A Novel Adaptive Kalman Filter Based on Credibility Measure

It is quite often that the theoretic model used in the Kalman filtering may not be sufficiently accurate for practical applications,due to the fact that the covariances of noises are not exactly known.Our previous work reveals that in such scenario the filter calculated mean square errors(FMSE)and the true mean square errors(TMSE)become inconsistent,while FMSE and TMSE are consistent in the Kalman filter with accurate models.This can lead to low credibility of state estimation regardless of using Kalman filters or adaptive Kalman filters.Obviously,it is important to study the inconsistency issue since it is vital to understand the quantitative influence induced by the inaccurate models.Aiming at this,the concept of credibility is adopted to discuss the inconsistency problem in this paper.In order to formulate the degree of the credibility,a trust factor is constructed based on the FMSE and the TMSE.However,the trust factor can not be directly computed since the TMSE cannot be found for practical applications.Based on the definition of trust factor,the estimation of the trust factor is successfully modified to online estimation of the TMSE.More importantly,a necessary and sufficient condition is found,which turns out to be the basis for better design of Kalman filters with high performance.Accordingly,beyond trust factor estimation with Sage-Husa technique(TFE-SHT),three novel trust factor estimation methods,which are directly numerical solving method(TFE-DNS),the particle swarm optimization method(PSO)and expectation maximization-particle swarm optimization method(EM-PSO)are proposed.The analysis and simulation results both show that the proposed TFE-DNS is better than the TFE-SHT for the case of single unknown noise covariance.Meanwhile,the proposed EMPSO performs completely better than the EM and PSO on the estimation of the credibility degree and state when both noise covariances should be estimated online.

The influence of calculation error of hourly marine meteorological parameter on building energy consumption calculation

The ocean is a crucial area for future economic development.The marine environment has high energy-efficient and ecological requirements for building construction.Meteorological parameters are the key basis for the analysis and design of building energy efficiency.The lack of meteorological parameters for energy efficiency,particularly hourly data,under oceanic climatic conditions is a universal problem.The appropriate calculation methods of hourly meteorological parameters under oceanic climatic conditions are explored in this study.The impact of the calculation errors of the hourly meteorological parameters on building energy consumption is also analyzed.Three key meteorological parameters are selected:temperature,humidity,and wind speed.Five hourly calculations methods,including linear interpolation,cubic spline interpolation,pieceated three-Hermite interpolation,Akima interpolation,and radial basis function interpolation,are selected to calculate the error of the difference method,with Xiamen,Haikou,and Sanya as the locations of meteorological research.Appropriate interpolation methods are selected for the three parameters,and the seasonal and regional characteristics of the errors of each parameter are compared.Different interpolation methods should be selected for different meteorological parameters in different seasons.The error data of the three parameters of different magnitudes are constructed.A quantitative relationship between the sum of squares due to error of the three meteorological parameters and the rate of change of cooling energy consumption is established.The hourly calculation errors of meteorological parameters have an important impact on the calculation of dynamic energy consumption.The energy consumption differences caused by the errors of different parameters are significant.Obvious regional and seasonal differences also exist.This research strengthens the research foundation of building energy consumption calculation under oceanic climate conditions.

An effective timing characterization method for an accuracy-proved VLSI standard cell library

This paper presents a method of tailoring the characterization and modeling timing of a VLSI standard cell library. The paper also presents a method to validate the reasonability of the value through accuracy analysis. In the process of designing a standard cell library, this method is applied to characterize the cell library. In addition, the error calculations of some simple circuit path delays are compared between using the characterization file and an Hspice simulation. The comparison results demonstrate the accuracy of the generated timing library file.