diff --git a/notebooks/MPC_racecar_crosstrack-Copy1.ipynb b/notebooks/MPC_racecar_crosstrack.ipynb
similarity index 100%
rename from notebooks/MPC_racecar_crosstrack-Copy1.ipynb
rename to notebooks/MPC_racecar_crosstrack.ipynb
diff --git a/notebooks/MPC_racecar_tracking.ipynb b/notebooks/MPC_racecar_tracking.ipynb
index 0ea2b34..05efd51 100644
--- a/notebooks/MPC_racecar_tracking.ipynb
+++ b/notebooks/MPC_racecar_tracking.ipynb
@@ -477,8 +477,13 @@
     "        \n",
     "        final_xp=np.append(final_xp,fx(interp_range))\n",
     "        final_yp=np.append(final_yp,fy(interp_range))\n",
+    "    \n",
+    "    dx = np.append(0, np.diff(final_xp))\n",
+    "    dy = np.append(0, np.diff(final_yp))\n",
+    "    theta = np.arctan2(dy, dx)\n",
+    "\n",
+    "    return np.vstack((final_xp,final_yp,theta))\n",
     "\n",
-    "    return np.vstack((final_xp,final_yp))\n",
     "\n",
     "def get_nn_idx(state,path):\n",
     "    \"\"\"\n",
@@ -487,7 +492,7 @@
     "\n",
     "    dx = state[0]-path[0,:]\n",
     "    dy = state[1]-path[1,:]\n",
-    "    dist = np.sqrt(dx**2 + dy**2)\n",
+    "    dist = np.hypot(dx,dy)\n",
     "    nn_idx = np.argmin(dist)\n",
     "\n",
     "    try:\n",
@@ -508,10 +513,45 @@
     "\n",
     "    return target_idx\n",
     "\n",
-    "def get_course(state, path):\n",
+    "def get_ref_trajectory(state, path, target_v):\n",
     "    \"\"\"\n",
     "    \"\"\"\n",
-    "    "
+    "    xref = np.zeros((N, T + 1))\n",
+    "    dref = np.zeros((1, T + 1))\n",
+    "    \n",
+    "    #sp = np.ones((1,T +1))*target_v #speed profile\n",
+    "    \n",
+    "    ncourse = path.shape[1]\n",
+    "\n",
+    "    ind = get_nn_index(state, path)\n",
+    "\n",
+    "    xref[0, 0] = path[0,ind] #X\n",
+    "    xref[1, 0] = path[1,ind] #Y\n",
+    "    xref[2, 0] = target_v #sp[ind]     #V\n",
+    "    xref[3, 0] = path[2,ind]   #Theta\n",
+    "    dref[0, 0] = 0.0  # steer operational point should be 0\n",
+    "    \n",
+    "    dl = 0.05 # Waypoints spacing\n",
+    "    travel = 0.0\n",
+    "\n",
+    "    for i in range(T + 1):\n",
+    "        travel += abs(state[2]) * DT #current V or target V?\n",
+    "        dind = int(round(travel / dl))\n",
+    "\n",
+    "        if (ind + dind) < ncourse:\n",
+    "            xref[0, i] = path[0,ind + dind]\n",
+    "            xref[1, i] = path[1,ind + dind]\n",
+    "            xref[2, i] = target_v #sp[ind + dind]\n",
+    "            xref[3, i] = path[2,ind + dind]\n",
+    "            dref[0, i] = 0.0\n",
+    "        else:\n",
+    "            xref[0, i] = path[0,ncourse - 1]\n",
+    "            xref[1, i] = path[1,ncourse - 1]\n",
+    "            xref[2, i] = target_v #sp[ncourse - 1]\n",
+    "            xref[3, i] = path[2,ncourse - 1]\n",
+    "            dref[0, i] = 0.0\n",
+    "\n",
+    "    return xref, dref"
    ]
   },
   {
@@ -529,9 +569,9 @@
    "cell_type": "markdown",
    "metadata": {},
    "source": [
-    "![mpc](img/mpc_block_diagram.png)\n",
+    "<!-- ![mpc](img/mpc_block_diagram.png) -->\n",
     "\n",
-    "![mpc](img/mpc_t.png)"
+    "<!-- ![mpc](img/mpc_t.png) -->"
    ]
   },
   {
@@ -662,10 +702,10 @@
     "\n",
     "# Starting Condition\n",
     "x0 = np.zeros(N)\n",
-    "x0[0] = 0\n",
-    "x0[1] = -0.25\n",
-    "x0[2] = 0.0\n",
-    "x0[3] = np.radians(-0)\n",
+    "x0[0] = 0               #x\n",
+    "x0[1] = -0.25           #y\n",
+    "x0[2] = 0.0             #v\n",
+    "x0[3] = np.radians(-0)  #yaw\n",
     "                 \n",
     "#starting guess\n",
     "u_bar = np.zeros((M,T))\n",
@@ -1150,7 +1190,7 @@
    "name": "python",
    "nbconvert_exporter": "python",
    "pygments_lexer": "ipython3",
-   "version": "3.8.4"
+   "version": "3.8.5"
   }
  },
  "nbformat": 4,