  This paper presents algorithms to navigate and avoid obstacles for an in-door
autonomous mobile robot. A laser range finder is used to obtain 3D images of
the environment. A new algorithm, namely 3D-to-2D image pressure and barriers
detection (IPaBD), is proposed to create a 2D global map from the 3D images.
This map is basic to design the trajectory. A tracking controller is developed
to control the robot to follow the trajectory. The obstacle avoidance is
addressed with the use of sonar sensors. An improved vector field histogram
(Improved-VFH) algorithm is presented with improvements to overcome some
limitations of the original VFH. Experiments have been conducted and the result
is encouraged.
