自动控制原理期末试卷07-08B.pdf

东华大学 2007 2008 学年第二学期 终 试题 B 踏实学习 弘扬正气 诚信做人 诚实考试 作弊可耻 后果自负 踏实学习 弘扬正气 诚信做人 诚实考试 作弊可耻 后果自负 课程名称 自动控制原理 使用专业 电信 06 级 班级 姓名 学号 一 二 三 四 五 六 总分 试题 得分 1 10 judge true or false true tick false tick 1 When the parameters of a control system are stationary with respect to time during the operation of the system the system is called a time invariant system 2 For BIBO stability the roots of the characteristic equation cannot be located in the right half s plane or on the jw axis 3 Routh Hurwitz criterion is an algebraic method that provides information on the relative stability of a linear time invariant shystem 4 The time domain specifications includes Maximum overshoot Rise time Settling time and Bandwidth 5 A minimum phase system does not have poles or zeros in the right half s plane or on the jw axis excluding the origin 6 According to the Nyquist criterion N Z P for closed loop stability Z must equal zero and for open loop stability p must equal zero 7 A closed loop control system uses a measurement of the output and feedback of this signal to compare it with the desired output 8 The transfer function of a linear system is defined as the ratio of the Laplace transform of the output variable to the Laplace transform of the input variable with all initial conditions assumed to be zero 9 We called a prototype second order system critically damped when the two roots of the characteristic equation are real and equal 10 A necessary and sufficient condition for a feedback system to be stable is that all the poles of the system transfer function have negative real parts 2 10 A control system is shown in fig 2 determine the transfer function Y sE s R sR s G1G2 R s E s H1 Y s H2 Fig 2 3 20 A control system is shown in Fig 3 1 When 0 h K find the percent overshoot and settling time 2 If 0 h K and damping ratio of the system is 0 5 determine the value of h K 3 At the h K of part 2 determine the steady state error for a unit ramp input 4 Find out the unit step response y t for the h K of part 2 10 s s 1 R s 1 Khs Y s 4 20 The open loop transfer function and their polar plots for 0 to have been given as follows Using Nyquist criterion determine stability for closed loop systems respectively For unstable system find out the number of the closed loop poles on the right half splane 1 123 0 0 1 1 1 i K GH sTK TsT sT s 2 56 1234 1 1 0 0 1 1 1 1 i K T sT s GH sTK s TsT sT sT s Im Gh plane Re0 1 1 0 Im Re Gh plane 5 20 A unity feedback system has a plant 1 1 3 K s G s s ss 1 Sketch the root locus for 0K 2 Determine the range of K for the stable system 3 Show that the breakaway point is at s 0 4505 and determine the value of K at this point 6 20 The bode plot of the open loop system with unity feedback is shown in figure 6 1 Find out the open loop transfer function G1 G2 2 Determine the steady state error of G1 and