The robot localization problem is a key problem in making truly autonomous robots. In this work we provide thorough discussions of Ultrasonic Positioning System can be applied to the localization problem. First, we look at the use of Kalman filters and basic concept and the equation involved in Kalman filters. Secondly, we create understanding of how the Kalman filters can be implemented in robot localization. We show our discussion and experiments how Kalman filters applied to the localization problem. Lastly, we perform simulations using Usat Wheel Chair robot in our own general Kalman filters robot monitoring software.