update notebook

Author: AtsushiSakai

PathTracking/model_predictive_speed_and_steer_control/notebook.ipynb

@@ -11,7 +11,13 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "# Linear vehicle model"
+    "# Linear vehicle model\n",
+    "\n",
+    "State vector is:\n",
+    "$$ x = [x, y, v,\\phi]$$ x: x-position, y:y-position, v:velocity, φ: yaw angle\n",
+    "\n",
+    "Input vector is:\n",
+    "$$ u = [a, \\delta]$$ a: accellation, 出るた: yaw angle\n"
    ]
   },
   {