“…Moreover, the authors have also proposed a method to improve the estimation precision of the position while being robust with respect to changes in the environment traveled by the mobile robot by using speeded up robust features (SURF), which is robust with respect to changes in image illumination, scale, and rotation, for image referencing. In a paper, they tested through experiments using stationary and moving obstacles shading, one more form of change to the background color, and showed that this approach was robust up to a shading level of 55%. However, all of these methods assume travel along a training path, and have the problem of position estimation becoming difficult when the robot deviates from a training path.…”