232k views
2 votes
4. (25\%) Find the transfer function of the system specified in the Bode Plot as follows: note that the horizontal axis is in the unit of radian/second. a) (5\%) Magnitude plot: Number of pole and zeros, type and DC gain. b) (5\%) Magnitude plot: Frequency of poles and zeros ( 111 order or 2nd order). c) (5\%6) Phase plot: Minimum phase or non-minimum phase. d) (5\%) Standard form of the transfer function. c) (5%) Why does the phase drop rapidly araund ω=10rad/s ?

User Adit Gupta
by
8.3k points

1 Answer

4 votes

4. To find the transfer function of the system specified in the Bode Plot, we need to analyze the information given. Let's go through each part of the question step by step:

a) Magnitude plot: The magnitude plot provides information about the number of poles and zeros, the type, and the DC gain of the system. By examining the Bode Plot, we can count the number of poles and zeros represented by the peaks and valleys in the graph. The type of the system can be determined by the number of poles and zeros, where the type is equal to the number of poles minus the number of zeros. The DC gain is the magnitude of the transfer function at low frequencies (where ω=0). By looking at the Bode Plot, we can determine the value of the DC gain.

b) Frequency of poles and zeros: The Bode Plot provides information about the frequency of poles and zeros. By examining the graph, we can determine the location of the poles and zeros along the horizontal axis, which represents the frequency in radians per second. The order of the system can be determined by counting the number of poles or zeros at the highest frequency.

c) Phase plot: The phase plot provides information about whether the system is minimum phase or non-minimum phase. A minimum phase system is one where the phase decreases as the frequency increases. A non-minimum phase system is one where the phase increases as the frequency increases. By examining the phase plot in the Bode Plot, we can determine whether the system is minimum phase or non-minimum phase.

d) Standard form of the transfer function: The standard form of the transfer function can be determined by analyzing the Bode Plot and writing down the expression for the transfer function based on the number of poles and zeros, their locations, and their magnitudes.

e) Explanation of the phase drop: The phase drop around ω=10 rad/s occurs because of the presence of poles or zeros in the transfer function at that frequency. Poles and zeros in the transfer function cause phase shifts, and when there is a pole or zero at ω=10 rad/s, it leads to a rapid drop in the phase at that frequency.

In conclusion, to find the transfer function and understand various aspects of the system specified in the Bode Plot, we need to carefully analyze the magnitude plot, frequency of poles and zeros, phase plot, and determine the standard form of the transfer function. Additionally, the phase drop around ω=10 rad/s can be explained by the presence of poles or zeros at that frequency causing a rapid drop in phase.

User Hardy Le Roux
by
7.8k points