针对Robo Cup Rescue救援机器人项目中操控灵活性的比赛要求,提出了一种对目标物进行快速简单位姿估计的方法,通过准确估计出目标物的位姿,实现救援机器人机械臂的灵活操控。该方法首先通过图像配准获取目标物在相机坐标系下的点云;然...针对Robo Cup Rescue救援机器人项目中操控灵活性的比赛要求,提出了一种对目标物进行快速简单位姿估计的方法,通过准确估计出目标物的位姿,实现救援机器人机械臂的灵活操控。该方法首先通过图像配准获取目标物在相机坐标系下的点云;然后运用基于4个不共面的特征点的P4P方法估计相机位姿;最后采用稳定特征值法、向量法确定目标物的姿态和均值法确定位置。实验结果表明,位姿估计算法具有较高精度和准确性,能够满足操控灵活性要求。展开更多
This paper presents the application of bifurcation method on the steady state three-phase load-flow Jacobian method to study the voltage stability of unbalanced distribution systems. The eigenvalue analysis is used to...This paper presents the application of bifurcation method on the steady state three-phase load-flow Jacobian method to study the voltage stability of unbalanced distribution systems. The eigenvalue analysis is used to study distribution system behavior under different operating conditions. Two-bus connected by asymmetrical line is used as the study system. The effects of both unbalance and extreme loading conditions are investigated. Also, the impact of distributed energy resources is studied. Different case studies and loading scenarios are presented to trace the eigenvalues of the Jacobian matrix. The results exhibit the existence of a new bifurcation point which may not be related to the voltage stability.展开更多
The eigenvalues analysis method is generally applied to synchronous machines by using d, q-components. This paper presents the application of this method on an equivalent model for the synchronous machine based on pha...The eigenvalues analysis method is generally applied to synchronous machines by using d, q-components. This paper presents the application of this method on an equivalent model for the synchronous machine based on phase variables a, b, c instead of d, q-components. The advantages of this approach, essential for programs using phase variables as state variables, are presented. The application of this method to a complete hydroelectric production site including hydraulic components （pump-turbine, penstock, gallery, reservoir...） permits the study and analysis of the interactions between the hydraulic, electric and regulation parts of the system. Results coming from the proposed eigenvalues analysis method and the numerical simulations confirm the interest of the presented approach.展开更多
Calculation of eigen-solutions plays an important role in the small signal stability analysis of power systems.In this paper,a novel approach based on matrix perturbation theory is proposed for the calculation of eige...Calculation of eigen-solutions plays an important role in the small signal stability analysis of power systems.In this paper,a novel approach based on matrix perturbation theory is proposed for the calculation of eigen-solutions in a perturbed system.Rigorous theoretical analysis is conducted on the solution of distinct,multiple,and close eigen-solutions,respectively,under perturbations of parameters.The computational flowchart of the unified solution of eigen-solutions is then proposed,aimed toward obtaining eigen-solutions of a perturbed system directly with algebraic formulas without solving an eigenvalue problem repeatedly.Finally,the effectiveness of the matrix perturbation based approach for eigen-solutions’calculation in power systems is verified by numerical examples on a two-area four-machine system.展开更多
Sensitivities of eigen-solutions to control variables play an important role in microgrid studies,such as coordinated optimal design of controllers and parameters,robust stability analysis on control variables,oscilla...Sensitivities of eigen-solutions to control variables play an important role in microgrid studies,such as coordinated optimal design of controllers and parameters,robust stability analysis on control variables,oscillation modes analysis on a system,etc.Considering the importance of sensitivities and the complexity of state matrix in a microgrid,parameter perturbations are utilized in this paper to analyze the construction characteristics of state matrix.Then,the sensitivities of eigenvalues and eigenvectors to control variables are obtained based on the first-order matrix perturbation theory,which makes the complex derivations of sensitivity formulas and repeated solutions of eigenvalue problem unnecessary.Finally,the effectiveness of the matrix perturbation based approach for sensitivity calculation in a microgrid is verified by a numerical example on a low-voltage microgrid prototype.展开更多
A computable expression of the asymptotic expansion of the return map for a degenerate singular point of a class of planar differential system is given, and hence the stability and the type of the singular point can b...A computable expression of the asymptotic expansion of the return map for a degenerate singular point of a class of planar differential system is given, and hence the stability and the type of the singular point can be decided. These results generalize the corresponding results in [Nonlinearity, 13 （2000）, p.709].展开更多
文摘针对Robo Cup Rescue救援机器人项目中操控灵活性的比赛要求,提出了一种对目标物进行快速简单位姿估计的方法,通过准确估计出目标物的位姿,实现救援机器人机械臂的灵活操控。该方法首先通过图像配准获取目标物在相机坐标系下的点云;然后运用基于4个不共面的特征点的P4P方法估计相机位姿;最后采用稳定特征值法、向量法确定目标物的姿态和均值法确定位置。实验结果表明,位姿估计算法具有较高精度和准确性,能够满足操控灵活性要求。
文摘This paper presents the application of bifurcation method on the steady state three-phase load-flow Jacobian method to study the voltage stability of unbalanced distribution systems. The eigenvalue analysis is used to study distribution system behavior under different operating conditions. Two-bus connected by asymmetrical line is used as the study system. The effects of both unbalance and extreme loading conditions are investigated. Also, the impact of distributed energy resources is studied. Different case studies and loading scenarios are presented to trace the eigenvalues of the Jacobian matrix. The results exhibit the existence of a new bifurcation point which may not be related to the voltage stability.
文摘The eigenvalues analysis method is generally applied to synchronous machines by using d, q-components. This paper presents the application of this method on an equivalent model for the synchronous machine based on phase variables a, b, c instead of d, q-components. The advantages of this approach, essential for programs using phase variables as state variables, are presented. The application of this method to a complete hydroelectric production site including hydraulic components （pump-turbine, penstock, gallery, reservoir...） permits the study and analysis of the interactions between the hydraulic, electric and regulation parts of the system. Results coming from the proposed eigenvalues analysis method and the numerical simulations confirm the interest of the presented approach.
基金supported in part by the National Science Foundation of United States(NSF)(Grant No.0844707)in part by the International S&T Cooperation Program of China(ISTCP)(Grant No.2013DFA60930)
文摘Calculation of eigen-solutions plays an important role in the small signal stability analysis of power systems.In this paper,a novel approach based on matrix perturbation theory is proposed for the calculation of eigen-solutions in a perturbed system.Rigorous theoretical analysis is conducted on the solution of distinct,multiple,and close eigen-solutions,respectively,under perturbations of parameters.The computational flowchart of the unified solution of eigen-solutions is then proposed,aimed toward obtaining eigen-solutions of a perturbed system directly with algebraic formulas without solving an eigenvalue problem repeatedly.Finally,the effectiveness of the matrix perturbation based approach for eigen-solutions’calculation in power systems is verified by numerical examples on a two-area four-machine system.
基金supported by the National Natural Science Foundation of China (Grant No. 50595412)the National Basic Research Program of China ("973" Program) (Grant No. 2009CB219700)
文摘Sensitivities of eigen-solutions to control variables play an important role in microgrid studies,such as coordinated optimal design of controllers and parameters,robust stability analysis on control variables,oscillation modes analysis on a system,etc.Considering the importance of sensitivities and the complexity of state matrix in a microgrid,parameter perturbations are utilized in this paper to analyze the construction characteristics of state matrix.Then,the sensitivities of eigenvalues and eigenvectors to control variables are obtained based on the first-order matrix perturbation theory,which makes the complex derivations of sensitivity formulas and repeated solutions of eigenvalue problem unnecessary.Finally,the effectiveness of the matrix perturbation based approach for sensitivity calculation in a microgrid is verified by a numerical example on a low-voltage microgrid prototype.
基金The work is supported by Zhejiang Provincial Natural Science Foundations(No.Y604359) National Natural Science Foundation of China (No.10371123,10471130).
文摘A computable expression of the asymptotic expansion of the return map for a degenerate singular point of a class of planar differential system is given, and hence the stability and the type of the singular point can be decided. These results generalize the corresponding results in [Nonlinearity, 13 （2000）, p.709].
