This paper, with the use of Fourier transform and the filtering theory of linear timeinvariant system, reaches a conclusion that there are high-pass filter characteristicsin derivative and low-pass filter characterist...This paper, with the use of Fourier transform and the filtering theory of linear timeinvariant system, reaches a conclusion that there are high-pass filter characteristicsin derivative and low-pass filter characteristics in integration after analysising fromthe view point of filtering. On the basis above, the author explores the numericalalgorithm of calculus-FFT algorithms and its adaptable condition by combining thesampling theorem of time with frequency domain, which is popularized to the numericalcomputation (NC) of non-integral-order calculus. The analysis and results of NC showthat the algorithm is convenient, fast, and applicable for the NC of low-order calculus,and specially suited to the engineering computation. It will aid in the NC, practicalutilization and error analysis of non-integer-order calculus.展开更多
Two new methods, the generalized Levy method and the weighted iteration method, are presented for identification of non-integer order systems. The first method generalizes the Levy identification method from the integ...Two new methods, the generalized Levy method and the weighted iteration method, are presented for identification of non-integer order systems. The first method generalizes the Levy identification method from the integer order systems to the non-integer order systems. Then, the weighted iteration method is presented to overcome the shortcomings of the first method. Results show that the proposed methods have better performance compared with the integer order identification method. For the non-integer order systems, the proposed methods have the better fitting for the system frequency response. For the integer order system, if commensurate order scanning is applied, the proposed methods can also achieve the best integer order model which fits the system frequency response. At the same time, the proposed algorithms are more stable.展开更多
文摘This paper, with the use of Fourier transform and the filtering theory of linear timeinvariant system, reaches a conclusion that there are high-pass filter characteristicsin derivative and low-pass filter characteristics in integration after analysising fromthe view point of filtering. On the basis above, the author explores the numericalalgorithm of calculus-FFT algorithms and its adaptable condition by combining thesampling theorem of time with frequency domain, which is popularized to the numericalcomputation (NC) of non-integral-order calculus. The analysis and results of NC showthat the algorithm is convenient, fast, and applicable for the NC of low-order calculus,and specially suited to the engineering computation. It will aid in the NC, practicalutilization and error analysis of non-integer-order calculus.
文摘Two new methods, the generalized Levy method and the weighted iteration method, are presented for identification of non-integer order systems. The first method generalizes the Levy identification method from the integer order systems to the non-integer order systems. Then, the weighted iteration method is presented to overcome the shortcomings of the first method. Results show that the proposed methods have better performance compared with the integer order identification method. For the non-integer order systems, the proposed methods have the better fitting for the system frequency response. For the integer order system, if commensurate order scanning is applied, the proposed methods can also achieve the best integer order model which fits the system frequency response. At the same time, the proposed algorithms are more stable.
