Tham khảo tài liệu 'new approaches in automation and robotics part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Nonparametric Identification of Nonlinear Dynamics of Systems Based on the Active Experiment 143 R A2 A4 A6 A-8 Co C1 C2 Th Tn 1 2 3 4 5 6 Table 1. The coefficients A and corrector parameters C and T for the Nuttall window of 1st to 6th order. Figure 5 shows the variability of the slack variables x y and thereby the time constants T1 and T2. The minimum of function h y is for y or and consequently T2 and . The time constant T1 obtained from Equations 41 and 36 is T1 or . Because the product of the time constants and the width d of the averaging interval expressed in the samples must be integer so they have to be recalculated using the following relation Trdi round Tdi d d 42 The correction procedure of 2nd order corresponds to the change of the basic window spectrum to the following form Gz G o Gk G o Introducing the auxiliary variable 2 C0 V Ci cos Ti i 1 the definition 15 can be rewritten in the following form 43 44 G Q d fg u cosi Q u du 45 and the spectrum of the corrected window assumes the form GZ Q 4 zV d C0 E Ci cos Tui f g u cos Q u du i 1 J 0 46 The relation 46 allows to obtain the maximum normalised frequency t A which can be transferred with the assumed accuracy a through the corrected window solving the following equation a 1 - Gz Q 47 The evaluation of the corrector parameters Ci and Ti should be done on the basis of two criteria the minimisation of the deviation G jQ from 1 in the pass band and the magnitude n v u - - 2 d 144 New Approaches in Automation and Robotics QnG jQ in the stop band. The application of the procedures is a trial of the window approach to the ideal window with wall .
