24 papers · ranked by Valyu relevance
Jin‐Woo Choi, Capprin Bass, Ross L. Hatton
— The Robotic locomotion community is interested in optimal gaits for control. Based on the optimization criterion, however, there could be a number of possible optimal gaits. For example, the optimal gait for maximizing displacement with respect to cost is quite different from the maximum displacement optimal gait.…
Jin‐Woo Choi, Siming Deng, Nathan Justus, Noah J. Cowan + 1 more
—Motion planning for locomotion systems typically requires translating high-level rigid-body tasks into low-level joint trajectories—a process that is straightforward for carlike robots with fixed, unbounded actuation inputs but more challenging for systems like snake robots, where the mapping depends on the current…
Rachid Ramadan, Fabian Meischein, Hendrik Reimann
Humans are able to adopt almost any desired gait pattern on the fly when walking. We postulate that this flexibility in humans is partially due to the ability to control the whole body during walking as a volitional, goal-directed movement that can be planned and changed, rather than having to rely on habitual…
Jessica C. Selinger, Jeremy D. Wong, Surabhi N. Simha, J. Maxwell Donelan
A central principle in motor control is that the coordination strategies learned by our nervous system are often optimal. Here we combined human experiments with computational reinforcement learning models to study how the nervous system navigates possible movements to arrive at an optimal coordination. Our experiments…
Lei Sun, Hongxu Ma, Honglei An, Qing Wei + 1 more
An intelligent lower-limb prosthesis can provide walking support and convenience for lower-limb amputees. Trajectory planning of prosthesis joints plays an important role in the intelligent prosthetic control system, which directly determines the performance and helps improve comfort when wearing the prosthesis. Due to…
Andrea Di Russo, Dimitar Stanev, Stéphane Armand, Auke Ijspeert
The central nervous system of humans and animals is able to modulate the activity in the spinal cord to achieve several locomotion behaviors. Previous neuromechanical models investigated the modulation of human gait changing selected parameters belonging to the CPGs (Central Pattern Generators) feedforward oscillatory…
John R. Rebula, Arthur D. Kuo, Yuri P. Ivanenko
Simple optimization models show that bipedal locomotion may largely be governed by the mechanical work performed by the legs, minimization of which can automatically discover walking and running gaits. Work minimization can reproduce broad aspects of human ground reaction forces, such as a double-peaked profile for…
Delyle T. Polet, John E. A. Bertram
It is widely held that quadrupeds choose steady gaits that minimize their energetic cost of transport, but it is difficult to explore the entire range of possible footfall sequences empirically. We present a simple model of a quadruped that can spontaneously produce any of the 2300+ planar footfall sequences available…
Samane Amini, Iman Kardan, Ajay Seth, Alireza Akbarzadeh
Human gait simulation plays a crucial role in providing insights into various aspects of locomotion, such as diagnosing injuries and impairments, assessing abnormal gait patterns, and developing assistive and rehabilitation technologies. To achieve more realistic results in gait simulation, it is necessary to utilize a…
Delyle T. Polet, John E. A. Bertram, Max Donelan
It is widely held that quadrupeds choose steady gaits that minimize their energetic cost of transport, but it is difficult to explore the entire range of possible footfall sequences empirically. We present a simple model of a quadruped that can spontaneously produce any of the thousands of planar footfall sequences…
Yijie Guo, Mingwei Zhang, Hao Dong, Mingguo Zhao
— The planning of whole-body motion and step time for bipedal locomotion is constructed as a model predictive control (MPC) problem, in which a sequence of optimization problems needs to be solved online. While directly solving these problems is extremely time-consuming, we propose a predictive gait synthesizer to…
David J. Kelly, Patrick M. Wensing, Seyed Hamed Mousavi
Template models, such as the Bipedal Spring-Loaded Inverted Pendulum and the Virtual Pivot Point, have been widely used as low-dimensional representations of the complex dynamics in legged locomotion. Despite their ability to qualitatively match human walking characteristics like M-shaped ground reaction force (GRF)…
Umer Huzaifa, Catherine Maguire, Amy LaViers
—Humans are efficient, yet expressive in their motion. Human walking behaviors can be used to walk across a great variety of surfaces without falling and to communicate internal state to other humans through variable gait styles. This provides inspiration for creating similarly expressive bipedal robots. To this end, a…
Stuart Hagler
The biomechanics of the human body gives subjects a high degree of freedom in how they can execute movement. Nevertheless, subjects exhibit regularity in their movement patterns. One way to account for this regularity is to suppose that subjects select movement trajectories that are optimal in some sense. We adopt the…
Ling-Long Li, Yue-Peng Zhang, Guang-Zhong Cao, Wen-Zhou Li + 1 more
Lower-limb exoskeletons (LLEs) can provide rehabilitation training and walking assistance for individuals with lower-limb dysfunction or those in need of functionality enhancement. Adapting and personalizing the LLEs is crucial for them to form an intelligent human-machine system (HMS). However, numerous LLEs lack…
Chunguang Li, Mengru Li, Chongben Tao
Considering the dynamics and non-linear characteristics of biped robots, gait optimization is an extremely challenging task. To tackle this issue, a parallel heterogeneous policy Deep Reinforcement Learning (DRL) algorithm for gait optimization is proposed. Firstly, the Deep Deterministic Policy Gradient (DDPG)…
Yanhao Yang, Ross L. Hatton
— Inertia-dominated mechanical systems can achieve net displacement by 1) periodically changing their shape (known as kinematic gait) and 2) adjusting their inertia distribution to utilize the existing nonzero net momentum (known as momentum gait). Therefore, finding the gait that most effectively utilizes the two…
GilHwan Kim, Fabrizio Sergi
In this study, we determined the feasibility of modeling the relationship between robot control parameters and propulsion mechanics as a Gaussian process. Specifically, we used data obtained in a previous experiment that used pulses of torque applied at the hip and knee joint, at early and late stance, to establish the…
Rahm Ranjan, David Ahmedt‐Aristizabal, Mohammad Ali Armin, Juno Kim
Human Pose Estimation Authors: ['Rahm Ranjan' 'David Ahmedt‐Aristizabal' 'Mohammad Ali Armin' 'Juno Kim'] Abstract—Gait analysis using computer vision is an emerging field in AI, offering clinicians an objective, multi-feature approach to analyse complex movements. Despite its promise, current applications using RGB…
Authors not listed
Solving optimization problems, especially for nonlinear and constrained systems, is a challenge. Decades of specialized algorithms have been developed for general and special cases of root finding, minimization (including constraints), for parameter estimation, and mapping connected spaces. These approaches typically…
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This article presents an overview about the state of the art in the development of structured packings for distillation applications. The focus is on highlighting different approaches including heuristic development cycles, the development of new packing structures, 3D-printing as tool for manufacturing, and…
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Quantum mechanics/molecular mechanics (QM/MM) simulations are crucial for understanding enzymatic reactions, but their accuracy depends heavily on the quantum-mechanical method used. Semiempirical methods offer computational efficiency but often struggle with accuracy in complex systems. This work presents a novel…
Tobias Seidel, Lena-Marie Ränger, Thomas Grützner, Michael Bortz
In this work we present a new approach that we use to simulate and optimize multiple dividing wall columns at the same time. Instead of considering all model equations as constraints and all process variables as optimization variables in a large and highly nonlinear optimization problem we only incorporate a subset of…
Sterling Baird, Jason R. Hall, Taylor D. Sparks
Would you rather search for a line inside a cube or a point inside a square? This type of solution degeneracy often exists in physics-based simulations and wet-lab experiments, but constraining these degeneracies is often unsupported or difficult to implement in many optimization packages, requiring additional time and…