化する基盤技術として大いに資することが期待される．