Saturday, April 4, 2020

Automatic Control Exam free essay sample

Which equation do you get by using basic correspondence and rules of Laplace transform to derive the original differential equation from transfer function a) b) c) Y ( s) 0,5s ? 1 . ? X ( s) s 2 ? 4 What are the values of characteristic equation roots? Is system described by this transfer function stable? d) s1, 2 ? 2 e) The system is stable. f) The system is on border of stability or unstable. The system is described by transfer function 0,5/(1s+0,5). What are values of time constant T and system gain K? The control loop consists from the controller and the plant. The model is stable. b) The model is unstable. c) Step response of the model is monotonic without oscillation. We will write a custom essay sample on Automatic Control Exam or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page ) Step response of the model is oscillating. e) Characteristic equation of the model is first order. f) Characteristic equation of the model is second order. a) Roots of the system are two real numbers. b) Step response of the system is monotonic without oscillation. c) Step response of the system is bounded harmonic signal. d) Characteristic equation of the system is third order. e) Roots of the system are pair of conjugate complex numbers. f) The system is stable. g) The system is unstable. h) The system is on border of stability. a) The output will be oscillating with decreasing amplitude. ) The output will be oscillating with increasing amplitude. c) The output will be the same. The origin of complex plane will be lying d) on the right from Mikhalov curve e) on the left from Mikhalov curve f) on the Mikhailov curve if Mikhailov curve of the closed control loop is passed in the direction of increasing frequencies. Model of the controlled plant has three roots of characteristic eq uation: s1=-2 s2=-1+0,5j s3=-1-0,5j Which statements about the controlled plant are true? The roots of the system are depicted in Fig 3. What can you claim about the system? Im j 0 -j Re Fig 3. The input and the output of the open control loop are depicted in Fig 4. What will be the output after closing the control loop and disconnecting the external excitation (input)? 1 ? 2? 3? 4? Input -1 1 Output -1 A) Which claims about the Hurwitz criterion are true? B) Characteristic equation of the system is third order. First two Hurwitz determinants are: D1 ? 3 D2 ? 3 1 ? 1 1 A) a) It is necessary and sufficient condition of stability b) It is necessary condition of stability and sufficient condition of stability for first and second order systems only. ) It is necessary condition of stability B) a) The system is stable. b) The system is unstable c) To decision on stability to know the value of third Hurwitz determinant is needed. a) System A is stable. b) System B is stable. c) System A is on border of stability. d) System C is on border of stability. e) System B is unstable. f) System C is unstable. Mikhailov’s plots of three systems are in Fig 5 depic ted. Which claims about the systems are true? Im Re 2nd order system -A 3rd order system B 3rd order system C Fig 5. ?