text: The present invention relates to a path planning method and a related navigation device, and more particularly, to a path planning method and a related navigation device with real-time processing function without any database or environment map.
  In the field of automatic navigation, a conventional robot is extensively applied in the static working environment because of its predictable property. For example, the robotic cleaner is used to sweep indoor environment, a scanner of the robotic cleaner scans furniture decoration of the indoor environment to establish a map containing location information about the wall, the table, the chair, the cabinet and so on, and to plan a steering path without impacting the furniture in accordance with the map; if the robotic cleaner is put into a strange working environment or the furniture inside the static working environment is shifted, the robotic cleaner will be confused and cannot dodge the obstacle. Further, the scanner of the robotic cleaner includes a row of radars, the map made by the row of radars is one-directional information for determining a steering direction, the robotic cleaner is constrained to shift on the planar surface at the one-directional steering direction and unable to establish the two-dimensional map or the three-dimensional map for stereo navigation.