Effects of Foot Stiffness and Damping on Walking Robot Performance

Ethan, Schumann; Smit-Anseeuw, Nils; Zaytsev, Petr; Gleason, Rodney; Shorter, K. Alex; Remy, C. David

doi:10.1109/icra.2019.8794050

Cited by 7 publications

(4 citation statements)

References 35 publications

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“…Adaptation through compliance and features in the foot is a key factor in better interacting with the terrain. The effect of different stiffness and damping properties on stability and the energetic economy of bipedal walking of ball-like feet is studied in [58]. Quadruped robots Oncilla [59] and Cheetah-cub [60] have a springy ankle joint with a short foot mounted to improve robustness, speed, and cost of transport.…”

Section: State Of the Artmentioning

confidence: 99%

Design Guidelines for Bioinspired Adaptive Foot for Stable Interaction With the Environment

Ranjan,

Angelini,

Nanayakkara

et al. 2024

IEEE/ASME Trans. Mechatron.

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Robotic exploration in natural environments requires adaptable, resilient, and stable interactions with uncertain terrains. Most state-of-the-art legged robots utilize flat or ball feet that lack adaptability and are prone to slip due to point contact with the ground. In this article, we present guidelines to design an adaptive foot that can interact with the terrain to achieve a stable configuration. The foot is inspired by goat hoof anatomy that incorporates roll and yaw rotations in the Fetlock and Pastern joints, respectively. To ensure adaptability with stability in physical interaction and to prevent the foot from collapsing, we provide a lower bound on each joint's stiffness. In addition, we also render an upper bound to conform to the high force exchange during interactions with the ground consisting of certain roughness. Based on these guidelines, we design the hoof and experimentally validate the theoretical results with a loading test setup in lab settings. We use four different friction materials with various triangular, rectangular, and semicircular extrusions to simulate common ground features. We observe that hooved pads require more load for the system to be unstable. Any anatomically inspired foot can be designed based on the guidelines proved analytically and experimentally in this article.

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Section: State Of the Artmentioning

confidence: 99%

Design Guidelines for Bioinspired Adaptive Foot for Stable Interaction With the Environment

Ranjan,

Angelini,

Nanayakkara

et al. 2024

IEEE/ASME Trans. Mechatron.

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show abstract

“…Several examples of systems that use SEA can be found in the literature, mainly in areas such as Rehabilitation Robots (Chen et al, 2019;DeBoon et al, 2019;Miyata and Ahmadi, 2019;Lee et al, 2018), and Exoskeletons and Prostheses (Alamdari et al, 2019;Bianchi et al, 2018;Chen et al, 2019;Convens et al, 2019;Freitas et al, 2019;Woo et al, 2017). Other major areas where this type of actuator can also be found are in the study of locomotion of robotic platforms (Knabe et al, 2015;Ruppert and Sprowitz, 2019;Schumann et al, 2019;Zhang et al, 2019), and in Physical Human-Robot Interaction (pHRI) Shi et al, 2020).…”

Section: Introductionmentioning

confidence: 99%

Modeling and Control of Four-bar Mechanism with Series Elastic Actuators

Lopes

Meggiolaro

2020

Anais Do Congresso Brasileiro De Automática 2020

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A new generation of robots that work in cooperation with humans (called collaborative robots) needs some flexibility to adapt to the environment and activities with people. That is why the Series Elastic Actuator (SEA) has been a breakthrough in actuator technologies. The idea of inserting an elastic element in series with a motor allows a lower output impedance, consequently a flexible behavior in the manipulator, in addition to providing torque feedback to better compensate disturbances caused e.g. by friction losses. This article presents a four-bar mechanism with SEA for the purpose of robotic manipulation. Its kinematics and dynamicsare studied, as well as its regulation and trajectory control. The behavior of the decoupled four-bar mechanism and the characteristics of the SEA are also analyzed. Then the regulation control of the complete system is carried out using LQR control. Finally, a circular trajectory is controlled in a simulation to validate the proposed control strategy. The simulation results show the effectiveness of the proposed controller for the mechanism in the presence of SEAs estimating torque and providing the desired compliance for human interaction.

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“…Polymers derived from ring-opening metathesis polymerization (ROMP) are industrially important elastomers (e.g., Norsorex) and thermosets. − A challenge with thermoset polymers is their poor solubility and processability, in part due to their cross-linked networks − exactly the characteristics that present challenges for traditional molecular weight characterization methods but that we envisioned would be well-suited to FLIM methods.…”

mentioning

confidence: 99%

Polymer Molecular Weight Determination via Fluorescence Lifetime

García

Blum

2022

J. Am. Chem. Soc.

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Control of polymer molecular weight is critical for tailoring structure–function properties; however, traditional molecular weight characterization techniques have limited ability to determine the molecular weight of polymers in real time without sample removal from the reaction mixture, with spatial resolution, and of insoluble polymers. In this work, a fluorescence lifetime imaging microscopy (FLIM) method was developed that overcomes these limitations. The method is demonstrated with polynorbornene and polydicyclopentadiene, polymers derived from ruthenium-catalyzed ring-opening metathesis polymerization (ROMP). The polymer M w, ranging from 35 to 570 kg/mol as determined by gel-permeation chromatography, was quantitatively correlated with the fluorescence lifetime. The revealed correlation then enabled time-resolved measurement of M w during an ongoing ROMP reaction, requiring only 1 s per measurement (of a 45 μm × 45 μm polymer sample area), and provided spatial resolution, resulting in simultaneous characterization of polymer morphology. To provide the fluorescence signal, the initial reaction solutions contained a very low doping of a reactive norbornene monomer labeled with fluorescent boron dipyrromethene (BODIPY), such that 1 in every 107 monomers contained a fluorophore. The resulting FLIM visualization method enables the rapid determination of the molecular weights of growing polymers without removal from the reaction mixture and regardless of polymer solubility.

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Effects of Foot Stiffness and Damping on Walking Robot Performance

Cited by 7 publications

References 35 publications

Design Guidelines for Bioinspired Adaptive Foot for Stable Interaction With the Environment

Design Guidelines for Bioinspired Adaptive Foot for Stable Interaction With the Environment

Modeling and Control of Four-bar Mechanism with Series Elastic Actuators

Polymer Molecular Weight Determination via Fluorescence Lifetime

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