Fuzzy Approximation of DES State

2011 ◽  
pp. 677-687
Author(s):  
Juan Carlos González-Castolo ◽  
Ernesto López-Mellado
Keyword(s):  
State Estimation ◽  
Petri Net ◽  
Current System ◽  
Discrete Event ◽  
The State ◽  
System State ◽  
State Monitoring ◽  
Cyclic Behaviour ◽  
Strongly Connected ◽  
Marked Graph

State estimation of dynamic systems is a resort often used when only a subset of the state variables can be directly measured; observers are the entities computing the system state from the knowledge of its internal structure and its (partially) measured behaviour. The problem of discrete event systems (DES) estimation has been addressed in (Ramirez, 2003) and (Giua 2003); in these works the marking of a Petri net (PN) model of a partially observed event driven system is computed from the evolution of its inputs and outputs. The state of a system can be also inferred using the knowledge on the duration of activities. However this task becomes complex when, besides the absence of sensors, the durations of the operations are uncertain; in this situation the observer obtains and revise a belief that approximates the current system state. Consequently this approach is useful for non critical applications of state monitoring and feedback in which an approximate computation is allows. The uncertainty of activities duration in DES can be handled using fuzzy PN (FPN) (Murata, 1996), (Cardoso, 1999), (Hennequin, 2001), (Pedrycz, 2003), (Ding, 2005); this PN extension has been applied to knowledge modelling (Chen, 1990), (Koriem, 2000), (Shen, 2003), planning (Cao, 1996), reasoning (Gao, 2003) and controller design (Andreu, 1997), (Leslaw, 2004). In these works the proposed techniques include the computation of imprecise markings; however the class of models dealt does not include strongly connected PN for the modelling of cyclic behaviour. In this article we address the problem of state estimation of DES for calculating the fuzzy marking of a Fuzzy Timed Petri Net (FTPN); for this purpose a set of matrix expressions for the recursive computing the current fuzzy marking is developed. The article focuses on FTPN whose structure is a Marked Graph (called Fuzzy Timed Marked Graph -FTMG) because it allows showing intuitively the problems of the marking estimation in exhibiting cyclic behaviour.

State Estimation of Power System Based on Taylor Series Method

2014 ◽  
Vol 960-961 ◽  
pp. 1039-1042
Author(s):  
Gui Hua Lin ◽  
Yu Ying Wang ◽  
Tao Wang
Keyword(s):  
Power System ◽  
State Estimation ◽  
Taylor Series ◽  
Calculation Method ◽  
Measurement Data ◽  
The State ◽  
System State ◽  
Series Method ◽  
State Time ◽  
Taylor Series Method

Take full advantage of the PMU's accurate mass measurement data is the effective method to improve the calculation accuracy of power system state estimation. This essay puts forward the state estimation method of power system based on the Taylor series method. It analysis of power system operating conditions based on the real-time measurement of Wide area measurement system, divides the state time, establishes the equation of state of the measurement data by curve fitting method in the period of state time, creates a new state estimation calculation method by Taylor series method, constructs a new voltage characteristic curve calculation method, determines the system state and achieve the continuity of power systems steady-state analysis. The method put forward in this essay has been verified through IEEE-30 Node System, and the efficiency of it has been fully proved by the example results.

Weight Set of State Estimation Based on Partition

2013 ◽  
Vol 347-350 ◽  
pp. 2077-2081
Author(s):  
Jia Yi Zang
Keyword(s):  
Power System ◽  
State Estimation ◽  
Great Influence ◽  
Local Area ◽  
The State ◽  
Estimation Result ◽  
System State ◽  
Power System State Estimation ◽  
Accuracy Of Measurement ◽  
Bad Data

In power system state estimation, bad data of local area can make state estimation difficult, and accuracy of measurement can also have great influence on the result of state estimation. Based on grid partition, this paper forms a lot of independent sub area, then measurement weights are adjusted using the state estimation result of sub area. This overcomes the defects of uniform weights distribution, and improves the accuracy of state estimation

scholarly journals Particle filter in power system state estimation – bad measurement data and branch disconnection

2015 ◽  
Vol 64 (2) ◽  
pp. 237-248
Author(s):  
Piotr Kozierski ◽  
Marcin Lis ◽  
Adam Owczarkowski ◽  
Dariusz Horla
Keyword(s):  
Power System ◽  
Particle Filter ◽  
State Estimation ◽  
Measurement Data ◽  
The State ◽  
Filter Method ◽  
System State ◽  
State Variables ◽  
Zero Bias ◽  
Power System State Estimation

Abstract An approach to power system state estimation using a particle filter has been proposed in the paper. Two problems have been taken into account during research, namely bad measurements data and a network structure modification with rapid changes of the state variables. For each case the modification of the algorithm has been proposed. It has also been observed that anti-zero bias modification has a very positive influence on the obtained results (few orders of magnitude, in comparison to the standard particle filter), and additional calculations are quite symbolic. In the second problem, used modification also improved estimation quality of the state variables. The obtained results have been compared to the extended Kalman filter method

scholarly journals A Nonlinear System State Estimation Method Based on Adaptive Fusion of Multiple Kernel Functions

Complexity ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Daxing Xu ◽  
Aiyu Hu ◽  
Xuelong Han ◽  
Lu Zhang
Keyword(s):  
Neural Network ◽  
State Estimation ◽  
Estimation Method ◽  
Kernel Functions ◽  
The State ◽  
System State ◽  
Multiple Kernel ◽  
Cubature Kalman Filter ◽  
Adaptive Fusion ◽  
High Degree

With the development of the industry, the physical model of controlled object tends to be complicated and unknown. It is particularly important to estimate the state variables of a nonlinear system when the model is unknown. This paper proposes a state estimation method based on adaptive fusion of multiple kernel functions to improve the accuracy of system state estimation. First, a dynamic neural network is used to build the system state model, where the kernel function node is constructed by a weighted linear combination of multiple local kernel functions and global kernel functions. Then, the state of the system and the weight of the kernel functions are put together to form an augmented state vector, which can be estimated in real time by using high-degree cubature Kalman filter. The high-degree cubature Kalman filter performs adaptive fusion of the kernel function weights according to specific samples, which makes the neural network function approximate the real system model, and the state estimate follows the real value. Finally, the simulation results verify the feasibility and effectiveness of the proposed algorithm.

TEMPERATURE MODELS FOR GRINDING SYSTEM STATE MONITORING

2019 ◽  
Vol 2 (3) ◽  
pp. 216-229
Author(s):  
Vasily Larshin ◽  
Natalia Lishchenko
Keyword(s):  
System State ◽  
State Monitoring ◽  
Grinding System

Is This the Care We Need?: An Examination of Childcare Policy in Pennsylvania

Commonwealth ◽  
2017 ◽  
Vol 19 (2) ◽  
Author(s):  
Jennie Sweet-Cushman ◽  
Ashley Harden
Keyword(s):  
United States ◽  
Child Care ◽  
Current System ◽  
The United States ◽  
The State ◽  
Federal State ◽  
Women And Politics ◽  
Richard Nixon ◽  
State And Local ◽  
Childcare Policy

For many families across Pennsylvania, child care is an ever-present concern. Since the 1970s, when Richard Nixon vetoed a national childcare program, child care has received little time in the policy spotlight. Instead, funding for child care in the United States now comes from a mixture of federal, state, and local programs that do not help all families. This article explores childcare options available to families in the state of Pennsylvania and highlights gaps in the current system. Specifically, we examine the state of child care available to families in the Commonwealth in terms of quality, accessibility, flexibility, and affordability. We also incorporate survey data from a nonrepresentative sample of registered Pennsylvania voters conducted by the Pennsylvania Center for Women and Politics. As these results support the need for improvements in the current childcare system, we discuss recommendations for the future.

Analyzing the State Estimation Software Package Reliability Using the Fault Tree Technology

2018 ◽  
Vol 6 (6) ◽  
pp. 24-34
Author(s):  
Irina N. KOLOSOK ◽  
◽  
Elena S. KORKINA ◽  
Alexandr V. TIKHONOV ◽  
◽  
...  
Keyword(s):  
State Estimation ◽  
Software Package ◽  
Fault Tree ◽  
The State ◽  
Package Reliability

Review of research in the field of hygiene safety of recreational and drinking water use of the population of the Top Don basin

2020 ◽  
pp. 63-72
Author(s):  
Igor Mekhantiev
Keyword(s):  
Drinking Water ◽  
Water Use ◽  
Current System ◽  
Water Supply Systems ◽  
State Monitoring ◽  
Scientific Publications ◽  
Chemical Indicators ◽  
State Of Water ◽  
Supply Systems ◽  
Regional Problems

The article provides an overview of regional studies addressing the hygienic safety of recreational and drinking water use of the population of the Upper Don basin, conducted on the territory of the Voronezh region. The results of dissertation research for 1997–2019 and materials of modern scientific publications on the studied problem for 2015–2019, showing priority regional problems of water use of the population of the Upper Don Basin are considered. The data of scientific and practical work and state monitoring on the inconsistency of water quality with current standards in places of recreation at water bodies and drinking water of centralized water supply systems for sanitary and chemical indicators and microbiological safety indicators are presented. A description of the current system for monitoring the state of water resources is presented and attention is drawn to the need for its improvement.

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