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一种基于轨迹动力学的任务导向型飞行自组网赛博物理路由协议 Article

胡蝶, 杨少石, 龚旻, 冯志勇, 祝学军

《工程(英文)》 2022年 第19卷 第12期   页码 217-227 doi: 10.1016/j.eng.2021.10.022

摘要:

As a special type of mobile ad hoc network (MANET), the flying ad hoc network (FANET) has the potential to enable a variety of emerging applications in both civilian wireless communications (e.g., 5G and 6G) and the defense industry. The routing protocol plays a pivotal role in FANET. However, when designing the routing protocol for FANET, it is conventionally assumed that the aerial nodes move randomly. This is clearly inappropriate for a mission-oriented FANET (MO-FANET), in which the aerial nodes typically move toward a given destination from given departure point(s), possibly along a roughly deterministic flight path while maintaining a well-established formation, in order to carry out certain missions. In this paper, a novel cyber-physical routing protocol exploiting the particular mobility pattern of an MO-FANET is proposed based on cross-disciplinary integration, which makes full use of the mission-determined trajectory dynamics to construct the time sequence of rejoining and separating, as well as the adjacency matrix for each node, as prior information. Compared with the existing representative routing protocols used in FANETs, our protocol achieves a higher packet-delivery ratio (PDR) at the cost of even lower overhead and lower average end-to-end latency, while maintaining a reasonably moderate and stable network jitter, as demonstrated by extensive ns-3-based simulations assuming realistic configurations in an MO-FANET.

关键词: Cyber-physical system     Flying ad hoc network (FANET)     Routing protocol     Trajectory dynamics     Unmanned aerial vehicle (UAV)    

基于车辆动力学的轨迹跟踪器设计

陈杨,刘大学,贺汉根,戴斌

《中国工程科学》 2007年 第9卷 第11期   页码 68-73

摘要:

轨迹跟踪是移动机器人导航中的核心问题之一。针对非完整运动约束车辆,利用反馈线性化方法设计了轨迹跟踪器,仿真研究了跟踪算法的鲁棒性。最后,介绍了工程实现中参数观测器设计等相关问题。

关键词: 轨迹跟踪     反馈线性化     导航    

Multiobjective trajectory optimization of intelligent electro-hydraulic shovel

《机械工程前沿(英文)》 2022年 第17卷 第4期 doi: 10.1007/s11465-022-0706-2

摘要: Multiobjective trajectory planning is still face challenges due to certain practical requirements and multiple contradicting objectives optimized simultaneously. In this paper, a multiobjective trajectory optimization approach that sets energy consumption, execution time, and excavation volume as the objective functions is presented for the electro-hydraulic shovel (EHS). The proposed cubic polynomial S-curve is employed to plan the crowd and hoist speed of EHS. Then, a novel hybrid constrained multiobjective evolutionary algorithm based on decomposition is proposed to deal with this constrained multiobjective optimization problem. The normalization of objectives is introduced to minimize the unfavorable effect of orders of magnitude. A novel hybrid constraint handling approach based on -constraint and the adaptive penalty function method is utilized to discover infeasible solution information and improve population diversity. Finally, the entropy weight technique for order preference by similarity to an ideal solution method is used to select the most satisfied solution from the Pareto optimal set. The performance of the proposed strategy is validated and analyzed by a series of simulation and experimental studies. Results show that the proposed approach can provide the high-quality Pareto optimal solutions and outperforms other trajectory optimization schemes investigated in this article.

关键词: trajectory planning     electro-hydraulic shovel     cubic polynomial S-curve     multiobjective optimization     entropy weight technique    

Robust train speed trajectory optimization: A stochastic constrained shortest path approach

Li WANG, Lixing YANG, Ziyou GAO, Yeran HUANG

《工程管理前沿(英文)》 2017年 第4卷 第4期   页码 408-417 doi: 10.15302/J-FEM-2017042

摘要: Train speed trajectory optimization is a significant issue in railway traffic systems, and it plays a key role in determining energy consumption and travel time of trains. Due to the complexity of real-world operational environments, a variety of factors can lead to the uncertainty in energy-consumption. To appropriately characterize the uncertainties and generate a robust speed trajectory, this study specifically proposes distance-speed networks over the inter-station and treats the uncertainty with respect to energy consumption as discrete sample-based random variables with correlation. The problem of interest is formulated as a stochastic constrained shortest path problem with travel time threshold constraints in which the expected total energy consumption is treated as the evaluation index. To generate an approximate optimal solution, a Lagrangian relaxation algorithm combined with dynamic programming algorithm is proposed to solve the optimal solutions. Numerical examples are implemented and analyzed to demonstrate the performance of proposed approaches.

关键词: train speed trajectory optimization     railway operation     stochastic programming    

autonomous mining: design and development of an unmanned electric shovel via point cloud-based optimal trajectory

《机械工程前沿(英文)》 2022年 第17卷 第3期 doi: 10.1007/s11465-022-0686-2

摘要: With the proposal of intelligent mines, unmanned mining has become a research hotspot in recent years. In the field of autonomous excavation, environmental perception and excavation trajectory planning are two key issues because they have considerable influences on operation performance. In this study, an unmanned electric shovel (UES) is developed, and key robotization processes consisting of environment modeling and optimal excavation trajectory planning are presented. Initially, the point cloud of the material surface is collected and reconstructed by polynomial response surface (PRS) method. Then, by establishing the dynamical model of the UES, a point to point (PTP) excavation trajectory planning method is developed to improve both the mining efficiency and fill factor and to reduce the energy consumption. Based on optimal trajectory command, the UES performs autonomous excavation. The experimental results show that the proposed surface reconstruction method can accurately represent the material surface. On the basis of reconstructed surface, the PTP trajectory planning method rapidly obtains a reasonable mining trajectory with high fill factor and mining efficiency. Compared with the common excavation trajectory planning approaches, the proposed method tends to be more capable in terms of mining time and energy consumption, ensuring high-performance excavation of the UES in practical mining environment.

关键词: autonomous excavation     unmanned electric shovel     point cloud     excavation trajectory planning    

Real-time immune-inspired optimum state-of-charge trajectory estimation using upcoming route information

Ahmad MOZAFFARI,Mahyar VAJEDI,Nasser L. AZAD

《机械工程前沿(英文)》 2015年 第10卷 第2期   页码 154-167 doi: 10.1007/s11465-015-0336-z

摘要:

The main proposition of the current investigation is to develop a computational intelligence-based framework which can be used for the real-time estimation of optimum battery state-of-charge (SOC) trajectory in plug-in hybrid electric vehicles (PHEVs). The estimated SOC trajectory can be then employed for an intelligent power management to significantly improve the fuel economy of the vehicle. The devised intelligent SOC trajectory builder takes advantage of the upcoming route information preview to achieve the lowest possible total cost of electricity and fossil fuel. To reduce the complexity of real-time optimization, the authors propose an immune system-based clustering approach which allows categorizing the route information into a predefined number of segments. The intelligent real-time optimizer is also inspired on the basis of interactions in biological immune systems, and is called artificial immune algorithm (AIA). The objective function of the optimizer is derived from a computationally efficient artificial neural network (ANN) which is trained by a database obtained from a high-fidelity model of the vehicle built in the Autonomie software. The simulation results demonstrate that the integration of immune inspired clustering tool, AIA and ANN, will result in a powerful framework which can generate a near global optimum SOC trajectory for the baseline vehicle, that is, the Toyota Prius PHEV. The outcomes of the current investigation prove that by taking advantage of intelligent approaches, it is possible to design a computationally efficient and powerful SOC trajectory builder for the intelligent power management of PHEVs.

关键词: trip information preview     intelligent transportation     state-of-charge trajectory builder     immune systems     artificial neural network    

Longitudinal and lateral slip control of autonomous wheeled mobile robot for trajectory tracking

Hamza KHAN,Jamshed IQBAL,Khelifa BAIZID,Teresa ZIELINSKA

《信息与电子工程前沿(英文)》 2015年 第16卷 第2期   页码 166-172 doi: 10.1631/FITEE.1400183

摘要: This research formulates a path-following control problem subjected to wheel slippage and skid and solves it using a logic-based control scheme for a wheeled mobile robot (WMR). The novelty of the proposed scheme lies in its methodology that considers both longitudinal and lateral slip components. Based on the derived slip model, the controller for longitudinal motion slip has been synthesized. Various control parameters have been studied to investigate their effects on the performance of the controller resulting in selection of their optimum values. The designed controller for lateral slip or skid is based on the proposed side friction model and skid check condition. Considering a car-like WMR, simulation results demonstrate the effectiveness of the proposed control scheme. The robot successfully followed the desired circular trajectory in the presence of wheel slippage and skid. This research finds its potential in various applications involving WMR navigation and control.

关键词: Robot modeling     Robot navigation     Slip and skid control     Wheeled mobile robots    

Trajectory planning of mobile robots using indirect solution of optimal control method in generalized

M. NAZEMIZADEH, H. N. RAHIMI, K. AMINI KHOIY

《机械工程前沿(英文)》 2012年 第7卷 第1期   页码 23-28 doi: 10.1007/s11465-012-0304-9

摘要:

This paper presents an optimal control strategy for optimal trajectory planning of mobile robots by considering nonlinear dynamic model and nonholonomic constraints of the system. The nonholonomic constraints of the system are introduced by a nonintegrable set of differential equations which represent kinematic restriction on the motion. The Lagrange’s principle is employed to derive the nonlinear equations of the system. Then, the optimal path planning of the mobile robot is formulated as an optimal control problem. To set up the problem, the nonlinear equations of the system are assumed as constraints, and a minimum energy objective function is defined. To solve the problem, an indirect solution of the optimal control method is employed, and conditions of the optimality derived as a set of coupled nonlinear differential equations. The optimality equations are solved numerically, and various simulations are performed for a nonholonomic mobile robot to illustrate effectiveness of the proposed method.

关键词: mobile robot     trajectory planning     nonlinear dynamic     optimal control    

Computational fluid dynamics simulation of aerosol transport and deposition

Yingjie TANG, Bing GUO

《环境科学与工程前沿(英文)》 2011年 第5卷 第3期   页码 362-377 doi: 10.1007/s11783-011-0365-8

摘要: In this article computational fluid dynamics (CFD) simulation of aerosol transport and deposition, i.e. the transport and deposition of particles in an aerosol, is reviewed. The review gives a brief account of the basics of aerosol mechanics, followed by a description of the general CFD approach for flow field simulation, turbulence modeling, wall treatments and simulation of particle motion and deposition. Then examples from the literature are presented, including CFD simulation of particle deposition in human respiratory tract and particle deposition in aerosol devices. CFD simulation of particle transport and deposition may provide information that is difficult to obtain through physical experiments, and it may help reduce the number of experiments needed for device design. Due to the difficulty of describing turbulent flow and particle-eddy interaction, turbulent dispersion of particles remains one of the greatest challenges for CFD simulation. However, it is possible to take a balanced approach toward quantitative description of aerosol dispersion using CFD simulation in conjunction with empirical relations.

关键词: computational fluid dynamics (CFD)     aerosol     transport     deposition    

一种用于自动驾驶的车辆概率性长期轨迹预测框架 Article

刘金鑫, 罗禹贡, 钟志华, 李克强, 黄荷叶, 熊辉

《工程(英文)》 2022年 第19卷 第12期   页码 228-239 doi: 10.1016/j.eng.2021.12.020

摘要:

In mixed and dynamic traffic environments, accurate long-term trajectory forecasting of surrounding vehicles is one of the indispensable preconditions for autonomous vehicles (AVs) to accomplish reasonable behavioral decisions and guarantee driving safety. In this paper, we propose an integrated probabilistic architecture for long-term vehicle trajectory prediction, which consists of a driving inference model (DIM) and a trajectory prediction model (TPM). The DIM is designed and employed to accurately infer the potential driving intention based on a dynamic Bayesian network. The proposed DIM incorporates the basic traffic rules and multivariate vehicle motion information. To further improve the prediction accuracy and realize uncertainty estimation, we develop a Gaussian process (GP)-based TPM, considering both the short-term prediction results of the vehicle model and the driving motion characteristics. Afterward, the effectiveness of our novel approach is demonstrated by conducting experiments on a public naturalistic driving dataset under lane-changing scenarios. The superior performance on the task of long-term trajectory prediction is presented and verified by comparing with other advanced methods.

关键词: Autonomous driving     Dynamic Bayesian network     Driving intention recognition     Gaussian process     Vehicle trajectory prediction    

Recent developments in passive interconnected vehicle suspension

Wade A. SMITH, Nong ZHANG,

《机械工程前沿(英文)》 2010年 第5卷 第1期   页码 1-18 doi: 10.1007/s11465-009-0092-z

摘要: This paper presents an overall review on the historical concept development and research advancement of passive hydraulically interconnected suspension (HIS) systems. It starts with an introduction to passive HIS systems and their various incarnations developed over many decades. Next, a description is provided of a recently proposed multidisciplinary approach for the frequency-domain analysis of vehicles fitted with an HIS. The experimental validation and applications of the method to both free and forced vibration analysis are discussed based on a simplified, roll-plane half-car model. A finite-element-method-based approddach for modelling the transient dynamics of an HIS vehicle is also briefly outlined. In addition, recent work on the investigation of NVH associated with HIS-equipped vehicles is mentioned. Discussion is then provided on future work to the further understanding of HIS and its applications. The paper concludes that interconnected suspension schemes can provide much greater flexibility to independently specify modal stiffness and damping parameters – a characteristic unique among passive suspensions. It points out that there is a need for system optimisation, and there are troublesome NVH issues that require solutions. It suggests that further research attention and effort be paid to NVH issues and system level optimisation to gain a greater understanding of HIS and to broaden its applications.

关键词: interconnected suspensions     rollover prevention     vehicle dynamics     ride comfort     multibody system dynamics     hydraulic system dynamics    

Model reduction of contact dynamics simulation using a modified Lyapunov balancing method

Jianxun LIANG, Ou MA, Caishan LIU

《机械工程前沿(英文)》 2011年 第6卷 第4期   页码 383-391 doi: 10.1007/s11465-011-0244-9

摘要:

Finite element models are often used to simulate impact and contact dynamics responses of multibody dynamical systems. However, such a simulation remains very inefficient because very small integration time step must be used when solving the involved differential equations, especially when the involved contact stiffness is high. Although many model reduction techniques have been available to improve the efficiency of finite element based simulations, these techniques cannot be readily applied to contact dynamics simulations due to the high nonlinearity of the contact dynamics models. This paper presents a model reduction approach for finite-element based multibody contact dynamics simulation, based on a modified Lyapunov balanced truncation method. An example is presented to demonstrate that, by applying the model reduction the simulation process is significantly speeded up and the resulting error is bounded within an acceptable level. The performance of the method with respect to some influential factors such as element size, shape and contact stiffness is also investigated.

关键词: contact dynamics     dynamic simulation     model reduction     finite element method    

Nonlinear dynamics of a wind turbine tower

A. GESUALDO, A. IANNUZZO, F. PENTA, M. MONACO

《机械工程前沿(英文)》 2019年 第14卷 第3期   页码 342-350 doi: 10.1007/s11465-019-0524-3

摘要: The recent proliferation of wind turbines has revealed problems in their vulnerability under different site conditions, as evidenced by recent collapses of wind towers after severe actions. Analyses of structures subjected to variable actions can be conducted through several methods with different accuracy levels. Nonlinear dynamics is the most reliable among such methods. This study develops a numerical procedure to obtain approximate solutions for rigid-plastic responses of structures subjected to base harmonic pulses. The procedure’s model is applied to a wind turbine tower subjected to inertial forces generated by harmonic ground acceleration, and failure is assumed to depend on the formation of shear hinges. The proposed approach provides an efficient representation of the post-elastic behavior of the structure, has a low computational cost and high effectiveness, and uses a limited number of mechanical parameters.

关键词: nonlinear dynamics     plastic shear failure     modal approximation     time history    

styrene-butadiene-styrene copolymer on the aging resistance of asphalt: An atomistic understanding from reactive molecular dynamics

《结构与土木工程前沿(英文)》 2021年 第15卷 第5期   页码 1261-1276 doi: 10.1007/s11709-021-0761-5

摘要: To reveal the potential influence of styrene-butadiene-styrene (SBS) polymer modification on the anti-aging performance of asphalt, and its mechanism, we explored the aging characteristics of base asphalt and SBS-modified asphalt by reaction force field (ReaxFF) and classical molecular dynamics simulations. The results illustrate that the SBS asphalt is more susceptible to oxidative aging than the base asphalt under oxygen-deficient conditions due to the presence of unsaturated C=C bonds in the SBS polymer. In the case of sufficient oxygen, the SBS polymer inhibits the oxidation of asphalt by restraining the diffusion of asphalt molecules. Compared with the base asphalt, the SBS asphalt exhibits a higher degree of oxidation at the early stage of pavement service and a lower degree of oxidation in the long run. In addition, SBS polymer degrades into small blocks during aging, thus counteracting the hardening of aged asphalt and partially restoring its low-temperature cracking resistance.

关键词: SBS asphalt     oxidative aging     asphalt hardening     ReaxFF     molecular dynamics    

Effect of ligand chain length on hydrophobic charge induction chromatography revealed by molecular dynamics

Lin ZHANG, Yan SUN

《化学科学与工程前沿(英文)》 2013年 第7卷 第4期   页码 456-463 doi: 10.1007/s11705-013-1357-y

摘要: Hydrophobic charge induction chromatography (HCIC) is a mixed-mode chromatography which is advantageous for high adsorption capacity and facile elution. The effect of the ligand chain length on protein behavior in HCIC was studied. A coarse-grain adsorbent pore model established in an earlier work was modified to construct adsorbents with different chain lengths, including one with shorter ligands (CL2) and one with longer ligands (CL4). The adsorption, desorption, and conformational transition of the proteins with CL2 and CL4 were examined using molecular dynamics simulations. The ligand chain length has a significant effect on both the probability and the irreversibility of the adsorption/desorption. Longer ligands reduced the energy barrier of adsorption, leading to stronger and more irreversible adsorption, as well as a little more unfolding of the protein. The simulation results elucidated the effect of the ligand chain length, which is beneficial for the rational design of adsorbents and parameter optimization for high-performance HCIC.

关键词: adsorption     desorption     irreversibility     protein conformational transition     molecular dynamics simulation    

标题 作者 时间 类型 操作

一种基于轨迹动力学的任务导向型飞行自组网赛博物理路由协议

胡蝶, 杨少石, 龚旻, 冯志勇, 祝学军

期刊论文

基于车辆动力学的轨迹跟踪器设计

陈杨,刘大学,贺汉根,戴斌

期刊论文

Multiobjective trajectory optimization of intelligent electro-hydraulic shovel

期刊论文

Robust train speed trajectory optimization: A stochastic constrained shortest path approach

Li WANG, Lixing YANG, Ziyou GAO, Yeran HUANG

期刊论文

autonomous mining: design and development of an unmanned electric shovel via point cloud-based optimal trajectory

期刊论文

Real-time immune-inspired optimum state-of-charge trajectory estimation using upcoming route information

Ahmad MOZAFFARI,Mahyar VAJEDI,Nasser L. AZAD

期刊论文

Longitudinal and lateral slip control of autonomous wheeled mobile robot for trajectory tracking

Hamza KHAN,Jamshed IQBAL,Khelifa BAIZID,Teresa ZIELINSKA

期刊论文

Trajectory planning of mobile robots using indirect solution of optimal control method in generalized

M. NAZEMIZADEH, H. N. RAHIMI, K. AMINI KHOIY

期刊论文

Computational fluid dynamics simulation of aerosol transport and deposition

Yingjie TANG, Bing GUO

期刊论文

一种用于自动驾驶的车辆概率性长期轨迹预测框架

刘金鑫, 罗禹贡, 钟志华, 李克强, 黄荷叶, 熊辉

期刊论文

Recent developments in passive interconnected vehicle suspension

Wade A. SMITH, Nong ZHANG,

期刊论文

Model reduction of contact dynamics simulation using a modified Lyapunov balancing method

Jianxun LIANG, Ou MA, Caishan LIU

期刊论文

Nonlinear dynamics of a wind turbine tower

A. GESUALDO, A. IANNUZZO, F. PENTA, M. MONACO

期刊论文

styrene-butadiene-styrene copolymer on the aging resistance of asphalt: An atomistic understanding from reactive molecular dynamics

期刊论文

Effect of ligand chain length on hydrophobic charge induction chromatography revealed by molecular dynamics

Lin ZHANG, Yan SUN

期刊论文