Update README.md

README.md

@@ -73,6 +73,12 @@ Directory Structure
     <td><img src="https://github.com/zhm-real/path-planning-algorithms/blob/master/Search-based%20Planning/gif/D_star_Lite.gif" alt="dstarlite" width="400"/></a></td>
   </tr>
 </table>
+<table>
+  <tr>
+    <td><img src="https://github.com/zhm-real/path-planning-algorithms/blob/master/Search-based%20Planning/gif/ADstar_small.gif" alt="lpastar" width="400"/></a></td>
+    <td><img src="https://github.com/zhm-real/path-planning-algorithms/blob/master/Search-based%20Planning/gif/ADstar_sig.giff" alt="dstarlite" width="400"/></a></td>
+  </tr>
+</table>
 </div>
 
 ### Value/Policy/Q-value/Q-policy Iteration