Abstract—The paper presents a technique and a system that can be used to smoothly dock a differential drive mobile robot. The system consists of only a robot, a RGBD camera, and a notebook computer which are connected via USB cable. The RGBD camera with the proposed processing technique is capable of determining the Cartesian positions of a home base, obstacles, a floor, and a wall. They are then plotted on a 2D grip map where a free trajectory towards the home based can be constructed. This trajectory is then used to guide the robot to dock at the home base. Experimental result is used to demonstrate the applicable of the proposed technique.