{"id":6134,"date":"2024-01-22T18:24:12","date_gmt":"2024-01-22T09:24:12","guid":{"rendered":"https:\/\/now0930.pe.kr\/wordpress\/?p=6134"},"modified":"2026-10-04T08:34:40","modified_gmt":"2026-10-03T23:34:40","slug":"nyquist-plot","status":"publish","type":"post","link":"https:\/\/now0930.pe.kr\/wordpress\/nyquist-plot\/","title":{"rendered":"Nyquist Plot"},"content":{"rendered":"\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1498\" height=\"2048\" src=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-29.png\" alt=\"\" class=\"wp-image-6139\" srcset=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-29.png 1498w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-29-768x1050.png 768w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-29-1124x1536.png 1124w\" sizes=\"auto, (max-width: 1498px) 100vw, 1498px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1498\" height=\"2048\" src=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-30.png\" alt=\"\" class=\"wp-image-6140\" srcset=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-30.png 1498w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-30-768x1050.png 768w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-30-1124x1536.png 1124w\" sizes=\"auto, (max-width: 1498px) 100vw, 1498px\" \/><\/figure>\n\n\n\n<pre class=\"wp-block-code\"><code><iframe loading=\"lazy\" src=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/Nyquist-Criterion-Example.html\" width=\"600\" height=\"800\" iframe=\"\"><\/code><\/pre><\/iframe><\/code><\/pre>\n\n\n\n<h4 class=\"wp-block-heading\">Open Loop Transfer Function Pole\uc774 \uc6d0\uc810\uc744 \uc9c0\ub098\ub294 \uacbd\uc6b0<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1322\" height=\"1063\" src=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-27.png\" alt=\"\" class=\"wp-image-6135\" srcset=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-27.png 1322w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-27-768x618.png 768w\" sizes=\"auto, (max-width: 1322px) 100vw, 1322px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1498\" height=\"2048\" src=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-31.png\" alt=\"\" class=\"wp-image-6141\" srcset=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-31.png 1498w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-31-768x1050.png 768w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-31-1124x1536.png 1124w\" sizes=\"auto, (max-width: 1498px) 100vw, 1498px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1498\" height=\"2048\" src=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-32.png\" alt=\"\" class=\"wp-image-6142\" srcset=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-32.png 1498w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-32-768x1050.png 768w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-32-1124x1536.png 1124w\" sizes=\"auto, (max-width: 1498px) 100vw, 1498px\" \/><\/figure>\n\n\n\n<h4 class=\"wp-block-heading\">Gain Margin \uad6c\ud558\ub294 \ubc29\ubc95 \uc608\uc81c<\/h4>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1319\" height=\"1057\" src=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-28.png\" alt=\"\" class=\"wp-image-6137\" srcset=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-28.png 1319w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-28-768x615.png 768w\" sizes=\"auto, (max-width: 1319px) 100vw, 1319px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1498\" height=\"2048\" src=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-33.png\" alt=\"\" class=\"wp-image-6143\" srcset=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-33.png 1498w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-33-768x1050.png 768w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-33-1124x1536.png 1124w\" sizes=\"auto, (max-width: 1498px) 100vw, 1498px\" \/><\/figure>\n\n\n\n<figure class=\"wp-block-image size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"1498\" height=\"2048\" src=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-34.png\" alt=\"\" class=\"wp-image-6144\" srcset=\"https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-34.png 1498w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-34-768x1050.png 768w, https:\/\/now0930.pe.kr\/wordpress\/wp-content\/uploads\/2024\/01\/image-34-1124x1536.png 1124w\" sizes=\"auto, (max-width: 1498px) 100vw, 1498px\" \/><\/figure>\n\n\n\n&#8220;`html\n<div class=\"chapter19-wide\">\n\n  <h1>Nyquist Plot<\/h1>\n\n  <div class=\"subtitle\">\n    Nyquist Contour \u00b7 Frequency Response \u00b7 Origin Pole \u00b7 Gain Margin \u00b7 Phase Margin\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>1. \uc608\uc81c: G(s) = 1\/(s+1)\u00b2<\/h2>\n\n  <div class=\"card\">\n\n    <div class=\"formula\">\n      G(s)\n      =\n      1\/(s+1)<sup>2<\/sup>\n    <\/div>\n\n    <p>\n      Frequency response\ub97c \uad6c\ud558\uae30 \uc704\ud574\n    <\/p>\n\n    <div class=\"formula\">\n      s = j\u03c9\n    <\/div>\n\n    <p>\n      \ub97c \ub300\uc785\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      G(j\u03c9)\n      =\n      1\/(j\u03c9+1)<sup>2<\/sup>\n    <\/div>\n\n    <p>\n      \ubd84\ubaa8\ub97c \uc804\uac1c\ud558\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      G(j\u03c9)\n      =\n      1\/(1-\u03c9<sup>2<\/sup>+j2\u03c9)\n    <\/div>\n\n    <p>\n      \ucf24\ub808\ubcf5\uc18c\uc218\ub97c \uacf1\ud558\uc5ec \uc2e4\uc218\ubd80\uc640 \ud5c8\uc218\ubd80\ub85c \uc815\ub9ac\ud558\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      G(j\u03c9)\n      =\n      [(1-\u03c9<sup>2<\/sup>) &#8211; j2\u03c9]\n      \/\n      [(1-\u03c9<sup>2<\/sup>)<sup>2<\/sup> + 4\u03c9<sup>2<\/sup>]\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>2. Magnitude\uc640 Phase<\/h2>\n\n  <div class=\"card\">\n\n    <div class=\"formula\">\n      |G(j\u03c9)|\n      =\n      1\n      \/\n      \u221a{\n      (1-\u03c9<sup>2<\/sup>)<sup>2<\/sup>\n      +\n      4\u03c9<sup>2<\/sup>\n      }\n    <\/div>\n\n    <div class=\"formula\">\n      \u2220G(j\u03c9)\n      =\n      tan<sup>-1<\/sup>\n      [\n      -2\u03c9\/(1-\u03c9<sup>2<\/sup>)\n      ]\n    <\/div>\n\n    <p>\n      \u03c9=0\uc5d0\uc11c\n    <\/p>\n\n    <div class=\"formula\">\n      |G(j0)| = 1\n    <\/div>\n\n    <div class=\"formula\">\n      \u2220G(j0) = 0\u00b0\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c Nyquist plot\uc740\n      \uc2e4\uc218\ucd95\uc758\n    <\/p>\n\n    <div class=\"formula\">\n      1 + j0\n    <\/div>\n\n    <p>\n      \uc5d0\uc11c \uc2dc\uc791\ud55c\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>3. \u03c9 \u2192 \u221e<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \u03c9\uac00 \ub9e4\uc6b0 \ucee4\uc9c0\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      |G(j\u03c9)|\n      \u2248\n      1\/\u03c9<sup>2<\/sup>\n      \u2192\n      0\n    <\/div>\n\n    <p>\n      \uc774\ubbc0\ub85c Nyquist plot\uc740 \uc6d0\uc810\uc73c\ub85c \uc811\uadfc\ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      \ub450 pole\uc758 \uc601\ud5a5\uc73c\ub85c \ucd1d \uc704\uc0c1\uc740\n      \ucd5c\uc885\uc801\uc73c\ub85c -180\u00b0 \ubc29\ud5a5\uc73c\ub85c \uc811\uadfc\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"memory\">\n      <strong>\n        G(s)=1\/(s+1)\u00b2\uc758 Nyquist plot\uc740\n        1+j0\uc5d0\uc11c \uc2dc\uc791\ud558\uc5ec\n        \ud558\ubc18\ud3c9\uba74\uc744 \uc9c0\ub098 \uc6d0\uc810\uc73c\ub85c \uc811\uadfc\ud558\uace0,\n        \uc74c\uc758 \uc8fc\ud30c\uc218 \uc601\uc5ed\uc740 \uc2e4\uc218\ucd95\uc5d0 \ub300\ud55c \ub300\uce6d\uc73c\ub85c \ub098\ud0c0\ub09c\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>4. \u03c9 = 1\uc5d0\uc11c\uc758 \uac12<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \u03c9=1\uc744 \ub300\uc785\ud558\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      G(j)\n      =\n      1\/(j+1)<sup>2<\/sup>\n    <\/div>\n\n    <div class=\"formula\">\n      =\n      1\/(j2)\n    <\/div>\n\n    <div class=\"formula\">\n      =\n      -j\/2\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c\n    <\/p>\n\n    <div class=\"formula\">\n      |G(j)| = 1\/2\n    <\/div>\n\n    <div class=\"formula\">\n      \u2220G(j) = -90\u00b0\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>\n        Nyquist plot\uc740 \u03c9=1\uc5d0\uc11c\n        -j0.5 \uc9c0\uc810\uc744 \ud1b5\uacfc\ud55c\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>5. \uc6d0\uc810\uc5d0 Pole\uc774 \uc788\ub294 \uacbd\uc6b0<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \uc6d0\ubb38 \uc608\uc81c\uc5d0\uc11c\ub294\n      open-loop transfer function\uc758 pole\uc774\n      \uc6d0\uc810\uc5d0 \uc874\uc7ac\ud558\ub294 \uacbd\uc6b0\ub97c \ub2e4\ub8ec\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      G(s)\n      =\n      (s+2)\/s<sup>2<\/sup>\n    <\/div>\n\n    <p>\n      \uc774 \uacbd\uc6b0 Nyquist contour\uac00\n      \uc6d0\uc810\uc758 pole\uc744 \uc9c1\uc811 \uc9c0\ub098\uac08 \uc218 \uc5c6\ub2e4.\n    <\/p>\n\n    <p>\n      \ub530\ub77c\uc11c s-plane\uc5d0\uc11c \uc6d0\uc810\uc744\n      \uc791\uc740 \ubc18\uc6d0\uc73c\ub85c \uc6b0\ud68c\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      s\n      =\n      \u03b5e<sup>j\u03b8<\/sup>\n    <\/div>\n\n    <p>\n      \uc5ec\uae30\uc11c\n    <\/p>\n\n    <div class=\"formula\">\n      \u03b5 \u2192 0\n    <\/div>\n\n    <p>\n      \uc774\ub2e4.\n    <\/p>\n\n    <div class=\"warning\">\n      <strong>\n        Nyquist contour \uc704\uc5d0 pole\uc774 \uc874\uc7ac\ud558\uba74\n        \uadf8 pole\uc744 \uc791\uc740 \ubc18\uc6d0\uc73c\ub85c \uc6b0\ud68c\ud574\uc57c \ud55c\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>6. \uc6d0\uc810 Pole \uc6b0\ud68c \uacbd\ub85c\uc758 Mapping<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \uc6d0\uc810 \ubd80\uadfc\uc5d0\uc11c\ub294\n    <\/p>\n\n    <div class=\"formula\">\n      G(s)\n      =\n      (s+2)\/s<sup>2<\/sup>\n    <\/div>\n\n    <p>\n      \uc5d0\n    <\/p>\n\n    <div class=\"formula\">\n      s = \u03b5e<sup>j\u03b8<\/sup>\n    <\/div>\n\n    <p>\n      \ub97c \ub300\uc785\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      G(s)\n      =\n      [\u03b5e<sup>j\u03b8<\/sup>+2]\n      \/\n      [\u03b5\u00b2e<sup>j2\u03b8<\/sup>]\n    <\/div>\n\n    <p>\n      \u03b5\u21920\uc774\uba74 \ubd84\uc790\uc758 2\uac00 \uc9c0\ubc30\uc801\uc774\ubbc0\ub85c\n    <\/p>\n\n    <div class=\"formula\">\n      G(s)\n      \u2248\n      2\n      \/\n      [\u03b5\u00b2e<sup>j2\u03b8<\/sup>]\n    <\/div>\n\n    <div class=\"formula\">\n      =\n      (2\/\u03b5\u00b2)e<sup>-j2\u03b8<\/sup>\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c\n    <\/p>\n\n    <div class=\"formula\">\n      |G(s)| \u2192 \u221e\n    <\/div>\n\n    <div class=\"formula\">\n      \u2220G(s) = -2\u03b8\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>\n        s-plane\uc5d0\uc11c \uc6d0\uc810\uc744 \uc6b0\ud68c\ud558\ub294 \ub9e4\uc6b0 \uc791\uc740 \ubc18\uc6d0\uc740\n        GH-plane\uc5d0\uc11c\ub294 \ubb34\ud55c\ud788 \ud070 \ubc18\uc6d0\uc73c\ub85c mapping\ub41c\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>7. Nyquist Stability Criterion<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Nyquist \ud310\uc815\uc5d0\uc11c\ub294 \ub2e4\uc74c \uc138 \uac12\uc744 \uc0ac\uc6a9\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"table-wrap\">\n\n      <table>\n\n        <thead>\n          <tr>\n            <th>\uae30\ud638<\/th>\n            <th>\uc758\ubbf8<\/th>\n          <\/tr>\n        <\/thead>\n\n        <tbody>\n\n          <tr>\n            <td>P<\/td>\n            <td>Open-loop transfer function\uc758 RHP pole \uac1c\uc218<\/td>\n          <\/tr>\n\n          <tr>\n            <td>N<\/td>\n            <td>Nyquist plot\uc774 -1\uc810\uc744 \ub458\ub7ec\uc2f8\ub294 \ud69f\uc218<\/td>\n          <\/tr>\n\n          <tr>\n            <td>Z<\/td>\n            <td>Closed-loop characteristic equation\uc758 RHP zero \uac1c\uc218<\/td>\n          <\/tr>\n\n        <\/tbody>\n\n      <\/table>\n\n    <\/div>\n\n    <div class=\"formula\">\n      Z = P + N\n    <\/div>\n\n    <p>\n      \uc5ec\uae30\uc11c N\uc758 \ubd80\ud638\ub294 \uc0ac\uc6a9\ud558\ub294\n      encirclement \ubc29\ud5a5 \uc815\uc758\uc5d0 \ub530\ub77c \ub2ec\ub77c\uc9c8 \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"memory\">\n      <strong>\n        Closed-loop \uc548\uc815\uc870\uac74\uc740\n        Z=0\uc774 \ub418\ub3c4\ub85d -1\uc810\uc758 encirclement \uc218\uac00 \uacb0\uc815\ub418\ub294 \uac83\uc774\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>8. Gain Margin \uc608\uc81c<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \uc6d0\ubb38 \uc608\uc81c\uc758 open-loop transfer function\uc740\n    <\/p>\n\n    <div class=\"formula\">\n      G(s)\n      =\n      K\n      \/\n      [s(s+3)(s+5)]\n    <\/div>\n\n    <p>\n      \uc774\ub2e4.\n    <\/p>\n\n    <p>\n      \uba3c\uc800 K=1\ub85c \ub450\uace0 Nyquist plot\uc744 \uadf8\ub9b0\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      G(j\u03c9)\n      =\n      1\n      \/\n      [j\u03c9(j\u03c9+3)(j\u03c9+5)]\n    <\/div>\n\n    <p>\n      \uc815\ub9ac\ud558\uba74 \uc6d0\ubb38\uc5d0\uc11c\ub294\n    <\/p>\n\n    <div class=\"formula\">\n      G(j\u03c9)\n      =\n      [-8\u03c9<sup>2<\/sup> &#8211; j(15\u03c9-\u03c9<sup>3<\/sup>)]\n      \/\n      [64\u03c9<sup>4<\/sup> + \u03c9<sup>2<\/sup>(15-\u03c9<sup>2<\/sup>)<sup>2<\/sup>]\n    <\/div>\n\n    <p>\n      \ub85c \ub098\ud0c0\ub0b8\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>9. Negative Real Axis \uad50\uc810<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Nyquist plot\uc774 \uc74c\uc758 \uc2e4\uc218\ucd95\uacfc \ub9cc\ub098\ub294 \uc9c0\uc810\uc5d0\uc11c\ub294\n      imaginary part\uac00 0\uc774\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      15\u03c9 &#8211; \u03c9<sup>3<\/sup> = 0\n    <\/div>\n\n    <div class=\"formula\">\n      \u03c9(15-\u03c9<sup>2<\/sup>) = 0\n    <\/div>\n\n    <p>\n      \u03c9\u22600\uc778 \uad50\uc810\uc740\n    <\/p>\n\n    <div class=\"formula\">\n      \u03c9\n      =\n      \u221a15\n    <\/div>\n\n    <p>\n      \uc774\ub2e4.\n    <\/p>\n\n    <p>\n      \uc774\ub54c real part\ub294 \uc57d\n    <\/p>\n\n    <div class=\"formula\">\n      Re[G(j\u03c9)]\n      \u2248\n      -0.0083\n    <\/div>\n\n    <p>\n      \uc774\ub2e4.\n    <\/p>\n\n    <div class=\"memory\">\n      <strong>\n        K=1\uc5d0\uc11c Nyquist plot\uc740\n        \u03c9=\u221a15 rad\/s\uc5d0\uc11c\n        \uc57d -0.0083+j0 \uc9c0\uc810\uc744 \ud1b5\uacfc\ud55c\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>10. Gain Margin \uacc4\uc0b0<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \uc548\uc815 \ud55c\uacc4\uc5d0\uc11c\ub294 \ud574\ub2f9 \uad50\uc810\uc774\n      critical point -1+j0\uc5d0 \ub3c4\ub2ec\ud55c\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      K \u00d7 0.0083 = 1\n    <\/div>\n\n    <p>\n      \ub530\ub77c\uc11c\n    <\/p>\n\n    <div class=\"formula\">\n      K\n      \u2248\n      1\/0.0083\n    <\/div>\n\n    <div class=\"formula\">\n      K\n      \u2248\n      120.5\n    <\/div>\n\n    <p>\n      \uc989 K=1\uc5d0\uc11c \uc2dc\uc791\ud558\uba74 gain\uc744 \uc57d 120.5\ubc30\uae4c\uc9c0\n      \uc99d\uac00\uc2dc\ud0ac \uc218 \uc788\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      GM\n      =\n      120.5\n    <\/div>\n\n    <p>\n      dB\ub85c \ub098\ud0c0\ub0b4\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      GM<sub>dB<\/sub>\n      =\n      20log<sub>10<\/sub>(120.5)\n    <\/div>\n\n    <div class=\"formula\">\n      \u2248\n      41.6 dB\n    <\/div>\n\n    <div class=\"warning\">\n      <strong>\n        K=120.5\uc5d0\uc11c Nyquist plot\uc774 -1+j0\uc5d0 \ub3c4\ub2ec\ud558\uc5ec\n        \uc2dc\uc2a4\ud15c\uc740 marginally stable\uc774 \ub41c\ub2e4.\n      <\/strong>\n    <\/div>\n\n    <p>\n      \uc774\ub54c \uc9c4\ub3d9 \uc8fc\ud30c\uc218\ub294\n    <\/p>\n\n    <div class=\"formula\">\n      \u03c9 = \u221a15 rad\/s\n    <\/div>\n\n    <p>\n      \uc774\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>11. Gain Margin\uc758 \uc758\ubbf8<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Gain Margin\uc740 Nyquist plot\uc774\n      -180\u00b0 \uc704\uc0c1\uc5d0\uc11c critical point -1\uae4c\uc9c0\n      \uc5bc\ub9c8\ub098 \ub354 gain\uc744 \uc99d\uac00\uc2dc\ud0ac \uc218 \uc788\ub294\uc9c0\ub97c \ub098\ud0c0\ub0b8\ub2e4.\n    <\/p>\n\n    <div class=\"formula\">\n      GM\n      =\n      1\n      \/\n      |G(j\u03c9<sub>pc<\/sub>)H(j\u03c9<sub>pc<\/sub>)|\n    <\/div>\n\n    <p>\n      \uc5ec\uae30\uc11c\n    <\/p>\n\n    <div class=\"formula\">\n      \u2220G(j\u03c9<sub>pc<\/sub>)H(j\u03c9<sub>pc<\/sub>)\n      =\n      -180\u00b0\n    <\/div>\n\n    <p>\n      \uc774\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>12. Gain Margin \ud544\uae30 \uc608\uc81c<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \uc6d0\ubb38\uc758 \ub2e4\ub978 \uc608\uc81c\uc5d0\uc11c\ub294\n    <\/p>\n\n    <div class=\"formula\">\n      G(s)H(s)\n      =\n      K\n      \/\n      [(s\u00b2+2s+2)(s+2)]\n    <\/div>\n\n    <p>\n      \ub85c \ub450\uace0 K=6\uc778 \uacbd\uc6b0\n      Gain Margin\uacfc Phase Margin\uc744 \uacc4\uc0b0\ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      s=j\u03c9\ub97c \ub300\uc785\ud558\uba74 \ubd84\ubaa8\ub294\n    <\/p>\n\n    <div class=\"formula\">\n      (-\u03c9\u00b2+2+j2\u03c9)(2+j\u03c9)\n    <\/div>\n\n    <p>\n      \uc774\uace0 \uc815\ub9ac\ud558\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      -4(\u03c9\u00b2-1)\n      +\n      j\u03c9(6-\u03c9\u00b2)\n    <\/div>\n\n    <p>\n      \ud615\ud0dc\uac00 \ub41c\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>13. Phase Crossover Frequency<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Gain Margin\uc744 \uad6c\ud560 \ub54c\ub294\n      phase\uac00 -180\u00b0\uac00 \ub418\ub294 \uc8fc\ud30c\uc218\ub97c \ucc3e\ub294\ub2e4.\n    <\/p>\n\n    <p>\n      imaginary part\uac00 0\uc774\ubbc0\ub85c\n    <\/p>\n\n    <div class=\"formula\">\n      \u03c9(6-\u03c9\u00b2) = 0\n    <\/div>\n\n    <p>\n      \u03c9\u22600\uc5d0\uc11c\n    <\/p>\n\n    <div class=\"formula\">\n      \u03c9<sub>pc<\/sub>\n      =\n      \u221a6\n    <\/div>\n\n    <p>\n      \uc774\ub2e4.\n    <\/p>\n\n    <p>\n      \uc6d0\ubb38 \ud544\uae30\uc5d0\uc11c\ub294 \uc774 \uc8fc\ud30c\uc218\uc5d0\uc11c\n      Nyquist plot\uc758 \uc2e4\uc218\ucd95 \uad50\uc810\uc744 \uc57d\n    <\/p>\n\n    <div class=\"formula\">\n      -0.3\n    <\/div>\n\n    <p>\n      \uc73c\ub85c \uacc4\uc0b0\ud55c\ub2e4.\n    <\/p>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>14. Gain Margin<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      \uc74c\uc758 \uc2e4\uc218\ucd95 \uad50\uc810\uc758 \ud06c\uae30\uac00 0.3\uc774\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      GM\n      =\n      1\/0.3\n    <\/div>\n\n    <div class=\"formula\">\n      \u2248\n      3.33\n    <\/div>\n\n    <p>\n      dB\ub85c \ub098\ud0c0\ub0b4\uba74\n    <\/p>\n\n    <div class=\"formula\">\n      GM<sub>dB<\/sub>\n      =\n      20log<sub>10<\/sub>(3.33)\n    <\/div>\n\n    <div class=\"formula\">\n      \u2248\n      10.45 dB\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>15. Phase Margin<\/h2>\n\n  <div class=\"card\">\n\n    <p>\n      Phase Margin\uc740\n      Nyquist plot\uc774 unit circle,\n    <\/p>\n\n    <div class=\"formula\">\n      |G(j\u03c9)H(j\u03c9)| = 1\n    <\/div>\n\n    <p>\n      \uacfc \ub9cc\ub098\ub294 Gain Crossover Frequency\uc5d0\uc11c \uacc4\uc0b0\ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      \uc6d0\ubb38 \ud544\uae30\uc5d0\uc11c\ub294\n    <\/p>\n\n    <div class=\"formula\">\n      \u03c9<sub>gc<\/sub>\n      \u2248\n      1.233 rad\/s\n    <\/div>\n\n    <p>\n      \ub97c \uc5bb\uace0,\n      \uc774\ub54c \uc704\uc0c1\uc744 \uc57d\n    <\/p>\n\n    <div class=\"formula\">\n      \u2220G(j\u03c9<sub>gc<\/sub>)H(j\u03c9<sub>gc<\/sub>)\n      \u2248\n      -112.3\u00b0\n    <\/div>\n\n    <p>\n      \ub85c \uacc4\uc0b0\ud55c\ub2e4.\n    <\/p>\n\n    <p>\n      \ub530\ub77c\uc11c Phase Margin\uc740\n    <\/p>\n\n    <div class=\"formula\">\n      PM\n      =\n      180\u00b0\n      +\n      \u2220G(j\u03c9<sub>gc<\/sub>)H(j\u03c9<sub>gc<\/sub>)\n    <\/div>\n\n    <div class=\"formula\">\n      PM\n      \u2248\n      180\u00b0 &#8211; 112.3\u00b0\n    <\/div>\n\n    <div class=\"formula\">\n      PM\n      \u2248\n      67.7\u00b0\n    <\/div>\n\n    <div class=\"memory\">\n      <strong>\n        Gain Margin\uc740 -180\u00b0 \uc9c0\uc810\uc5d0\uc11c\uc758 \ud06c\uae30\ub85c \uad6c\ud558\uace0,\n        Phase Margin\uc740 |GH|=1 \uc9c0\uc810\uc5d0\uc11c\uc758 \uc704\uc0c1\uc73c\ub85c \uad6c\ud55c\ub2e4.\n      <\/strong>\n    <\/div>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>16. Gain Margin \/ Phase Margin \uc815\ub9ac<\/h2>\n\n  <div class=\"table-wrap\">\n\n    <table>\n\n      <thead>\n        <tr>\n          <th>\ud56d\ubaa9<\/th>\n          <th>\uc870\uac74<\/th>\n          <th>\uacc4\uc0b0<\/th>\n        <\/tr>\n      <\/thead>\n\n      <tbody>\n\n        <tr>\n          <td><strong>Gain Margin<\/strong><\/td>\n          <td>\n            \u2220GH = -180\u00b0\n          <\/td>\n          <td>\n            GM = 1\/|GH|\n          <\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Gain Margin [dB]<\/strong><\/td>\n          <td>\n            Phase Crossover Frequency\n          <\/td>\n          <td>\n            20log\u2081\u2080(GM)\n          <\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Phase Margin<\/strong><\/td>\n          <td>\n            |GH| = 1\n          <\/td>\n          <td>\n            PM = 180\u00b0 + \u2220GH\n          <\/td>\n        <\/tr>\n\n      <\/tbody>\n\n    <\/table>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>17. \uc8fc\uc694 \uad00\uacc4\uc2dd<\/h2>\n\n  <div class=\"table-wrap\">\n\n    <table>\n\n      <thead>\n        <tr>\n          <th>\ud56d\ubaa9<\/th>\n          <th>\ub0b4\uc6a9<\/th>\n        <\/tr>\n      <\/thead>\n\n      <tbody>\n\n        <tr>\n          <td><strong>Frequency Response<\/strong><\/td>\n          <td>s=j\u03c9 \ub300\uc785<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Nyquist Critical Point<\/strong><\/td>\n          <td>-1+j0<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Closed-loop \uc548\uc815<\/strong><\/td>\n          <td>Z=0<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Nyquist \uad00\uacc4<\/strong><\/td>\n          <td>Z=P+N<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Contour \uc704 Pole<\/strong><\/td>\n          <td>\uc791\uc740 \ubc18\uc6d0\uc73c\ub85c \uc6b0\ud68c<\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Gain Margin<\/strong><\/td>\n          <td>\n            1\/|GH(j\u03c9<sub>pc<\/sub>)|\n          <\/td>\n        <\/tr>\n\n        <tr>\n          <td><strong>Phase Margin<\/strong><\/td>\n          <td>\n            180\u00b0 + \u2220GH(j\u03c9<sub>gc<\/sub>)\n          <\/td>\n        <\/tr>\n\n      <\/tbody>\n\n    <\/table>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <h2>18. \ud575\uc2ec \uae30\uc5b5 \ubb38\uc7a5<\/h2>\n\n  <div class=\"memory\">\n\n    <ol>\n\n      <li>\n        <strong>\n          Nyquist plot\uc740 open-loop transfer function\uc5d0\n          s=j\u03c9\ub97c \ub300\uc785\ud558\uc5ec \ubcf5\uc18c\ud3c9\uba74\uc5d0 \uadf8\ub9b0 frequency response\uc774\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Nyquist \uc548\uc815\ub3c4 \ud310\uc815\uc758 \uae30\uc900\uc810\uc740\n          -1+j0\uc774\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Open-loop pole\uc774 Nyquist contour \uc704\uc5d0 \uc788\uc73c\uba74\n          \uc791\uc740 \ubc18\uc6d0\uc73c\ub85c \uc6b0\ud68c\ud55c\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          s-plane\uc758 \uc791\uc740 \uc6b0\ud68c \uacbd\ub85c\ub294\n          GH-plane\uc5d0\uc11c \ud070 \ubc18\uc6d0\uc73c\ub85c mapping\ub420 \uc218 \uc788\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Nyquist criterion\uc740\n          open-loop RHP pole P\uc640\n          -1\uc810 encirclement N\uc744 \uc774\uc6a9\ud558\uc5ec\n          closed-loop RHP pole Z\ub97c \ud310\uc815\ud55c\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Gain Margin\uc740\n          phase\uac00 -180\u00b0\uac00 \ub418\ub294 \uc8fc\ud30c\uc218\uc5d0\uc11c \uad6c\ud55c\ub2e4.\n        <\/strong>\n      <\/li>\n\n      <li>\n        <strong>\n          Phase Margin\uc740\n          |GH|=1\uc774 \ub418\ub294 \uc8fc\ud30c\uc218\uc5d0\uc11c \uad6c\ud55c\ub2e4.\n        <\/strong>\n      <\/li>\n\n    <\/ol>\n\n  <\/div>\n\n\n  <!-- ================================================= -->\n  <div class=\"keywords\">\n    Nyquist Plot, Nyquist Criterion, Frequency Response,\n    Nyquist Contour, Critical Point, -1+j0,\n    Encirclement, RHP Pole, Origin Pole,\n    Gain Margin, Phase Margin,\n    Phase Crossover Frequency, Gain Crossover Frequency\n  <\/div>\n\n<\/div>\n&#8220;`\n","protected":false},"excerpt":{"rendered":"<p>Open Loop Transfer Function Pole\uc774 \uc6d0\uc810\uc744 \uc9c0\ub098\ub294 \uacbd\uc6b0 Gain Margin \uad6c\ud558\ub294 \ubc29\ubc95 \uc608\uc81c &#8220;`html Nyquist Plot Nyquist Contour \u00b7 Frequency Response \u00b7 Origin Pole \u00b7 Gain Margin \u00b7 Phase Margin 1. \uc608\uc81c: G(s) = 1\/(s+1)\u00b2 G(s) = 1\/(s+1)2 Frequency response\ub97c \uad6c\ud558\uae30 \uc704\ud574 s = j\u03c9 \ub97c \ub300\uc785\ud55c\ub2e4. G(j\u03c9) = 1\/(j\u03c9+1)2 \ubd84\ubaa8\ub97c \uc804\uac1c\ud558\uba74 G(j\u03c9) = 1\/(1-\u03c92+j2\u03c9) [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_post_was_ever_published":false},"categories":[1185],"tags":[1222,1223],"class_list":["post-6134","post","type-post","status-publish","format-standard","hentry","category-1185","tag-nyquist","tag-nyquistplot"],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"","_links":{"self":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/6134","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/comments?post=6134"}],"version-history":[{"count":11,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/6134\/revisions"}],"predecessor-version":[{"id":9549,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/posts\/6134\/revisions\/9549"}],"wp:attachment":[{"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/media?parent=6134"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/categories?post=6134"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/now0930.pe.kr\/wordpress\/wp-json\/wp\/v2\/tags?post=6134"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}