Time-Domain Analysis of Systems Continuous Time 8/2/13 M. J. Roberts - All Rights Reserved 2 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 3 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 4 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 5 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 6 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 7 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 8 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 9 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 10 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 11 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 12 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 13 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 14 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 15 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 16 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 17 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 18 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 19 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 20 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 21 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 22 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 23 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 24 The Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 25 A Graphical Illustration of the Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 26 A Graphical Illustration of the Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 27 A Graphical Illustration of the Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 28 A Graphical Illustration of the Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 29 A Graphical Illustration of the Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 30 A Graphical Illustration of the Convolution Integral The process of convolving to find y(t) is illustrated below. 8/2/13 M. J. Roberts - All Rights Reserved 31 A Graphical Illustration of the Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 32 A Graphical Illustration of the Convolution Integral 8/2/13 M. J. Roberts - All Rights Reserved 33 Convolution Example 8/2/13 M. J. Roberts - All Rights Reserved 34 Convolution Example 8/2/13 M. J. Roberts - All Rights Reserved 35 Convolution Integral Properties 8/2/13 M. J. Roberts - All Rights Reserved 36 The Unit Triangle Function The unit triangle, is the convolution of a unit rectangle with Itself. *8/2/13 M. J. Roberts - All Rights Reserved 37 System Interconnections If the output signal from a system is the input signal to a second system the systems are said to be cascade connected. It follows from the associative property of convolution that the impulse response of a cascade connection of LTI systems is the convolution of the individual impulse responses of those systems. 8/2/13 M. J. Roberts - All Rights Reserved 38 System Interconnections If two systems are excited by the same signal and their responses are added they are said to be parallel connected. It follows from the distributive property of convolution that the impulse response of a parallel connection of LTI systems is the sum of the individual impulse responses. 8/2/13 M. J. Roberts - All Rights Reserved 39 Unit Impulse Response and Unit Step Response 8/2/13 M. J. Roberts - All Rights Reserved 40 Stability and Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 41 Systems Described by Differential Equations 8/2/13 M. J. Roberts - All Rights Reserved 42 Systems Described by Differential Equations 8/2/13 M. J. Roberts - All Rights Reserved 43 Systems Described by Differential Equations 8/2/13 M. J. Roberts - All Rights Reserved 44 Systems Described by Differential Equations 8/2/13 M. J. Roberts - All Rights Reserved 45 MATLAB System Objects 8/2/13 M. J. Roberts - All Rights Reserved 46 MATLAB System Objects 8/2/13 M. J. Roberts - All Rights Reserved 47 Discrete Time 8/2/13 M. J. Roberts - All Rights Reserved 48 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 49 Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 50 Impulse Response Example 8/2/13 M. J. Roberts - All Rights Reserved 51 Impulse Response Example 8/2/13 M. J. Roberts - All Rights Reserved 52 Impulse Response Example 8/2/13 M. J. Roberts - All Rights Reserved 53 Impulse Response Example 8/2/13 M. J. Roberts - All Rights Reserved 54 Impulse Response Example 8/2/13 M. J. Roberts - All Rights Reserved 55 Impulse Response Example 8/2/13 M. J. Roberts - All Rights Reserved 56 System Response • Once the response to a unit impulse is known, the response of any LTI system to any arbitrary excitation can be found • Any arbitrary excitation is simply a sequence of amplitude-scaled and time-shifted impulses • Therefore the response is simply a sequence of amplitude-scaled and time-shifted impulse responses 8/2/13 M. J. Roberts - All Rights Reserved 57 Simple System Response Example 8/2/13 M. J. Roberts - All Rights Reserved 58 More Complicated System Response Example System Excitation System Impulse Response System Response 8/2/13 M. J. Roberts - All Rights Reserved 59 The Convolution Sum 8/2/13 M. J. Roberts - All Rights Reserved 60 A Convolution Sum Example 8/2/13 M. J. Roberts - All Rights Reserved 61 A Convolution Sum Example 8/2/13 M. J. Roberts - All Rights Reserved 62 A Convolution Sum Example 8/2/13 M. J. Roberts - All Rights Reserved 63 Convolution Sum Properties 8/2/13 M. J. Roberts - All Rights Reserved 64 Convolution Sum Properties (continued) 8/2/13 M. J. Roberts - All Rights Reserved 65 Numerical Convolution 8/2/13 M. J. Roberts - All Rights Reserved 66 Numerical Convolution 8/2/13 M. J. Roberts - All Rights Reserved 67 Numerical Convolution 8/2/13 M. J. Roberts - All Rights Reserved 68 Numerical Convolution 8/2/13 M. J. Roberts - All Rights Reserved 69 Numerical Convolution 8/2/13 M. J. Roberts - All Rights Reserved 70 Stability and Impulse Response 8/2/13 M. J. Roberts - All Rights Reserved 71 System Interconnections The cascade connection of two systems can be viewed as a single system whose impulse response is the convolution of the two individual system impulse responses. This is a direct consequence of the associativity property of convolution. 8/2/13 M. J. Roberts - All Rights Reserved 72 System Interconnections The parallel connection of two systems can be viewed as a single system whose impulse response is the sum of the two individual system impulse responses. This is a direct consequence of the distributivity property of convolution. 8/2/13 M. J. Roberts - All Rights Reserved 73 Unit Impulse Response and Unit Sequence Response 8/2/13 M. J. Roberts - All Rights Reserved 74 Systems Described by Difference Equations 8/2/13 M. J. Roberts - All Rights Reserved 75 Systems Described by Difference Equations 8/2/13 M. J. Roberts - All Rights Reserved 76 Frequency Response 8/2/13 M. J. Roberts - All Rights Reserved 77 Frequency Response 8/2/13 M. J. Roberts - All Rights Reserved 78 Frequency Response Example 8/2/13 M. J. Roberts - All Rights Reserved 79 Frequency Response Example 8/2/13 M. J. Roberts - All Rights Reserved 80 8/2/13 M. J. Roberts - All Rights Reserved 81 8/2/13 M. J. Roberts - All Rights Reserved 82 8/2/13 M. J. Roberts - All Rights Reserved 83 8/2/13 M. J. Roberts - All Rights Reserved 84 8/2/13 M. J. Roberts - All Rights Reserved 85 8/2/13 M. J. Roberts - All Rights Reserved 86 8/2/13 M. J. Roberts - All Rights Reserved 87 8/2/13 M. J. Roberts - All Rights Reserved 88 8/2/13 M. J. Roberts - All Rights Reserved 89