Intrinsic toe joint stabilization in foot-slip turning motion of musculoskeletal robot with DSP-SLIP model

• Published in: Advanced robotics Vol. 38; no. 16; pp. 1153 - 1165
• Main Authors: Nipatphonsakun, Kawinna, Kawasetsu, Takumi, Hosoda, Koh
• Format: Journal Article
• Language: English
• Published: Taylor & Francis 17.08.2024
• Subjects: bioinspired robotics foot; bipedal locomotion; foot-slip turning motion; Musculoskeletal robot; toe joint
• ISSN: 0169-1864; 1568-5535
• DOI: 10.1080/01691864.2024.2362201

This paper introduces the foot-slip turning motion by combining a slider-like mechanism with the double-support parallel spring-loaded inverted pendulum model, in which the musculoskeletal robot uses the model to simplify the slip-turning motion with its compliant structure and utilizes the foot muscle to improve its postural stability. The slip-turning motion, characterized by slight movements for swift turning via foot slippage, is advantageous for musculoskeletal robots due to their limited range of movement. The challenge lies in the reduced support area during the motion, which impacts stability. In our previous study, the robot ‘PneuTurn-T’ successfully executed said motion, whereas the details of the turning mechanism were lacking. This study investigated the utilization of leg compliance in the motion and its static postural stability in the landing stance. Experimental results exhibited a leg compression rate derived from the collected data in the early phase of the motion and validated intrinsic toe joint stabilization with foot muscle for passive postural control. The ground reaction force proves the capability to maintain the posture for 130% longer in the foot with plantar intrinsic muscle. Despite structural challenges, this approach shows promise for musculoskeletal robots, highlighting their ability to handle a turning task with simple control.