**3. Experiment and Analysis**

To evaluate the performance of the proposed idea, we use a Turtlebot robot to demonstrate the algorithm in the real environment where we have built a known map. The nurse robot plays as a moving obstacle in the map. To simplify the problem, the map of the environment and the motion status of the obstacle (nurse robot) are known for the Turtlebot. The Turtlebot robot and experimental environment are shown in Figure 5. We first compare the DAPF to the standard APF approach in the static environment to show how the dynamic window approach can improve the performance of the APF, and then compare the DIAPF with the DAPF, the DVAPF and ROS (robot operating system) path planning algorithm to show how the danger index can help the robot avoid the moving obstacle.

**Figure 5.** (**a**) Turtlebot robot and (**b**) experimental environment.
