Efficient bipedal locomotion on rough terrain via compliant ankle actuation with energy regulation

2021-09-01
Kerimoglu, Deniz
Karkoub, Mansour
Ismail, Uyanik
MORGÜL, ÖMER
Saranlı, Uluç
Legged locomotion enables robotic platforms to traverse on rough terrain, which is quite challenging for other locomotion types, such as in wheeled and tracked systems. However, this benefit-moving robustly on rough terrain-comes with an inherent drawback due to the higher cost of transport in legged robots. The ultimate need for energy efficiency motivated the utilization of passive dynamics in legged locomotion. Nevertheless, a handicap in passive dynamic walking is the fragile basin of attraction that limits the locomotion capabilities of such systems. There have been various extensions to overcome such limitations by incorporating additional actuators and active control approaches at the expense of compromising the benefits of passivity. Here, we present a novel actuation and control framework, enabling efficient and sustained bipedal locomotion on significantly rough terrain. The proposed approach reinforces the passive dynamics by intermittent active feedback control within a bio-inspired compliant ankle actuation framework. Specifically, we use once-per-step energy regulation to adjust the spring precompression of the compliant ankle based on the liftoff instants-when the toe liftoffs from the ground-of the locomotion. Our results show that the proposed approach achieves highly efficient (with a cost of transport of 0.086) sustained locomotion on rough terrain, withstanding height variations up to 15% of the leg length. We provide theoretical and numerical analysis to demonstrate the performance of our approach, including systematic comparisons with the recent and state-of-the-art techniques in the literature.
BIOINSPIRATION & BIOMIMETICS

Suggestions

Flexible multibody dynamic modeling and simulation of rhex hexapod robot with half circular compliant legs
Oral, Gökhan; Yazıcıoğlu, Yiğit; Department of Mechanical Engineering (2008)
The focus of interest in this study is the RHex robot, which is a hexapod robot that is capable of locomotion over rugged, fractured terrain through statically and dynamically stable gaits while stability of locomotion is preserved. RHex is primarily a research platform that is based on over five years of previous research. The purpose of the study is to build a virtual prototype of RHex robot in order to simulate different behavior without manufacturing expensive prototypes. The virtual prototype is modele...
Modelling the effects of half circular compliant legs on the kinematics and dynamics of a legged robot
Saygıner, Ege; Saranlı, Afşar; Department of Electrical and Electronics Engineering (2010)
RHex is an autonomous hexapedal robot capable of locomotion on rough terrain. Up to now, most modelling and simulation efforts on RHex were based on the linear leg assumption. These models disregarded what might be seen as the most characteristic feature of the latest iterations of this robot: the half circular legs. This thesis focuses on developing a more realistic model for this specially shaped compliant leg and studying its effects on the kinematics and dynamics of the resulting platform. One important...
Control of hexapedal pronking through a dynamically embedded spring loaded inverted pendulum template
Ankaralı, Mustafa Mert; Saranlı, Afşar; Department of Electrical and Electronics Engineering (2010)
Pronking is a legged locomotory gait in which all legs are used in synchrony, usually resulting in slow speeds but long flight phases and large jumping heights that may potentially be useful for mobile robots locomoting in cluttered natural environments. Instantiations of this gait for robotic systems suffer from severe pitch instability either due to underactuated leg designs, or the open-loop nature of proposed controllers. Nevertheless, both the kinematic simplicity of this gait and its dynamic nature su...
Control of Underactuated Planar Hexapedal Pronking Through a Dynamically Embedded SLIP Monopod
Ankaralı, Mustafa Mert; Saranlı, Uluç; Saranlı, Afşar (2010-05-08)
Pronking (aka. stotting) is a gait in which all legs are used in synchrony, resulting in long flight phases and large jumping heights that may potentially be useful for mobile robots on rough terrain. Robotic instantiations of this gait suffer from severe pitch instability either due to underactuation, or the lack of sufficient feedback. Nevertheless, the dynamic nature of this gait suggests that the Spring-Loaded Inverted Pendulum Model (SLIP), a very successful predictive model for both natural and roboti...
Modeling and control of the three degrees-of-freedom parallel manipulated robotic sensor head
Öğücü, Muhammed Orkun; Saranlı, Afşar; Department of Electrical and Electronics Engineering (2014)
Legged robot platforms have distinct advantages over wheels in rough terrain and provide better mobility. Also in many applications, including military reconnaissance, disaster relief, hazardous site inspection, search and rescue applications benefit from the legged robots which is capable of moving safely at high speeds through rough natural terrain. However, with the increasing speed, fundamental difficulties like dynamic and mechanical limitations as well as control and computational limitations arise. A...
Citation Formats
D. Kerimoglu, M. Karkoub, U. Ismail, Ö. MORGÜL, and U. Saranlı, “Efficient bipedal locomotion on rough terrain via compliant ankle actuation with energy regulation,” BIOINSPIRATION & BIOMIMETICS, vol. 16, no. 5, pp. 0–0, 2021, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/92025.