Article
Engineering, Multidisciplinary
Zhifa Gao, Xuechao Chen, Zhangguo Yu, Lianqiang Han, Jintao Zhang, Gao Huang
Summary: This article presents a hybrid momentum compensation control method for torque-controlled biped robots to adapt to unknown disturbances during dynamic walking. The method compensates for the disturbance caused by the swinging leg and realizes stable dynamic walking through a mixed-momentum quadratic programming controller based on real-time dynamic state changes of the legs.
Article
Engineering, Biomedical
Genki Hisano, Hiroto Murata, Toshiki Kobayashi, Matthew J. Major, Motomu Nakashima, Hiroaki Hobara
Summary: The study found that unilateral transfemoral prosthesis users maintain dynamic balance through different segment-to-segment cancellation strategies, with significant differences observed in the sagittal and transverse planes but not in the frontal plane. This research is important for understanding the mechanisms of dynamic balance control in prosthesis users and improving gait safety.
IEEE TRANSACTIONS ON NEURAL SYSTEMS AND REHABILITATION ENGINEERING
(2023)
Article
Biology
Jennifer K. Leestma, Pawel R. Golyski, Courtney R. Smith, Gregory S. Sawicki, Aaron J. Young
Summary: This study reveals that human locomotion is robust to environmental disturbances and establishes a strong relationship between balance and recovery strategies. The open-source dataset provided in this investigation enables further research on the effects of multifactorial ground surface perturbations on balance and recovery strategies.
JOURNAL OF EXPERIMENTAL BIOLOGY
(2023)
Article
Clinical Neurology
Chang Liu, Jill L. L. McNitt-Gray, James M. M. Finley
Summary: This study examined the biomechanical effects of reactive control strategies following forward losses of balance in post-stroke individuals. The results showed that post-stroke participants had larger increases in forward angular momentum compared to neurotypical individuals when perturbations were applied to the paretic limb. Neurotypical individuals were able to coordinate reaction forces generated by both legs to reduce forward angular impulse, while post-stroke individuals did not reduce forward angular impulse or increase leading limb impulse using their paretic limb. Additionally, individuals with poorer balance and greater motor impairment made less use of the paretic limb to reduce forward momentum. These findings suggest that paretic deficits limit the ability to recover from forward loss of balance.
FRONTIERS IN NEUROLOGY
(2022)
Article
Engineering, Mechanical
Linqi Ye, Xueqian Wang, Houde Liu, Bin Liang, Bo Yuan
Summary: This paper investigates how to walk faster for two simple 2D walking models. Open-loop analysis is conducted and the concept of acceleration factor is proposed. It is found that the acceleration factor has a fixed correlation with the velocity transition trend, independent of the step length. Based on this, walking controllers are designed and closed-loop simulations are performed to achieve faster walking speeds.
NONLINEAR DYNAMICS
(2023)
Article
Biophysics
Corbin M. Rasmussen, Nathaniel H. Hunt
Summary: This study found that slip onset time is significantly correlated with slip direction, severity, and compensatory stepping responses. As slip onset occurs later in stance, slip severity decreases while compensatory steps become longer and progress from a posterior to anterior placement.
JOURNAL OF BIOMECHANICS
(2021)
Article
Clinical Neurology
Sungwoo Park, Chang Liu, Natalia Sanchez, Julie K. Tilson, Sara J. Mulroy, James M. Finley
Summary: This study aimed to explore the relationship between whole-body angular momentum and balance in individuals poststroke, finding that reducing step length asymmetry may lead to improvements in dynamic balance, especially in stroke survivors. The results of the study indicate a negative correlation between step length symmetry and whole-body angular momentum in the sagittal and frontal plane, suggesting that reducing asymmetry may increase balance momentum.
NEUROREHABILITATION AND NEURAL REPAIR
(2021)
Article
Multidisciplinary Sciences
Johanna Vielemeyer, Lucas Schreff, Stefan Hochstein, Roy Mueller
Summary: This study investigated the effects of manipulating the center of pressure on the kinetics and kinematics of human walking and its influence on the virtual pivot point (VPP). The results showed that the majority of participants exhibited a VPP in various conditions, with the exception of one participant during handstand walking. There were no significant differences in the horizontal and vertical position of the VPP between the conditions.
Article
Biophysics
Mitchell Tillman, Janine Molino, Antonia M. Zaferiou
Summary: This study evaluated frontal-plane dynamic balance control during 90 degrees left turns while walking and found that the range of rotational balance control was larger during turns compared to straight-line gait, and even larger during late-cued turns compared to pre-planned turns. The lateral distance was smaller during turns compared to straight-line gait, and even smaller during pre-planned turns compared to late-cued turns. The study also observed differences in gait speed, footfalls, turn phase duration, and turn strategies used during late-cued turns compared to pre-planned turns.
JOURNAL OF BIOMECHANICS
(2022)
Article
Multidisciplinary Sciences
Lu Chen, Wenqi Zhu, Pengcheng Huo, Junyeob Song, Henri J. Lezec, Ting Xu, Amit Agrawal
Summary: Researchers have proposed a flexible approach to synthesize ultrafast optical transients with arbitrary control over its complete spatiotemporal evolution by leveraging the multifunctional control of light at the nanoscale. This method supports an ultrawide bandwidth with high spectral and spatial resolution, enabling the synthesis of complex states of structured space-time wave packets.
Article
Biochemical Research Methods
Nicholas A. Bianco, Steven H. Collins, Karen Liu, Scott L. Delp
Summary: Walking balance is crucial for independent mobility, but falls due to loss of balance are a leading cause of death among the elderly. Exoskeleton assistance could help individuals with neuromuscular deficits by providing stabilizing torques at lower-limb joints. However, the effects of exoskeleton torques on walking kinematics are still unclear.
PLOS COMPUTATIONAL BIOLOGY
(2023)
Article
Multidisciplinary Sciences
Mitchell Tillman, Janine Molino, Antonia M. Zaferiou
Summary: Turning while walking requires the generation of linear and angular momenta to change body trajectory. This study investigated the strategies used by healthy young adults during different phases of walking to generate transverse-plane momenta during planned and late-cued turns. The results showed that certain gait phases have specific roles in generating momenta during turns, although not all hypotheses were fully supported. Overall, the generation of transverse-plane angular momentum during turns is similar to its generation during straight-line walking.
SCIENTIFIC REPORTS
(2023)
Article
Optics
Kayn A. Forbes, Dale Green
Summary: We demonstrate that the ellipticity g and degree of polarization P have a significant impact on the extraordinary optical chirality properties of nonparaxial vortex beams. Under tight focusing, optical vortex beams can generate rich and tunable spatial distributions of optical chirality density, unlike paraxial optics and nonvortex modes. By manipulating the state g and degree of polarization P of the input vortex mode, as well as the magnitude and sign of optical orbital angular momentum via the pseudoscalar topological charge £, the optical chirality can be tailored for specific purposes. These findings are expected to contribute to the advancement of chiral nano-optics and structured light photonics.
Article
Biophysics
Daekyoo Kim, Cara L. Lewis, Anne K. Silverman, Simone V. Gill
Summary: There are differences in how obese adults regulate wholebody angular momentum (WBAM) during walking compared to non-obese adults. Obese adults walk slower with shorter step length, wider step width, and longer double support time. The ranges of frontal- and transverse-plane WBAM are also greater in obese adults.
JOURNAL OF BIOMECHANICS
(2022)
Article
Robotics
Elham Daneshmand, Majid Khadiv, Felix Grimminger, Ludovic Righetti
Summary: The study introduces a novel two-level variable Horizon Model Predictive Control (VH-MPC) framework for bipedal locomotion, stabilizing the unstable part of center of mass (CoM) dynamics and considering the landing time and location of the swing foot. The effectiveness of the proposed control framework is demonstrated through simulations and experiments on the biped robot Bolt under various disturbances and uncertainties.
IEEE ROBOTICS AND AUTOMATION LETTERS
(2021)
Article
Engineering, Multidisciplinary
Jesus Martinez-Frutos, David Herrero-Perez, Mathieu Kessler, Francisco Periago
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2018)
Article
Engineering, Multidisciplinary
Joan Baiges, Jesus Martinez-Frutos, David Herrero-Perez, Fermin Otero, Alex Ferrer
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2019)
Article
Chemistry, Analytical
Pablo Bernal-Polo, Humberto Martinez-Barbera
Article
Computer Science, Interdisciplinary Applications
Rogelio Ortigosa, Jesus Martinez-Frutos, Antonio J. Gil, David Herrero-Perez
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2019)
Article
Engineering, Electrical & Electronic
Pablo Bernal-Polo, Humberto Martinez-Barbera
IEEE SENSORS JOURNAL
(2020)
Article
Chemistry, Analytical
Humberto Martinez-Barbera, Pablo Bernal-Polo, David Herrero-Perez
Summary: This paper introduces a framework for processing, modeling, and fusing underwater sensor signals to provide reliable perception for underwater localization in structured environments. By adopting uncertain modeling and multi-sensor fusion techniques, the framework can maintain a coherent representation of the environment and filter out useless information. Experimental results demonstrate that the framework can provide a reliable environment representation during underwater navigation and improve localization compared to using reliable dead-reckoning systems.
Article
Computer Science, Interdisciplinary Applications
David Herrero-Perez, Pedro J. Martinez Castejon
Summary: This study presents a parallel implementation of density-based topology optimization using distributed GPU computing systems, which accelerates the computing process and increases device memory for handling large models. By utilizing aggregation-based AMG, memory requirements are reduced and efficiency is improved in GPU computing with multiple devices.
ADVANCES IN ENGINEERING SOFTWARE
(2021)
Article
Computer Science, Interdisciplinary Applications
David Herrero-Perez, Sebastian Gines Pico-Vicente, Humberto Martinez-Barbera
Summary: This work presents an efficient parallel implementation of density-based topology optimization using the Adaptive Mesh Refinement (AMR) scheme to reduce computational burden. The proposed method achieves equivalent designs at lower computational cost compared to uniformly fine mesh. By evaluating the objective function on a coarse mesh and employing the algebraic multigrid (AMG) method, the method demonstrates computational advantages. The numerical results show significant improvement in computing performance by combining dynamic coarsening, adaptive mesh refinement, and distributed memory computing architectures.
COMPUTERS & STRUCTURES
(2022)
Article
Chemistry, Multidisciplinary
David Herrero-Perez, Humberto Martinez-Barbera
Summary: This study presents the design and fabrication of an underwater soft gripper, utilizing soft robotics technology to address the limitations in versatility and robustness in underwater manipulation. The soft gripper is cost-effective, easily deployable, and capable of adapting to uncertain environmental conditions, with the ability to be rapidly redesigned for different applications. The feasibility and performance of the soft gripper are validated in a challenging underwater scenario using a subaquatic vehicle.
APPLIED SCIENCES-BASEL
(2022)
Article
Computer Science, Interdisciplinary Applications
David Herrero-Perez, Sebastian Gines Pico-Vicente, Humberto Martinez-Barbera
Summary: This work presents an efficient parallel implementation of density-based robust topology optimization using adaptive mesh refinement schemes. We use sparse grid stochastic collocation methods to transform the problem into a deterministic problem at the collocation points. We combine distributed-memory parallel computing and AMR techniques to address the problem efficiently, resulting in significant performance improvements.
ENGINEERING WITH COMPUTERS
(2023)
Article
Computer Science, Interdisciplinary Applications
David Herrero-Perez, Sebastian Gines Pico-Vicente
Summary: This work presents an efficient parallel geometric multigrid (GMG) implementation for preconditioning Krylov subspace methods solving differential equations using non-conforming meshes for discretization. The approach calculates the restriction and interpolation operators for grid transferring between the non-conforming hierarchical meshes. Using non-Cartesian grids in topology optimization, it reduces the mesh size by discretizing only the design domain. The performance of the proposed method is evaluated using topology optimization problems, showing its computational advantages.
STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION
(2023)
Article
Computer Science, Interdisciplinary Applications
D. Herrero-Perez, S. G. Pico-Vicente
Summary: This work presents an efficient, flexible, and scalable strategy for implementing density-based topology optimization formulation in fail-safe structural design. The use of non-overlapping domain decomposition, adaptive mesh refinement, and computing buffers allows for successful evaluation of fault cases.
COMPUTERS & STRUCTURES
(2024)
Proceedings Paper
Computer Science, Artificial Intelligence
P. Bernal-Polo, H. Martinez-Barbera
ROBOT 2017: THIRD IBERIAN ROBOTICS CONFERENCE, VOL 2
(2018)
