Evaluation of ultrasonic sensor in robot mapping

This paper presents the simulation and experimental investigation on mapping done using ultrasonic sensor(HC-SR04). Issues related to exploration, mapping and localization are discussed. Kobuki base with three ultrasonic sensors was kept as robot mobile base platform. A 2D occupancy grid map is updated by the robot when it moves and collects information from ultrasonic sensor. The sensor being noisy in nature generates unwanted ghost points. This results in outliers in the map especially in corners of the environment due to specular reflections. The issues like outliers are dealt with image processing techniques.