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Hierarchical parameter estimation of DFIG and drive train system in a wind turbine generator

Xueping PAN, Ping JU, Feng WU, Yuqing JIN

《机械工程前沿(英文)》 2017年 第12卷 第3期   页码 367-376 doi: 10.1007/s11465-017-0429-y

摘要:

A new hierarchical parameter estimation method for doubly fed induction generator (DFIG) and drive train system in a wind turbine generator (WTG) is proposed in this paper. Firstly, the parameters of the DFIG and the drive train are estimated locally under different types of disturbances. Secondly, a coordination estimation method is further applied to identify the parameters of the DFIG and the drive train simultaneously with the purpose of attaining the global optimal estimation results. The main benefit of the proposed scheme is the improved estimation accuracy. Estimation results confirm the applicability of the proposed estimation technique.

关键词: wind turbine generator     DFIG     drive train system     hierarchical parameter estimation method     trajectory sensitivity technique    

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    

Control efficiency optimization and Sobol’s sensitivity indices of MTMDs design parameters for buffeting

Nazim Abdul NARIMAN

《结构与土木工程前沿(英文)》 2017年 第11卷 第1期   页码 66-89 doi: 10.1007/s11709-016-0356-8

摘要: This paper studies optimization of three design parameters (mass ratio, frequency ratio and damping ratio) of multiple tuned mass dampers MTMDs that are applied in a cable stayed bridge excited by a strong wind using minimax optimization technique. ABAQUS finite element program is utilized to run numerical simulations with the support of MATLAB codes and Fast Fourier Transform FFT technique. The optimum values of these three parameters are validated with two benchmarks from the literature, first with Wang and coauthors and then with Lin and coauthors. The validation procedure detected a good agreement between the results. Box-Behnken experimental method is dedicated to formulate the surrogate models to represent the control efficiency of the vertical and torsional vibrations. Sobol’s sensitivity indices are calculated for the design parameters in addition to their interaction orders. The optimization results revealed better performance of the MTMDs in controlling the vertical and the torsional vibrations for higher mode shapes. Furthermore, the calculated rational effects of each design parameter facilitate to increase the control efficiency of the MTMDs in conjunction with the support of the surrogate models.

关键词: MTMDs     power spectral density     fast Fourier transform     minimax optimization technique     Sobol’s sensitivity indices     Box-Behnken method    

Application of machine learning technique for predicting and evaluating chloride ingress in concrete

Van Quan TRAN; Van Loi GIAP; Dinh Phien VU; Riya Catherine GEORGE; Lanh Si HO

《结构与土木工程前沿(英文)》 2022年 第16卷 第9期   页码 1153-1169 doi: 10.1007/s11709-022-0830-4

摘要: The degradation of concrete structure in the marine environment is often related to chloride-induced corrosion of reinforcement steel. Therefore, the chloride concentration in concrete is a vital parameter for estimating the corrosion level of reinforcement steel. This research aims at predicting the chloride content in concrete using three hybrid models of gradient boosting (GB), artificial neural network (ANN), and random forest (RF) in combination with particle swarm optimization (PSO). The input variables for modeling include exposure condition, water/binder ratio (W/B), cement content, silica fume, time exposure, and depth of measurement. The results indicate that three models performed well with high accuracy of prediction (R2 ≥ 0.90). Among three hybrid models, the model using GB_PSO achieved the highest prediction accuracy (R2 = 0.9551, RMSE = 0.0327, and MAE = 0.0181). Based on the results of sensitivity analysis using SHapley Additive exPlanation (SHAP) and partial dependence plots 1D (PDP-1D), it was found that the exposure condition and depth of measurement were the two most vital variables affecting the prediction of chloride content. When the number of different exposure conditions is larger than two, the exposure significantly impacted the chloride content of concrete because the chloride ion ingress is affected by both chemical and physical processes. This study provides an insight into the evaluation and prediction of the chloride content of concrete in the marine environment.

关键词: gradient boosting     random forest     chloride content     concrete     sensitivity analysis.    

Dynamic prediction of moving trajectory in pipe jacking: GRU-based deep learning framework

《结构与土木工程前沿(英文)》   页码 994-1010 doi: 10.1007/s11709-023-0942-5

摘要: The moving trajectory of the pipe-jacking machine (PJM), which primarily determines the end quality of jacked tunnels, must be controlled strictly during the entire jacking process. Developing prediction models to support drivers in performing rectifications in advance can effectively avoid considerable trajectory deviations from the designed jacking axis. Hence, a gated recurrent unit (GRU)-based deep learning framework is proposed herein to dynamically predict the moving trajectory of the PJM. In this framework, operational data are first extracted from a data acquisition system; subsequently, they are preprocessed and used to establish GRU-based multivariate multistep-ahead direct prediction models. To verify the performance of the proposed framework, a case study of a large pipe-jacking project in Shanghai and comparisons with other conventional models (i.e., long short-term memory (LSTM) network and recurrent neural network (RNN)) are conducted. In addition, the effects of the activation function and input time-step length on the prediction performance of the proposed framework are investigated and discussed. The results show that the proposed framework can dynamically and precisely predict the PJM moving trajectory during the pipe-jacking process, with a minimum mean absolute error and root mean squared error (RMSE) of 0.1904 and 0.5011 mm, respectively. The RMSE of the GRU-based models is lower than those of the LSTM- and RNN-based models by 21.46% and 46.40% at the maximum, respectively. The proposed framework is expected to provide an effective decision support for moving trajectory control and serve as a foundation for the application of deep learning in the automatic control of pipe jacking.

关键词: dynamic prediction     moving trajectory     pipe jacking     GRU     deep learning    

Research on Anthropomorphic Obstacle Avoidance Trajectory Planning for Adaptive Driving Scenarios Based

Jian Wu,Yang Yan,Yulong Liu,Yahui Liu,

《工程(英文)》 doi: 10.1016/j.eng.2023.07.018

摘要: The forward design of trajectory planning strategies requires preset trajectory optimization functions, resulting in poor adaptability of the strategy and an inability to accurately generate obstacle avoidance trajectories that conform to real driver behavior habits. In addition, owing to the strong time-varying dynamic characteristics of obstacle avoidance scenarios, it is necessary to design numerous trajectory optimization functions and adjust the corresponding parameters. Therefore, an anthropomorphic obstacle-avoidance trajectory planning strategy for adaptive driving scenarios is proposed. First, numerous expert-demonstrated trajectories are extracted from the HighD natural driving dataset. Subsequently, a trajectory expectation feature-matching algorithm is proposed that uses maximum entropy inverse reinforcement learning theory to learn the extracted expert-demonstrated trajectories and achieve automatic acquisition of the optimization function of the expert-demonstrated trajectory. Furthermore, a mapping model is constructed by combining the key driving scenario information that affects vehicle obstacle avoidance with the weight of the optimization function, and an anthropomorphic obstacle avoidance trajectory planning strategy for adaptive driving scenarios is proposed. Finally, the proposed strategy is verified based on real driving scenarios. The results show that the strategy can adjust the weight distribution of the trajectory optimization function in real time according to the “emergency degree” of obstacle avoidance and the state of the vehicle. Moreover, this strategy can generate anthropomorphic trajectories that are similar to expert-demonstrated trajectories, effectively improving the adaptability and acceptability of trajectories in driving scenarios.

关键词: Obstacle avoidance trajectory planning     Inverse reinforcement theory     Anthropomorphic     Adaptive driving scenarios    

Research on acoustic-structure sensitivity using FEM and BEM

ZHANG Jun, ZHAO Wenzhong, ZHANG Weiying

《机械工程前沿(英文)》 2007年 第2卷 第1期   页码 62-67 doi: 10.1007/s11465-007-0010-1

摘要: Acoustic-structure sensitivity is used to predict the change of acoustic pressure when a structure design variable is changed. The sensitivity is significant for reducing noise of structure. Using FEM (finite element method) and BEM (boundary element method) acoustic-structure sensitivity was formulated and presented. The dynamic response and response velocity sensitivity with respect to structure design variable were carried out by using structural FEM, the acoustic response and acoustic pressure sensitivity with respect to structure velocity were carried out by using acoustic BEM. Then, acoustic-structure sensitivity was computed by linking velocity sensitivity in FEM and acoustic sensitivity in BEM. This method was applied to an empty box as an example. Acoustic pressure sensitivity with respect to structure thickness achieved in frequency ranges 1 100 Hz, and its change rule along with stimulating frequency and design variable were analyzed. Results show that acoustic-structure sensitivity method linked with FEM and BEM is effective and correct.

关键词: sensitivity method     BEM     acoustic pressure     pressure sensitivity     frequency    

decoupled framework for reliability-based design optimization of structures using a robust shifting technique

Mohammad Reza GHASEMI, Charles V. CAMP, Babak DIZANGIAN

《结构与土木工程前沿(英文)》 2019年 第13卷 第4期   页码 800-820 doi: 10.1007/s11709-019-0517-7

摘要: In a reliability-based design optimization (RBDO), computation of the failure probability ( ) at all design points through the process may suitably be avoided at the early stages. Thus, to reduce extensive computations of RBDO, one could decouple the optimization and reliability analysis. The present work proposes a new methodology for such a decoupled approach that separates optimization and reliability analysis into two procedures which significantly improve the computational efficiency of the RBDO. This technique is based on the probabilistic sensitivity approach (PSA) on the shifted probability density function. Stochastic variables are separated into two groups of desired and non-desired variables. The three-phase procedure may be summarized as: Phase 1, apply deterministic design optimization based on mean values of random variables; Phase 2, move designs toward a reliable space using PSA and finding a primary reliable optimum point; Phase 3, applying an intelligent self-adaptive procedure based on cubic B-spline interpolation functions until the targeted failure probability is reached. An improved response surface method is used for computation of failure probability. The proposed RBDO approach could significantly reduce the number of analyses required to less than 10% of conventional methods. The computational efficacy of this approach is demonstrated by solving four benchmark truss design problems published in the structural optimization literature.

关键词: reliability-based design optimization     trusses     sensitivity analysis     shifting technique     cubic B-splines     response surface method    

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    

Parametric sensitivity analysis of cellular diaphragm wall

Xi CHEN, Wei XU

《结构与土木工程前沿(英文)》 2012年 第6卷 第4期   页码 358-364 doi: 10.1007/s11709-012-0177-3

摘要: The deformation law of the cellular diaphragm wall in deep foundation pits was studied through numerical simulation. Based on the example of the dock wall in engineering, the full three-dimensional finite element model was used to simulate the excavation of the foundation pit. Interaction between the cellular diaphragm wall and the soil was also taken into account in the calculation. The results indicated that the maximum lateral displacement, which is the evaluation index of sensitivity analysis, appeared on the top of the interior longitudinal wall with an excavation depth of 10 m. The centrifuge model test was carried out to study the deformation regulation for a cellular diaphragm wall. The most sensitive factor was found by adjusting the length of the partition wall, the spacing of the partition wall and the thickness of the wall. In the end, a suggestion was proposed to optimize the cellular diaphragm by adjusting the length of the partition wall.

关键词: cellular diaphragm wall     sensitivity analysis     optimization     centrifuge model test    

Probability strength design of steam turbine blade and sensitivity analysis with respect to random parameters

DUAN Wei

《能源前沿(英文)》 2008年 第2卷 第1期   页码 107-115 doi: 10.1007/s11708-008-0018-1

摘要: Many stochastic parameters have an effect on the reliability of a steam turbine blade during practical operation. To improve the reliability of blade design, it is necessary to take these stochastic parameters into account. An equal cross-section blade is investigated and a finite element model is built parametrically. Geometrical parameters, material parameters and load parameters of the blade are considered as input random variables while the maximum deflection and maximum equivalent stress are output random variables. Analysis file of the blade is compiled by deterministic finite element method and applied to be loop file to create sample points. A quadratic polynomial with cross terms is chosen to regress these samples by step-forward regression method and employed as a surrogate of numerical solver to drastically reduce the number of solvers call. Then, Monte Carlo method is used to obtain the statistical characteristics and cumulative distribution function of the maximum deflection and maximum equivalent stress of the blade. Probability sensitivity analysis, which combines the slope of the gradient and the width of the scatter range of the random input variables, is applied to evaluate how much the output parameters are influenced by the random input parameters. The scatter plots of structural responses with respect to the random input variables are illustrated to analyze how to change the input random variables to improve the reliability of the blade. The results show that combination of the finite element method, the response surface method and Monte Carlo method is an ideal way for the reliability analysis and probability strength design of the blade.

关键词: Probability sensitivity     sensitivity analysis     number     cross-section     statistical    

General Optimal Trajectory Planning: Enabling Autonomous Vehicles with the Principle of Least Action

Heye Huang,Yicong Liu,Jinxin Liu,Qisong Yang,Jianqiang Wang,David Abbink,Arkady Zgonnikov,

《工程(英文)》 doi: 10.1016/j.eng.2023.10.001

摘要: This study presents a general optimal trajectory planning (GOTP) framework for autonomous vehicles (AVs) that can effectively avoid obstacles and guide AVs to complete driving tasks safely and efficiently. Firstly, we employ the fifth-order Bezier curve to generate and smooth the reference path along the road centerline. Cartesian coordinates are then transformed to achieve the curvature continuity of the generated curve. Considering the road constraints and vehicle dynamics, limited polynomial candidate trajectories are generated and smoothed in a curvilinear coordinate system. Furthermore, in selecting the optimal trajectory, we develop a unified and auto-tune objective function based on the principle of least action by employing AVs to simulate drivers’ behavior and summarizing their manipulation characteristics of “seeking benefits and avoiding losses.” Finally, by integrating the idea of receding-horizon optimization, the proposed framework is achieved by considering dynamic multi-performance objectives and selecting trajectories that satisfy feasibility, optimality, and adaptability. Extensive simulations and experiments are performed, and the results demonstrate the framework’s feasibility and effectiveness, which avoids both dynamic and static obstacles and applies to various scenarios with multi-source interactive traffic participants. Moreover, we prove that the proposed method can guarantee real-time planning and safety requirements compared to drivers’ manipulation.

关键词: Autonomous vehicle     Trajectory planning     Multi-performance objectives     Principle of least action    

Wheel tracking methods to evaluate moisture sensitivity of hot-mix asphalt mixtures

Jie HAN,Harihar Shiwakoti

《结构与土木工程前沿(英文)》 2016年 第10卷 第1期   页码 30-43 doi: 10.1007/s11709-016-0318-1

摘要: Existing test methods to determine moisture sensitivity in hot-mix asphalt (HMA) mixtures are time consuming and inconsistent. This research focused on wheel tracking devices to evaluate moisture sensitivity. The Asphalt Pavement Analyzer (APA) and the Hamburg Wheel Tracking Device (HWTD) were used for this research. Compacted cylindrical samples were fabricated using a Superpave Gyratory compactor. This study selected two most commonly used mixtures, SM-12.5A with PG 64-22 binder in overlay projects and SM-19A mixtures with PG 64-22 binder for major modification projects at Kansas Department of Transportation. Test results show that APA tests could induce stripping in most samples without any anti-stripping agent, which could be identified visually. However, APA results did not indicate any stripping inflection point while the HWTD results showed stripping inflection points, which are important to identify stripping potential of mixtures. The APA results show that wet tests are severe at lower temperatures. The HWTD results show improvement in the performance using anti-stripping agents at later stage. The HWTD test is more effective as a rapid test method in case of determining moisture sensitivity. Laboratory results from this study should be verified and correlated with field performance.

关键词: hot-mix asphalt     moisture sensitivity     rutting     wheel tracking test    

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    

标题 作者 时间 类型 操作

Hierarchical parameter estimation of DFIG and drive train system in a wind turbine generator

Xueping PAN, Ping JU, Feng WU, Yuqing JIN

期刊论文

Multiobjective trajectory optimization of intelligent electro-hydraulic shovel

期刊论文

Control efficiency optimization and Sobol’s sensitivity indices of MTMDs design parameters for buffeting

Nazim Abdul NARIMAN

期刊论文

Application of machine learning technique for predicting and evaluating chloride ingress in concrete

Van Quan TRAN; Van Loi GIAP; Dinh Phien VU; Riya Catherine GEORGE; Lanh Si HO

期刊论文

Dynamic prediction of moving trajectory in pipe jacking: GRU-based deep learning framework

期刊论文

Research on Anthropomorphic Obstacle Avoidance Trajectory Planning for Adaptive Driving Scenarios Based

Jian Wu,Yang Yan,Yulong Liu,Yahui Liu,

期刊论文

Research on acoustic-structure sensitivity using FEM and BEM

ZHANG Jun, ZHAO Wenzhong, ZHANG Weiying

期刊论文

decoupled framework for reliability-based design optimization of structures using a robust shifting technique

Mohammad Reza GHASEMI, Charles V. CAMP, Babak DIZANGIAN

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

Parametric sensitivity analysis of cellular diaphragm wall

Xi CHEN, Wei XU

期刊论文

Probability strength design of steam turbine blade and sensitivity analysis with respect to random parameters

DUAN Wei

期刊论文

General Optimal Trajectory Planning: Enabling Autonomous Vehicles with the Principle of Least Action

Heye Huang,Yicong Liu,Jinxin Liu,Qisong Yang,Jianqiang Wang,David Abbink,Arkady Zgonnikov,

期刊论文

Wheel tracking methods to evaluate moisture sensitivity of hot-mix asphalt mixtures

Jie HAN,Harihar Shiwakoti

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