DEVICE AND METHOD FOR ESTIMATING CLOSEST APPROACH ORBIT

摘要

PROBLEM TO BE SOLVED: To estimate an approach orbit fast with ease. SOLUTION: A signal measurement part 2 measures the brain waves of an examinee who has electrodes stuck and closes the eyes. Then a data input part 2 after filtering only a signal of theα-wave band at a time-series signal preprocessing part having an amplifying circuit having a cutoff frequency of 24 kHz digitizes an analog signal into a 16-bit digital signal at a sampling frequency of 12 kHz and inputs the signal to a data holding part 3. An arithmetic processing part 4 finds a series *x of dots forming a part of an orbit by embedding a signal in a 5-dimensional phase space atτ=0.03 second by an orbit generation part 6. A closest approach orbit estimation part 6 finds the closest approach orbit from the series *x of dots and a maximum Lyapunov number estimation part 7 computes the largest Lyapunov number. The result is stored in a database in an external storage part 8, printed on paper by a printing part 9, and displayed on a display by a display part 10.