Multibody System Dynamics最新文献_第8页

Theoretical framework and experimental solution for the air-water interface adsorption problem in cryoEM. 低温电镜中空气-水界面吸附问题的理论框架和实验解决方案。

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-31 DOI: 10.1101/2023.05.23.541984

Joon S Kang, Xueting Zhou, Yun-Tao Liu, Kaituo Wang, Z Hong Zhou

{"title":"Theoretical framework and experimental solution for the air-water interface adsorption problem in cryoEM.","authors":"Joon S Kang, Xueting Zhou, Yun-Tao Liu, Kaituo Wang, Z Hong Zhou","doi":"10.1101/2023.05.23.541984","DOIUrl":"10.1101/2023.05.23.541984","url":null,"abstract":"<p><p>As cryogenic electron microscopy (cryoEM) gains traction in the structural biology community as a method of choice for determining atomic structures of biological complexes, it has been increasingly recognized that many complexes that behave well under conventional negative-stain electron microscopy tend to have preferential orientation, aggregate or simply mysteriously \"disappear\" on cryoEM grids, but the reasons for such misbehavior are not well understood, limiting systematic approaches to solving the problem. Here, we have developed a theoretical formulation that explains these observations. Our formulation predicts that all particles migrate to the air-water interface (AWI) to lower the total potential surface energy - rationalizing the use of surfactant, which is a direct solution to reducing the surface tension of the aqueous solution. By conducting cryogenic electron tomography (cryoET) with the widely-tested sample, GroEL, we demonstrate that, in a standard buffer solution, nearly all particles migrate to the AWI. Gradual reduction of the surface tension by introducing surfactants decreased the percentage of particles exposed to the surface. By conducting single-particle cryoEM, we confirm that applicable surfactants do not damage the biological complex, thus suggesting that they might offer a practical, simple, and general solution to the problem for high-resolution cryoEM. Application of this solution to a real-world AWI adsorption problem with a more challenging membrane protein, namely, the ClC-1 channel, has led to its first near-atomic structure using cryoEM.</p>","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10634880/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74070127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Influence of gravity on the vibration characteristics of a geometrically nonlinear McPherson-suspension model 重力对几何非线性mcpherson悬架模型振动特性的影响

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-30 DOI: 10.1007/s11044-023-09946-0

Vaibhav Dhar Dwivedi, Pankaj Wahi

引用次数: 0

Analytical and numerical investigations of linear and nonlinear torsional strains using position gradients 使用位置梯度的线性和非线性扭转应变的解析和数值研究

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-30 DOI: 10.1007/s11044-023-09944-2

Ahmed A. Shabana, Ahmed E. Eldeeb, Hao Ling

引用次数: 0

Estimation of wheelset equivalent conicity using the dual extended Kalman filter 利用对偶扩展卡尔曼滤波估计轮对等效圆锥度

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-27 DOI: 10.1007/s11044-023-09942-4

Prapanpong Damsongsaeng, Rickard Persson, Sebastian Stichel, Carlos Casanueva

{"title":"Estimation of wheelset equivalent conicity using the dual extended Kalman filter","authors":"Prapanpong Damsongsaeng, Rickard Persson, Sebastian Stichel, Carlos Casanueva","doi":"10.1007/s11044-023-09942-4","DOIUrl":"https://doi.org/10.1007/s11044-023-09942-4","url":null,"abstract":"Abstract This paper presents the implementation of the dual extended Kalman filter (DEKF) to estimate wheelset equivalent conicity, an accurate understanding of which can facilitate the implementation of an effective model-based estimator. The estimator is developed to identify the wheelset equivalent conicity of high-speed railway vehicles while negotiating a curve. The designed DEKF estimator employs two discrete-time extended Kalman filters combining state and parameter estimators in parallel. This estimator uses easily available measurements from acceleration sensors measuring at axle boxes and a rate gyroscope measuring bogie frame yaw velocity. Two tests, including linearized and actual wheel-rail geometry, are carried out at a speed of 250 km/h with stochastic and deterministic track features using multibody simulations, SIMPACK. The results with acceptable estimation errors for both track conditions indicate adequate performance and reliability of the designed DEKF estimator. They demonstrate the feasibility of utilizing this DEKF method in rail vehicle applications as the knowledge of time-varying parameters is not only important in achieving an effective estimator for vehicle control but also useful for vehicle condition monitoring.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136236002","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Space-time rigid multibody dynamics 时空刚体多体动力学

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-27 DOI: 10.1007/s11044-023-09945-1

C. Hesch, S. Glas, S. Schuß

引用次数: 0

Command shaped trajectory tracking control for a two-link flexible manipulator 双连杆柔性机械臂命令形轨迹跟踪控制

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-27 DOI: 10.1007/s11044-023-09947-z

Sandeep Kumar, Subir Kumar Saha, Ashish Singla, Satinder Paul Singh, Tarun Kumar Bera

引用次数: 0

Spatial locomotion of a metameric earthworm-like robot: generation and analysis of gaits 类蚯蚓机器人的空间运动:步态的生成与分析

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-26 DOI: 10.1007/s11044-023-09943-3

Qiwei Zhang, Jian Xu, Hongbin Fang

引用次数: 0

Exudyn – a C++-based Python package for flexible multibody systems Exudyn——一个基于c++的Python包，用于灵活的多体系统

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-09 DOI: 10.1007/s11044-023-09937-1

Johannes Gerstmayr

引用次数: 2

Investigation of the driving characteristics of electric bicycles by means of multibody simulation 基于多体仿真的电动自行车行驶特性研究

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-09 DOI: 10.1007/s11044-023-09940-6

Johannes Bolk, Burkhard Corves

引用次数: 0

Numerical and experimental investigation on the synthesis of extended Kalman filters for cable-driven parallel robots modeled through DAEs 基于DAEs建模的缆索驱动并联机器人扩展卡尔曼滤波器综合的数值与实验研究

2区工程技术

Multibody System Dynamics Pub Date : 2023-10-09 DOI: 10.1007/s11044-023-09941-5

Jason Bettega, Giovanni Boschetti, Borja R. Frade, Francisco González, Giulio Piva, Dario Richiedei, Alberto Trevisani

{"title":"Numerical and experimental investigation on the synthesis of extended Kalman filters for cable-driven parallel robots modeled through DAEs","authors":"Jason Bettega, Giovanni Boschetti, Borja R. Frade, Francisco González, Giulio Piva, Dario Richiedei, Alberto Trevisani","doi":"10.1007/s11044-023-09941-5","DOIUrl":"https://doi.org/10.1007/s11044-023-09941-5","url":null,"abstract":"Abstract Cable-driven parallel robots are parallel robots where light-weight cables replace rigid bodies to move an end-effector. Their peculiar design allows obtaining large workspaces, high-dynamic handlings, ease of reconfigurability and, in general, low-cost architecture. Knowing the full state variables of a cable robot may be essential to implement advanced control and monitoring strategies and imposes the development of state observers. In this work a general approach to develop nonlinear state observers based on an extended Kalman filter (EKF) is proposed and validated both numerically and experimentally by referring to a cable-suspended parallel robot. The state observer is based on a system model obtained by converting a set of differential algebraic equations into ordinary differential equations through different formulations: the penalty formulation, the Udwadia–Kalaba formulation, and the Udwadia–Kalaba–Phohomsiri formulation, which have been chosen since they can handle the presence of redundant constraints as often happens in cable-driven parallel robots. In the numerical investigation, the EKF is validated simulating encoders heavily affected by quantization errors to demonstrate the filtering capabilities of EKF. In the experimental investigation, a very challenging validation is proposed: only two sensors measuring the rotations of two motors are used to estimate the actual position and velocity of the end-effector. This result cannot be achieved by sole forward kinematics and clearly proves the effectiveness of the proposed observer.","PeriodicalId":49792,"journal":{"name":"Multibody System Dynamics","volume":"291 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135142113","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0